draft-ietf-cellar-ffv1-v4-04.txt   draft-ietf-cellar-ffv1-v4-05.txt 
cellar M. Niedermayer cellar M. Niedermayer
Internet-Draft Internet-Draft D. Rice
Intended status: Standards Track D. Rice Intended status: Standards Track J. Martinez
Expires: August 10, 2019 Expires: February 14, 2020 August 13, 2019
J. Martinez
February 6, 2019
FFV1 Video Coding Format Version 4 FFV1 Video Coding Format Version 4
draft-ietf-cellar-ffv1-v4-04 draft-ietf-cellar-ffv1-v4-05
Abstract Abstract
This document defines FFV1, a lossless intra-frame video encoding This document defines FFV1, a lossless intra-frame video encoding
format. FFV1 is designed to efficiently compress video data in a format. FFV1 is designed to efficiently compress video data in a
variety of pixel formats. Compared to uncompressed video, FFV1 variety of pixel formats. Compared to uncompressed video, FFV1
offers storage compression, frame fixity, and self-description, which offers storage compression, frame fixity, and self-description, which
makes FFV1 useful as a preservation or intermediate video format. makes FFV1 useful as a preservation or intermediate video format.
Status of This Memo Status of This Memo
skipping to change at page 1, line 36 skipping to change at page 1, line 34
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This Internet-Draft will expire on August 10, 2019. This Internet-Draft will expire on February 14, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Notation and Conventions . . . . . . . . . . . . . . . . . . 4 2. Notation and Conventions . . . . . . . . . . . . . . . . . . 4
2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 5
2.2.1. Pseudo-code . . . . . . . . . . . . . . . . . . . . . 5 2.2.1. Pseudo-code . . . . . . . . . . . . . . . . . . . . . 5
2.2.2. Arithmetic Operators . . . . . . . . . . . . . . . . 5 2.2.2. Arithmetic Operators . . . . . . . . . . . . . . . . 5
2.2.3. Assignment Operators . . . . . . . . . . . . . . . . 6 2.2.3. Assignment Operators . . . . . . . . . . . . . . . . 6
skipping to change at page 2, line 27 skipping to change at page 2, line 25
2.2.5. Mathematical Functions . . . . . . . . . . . . . . . 7 2.2.5. Mathematical Functions . . . . . . . . . . . . . . . 7
2.2.6. Order of Operation Precedence . . . . . . . . . . . . 7 2.2.6. Order of Operation Precedence . . . . . . . . . . . . 7
2.2.7. Range . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.7. Range . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2.8. NumBytes . . . . . . . . . . . . . . . . . . . . . . 8 2.2.8. NumBytes . . . . . . . . . . . . . . . . . . . . . . 8
2.2.9. Bitstream Functions . . . . . . . . . . . . . . . . . 8 2.2.9. Bitstream Functions . . . . . . . . . . . . . . . . . 8
3. Sample Coding . . . . . . . . . . . . . . . . . . . . . . . . 9 3. Sample Coding . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1. Border . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1. Border . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2. Samples . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2. Samples . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3. Median Predictor . . . . . . . . . . . . . . . . . . . . 10 3.3. Median Predictor . . . . . . . . . . . . . . . . . . . . 10
3.4. Context . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.4. Context . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.5. Quantization Table Sets . . . . . . . . . . . . . . . . . 11 3.5. Quantization Table Sets . . . . . . . . . . . . . . . . . 12
3.6. Quantization Table Set Indexes . . . . . . . . . . . . . 12 3.6. Quantization Table Set Indexes . . . . . . . . . . . . . 12
3.7. Color spaces . . . . . . . . . . . . . . . . . . . . . . 12 3.7. Color spaces . . . . . . . . . . . . . . . . . . . . . . 12
3.7.1. YCbCr . . . . . . . . . . . . . . . . . . . . . . . . 12 3.7.1. YCbCr . . . . . . . . . . . . . . . . . . . . . . . . 13
3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.8. Coding of the Sample Difference . . . . . . . . . . . . . 14 3.8. Coding of the Sample Difference . . . . . . . . . . . . . 15
3.8.1. Range Coding Mode . . . . . . . . . . . . . . . . . . 15 3.8.1. Range Coding Mode . . . . . . . . . . . . . . . . . . 15
3.8.2. Golomb Rice Mode . . . . . . . . . . . . . . . . . . 19 3.8.2. Golomb Rice Mode . . . . . . . . . . . . . . . . . . 19
4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.1. Parameters . . . . . . . . . . . . . . . . . . . . . . . 24 4.1. Parameters . . . . . . . . . . . . . . . . . . . . . . . 23
4.1.1. version . . . . . . . . . . . . . . . . . . . . . . . 25 4.1.1. version . . . . . . . . . . . . . . . . . . . . . . . 24
4.1.2. micro_version . . . . . . . . . . . . . . . . . . . . 26 4.1.2. micro_version . . . . . . . . . . . . . . . . . . . . 24
4.1.3. coder_type . . . . . . . . . . . . . . . . . . . . . 27 4.1.3. coder_type . . . . . . . . . . . . . . . . . . . . . 25
4.1.4. state_transition_delta . . . . . . . . . . . . . . . 27 4.1.4. state_transition_delta . . . . . . . . . . . . . . . 26
4.1.5. colorspace_type . . . . . . . . . . . . . . . . . . . 27 4.1.5. colorspace_type . . . . . . . . . . . . . . . . . . . 26
4.1.6. chroma_planes . . . . . . . . . . . . . . . . . . . . 28 4.1.6. chroma_planes . . . . . . . . . . . . . . . . . . . . 27
4.1.7. bits_per_raw_sample . . . . . . . . . . . . . . . . . 28 4.1.7. bits_per_raw_sample . . . . . . . . . . . . . . . . . 27
4.1.8. log2_h_chroma_subsample . . . . . . . . . . . . . . . 28 4.1.8. log2_h_chroma_subsample . . . . . . . . . . . . . . . 27
4.1.9. log2_v_chroma_subsample . . . . . . . . . . . . . . . 28 4.1.9. log2_v_chroma_subsample . . . . . . . . . . . . . . . 28
4.1.10. extra_plane . . . . . . . . . . . . . . . . . . . . . 28 4.1.10. extra_plane . . . . . . . . . . . . . . . . . . . . . 28
4.1.11. num_h_slices . . . . . . . . . . . . . . . . . . . . 29 4.1.11. num_h_slices . . . . . . . . . . . . . . . . . . . . 28
4.1.12. num_v_slices . . . . . . . . . . . . . . . . . . . . 29 4.1.12. num_v_slices . . . . . . . . . . . . . . . . . . . . 28
4.1.13. quant_table_set_count . . . . . . . . . . . . . . . . 29 4.1.13. quant_table_set_count . . . . . . . . . . . . . . . . 28
4.1.14. states_coded . . . . . . . . . . . . . . . . . . . . 29 4.1.14. states_coded . . . . . . . . . . . . . . . . . . . . 28
4.1.15. initial_state_delta . . . . . . . . . . . . . . . . . 29 4.1.15. initial_state_delta . . . . . . . . . . . . . . . . . 29
4.1.16. ec . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.1.16. ec . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1.17. intra . . . . . . . . . . . . . . . . . . . . . . . . 30 4.1.17. intra . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2. Configuration Record . . . . . . . . . . . . . . . . . . 30 4.2. Configuration Record . . . . . . . . . . . . . . . . . . 30
4.2.1. reserved_for_future_use . . . . . . . . . . . . . . . 31 4.2.1. reserved_for_future_use . . . . . . . . . . . . . . . 30
4.2.2. configuration_record_crc_parity . . . . . . . . . . . 31 4.2.2. configuration_record_crc_parity . . . . . . . . . . . 30
4.2.3. Mapping FFV1 into Containers . . . . . . . . . . . . 31 4.2.3. Mapping FFV1 into Containers . . . . . . . . . . . . 31
4.3. Frame . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.3. Frame . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.4. Slice . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.4. Slice . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.5. Slice Header . . . . . . . . . . . . . . . . . . . . . . 34 4.5. Slice Header . . . . . . . . . . . . . . . . . . . . . . 33
4.5.1. slice_x . . . . . . . . . . . . . . . . . . . . . . . 34 4.5.1. slice_x . . . . . . . . . . . . . . . . . . . . . . . 33
4.5.2. slice_y . . . . . . . . . . . . . . . . . . . . . . . 35 4.5.2. slice_y . . . . . . . . . . . . . . . . . . . . . . . 34
4.5.3. slice_width . . . . . . . . . . . . . . . . . . . . . 35 4.5.3. slice_width . . . . . . . . . . . . . . . . . . . . . 34
4.5.4. slice_height . . . . . . . . . . . . . . . . . . . . 35 4.5.4. slice_height . . . . . . . . . . . . . . . . . . . . 34
4.5.5. quant_table_set_index_count . . . . . . . . . . . . . 35 4.5.5. quant_table_set_index_count . . . . . . . . . . . . . 34
4.5.6. quant_table_set_index . . . . . . . . . . . . . . . . 35 4.5.6. quant_table_set_index . . . . . . . . . . . . . . . . 34
4.5.7. picture_structure . . . . . . . . . . . . . . . . . . 35 4.5.7. picture_structure . . . . . . . . . . . . . . . . . . 34
4.5.8. sar_num . . . . . . . . . . . . . . . . . . . . . . . 36 4.5.8. sar_num . . . . . . . . . . . . . . . . . . . . . . . 35
4.5.9. sar_den . . . . . . . . . . . . . . . . . . . . . . . 36 4.5.9. sar_den . . . . . . . . . . . . . . . . . . . . . . . 35
4.5.10. reset_contexts . . . . . . . . . . . . . . . . . . . 36 4.5.10. reset_contexts . . . . . . . . . . . . . . . . . . . 35
4.5.11. slice_coding_mode . . . . . . . . . . . . . . . . . . 36 4.5.11. slice_coding_mode . . . . . . . . . . . . . . . . . . 36
4.6. Slice Content . . . . . . . . . . . . . . . . . . . . . . 36 4.6. Slice Content . . . . . . . . . . . . . . . . . . . . . . 36
4.6.1. primary_color_count . . . . . . . . . . . . . . . . . 37 4.6.1. primary_color_count . . . . . . . . . . . . . . . . . 36
4.6.2. plane_pixel_height . . . . . . . . . . . . . . . . . 37 4.6.2. plane_pixel_height . . . . . . . . . . . . . . . . . 36
4.6.3. slice_pixel_height . . . . . . . . . . . . . . . . . 37 4.6.3. slice_pixel_height . . . . . . . . . . . . . . . . . 36
4.6.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 37 4.6.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 37
4.7. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.7. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.7.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 38 4.7.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 37
4.7.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 38 4.7.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 37
4.7.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 38 4.7.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 37
4.7.4. sample_difference . . . . . . . . . . . . . . . . . . 38 4.7.4. sample_difference . . . . . . . . . . . . . . . . . . 37
4.8. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 38 4.8. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 38
4.8.1. slice_size . . . . . . . . . . . . . . . . . . . . . 39 4.8.1. slice_size . . . . . . . . . . . . . . . . . . . . . 38
4.8.2. error_status . . . . . . . . . . . . . . . . . . . . 39 4.8.2. error_status . . . . . . . . . . . . . . . . . . . . 38
4.8.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 39 4.8.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 38
4.9. Quantization Table Set . . . . . . . . . . . . . . . . . 39 4.9. Quantization Table Set . . . . . . . . . . . . . . . . . 39
4.9.1. quant_tables . . . . . . . . . . . . . . . . . . . . 40 4.9.1. quant_tables . . . . . . . . . . . . . . . . . . . . 39
4.9.2. context_count . . . . . . . . . . . . . . . . . . . . 41 4.9.2. context_count . . . . . . . . . . . . . . . . . . . . 39
5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 41 5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 39
6. Security Considerations . . . . . . . . . . . . . . . . . . . 41 6. Security Considerations . . . . . . . . . . . . . . . . . . . 40
7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 42 7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 41
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 44 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42
9. Appendixes . . . . . . . . . . . . . . . . . . . . . . . . . 44 9. Appendixes . . . . . . . . . . . . . . . . . . . . . . . . . 42
9.1. Decoder implementation suggestions . . . . . . . . . . . 44 9.1. Decoder implementation suggestions . . . . . . . . . . . 42
9.1.1. Multi-threading Support and Independence of Slices . 44 9.1.1. Multi-threading Support and Independence of
10. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Slices . . . . . . . . . . . . . . . . . . . . . . . 43
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 44 10. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 43
11.1. Normative References . . . . . . . . . . . . . . . . . . 44 11. Normative References . . . . . . . . . . . . . . . . . . . . 43
11.2. Informative References . . . . . . . . . . . . . . . . . 45 12. Informative References . . . . . . . . . . . . . . . . . . . 44
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 45
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 46
1. Introduction 1. Introduction
This document describes FFV1, a lossless video encoding format. The This document describes FFV1, a lossless video encoding format. The
design of FFV1 considers the storage of image characteristics, data design of FFV1 considers the storage of image characteristics, data
fixity, and the optimized use of encoding time and storage fixity, and the optimized use of encoding time and storage
requirements. FFV1 is designed to support a wide range of lossless requirements. FFV1 is designed to support a wide range of lossless
video applications such as long-term audiovisual preservation, video applications such as long-term audiovisual preservation,
scientific imaging, screen recording, and other video encoding scientific imaging, screen recording, and other video encoding
scenarios that seek to avoid the generational loss of lossy video scenarios that seek to avoid the generational loss of lossy video
encodings. encodings.
This document defines a version 4 of FFV1. Prior versions of FFV1 This document defines a version 4 of FFV1. Prior versions of FFV1
are defined within [I-D.ietf-cellar-ffv1]. are defined within [I-D.ietf-cellar-ffv1].
The latest version of this document is available at The latest version of this document is available at
<https://raw.github.com/FFmpeg/FFV1/master/ffv1.md> https://raw.github.com/FFmpeg/FFV1/master/ffv1.md
(https://raw.github.com/FFmpeg/FFV1/master/ffv1.md)
This document assumes familiarity with mathematical and coding This document assumes familiarity with mathematical and coding
concepts such as Range coding [range-coding] and YCbCr color spaces concepts such as Range coding [range-coding] and YCbCr color spaces
[YCbCr]. [YCbCr].
2. Notation and Conventions 2. Notation and Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
2.1. Definitions 2.1. Definitions
"Container": Format that encapsulates "Frames" (see Section 4.3) and "Container": Format that encapsulates "Frames" (see the section on
(when required) a "Configuration Record" into a bitstream. Frames (#frame)) and (when required) a "Configuration Record" into a
bitstream.
"Sample": The smallest addressable representation of a color "Sample": The smallest addressable representation of a color
component or a luma component in a "Frame". Examples of "Sample" are component or a luma component in a "Frame". Examples of "Sample" are
Luma, Blue Chrominance, Red Chrominance, Transparency, Red, Green, Luma, Blue Chrominance, Red Chrominance, Transparency, Red, Green,
and Blue. and Blue.
"Plane": A discrete component of a static image comprised of "Plane": A discrete component of a static image comprised of
"Samples" that represent a specific quantification of "Samples" of "Samples" that represent a specific quantification of "Samples" of
that image. that image.
skipping to change at page 8, line 5 skipping to change at page 8, line 5
a_{b,c} the 'b,c'-th value of a sequence of a a_{b,c} the 'b,c'-th value of a sequence of a
2.2.6. Order of Operation Precedence 2.2.6. Order of Operation Precedence
When order of precedence is not indicated explicitly by use of When order of precedence is not indicated explicitly by use of
parentheses, operations are evaluated in the following order (from parentheses, operations are evaluated in the following order (from
top to bottom, operations of same precedence being evaluated from top to bottom, operations of same precedence being evaluated from
left to right). This order of operations is based on the order of left to right). This order of operations is based on the order of
operations used in Standard C. operations used in Standard C.
a++, a-- a++, a--
!a, -a !a, -a
a ^ b a ^ b
a * b, a / b, a % b a * b, a / b, a % b
a + b, a - b a + b, a - b
a << b, a >> b a << b, a >> b
a < b, a <= b, a > b, a >= b a < b, a <= b, a > b, a >= b
a == b, a != b a == b, a != b
a & b a & b
a | b a | b
a && b a && b
a || b a || b
a ? b : c a ? b : c
a = b, a += b, a -= b, a *= b a = b, a += b, a -= b, a *= b
2.2.7. Range 2.2.7. Range
"a...b" means any value starting from a to b, inclusive. "a...b" means any value starting from a to b, inclusive.
2.2.8. NumBytes 2.2.8. NumBytes
"NumBytes" is a non-negative integer that expresses the size in 8-bit "NumBytes" is a non-negative integer that expresses the size in 8-bit
octets of a particular FFV1 "Configuration Record" or "Frame". FFV1 octets of a particular FFV1 "Configuration Record" or "Frame". FFV1
relies on its "Container" to store the "NumBytes" values, see relies on its "Container" to store the "NumBytes" values, see the
Section 4.2.3. section on the Mapping FFV1 into Containers (#mapping-ffv1-into-
containers).
2.2.9. Bitstream Functions 2.2.9. Bitstream Functions
2.2.9.1. remaining_bits_in_bitstream 2.2.9.1. remaining_bits_in_bitstream
"remaining_bits_in_bitstream( )" means the count of remaining bits "remaining_bits_in_bitstream( )" means the count of remaining bits
after the pointer in that "Configuration Record" or "Frame". It is after the pointer in that "Configuration Record" or "Frame". It is
computed from the "NumBytes" value multiplied by 8 minus the count of computed from the "NumBytes" value multiplied by 8 minus the count of
bits of that "Configuration Record" or "Frame" already read by the bits of that "Configuration Record" or "Frame" already read by the
bitstream parser. bitstream parser.
skipping to change at page 9, line 13 skipping to change at page 9, line 13
)" is a multiple of 8, otherwise false. )" is a multiple of 8, otherwise false.
2.2.9.4. get_bits 2.2.9.4. get_bits
"get_bits( i )" is the action to read the next "i" bits in the "get_bits( i )" is the action to read the next "i" bits in the
bitstream, from most significant bit to least significant bit, and to bitstream, from most significant bit to least significant bit, and to
return the corresponding value. The pointer is increased by "i". return the corresponding value. The pointer is increased by "i".
3. Sample Coding 3. Sample Coding
For each "Slice" (as described in Section 4.4) of a "Frame", the For each "Slice" (as described in the section on Slices (#slice)) of
"Planes", "Lines", and "Samples" are coded in an order determined by a "Frame", the "Planes", "Lines", and "Samples" are coded in an order
the "Color Space" (see Section 3.7). Each "Sample" is predicted by determined by the "Color Space" (see the section on Color Space
the median predictor as described in Section 3.3 from other "Samples" (#color-spaces)). Each "Sample" is predicted by the median predictor
within the same "Plane" and the difference is stored using the method as described in the section of the Median Predictor (#median-
described in Section 3.8. predictor) from other "Samples" within the same "Plane" and the
difference is stored using the method described in Coding of the
Sample Difference (#coding-of-the-sample-difference).
3.1. Border 3.1. Border
A border is assumed for each coded "Slice" for the purpose of the A border is assumed for each coded "Slice" for the purpose of the
median predictor and context according to the following rules: median predictor and context according to the following rules:
o one column of "Samples" to the left of the coded slice is assumed * one column of "Samples" to the left of the coded slice is assumed
as identical to the "Samples" of the leftmost column of the coded as identical to the "Samples" of the leftmost column of the coded
slice shifted down by one row. The value of the topmost "Sample" slice shifted down by one row. The value of the topmost "Sample"
of the column of "Samples" to the left of the coded slice is of the column of "Samples" to the left of the coded slice is
assumed to be "0" assumed to be "0"
o one column of "Samples" to the right of the coded slice is assumed * one column of "Samples" to the right of the coded slice is assumed
as identical to the "Samples" of the rightmost column of the coded as identical to the "Samples" of the rightmost column of the coded
slice slice
o an additional column of "Samples" to the left of the coded slice * an additional column of "Samples" to the left of the coded slice
and two rows of "Samples" above the coded slice are assumed to be and two rows of "Samples" above the coded slice are assumed to be
"0" "0"
The following table depicts a slice of 9 "Samples" The following table depicts a slice of 9 "Samples"
"a,b,c,d,e,f,g,h,i" in a 3x3 arrangement along with its assumed "a,b,c,d,e,f,g,h,i" in a 3x3 arrangement along with its assumed
border. border.
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | 0 | | 0 | 0 | 0 | | 0 | | 0 | 0 | | 0 | 0 | 0 | | 0 |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | 0 | | 0 | 0 | 0 | | 0 | | 0 | 0 | | 0 | 0 | 0 | | 0 |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| | | | | | | | | | | | | | | | | |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | 0 | | a | b | c | | c | | 0 | 0 | | a | b | c | | c |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | a | | d | e | f | | f | | 0 | a | | d | e | f | | f |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | d | | g | h | i | | i | | 0 | d | | g | h | i | | i |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
3.2. Samples 3.2. Samples
Relative to any "Sample" "X", six other relatively positioned Relative to any "Sample" "X", six other relatively positioned
"Samples" from the coded "Samples" and presumed border are identified "Samples" from the coded "Samples" and presumed border are identified
according to the labels used in the following diagram. The labels according to the labels used in the following diagram. The labels
for these relatively positioned "Samples" are used within the median for these relatively positioned "Samples" are used within the median
predictor and context. predictor and context.
+---+---+---+---+ +---+---+---+---+
| | | T | | | | | T | |
+---+---+---+---+ +---+---+---+---+
| |tl | t |tr | | |tl | t |tr |
+---+---+---+---+ +---+---+---+---+
| L | l | X | | | L | l | X | |
+---+---+---+---+ +---+---+---+---+
The labels for these relative "Samples" are made of the first letters The labels for these relative "Samples" are made of the first letters
of the words Top, Left and Right. of the words Top, Left and Right.
3.3. Median Predictor 3.3. Median Predictor
The prediction for any "Sample" value at position "X" may be computed The prediction for any "Sample" value at position "X" may be computed
based upon the relative neighboring values of "l", "t", and "tl" via based upon the relative neighboring values of "l", "t", and "tl" via
this equation: this equation:
skipping to change at page 11, line 9 skipping to change at page 11, line 9
[HuffYUV]. [HuffYUV].
Exception for the median predictor: if "colorspace_type == 0 && Exception for the median predictor: if "colorspace_type == 0 &&
bits_per_raw_sample == 16 && ( coder_type == 1 || coder_type == 2 )", bits_per_raw_sample == 16 && ( coder_type == 1 || coder_type == 2 )",
the following median predictor MUST be used: the following median predictor MUST be used:
"median(left16s, top16s, left16s + top16s - diag16s)" "median(left16s, top16s, left16s + top16s - diag16s)"
where: where:
left16s = l >= 32768 ? ( l - 65536 ) : l left16s = l >= 32768 ? ( l - 65536 ) : l
top16s = t >= 32768 ? ( t - 65536 ) : t top16s = t >= 32768 ? ( t - 65536 ) : t
diag16s = tl >= 32768 ? ( tl - 65536 ) : tl diag16s = tl >= 32768 ? ( tl - 65536 ) : tl
Background: a two's complement signed 16-bit signed integer was used Background: a two's complement signed 16-bit signed integer was used
for storing "Sample" values in all known implementations of FFV1 for storing "Sample" values in all known implementations of FFV1
bitstream. So in some circumstances, the most significant bit was bitstream. So in some circumstances, the most significant bit was
wrongly interpreted (used as a sign bit instead of the 16th bit of an wrongly interpreted (used as a sign bit instead of the 16th bit of an
unsigned integer). Note that when the issue is discovered, the only unsigned integer). Note that when the issue is discovered, the only
configuration of all known implementations being impacted is 16-bit configuration of all known implementations being impacted is 16-bit
YCbCr with no Pixel transformation with Range Coder coder, as other YCbCr with no Pixel transformation with Range Coder coder, as other
potentially impacted configurations (e.g. 15/16-bit JPEG2000-RCT with potentially impacted configurations (e.g. 15/16-bit JPEG2000-RCT with
Range Coder coder, or 16-bit content with Golomb Rice coder) were Range Coder coder, or 16-bit content with Golomb Rice coder) were
skipping to change at page 11, line 33 skipping to change at page 11, line 33
JPEG2000-RCT with Range Coder coder was implemented without this JPEG2000-RCT with Range Coder coder was implemented without this
issue in one implementation and validated by one conformance checker. issue in one implementation and validated by one conformance checker.
It is expected (to be confirmed) to remove this exception for the It is expected (to be confirmed) to remove this exception for the
median predictor in the next version of the FFV1 bitstream. median predictor in the next version of the FFV1 bitstream.
3.4. Context 3.4. Context
Relative to any "Sample" "X", the Quantized Sample Differences "L-l", Relative to any "Sample" "X", the Quantized Sample Differences "L-l",
"l-tl", "tl-t", "T-t", and "t-tr" are used as context: "l-tl", "tl-t", "T-t", and "t-tr" are used as context:
context = Q_{0}[l - tl] + context = Q_{0}[l tl] +
Q_{1}[tl - t] + Q_{1}[tl t] +
Q_{2}[t - tr] + Q_{2}[t tr] +
Q_{3}[L - l] + Q_{3}[L l] +
Q_{4}[T - t] Q_{4}[T t]
If "context >= 0" then "context" is used and the difference between If "context >= 0" then "context" is used and the difference between
the "Sample" and its predicted value is encoded as is, else the "Sample" and its predicted value is encoded as is, else
"-context" is used and the difference between the "Sample" and its "-context" is used and the difference between the "Sample" and its
predicted value is encoded with a flipped sign. predicted value is encoded with a flipped sign.
3.5. Quantization Table Sets 3.5. Quantization Table Sets
The FFV1 bitstream contains 1 or more Quantization Table Sets. Each The FFV1 bitstream contains 1 or more Quantization Table Sets. Each
Quantization Table Set contains exactly 5 Quantization Tables with Quantization Table Set contains exactly 5 Quantization Tables with
each Quantization Table corresponding to 1 of the 5 Quantized Sample each Quantization Table corresponding to 1 of the 5 Quantized Sample
Differences. For each Quantization Table, both the number of Differences. For each Quantization Table, both the number of
quantization steps and their distribution are stored in the FFV1 quantization steps and their distribution are stored in the FFV1
bitstream; each Quantization Table has exactly 256 entries, and the 8 bitstream; each Quantization Table has exactly 256 entries, and the 8
least significant bits of the Quantized Sample Difference are used as least significant bits of the Quantized Sample Difference are used as
index: index:
Q_{j}[k] = quant_tables[i][j][k&255] Q_{j}[k] = quant_tables[i][j][k&255]
In this formula, "i" is the Quantization Table Set index, "j" is the In this formula, "i" is the Quantization Table Set index, "j" is the
Quantized Table index, "k" the Quantized Sample Difference. Quantized Table index, "k" the Quantized Sample Difference.
3.6. Quantization Table Set Indexes 3.6. Quantization Table Set Indexes
For each "Plane" of each slice, a Quantization Table Set is selected For each "Plane" of each slice, a Quantization Table Set is selected
from an index: from an index:
o For Y "Plane", "quant_table_set_index [ 0 ]" index is used * For Y "Plane", "quant_table_set_index[ 0 ]" index is used
o For Cb and Cr "Planes", "quant_table_set_index [ 1 ]" index is * For Cb and Cr "Planes", "quant_table_set_index[ 1 ]" index is used
used
o For extra "Plane", "quant_table_set_index [ (version <= 3 || * For extra "Plane", "quant_table_set_index[ (version <= 3 ||
chroma_planes) ? 2 : 1 ]" index is used chroma_planes) ? 2 : 1 ]" index is used
Background: in first implementations of FFV1 bitstream, the index for Background: in first implementations of FFV1 bitstream, the index for
Cb and Cr "Planes" was stored even if it is not used (chroma_planes Cb and Cr "Planes" was stored even if it is not used (chroma_planes
set to 0), this index is kept for version <= 3 in order to keep set to 0), this index is kept for version <= 3 in order to keep
compatibility with FFV1 bitstreams in the wild. compatibility with FFV1 bitstreams in the wild.
3.7. Color spaces 3.7. Color spaces
FFV1 supports several color spaces. The count of allowed coded FFV1 supports several color spaces. The count of allowed coded
skipping to change at page 12, line 46 skipping to change at page 13, line 8
The FFV1 bitstream interleaves data in an order determined by the The FFV1 bitstream interleaves data in an order determined by the
color space. In YCbCr for each "Plane", each "Line" is coded from color space. In YCbCr for each "Plane", each "Line" is coded from
top to bottom and for each "Line", each "Sample" is coded from left top to bottom and for each "Line", each "Sample" is coded from left
to right. In JPEG2000-RCT for each "Line" from top to bottom, each to right. In JPEG2000-RCT for each "Line" from top to bottom, each
"Plane" is coded and for each "Plane", each "Sample" is encoded from "Plane" is coded and for each "Plane", each "Sample" is encoded from
left to right. left to right.
3.7.1. YCbCr 3.7.1. YCbCr
This color space allows 1 to 4 "Planes". This color space allows 1 to 4 "Planes".
The Cb and Cr "Planes" are optional, but if used then MUST be used The Cb and Cr "Planes" are optional, but if used then MUST be used
together. Omitting the Cb and Cr "Planes" codes the frames in together. Omitting the Cb and Cr "Planes" codes the frames in
grayscale without color data. grayscale without color data.
An optional transparency "Plane" can be used to code transparency An optional transparency "Plane" can be used to code transparency
data. data.
An FFV1 "Frame" using YCbCr MUST use one of the following An FFV1 "Frame" using YCbCr MUST use one of the following
arrangements: arrangements:
o Y * Y
o Y, Transparency * Y, Transparency
o Y, Cb, Cr * Y, Cb, Cr
o Y, Cb, Cr, Transparency * Y, Cb, Cr, Transparency
The Y "Plane" MUST be coded first. If the Cb and Cr "Planes" are The Y "Plane" MUST be coded first. If the Cb and Cr "Planes" are
used then they MUST be coded after the Y "Plane". If a transparency used then they MUST be coded after the Y "Plane". If a transparency
"Plane" is used, then it MUST be coded last. "Plane" is used, then it MUST be coded last.
3.7.2. RGB 3.7.2. RGB
This color space allows 3 or 4 "Planes". This color space allows 3 or 4 "Planes".
An optional transparency "Plane" can be used to code transparency An optional transparency "Plane" can be used to code transparency
data. data.
JPEG2000-RCT is a Reversible Color Transform that codes RGB (red, JPEG2000-RCT is a Reversible Color Transform that codes RGB (red,
green, blue) "Planes" losslessly in a modified YCbCr color space green, blue) "Planes" losslessly in a modified YCbCr color space
[ISO.15444-1.2016]. Reversible Pixel transformations between YCbCr [ISO.15444-1.2016]. Reversible Pixel transformations between YCbCr
and RGB use the following formulae. and RGB use the following formulae.
Cb=b-g Cb=b-g
Cr=r-g
Y=g+(Cb+Cr)>>2 Cr=r-g
g=Y-(Cb+Cr)>>2 Y=g+(Cb+Cr)>>2
r=Cr+g g=Y-(Cb+Cr)>>2
b=Cb+g r=Cr+g
b=Cb+g
Exception for the JPEG2000-RCT conversion: if bits_per_raw_sample is Exception for the JPEG2000-RCT conversion: if bits_per_raw_sample is
between 9 and 15 inclusive and extra_plane is 0, the following between 9 and 15 inclusive and extra_plane is 0, the following
formulae for reversible conversions between YCbCr and RGB MUST be formulae for reversible conversions between YCbCr and RGB MUST be
used instead of the ones above: used instead of the ones above:
Cb=g-b Cb=g-b
Cr=r-b Cr=r-b
Y=b+(Cb+Cr)>>2 Y=b+(Cb+Cr)>>2
b=Y-(Cb+Cr)>>2
r=Cr+b b=Y-(Cb+Cr)>>2
g=Cb+b r=Cr+b
g=Cb+b
Background: At the time of this writing, in all known implementations Background: At the time of this writing, in all known implementations
of FFV1 bitstream, when bits_per_raw_sample was between 9 and 15 of FFV1 bitstream, when bits_per_raw_sample was between 9 and 15
inclusive and extra_plane is 0, GBR "Planes" were used as BGR inclusive and extra_plane is 0, GBR "Planes" were used as BGR
"Planes" during both encoding and decoding. In the meanwhile, 16-bit "Planes" during both encoding and decoding. In the meanwhile, 16-bit
JPEG2000-RCT was implemented without this issue in one implementation JPEG2000-RCT was implemented without this issue in one implementation
and validated by one conformance checker. Methods to address this and validated by one conformance checker. Methods to address this
exception for the transform are under consideration for the next exception for the transform are under consideration for the next
version of the FFV1 bitstream. version of the FFV1 bitstream.
When FFV1 uses the JPEG2000-RCT, the horizontal "Lines" are When FFV1 uses the JPEG2000-RCT, the horizontal "Lines" are
interleaved to improve caching efficiency since it is most likely interleaved to improve caching efficiency since it is most likely
that the JPEG2000-RCT will immediately be converted to RGB during that the JPEG2000-RCT will immediately be converted to RGB during
decoding. The interleaved coding order is also Y, then Cb, then Cr, decoding. The interleaved coding order is also Y, then Cb, then Cr,
and then if used transparency. and then if used transparency.
As an example, a "Frame" that is two "Pixels" wide and two "Pixels" As an example, a "Frame" that is two "Pixels" wide and two "Pixels"
high, could be comprised of the following structure: high, could be comprised of the following structure:
+------------------------+------------------------+ +------------------------+------------------------+
| Pixel[1,1] | Pixel[2,1] | | Pixel[1,1] | Pixel[2,1] |
| Y[1,1] Cb[1,1] Cr[1,1] | Y[2,1] Cb[2,1] Cr[2,1] | | Y[1,1] Cb[1,1] Cr[1,1] | Y[2,1] Cb[2,1] Cr[2,1] |
+------------------------+------------------------+ +------------------------+------------------------+
| Pixel[1,2] | Pixel[2,2] | | Pixel[1,2] | Pixel[2,2] |
| Y[1,2] Cb[1,2] Cr[1,2] | Y[2,2] Cb[2,2] Cr[2,2] | | Y[1,2] Cb[1,2] Cr[1,2] | Y[2,2] Cb[2,2] Cr[2,2] |
+------------------------+------------------------+ +------------------------+------------------------+
In JPEG2000-RCT, the coding order would be left to right and then top In JPEG2000-RCT, the coding order would be left to right and then top
to bottom, with values interleaved by "Lines" and stored in this to bottom, with values interleaved by "Lines" and stored in this
order: order:
Y[1,1] Y[2,1] Cb[1,1] Cb[2,1] Cr[1,1] Cr[2,1] Y[1,2] Y[2,2] Cb[1,2] Y[1,1] Y[2,1] Cb[1,1] Cb[2,1] Cr[1,1] Cr[2,1] Y[1,2] Y[2,2] Cb[1,2]
Cb[2,2] Cr[1,2] Cr[2,2] Cb[2,2] Cr[1,2] Cr[2,2]
3.8. Coding of the Sample Difference 3.8. Coding of the Sample Difference
Instead of coding the n+1 bits of the Sample Difference with Huffman Instead of coding the n+1 bits of the Sample Difference with Huffman
or Range coding (or n+2 bits, in the case of JPEG2000-RCT), only the or Range coding (or n+2 bits, in the case of JPEG2000-RCT), only the
n (or n+1, in the case of JPEG2000-RCT) least significant bits are n (or n+1, in the case of JPEG2000-RCT) least significant bits are
used, since this is sufficient to recover the original "Sample". In used, since this is sufficient to recover the original "Sample". In
the equation below, the term "bits" represents bits_per_raw_sample+1 the equation below, the term "bits" represents bits_per_raw_sample+1
for JPEG2000-RCT or bits_per_raw_sample otherwise: for JPEG2000-RCT or bits_per_raw_sample otherwise:
coder_input = coder_input =
[(sample_difference + 2^(bits-1)) & (2^bits - 1)] - 2^(bits-1) [(sample_difference + 2^(bits−1)) & (2^bits 1)] − 2^(bits−1)
3.8.1. Range Coding Mode 3.8.1. Range Coding Mode
Early experimental versions of FFV1 used the CABAC Arithmetic coder Early experimental versions of FFV1 used the CABAC Arithmetic coder
from H.264 as defined in [ISO.14496-10.2014] but due to the uncertain from H.264 as defined in [ISO.14496-10.2014] but due to the uncertain
patent/royalty situation, as well as its slightly worse performance, patent/royalty situation, as well as its slightly worse performance,
CABAC was replaced by a Range coder based on an algorithm defined by CABAC was replaced by a Range coder based on an algorithm defined by
G. Nigel and N. Martin in 1979 [range-coding]. G. Nigel and N. Martin in 1979 [range-coding].
3.8.1.1. Range Binary Values 3.8.1.1. Range Binary Values
To encode binary digits efficiently a Range coder is used. "C_{i}" To encode binary digits efficiently a Range coder is used. "C_{i}"
is the i-th Context. "B_{i}" is the i-th byte of the bytestream. is the i-th Context. "B_{i}" is the i-th byte of the bytestream.
"b_{i}" is the i-th Range coded binary value, "S_{0,i}" is the i-th "b_{i}" is the i-th Range coded binary value, "S_{0,i}" is the i-th
initial state. The length of the bytestream encoding n binary initial state. The length of the bytestream encoding n binary
symbols is "j_{n}" bytes. symbols is "j_{n}" bytes.
r_{i} = floor( ( R_{i} * S_{i,C_{i}} ) / 2^8 ) r_{i} = floor( ( R_{i} * S_{i,C_{i}} ) / 2^8 )
S_{i+1,C_{i}} = zero_state_{S_{i,C_{i}}} XOR S_{i+1,C_{i}} = zero_state_{S_{i,C_{i}}} XOR
l_i = L_i XOR l_i = L_i XOR
t_i = R_i - r_i <== t_i = R_i - r_i <==
b_i = 0 <==> b_i = 0 <==>
L_i < R_i - r_i L_i < R_i - r_i
S_{i+1,C_{i}} = one_state_{S_{i,C_{i}}} XOR S_{i+1,C_{i}} = one_state_{S_{i,C_{i}}} XOR
l_i = L_i - R_i + r_i XOR l_i = L_i - R_i + r_i XOR
t_i = r_i <== t_i = r_i <==
b_i = 1 <==> b_i = 1 <==>
L_i >= R_i - r_i L_i >= R_i - r_i
S_{i+1,k} = S_{i,k} <== C_i != k S_{i+1,k} = S_{i,k} <== C_i != k
R_{i+1} = 2^8 * t_{i} XOR
L_{i+1} = 2^8 * l_{i} + B_{j_{i}} XOR
j_{i+1} = j_{i} + 1 <==
t_{i} < 2^8
R_{i+1} = 2^8 * t_{i} XOR R_{i+1} = t_{i} XOR
L_{i+1} = 2^8 * l_{i} + B_{j_{i}} XOR L_{i+1} = l_{i} XOR
j_{i+1} = j_{i} + 1 <== j_{i+1} = j_{i} <==
t_{i} < 2^8 t_{i} >= 2^8
R_{i+1} = t_{i} XOR R_{0} = 65280
L_{i+1} = l_{i} XOR
j_{i+1} = j_{i} <==
t_{i} >= 2^8
R_{0} = 65280 L_{0} = 2^8 * B_{0} + B_{1}
L_{0} = 2^8 * B_{0} + B_{1} j_{0} = 2
j_{0} = 2
3.8.1.1.1. Termination 3.8.1.1.1. Termination
The range coder can be used in 3 modes. The range coder can be used in 3 modes.
o In "Open mode" when decoding, every symbol the reader attempts to * In "Open mode" when decoding, every symbol the reader attempts to
read is available. In this mode arbitrary data can have been read is available. In this mode arbitrary data can have been
appended without affecting the range coder output. This mode is appended without affecting the range coder output. This mode is
not used in FFV1. not used in FFV1.
o In "Closed mode" the length in bytes of the bytestream is provided * In "Closed mode" the length in bytes of the bytestream is provided
to the range decoder. Bytes beyond the length are read as 0 by to the range decoder. Bytes beyond the length are read as 0 by
the range decoder. This is generally 1 byte shorter than the open the range decoder. This is generally 1 byte shorter than the open
mode. mode.
o In "Sentinel mode" the exact length in bytes is not known and thus * In "Sentinel mode" the exact length in bytes is not known and thus
the range decoder MAY read into the data that follows the range the range decoder MAY read into the data that follows the range
coded bytestream by one byte. In "Sentinel mode", the end of the coded bytestream by one byte. In "Sentinel mode", the end of the
range coded bytestream is a binary symbol with state 129, which range coded bytestream is a binary symbol with state 129, which
value SHALL be discarded. After reading this symbol, the range value SHALL be discarded. After reading this symbol, the range
decoder will have read one byte beyond the end of the range coded decoder will have read one byte beyond the end of the range coded
bytestream. This way the byte position of the end can be bytestream. This way the byte position of the end can be
determined. Bytestreams written in "Sentinel mode" can be read in determined. Bytestreams written in "Sentinel mode" can be read in
"Closed mode" if the length can be determined, in this case the "Closed mode" if the length can be determined, in this case the
last (sentinel) symbol will be read non-corrupted and be of value last (sentinel) symbol will be read non-corrupted and be of value
0. 0.
skipping to change at page 17, line 10 skipping to change at page 17, line 24
255 contexts per 8-bit symbol that is not only a waste of memory but 255 contexts per 8-bit symbol that is not only a waste of memory but
also requires more past data to reach a reasonably good estimate of also requires more past data to reach a reasonably good estimate of
the probabilities. Alternatively assuming a Laplacian distribution the probabilities. Alternatively assuming a Laplacian distribution
and only dealing with its variance and mean (as in Huffman coding) and only dealing with its variance and mean (as in Huffman coding)
would also be possible, however, for maximum flexibility and would also be possible, however, for maximum flexibility and
simplicity, the chosen method uses a single symbol to encode if a simplicity, the chosen method uses a single symbol to encode if a
number is 0, and if not, encodes the number using its exponent, number is 0, and if not, encodes the number using its exponent,
mantissa and sign. The exact contexts used are best described by the mantissa and sign. The exact contexts used are best described by the
following code, followed by some comments. following code, followed by some comments.
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- void put_symbol(RangeCoder *c, uint8_t *state, int v, int \ | is_signed) { | int i; | put_rac(c, state+0, !v); | if (v) { | int a= abs(v); | int e= log2(a); | | for (i = 0; i < e; i++) { | put_rac(c, state+1+min(i,9), 1); //1..10 | } | | put_rac(c, state+1+min(i,9), 0); | for (i = e-1; i >= 0; i--) { | put_rac(c, state+22+min(i,9), (a>>i)&1); //22..31 | } | | if (is_signed) { | put_rac(c, state+11 + min(e, 10), v < 0); //11..21| } | } | } |
--------------------------------------------------------------|-----
void put_symbol(RangeCoder *c, uint8_t *state, int v, int \ |
is_signed) { |
int i; |
put_rac(c, state+0, !v); |
if (v) { |
int a= abs(v); |
int e= log2(a); |
|
for (i=0; i<e; i++) |
put_rac(c, state+1+min(i,9), 1); //1..10 |
|
put_rac(c, state+1+min(i,9), 0); |
for (i=e-1; i>=0; i--) |
put_rac(c, state+22+min(i,9), (a>>i)&1); //22..31 |
|
if (is_signed) |
put_rac(c, state+11 + min(e, 10), v < 0); //11..21|
} |
} |
3.8.1.3. Initial Values for the Context Model 3.8.1.3. Initial Values for the Context Model
At keyframes all Range coder state variables are set to their initial At keyframes all Range coder state variables are set to their initial
state. state.
3.8.1.4. State Transition Table 3.8.1.4. State Transition Table
one_state_{i} = one_state_{i} =
default_state_transition_{i} + state_transition_delta_{i} default_state_transition_{i} + state_transition_delta_{i}
zero_state_{i} = 256 - one_state_{256-i} zero_state_{i} = 256 - one_state_{256-i}
3.8.1.5. default_state_transition 3.8.1.5. default_state_transition
0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27,
28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42,
43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57,
58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73,
74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88,
89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99,100,101,102,103, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99,100,101,102,103,
104,105,106,107,108,109,110,111,112,113,114,114,115,116,117,118, 104,105,106,107,108,109,110,111,112,113,114,114,115,116,117,118,
119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,133, 119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,133,
134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149, 134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,
150,151,152,152,153,154,155,156,157,158,159,160,161,162,163,164, 150,151,152,152,153,154,155,156,157,158,159,160,161,162,163,164,
165,166,167,168,169,170,171,171,172,173,174,175,176,177,178,179, 165,166,167,168,169,170,171,171,172,173,174,175,176,177,178,179,
180,181,182,183,184,185,186,187,188,189,190,190,191,192,194,194, 180,181,182,183,184,185,186,187,188,189,190,190,191,192,194,194,
195,196,197,198,199,200,201,202,202,204,205,206,207,208,209,209, 195,196,197,198,199,200,201,202,202,204,205,206,207,208,209,209,
210,211,212,213,215,215,216,217,218,219,220,220,222,223,224,225, 210,211,212,213,215,215,216,217,218,219,220,220,222,223,224,225,
226,227,227,229,229,230,231,232,234,234,235,236,237,238,239,240, 226,227,227,229,229,230,231,232,234,234,235,236,237,238,239,240,
241,242,243,244,245,246,247,248,248, 0, 0, 0, 0, 0, 0, 0, 241,242,243,244,245,246,247,248,248, 0, 0, 0, 0, 0, 0, 0,
3.8.1.6. Alternative State Transition Table 3.8.1.6. Alternative State Transition Table
The alternative state transition table has been built using iterative The alternative state transition table has been built using iterative
minimization of frame sizes and generally performs better than the minimization of frame sizes and generally performs better than the
default. To use it, the coder_type (see Section 4.1.3) MUST be set default. To use it, the coder_type (see the section on coder_type
to 2 and the difference to the default MUST be stored in the (#codertype)) MUST be set to 2 and the difference to the default MUST
"Parameters", see Section 4.1. The reference implementation of FFV1 be stored in the "Parameters", see the section on Parameters
in FFmpeg uses this table by default at the time of this writing when (#parameters). The reference implementation of FFV1 in FFmpeg uses
Range coding is used. this table by default at the time of this writing when Range coding
is used.
0, 10, 10, 10, 10, 16, 16, 16, 28, 16, 16, 29, 42, 49, 20, 49, 0, 10, 10, 10, 10, 16, 16, 16, 28, 16, 16, 29, 42, 49, 20, 49,
59, 25, 26, 26, 27, 31, 33, 33, 33, 34, 34, 37, 67, 38, 39, 39, 59, 25, 26, 26, 27, 31, 33, 33, 33, 34, 34, 37, 67, 38, 39, 39,
40, 40, 41, 79, 43, 44, 45, 45, 48, 48, 64, 50, 51, 52, 88, 52, 40, 40, 41, 79, 43, 44, 45, 45, 48, 48, 64, 50, 51, 52, 88, 52,
53, 74, 55, 57, 58, 58, 74, 60,101, 61, 62, 84, 66, 66, 68, 69, 53, 74, 55, 57, 58, 58, 74, 60,101, 61, 62, 84, 66, 66, 68, 69,
87, 82, 71, 97, 73, 73, 82, 75,111, 77, 94, 78, 87, 81, 83, 97, 87, 82, 71, 97, 73, 73, 82, 75,111, 77, 94, 78, 87, 81, 83, 97,
85, 83, 94, 86, 99, 89, 90, 99,111, 92, 93,134, 95, 98,105, 98, 85, 83, 94, 86, 99, 89, 90, 99,111, 92, 93,134, 95, 98,105, 98,
105,110,102,108,102,118,103,106,106,113,109,112,114,112,116,125, 105,110,102,108,102,118,103,106,106,113,109,112,114,112,116,125,
115,116,117,117,126,119,125,121,121,123,145,124,126,131,127,129, 115,116,117,117,126,119,125,121,121,123,145,124,126,131,127,129,
165,130,132,138,133,135,145,136,137,139,146,141,143,142,144,148, 165,130,132,138,133,135,145,136,137,139,146,141,143,142,144,148,
147,155,151,149,151,150,152,157,153,154,156,168,158,162,161,160, 147,155,151,149,151,150,152,157,153,154,156,168,158,162,161,160,
172,163,169,164,166,184,167,170,177,174,171,173,182,176,180,178, 172,163,169,164,166,184,167,170,177,174,171,173,182,176,180,178,
175,189,179,181,186,183,192,185,200,187,191,188,190,197,193,196, 175,189,179,181,186,183,192,185,200,187,191,188,190,197,193,196,
197,194,195,196,198,202,199,201,210,203,207,204,205,206,208,214, 197,194,195,196,198,202,199,201,210,203,207,204,205,206,208,214,
209,211,221,212,213,215,224,216,217,218,219,220,222,228,223,225, 209,211,221,212,213,215,224,216,217,218,219,220,222,228,223,225,
226,224,227,229,240,230,231,232,233,234,235,236,238,239,237,242, 226,224,227,229,240,230,231,232,233,234,235,236,238,239,237,242,
241,243,242,244,245,246,247,248,249,250,251,252,252,253,254,255, 241,243,242,244,245,246,247,248,249,250,251,252,252,253,254,255,
3.8.2. Golomb Rice Mode 3.8.2. Golomb Rice Mode
The end of the bitstream of the "Frame" is filled with 0-bits until The end of the bitstream of the "Frame" is filled with 0-bits until
that the bitstream contains a multiple of 8 bits. that the bitstream contains a multiple of 8 bits.
3.8.2.1. Signed Golomb Rice Codes 3.8.2.1. Signed Golomb Rice Codes
This coding mode uses Golomb Rice codes. The VLC is split into 2 This coding mode uses Golomb Rice codes. The VLC is split into 2
parts, the prefix stores the most significant bits and the suffix parts, the prefix stores the most significant bits and the suffix
stores the k least significant bits or stores the whole number in the stores the k least significant bits or stores the whole number in the
ESC case. ESC case.
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- int get_ur_golomb(k) { | for (prefix = 0; prefix < 12; prefix++) { | if (get_bits(1)) { | return get_bits(k) + (prefix << k) | } | } | return get_bits(bits) + 11 | } | | int get_sr_golomb(k) { | v = get_ur_golomb(k); | if (v & 1) return - (v >> 1) - 1; | else return (v >> 1); | }
--------------------------------------------------------------|-----
int get_ur_golomb(k) { |
for (prefix = 0; prefix < 12; prefix++) { |
if ( get_bits(1) ) |
return get_bits(k) + (prefix << k) |
} |
return get_bits(bits) + 11 |
} |
|
int get_sr_golomb(k) { |
v = get_ur_golomb(k); |
if (v & 1) return - (v >> 1) - 1; |
else return (v >> 1); |
}
3.8.2.1.1. Prefix 3.8.2.1.1. Prefix
+----------------+-------+ +----------------+-------+
| bits | value | | bits | value |
+----------------+-------+ +================+=======+
| 1 | 0 | | 1 | 0 |
+----------------+-------+
| 01 | 1 | | 01 | 1 |
+----------------+-------+
| ... | ... | | ... | ... |
+----------------+-------+
| 0000 0000 0001 | 11 | | 0000 0000 0001 | 11 |
+----------------+-------+
| 0000 0000 0000 | ESC | | 0000 0000 0000 | ESC |
+----------------+-------+ +----------------+-------+
Table 1
3.8.2.1.2. Suffix 3.8.2.1.2. Suffix
+-------+-----------------------------------------------------------+ +---------+--------------------------------------------------+
| non | the k least significant bits MSB first | +=========+==================================================+
| ESC | | | non ESC | the k least significant bits MSB first |
| ESC | the value - 11, in MSB first order, ESC may only be used | +---------+--------------------------------------------------+
| | if the value cannot be coded as non ESC | | ESC | the value - 11, in MSB first order, ESC may only |
+-------+-----------------------------------------------------------+ | | be used if the value cannot be coded as non ESC |
+---------+--------------------------------------------------+
Table 2
3.8.2.1.3. Examples 3.8.2.1.3. Examples
+-----+-------------------------+-------+ +-----+-------------------------+-------+
| k | bits | value | | k | bits | value |
+-----+-------------------------+-------+ +=====+=========================+=======+
| 0 | "1" | 0 | | 0 | "1" | 0 |
+-----+-------------------------+-------+
| 0 | "001" | 2 | | 0 | "001" | 2 |
+-----+-------------------------+-------+
| 2 | "1 00" | 0 | | 2 | "1 00" | 0 |
+-----+-------------------------+-------+
| 2 | "1 10" | 2 | | 2 | "1 10" | 2 |
+-----+-------------------------+-------+
| 2 | "01 01" | 5 | | 2 | "01 01" | 5 |
+-----+-------------------------+-------+
| any | "000000000000 10000000" | 139 | | any | "000000000000 10000000" | 139 |
+-----+-------------------------+-------+ +-----+-------------------------+-------+
Table 3
3.8.2.2. Run Mode 3.8.2.2. Run Mode
Run mode is entered when the context is 0 and left as soon as a non-0 Run mode is entered when the context is 0 and left as soon as a non-0
difference is found. The level is identical to the predicted one. difference is found. The level is identical to the predicted one.
The run and the first different level are coded. The run and the first different level are coded.
3.8.2.2.1. Run Length Coding 3.8.2.2.1. Run Length Coding
The run value is encoded in 2 parts, the prefix part stores the more The run value is encoded in 2 parts, the prefix part stores the more
significant part of the run as well as adjusting the run_index that significant part of the run as well as adjusting the run_index that
determines the number of bits in the less significant part of the determines the number of bits in the less significant part of the
run. The 2nd part of the value stores the less significant part of run. The 2nd part of the value stores the less significant part of
the run as it is. The run_index is reset for each "Plane" and slice the run as it is. The run_index is reset for each "Plane" and slice
to 0. to 0.
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- log2_run[41]={ | 0, 0, 0, 0, 1, 1, 1, 1, | 2, 2, 2, 2, 3, 3, 3, 3, | 4, 4, 5, 5, 6, 6, 7, 7, | 8, 9,10,11,12,13,14,15, | 16,17,18,19,20,21,22,23, | 24, | }; | | if (run_count == 0 && run_mode == 1) { | if (get_bits(1)) { | run_count = 1 << log2_run[run_index]; | if (x + run_count <= w) { | run_index++; | } | } else { | if (log2_run[run_index]) { | run_count = get_bits(log2_run[run_index]); | } else { | run_count = 0; | } | if (run_index) { | run_index--; | } | run_mode = 2; | } | } |
--------------------------------------------------------------|-----
log2_run[41]={ |
0, 0, 0, 0, 1, 1, 1, 1, |
2, 2, 2, 2, 3, 3, 3, 3, |
4, 4, 5, 5, 6, 6, 7, 7, |
8, 9,10,11,12,13,14,15, |
16,17,18,19,20,21,22,23, |
24, |
}; |
|
if (run_count == 0 && run_mode == 1) { |
if (get_bits(1)) { |
run_count = 1 << log2_run[run_index]; |
if (x + run_count <= w) |
run_index++; |
} else { |
if (log2_run[run_index]) |
run_count = get_bits(log2_run[run_index]); |
else |
run_count = 0; |
if (run_index) |
run_index--; |
run_mode = 2; |
} |
} |
The log2_run function is also used within [ISO.14495-1.1999]. The log2_run function is also used within [ISO.14495-1.1999].
3.8.2.2.2. Level Coding 3.8.2.2.2. Level Coding
Level coding is identical to the normal difference coding with the Level coding is identical to the normal difference coding with the
exception that the 0 value is removed as it cannot occur: exception that the 0 value is removed as it cannot occur:
diff = get_vlc_symbol(context_state); diff = get_vlc_symbol(context_state); if (diff >= 0) { diff++; }
if (diff >= 0)
diff++;
Note, this is different from JPEG-LS, which doesn't use prediction in Note, this is different from JPEG-LS, which doesn't use prediction in
run mode and uses a different encoding and context model for the last run mode and uses a different encoding and context model for the last
difference On a small set of test "Samples" the use of prediction difference On a small set of test "Samples" the use of prediction
slightly improved the compression rate. slightly improved the compression rate.
3.8.2.3. Scalar Mode 3.8.2.3. Scalar Mode
Each difference is coded with the per context mean prediction removed Each difference is coded with the per context mean prediction removed
and a per context value for k. and a per context value for k.
get_vlc_symbol(state) { get_vlc_symbol(state) { i = state->count; k = 0; while (i < state->error_sum) { k++; i += i; } v = get_sr_golomb(k); if (2 * state->drift < -state->count) { v = -1 - v; } ret = sign_extend(v + state->bias, bits); state->error_sum += abs(v); state->drift += v; if (state->count == 128) { state->count >>= 1; state->drift >>= 1; state->error_sum >>= 1; } state->count++; if (state->drift <= -state->count) { state->bias = max(state->bias - 1, -128); state->drift = max(state->drift + state->count, -state->count + 1); } else if (state->drift > 0) { state->bias = min(state->bias + 1, 127); state->drift = min(state->drift - state->count, 0); } return ret; }
i = state->count;
k = 0;
while (i < state->error_sum) {
k++;
i += i;
}
v = get_sr_golomb(k);
if (2 * state->drift < -state->count)
v = - 1 - v;
ret = sign_extend(v + state->bias, bits);
state->error_sum += abs(v);
state->drift += v;
if (state->count == 128) {
state->count >>= 1;
state->drift >>= 1;
state->error_sum >>= 1;
}
state->count++;
if (state->drift <= -state->count) {
state->bias = max(state->bias - 1, -128);
state->drift = max(state->drift + state->count,
-state->count + 1);
} else if (state->drift > 0) {
state->bias = min(state->bias + 1, 127);
state->drift = min(state->drift - state->count, 0);
}
return ret;
}
3.8.2.4. Initial Values for the VLC context state 3.8.2.4. Initial Values for the VLC context state
At keyframes all coder state variables are set to their initial At keyframes all coder state variables are set to their initial
state. state.
drift = 0; drift = 0; error_sum = 4; bias = 0; count = 1;
error_sum = 4;
bias = 0;
count = 1;
4. Bitstream 4. Bitstream
An FFV1 bitstream is composed of a series of 1 or more "Frames" and An FFV1 bitstream is composed of a series of 1 or more "Frames" and
(when required) a "Configuration Record". (when required) a "Configuration Record".
Within the following sub-sections, pseudo-code is used to explain the Within the following sub-sections, pseudo-code is used to explain the
structure of each FFV1 bitstream component, as described in structure of each FFV1 bitstream component, as described in the
Section 2.2.1. The following table lists symbols used to annotate section on Pseudo-Code (#pseudocode). The following table lists
that pseudo-code in order to define the storage of the data symbols used to annotate that pseudo-code in order to define the
referenced in that line of pseudo-code. storage of the data referenced in that line of pseudo-code.
+--------+----------------------------------------------------------+ +--------+-------------------------------------------+
| Symbol | Definition | | Symbol | Definition |
+--------+----------------------------------------------------------+ +========+===========================================+
| u(n) | unsigned big endian integer using n bits | | u(n) | unsigned big endian integer using n bits |
| sg | Golomb Rice coded signed scalar symbol coded with the | +--------+-------------------------------------------+
| | method described in Section 3.8.2 | | sg | Golomb Rice coded signed scalar symbol |
| br | Range coded Boolean (1-bit) symbol with the method | | | coded with the method described in Signed |
| | described in Section 3.8.1.1 | | | Golomb Rice Codes (#golomb-rice-mode) |
| ur | Range coded unsigned scalar symbol coded with the method | +--------+-------------------------------------------+
| | described in Section 3.8.1.2 | | br | Range coded Boolean (1-bit) symbol with |
| sr | Range coded signed scalar symbol coded with the method | | | the method described in Range binary |
| | described in Section 3.8.1.2 | | | values (#range-binary-values) |
+--------+----------------------------------------------------------+ +--------+-------------------------------------------+
| ur | Range coded unsigned scalar symbol coded |
| | with the method described in Range non |
| | binary values (#range-non-binary-values) |
+--------+-------------------------------------------+
| sr | Range coded signed scalar symbol coded |
| | with the method described in Range non |
| | binary values (#range-non-binary-values) |
+--------+-------------------------------------------+
Table 4
The same context that is initialized to 128 is used for all fields in The same context that is initialized to 128 is used for all fields in
the header. the header.
The following MUST be provided by external means during The following MUST be provided by external means during
initialization of the decoder: initialization of the decoder:
"frame_pixel_width" is defined as "Frame" width in "Pixels". "frame_pixel_width" is defined as "Frame" width in "Pixels".
"frame_pixel_height" is defined as "Frame" height in "Pixels". "frame_pixel_height" is defined as "Frame" height in "Pixels".
skipping to change at page 25, line 5 skipping to change at page 23, line 52
4.1. Parameters 4.1. Parameters
The "Parameters" section contains significant characteristics about The "Parameters" section contains significant characteristics about
the decoding configuration used for all instances of "Frame" (in FFV1 the decoding configuration used for all instances of "Frame" (in FFV1
version 0 and 1) or the whole FFV1 bitstream (other versions), version 0 and 1) or the whole FFV1 bitstream (other versions),
including the stream version, color configuration, and quantization including the stream version, color configuration, and quantization
tables. The pseudo-code below describes the contents of the tables. The pseudo-code below describes the contents of the
bitstream. bitstream.
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- Parameters( ) { | version | ur if (version >= 3) { | micro_version | ur } | coder_type | ur if (coder_type > 1) { | for (i = 1; i < 256; i++) { | state_transition_delta[ i ] | sr } | } | colorspace_type | ur if (version >= 1) { | bits_per_raw_sample | ur } | chroma_planes | br log2_h_chroma_subsample | ur log2_v_chroma_subsample | ur extra_plane | br if (version >= 3) { | num_h_slices - 1 | ur num_v_slices - 1 | ur quant_table_set_count | ur } | for (i = 0; i < quant_table_set_count; i++) { | QuantizationTableSet( i ) | } | if (version >= 3) { | for (i = 0; i < quant_table_set_count; i++) { | states_coded | br if (states_coded) { | for (j = 0; j < context_count[ i ]; j++) { | for (k = 0; k < CONTEXT_SIZE; k++) { | initial_state_delta[ i ][ j ][ k ] | sr } | } | } | } | ec | ur intra | ur } | } |
--------------------------------------------------------------|-----
Parameters( ) { |
version | ur
if (version >= 3) |
micro_version | ur
coder_type | ur
if (coder_type > 1) |
for (i = 1; i < 256; i++) |
state_transition_delta[ i ] | sr
colorspace_type | ur
if (version >= 1) |
bits_per_raw_sample | ur
chroma_planes | br
log2_h_chroma_subsample | ur
log2_v_chroma_subsample | ur
extra_plane | br
if (version >= 3) { |
num_h_slices - 1 | ur
num_v_slices - 1 | ur
quant_table_set_count | ur
} |
for( i = 0; i < quant_table_set_count; i++ ) |
QuantizationTableSet( i ) |
if (version >= 3) { |
for( i = 0; i < quant_table_set_count; i++ ) { |
states_coded | br
if (states_coded) |
for( j = 0; j < context_count[ i ]; j++ ) |
for( k = 0; k < CONTEXT_SIZE; k++ ) |
initial_state_delta[ i ][ j ][ k ] | sr
} |
ec | ur
intra | ur
} |
} |
4.1.1. version 4.1.1. version
"version" specifies the version of the FFV1 bitstream. "version" specifies the version of the FFV1 bitstream.
Each version is incompatible with other versions: decoders SHOULD Each version is incompatible with other versions: decoders SHOULD
reject a file due to an unknown version. reject a file due to an unknown version.
Decoders SHOULD reject a file with version <= 1 && Decoders SHOULD reject a file with version <= 1 &&
ConfigurationRecordIsPresent == 1. ConfigurationRecordIsPresent == 1.
Decoders SHOULD reject a file with version >= 3 && Decoders SHOULD reject a file with version >= 3 &&
ConfigurationRecordIsPresent == 0. ConfigurationRecordIsPresent == 0.
+-------+-------------------------+ +-------+-------------------------+
| value | version | | value | version |
+-------+-------------------------+ +=======+=========================+
| 0 | FFV1 version 0 | | 0 | FFV1 version 0 |
+-------+-------------------------+
| 1 | FFV1 version 1 | | 1 | FFV1 version 1 |
+-------+-------------------------+
| 2 | reserved* | | 2 | reserved* |
+-------+-------------------------+
| 3 | FFV1 version 3 | | 3 | FFV1 version 3 |
+-------+-------------------------+
| 4 | FFV1 version 4 | | 4 | FFV1 version 4 |
+-------+-------------------------+
| Other | reserved for future use | | Other | reserved for future use |
+-------+-------------------------+ +-------+-------------------------+
Table 5
* Version 2 was never enabled in the encoder thus version 2 files * Version 2 was never enabled in the encoder thus version 2 files
SHOULD NOT exist, and this document does not describe them to keep SHOULD NOT exist, and this document does not describe them to keep
the text simpler. the text simpler.
4.1.2. micro_version 4.1.2. micro_version
"micro_version" specifies the micro-version of the FFV1 bitstream. "micro_version" specifies the micro-version of the FFV1 bitstream.
After a version is considered stable (a micro-version value is After a version is considered stable (a micro-version value is
assigned to be the first stable variant of a specific version), each assigned to be the first stable variant of a specific version), each
new micro-version after this first stable variant is compatible with new micro-version after this first stable variant is compatible with
the previous micro-version: decoders SHOULD NOT reject a file due to the previous micro-version: decoders SHOULD NOT reject a file due to
an unknown micro-version equal or above the micro-version considered an unknown micro-version equal or above the micro-version considered
as stable. as stable.
Meaning of micro_version for version 3: Meaning of micro_version for version 3:
+-------+-------------------------+ +-------+-------------------------+
skipping to change at page 26, line 34 skipping to change at page 25, line 7
assigned to be the first stable variant of a specific version), each assigned to be the first stable variant of a specific version), each
new micro-version after this first stable variant is compatible with new micro-version after this first stable variant is compatible with
the previous micro-version: decoders SHOULD NOT reject a file due to the previous micro-version: decoders SHOULD NOT reject a file due to
an unknown micro-version equal or above the micro-version considered an unknown micro-version equal or above the micro-version considered
as stable. as stable.
Meaning of micro_version for version 3: Meaning of micro_version for version 3:
+-------+-------------------------+ +-------+-------------------------+
| value | micro_version | | value | micro_version |
+-------+-------------------------+ +=======+=========================+
| 0...3 | reserved* | | 0...3 | reserved* |
| 4 | first stable variant | +-------+-------------------------+
| 4 | first stable variant |
+-------+-------------------------+
| Other | reserved for future use | | Other | reserved for future use |
+-------+-------------------------+ +-------+-------------------------+
Table 6
* development versions may be incompatible with the stable variants. * development versions may be incompatible with the stable variants.
Meaning of micro_version for version 4 (note: at the time of writing Meaning of micro_version for version 4 (note: at the time of writing
of this specification, version 4 is not considered stable so the of this specification, version 4 is not considered stable so the
first stable version value is to be announced in the future): first stable version value is to be announced in the future):
+---------+-------------------------+ +---------+-------------------------+
| value | micro_version | | value | micro_version |
+---------+-------------------------+ +=========+=========================+
| 0...TBA | reserved* | | 0...TBA | reserved* |
| TBA | first stable variant | +---------+-------------------------+
| Other | reserved for future use | | TBA | first stable variant |
+---------+-------------------------+
| Other | reserved for future use |
+---------+-------------------------+ +---------+-------------------------+
Table 7
* development versions which may be incompatible with the stable * development versions which may be incompatible with the stable
variants. variants.
4.1.3. coder_type 4.1.3. coder_type
"coder_type" specifies the coder used. "coder_type" specifies the coder used.
+-------+-------------------------------------------------+ +-------+-------------------------------------------------+
| value | coder used | | value | coder used |
+=======+=================================================+
| 0 | Golomb Rice |
+-------+-------------------------------------------------+
| 1 | Range Coder with default state transition table |
+-------+-------------------------------------------------+
| 2 | Range Coder with custom state transition table |
+-------+-------------------------------------------------+ +-------+-------------------------------------------------+
| 0 | Golomb Rice |
| 1 | Range Coder with default state transition table |
| 2 | Range Coder with custom state transition table |
| Other | reserved for future use | | Other | reserved for future use |
+-------+-------------------------------------------------+ +-------+-------------------------------------------------+
Table 8
4.1.4. state_transition_delta 4.1.4. state_transition_delta
"state_transition_delta" specifies the Range coder custom state "state_transition_delta" specifies the Range coder custom state
transition table. transition table.
If state_transition_delta is not present in the FFV1 bitstream, all If state_transition_delta is not present in the FFV1 bitstream, all
Range coder custom state transition table elements are assumed to be Range coder custom state transition table elements are assumed to be
0. 0.
4.1.5. colorspace_type 4.1.5. colorspace_type
"colorspace_type" specifies the color space encoded, the pixel "colorspace_type" specifies the color space encoded, the pixel
transformation used by the encoder, the extra plane content, as well transformation used by the encoder, the extra plane content, as well
as interleave method. as interleave method.
skipping to change at page 27, line 35 skipping to change at page 26, line 34
If state_transition_delta is not present in the FFV1 bitstream, all If state_transition_delta is not present in the FFV1 bitstream, all
Range coder custom state transition table elements are assumed to be Range coder custom state transition table elements are assumed to be
0. 0.
4.1.5. colorspace_type 4.1.5. colorspace_type
"colorspace_type" specifies the color space encoded, the pixel "colorspace_type" specifies the color space encoded, the pixel
transformation used by the encoder, the extra plane content, as well transformation used by the encoder, the extra plane content, as well
as interleave method. as interleave method.
+-------+-----------+----------------+---------------+--------------+ +-------+-------------+----------------+--------------+-------------+
| value | color | pixel | extra plane | interleave | | value | color space | pixel | extra plane | interleave |
| | space | transformation | content | method | | | encoded | transformation | content | method |
| | encoded | | | | +=======+=============+================+==============+=============+
+-------+-----------+----------------+---------------+--------------+ | 0 | YCbCr | None | Transparency | "Plane" |
| 0 | YCbCr | None | Transparency | "Plane" then | | | | | | then |
| | | | | "Line" | | | | | | "Line" |
| 1 | RGB | JPEG2000-RCT | Transparency | "Line" then | +-------+-------------+----------------+--------------+-------------+
| | | | | "Plane" | | 1 | RGB | JPEG2000-RCT | Transparency | "Line" |
| Other | reserved | reserved for | reserved for | reserved for | | | | | | then |
| | for | future use | future use | future use | | | | | | "Plane" |
| | future | | | | +-------+-------------+----------------+--------------+-------------+
| | use | | | | | Other | reserved | reserved for | reserved for | reserved |
+-------+-----------+----------------+---------------+--------------+ | | for future | future use | future use | for future |
| | use | | | use |
+-------+-------------+----------------+--------------+-------------+
Table 9
Restrictions: Restrictions:
If "colorspace_type" is 1, then "chroma_planes" MUST be 1, If "colorspace_type" is 1, then "chroma_planes" MUST be 1,
"log2_h_chroma_subsample" MUST be 0, and "log2_v_chroma_subsample" "log2_h_chroma_subsample" MUST be 0, and "log2_v_chroma_subsample"
MUST be 0. MUST be 0.
4.1.6. chroma_planes 4.1.6. chroma_planes
"chroma_planes" indicates if chroma (color) "Planes" are present. "chroma_planes" indicates if chroma (color) "Planes" are present.
+-------+---------------------------------+ +-------+---------------------------------+
| value | presence | | value | presence |
+=======+=================================+
| 0 | chroma "Planes" are not present |
+-------+---------------------------------+ +-------+---------------------------------+
| 0 | chroma "Planes" are not present | | 1 | chroma "Planes" are present |
| 1 | chroma "Planes" are present |
+-------+---------------------------------+ +-------+---------------------------------+
Table 10
4.1.7. bits_per_raw_sample 4.1.7. bits_per_raw_sample
"bits_per_raw_sample" indicates the number of bits for each "Sample". "bits_per_raw_sample" indicates the number of bits for each "Sample".
Inferred to be 8 if not present. Inferred to be 8 if not present.
+-------+-----------------------------------+ +-------+-----------------------------------+
| value | bits for each sample | | value | bits for each sample |
+=======+===================================+
| 0 | reserved* |
+-------+-----------------------------------+ +-------+-----------------------------------+
| 0 | reserved* |
| Other | the actual bits for each "Sample" | | Other | the actual bits for each "Sample" |
+-------+-----------------------------------+ +-------+-----------------------------------+
Table 11
* Encoders MUST NOT store bits_per_raw_sample = 0 Decoders SHOULD * Encoders MUST NOT store bits_per_raw_sample = 0 Decoders SHOULD
accept and interpret bits_per_raw_sample = 0 as 8. accept and interpret bits_per_raw_sample = 0 as 8.
4.1.8. log2_h_chroma_subsample 4.1.8. log2_h_chroma_subsample
"log2_h_chroma_subsample" indicates the subsample factor, stored in "log2_h_chroma_subsample" indicates the subsample factor, stored in
powers to which the number 2 must be raised, between luma and chroma powers to which the number 2 must be raised, between luma and chroma
width ("chroma_width = 2^(-log2_h_chroma_subsample) * luma_width"). width ("chroma_width = 2^(-log2_h_chroma_subsample) * luma_width").
4.1.9. log2_v_chroma_subsample 4.1.9. log2_v_chroma_subsample
skipping to change at page 29, line 7 skipping to change at page 28, line 17
"log2_v_chroma_subsample" indicates the subsample factor, stored in "log2_v_chroma_subsample" indicates the subsample factor, stored in
powers to which the number 2 must be raised, between luma and chroma powers to which the number 2 must be raised, between luma and chroma
height ("chroma_height=2^(-log2_v_chroma_subsample) * luma_height"). height ("chroma_height=2^(-log2_v_chroma_subsample) * luma_height").
4.1.10. extra_plane 4.1.10. extra_plane
"extra_plane" indicates if an extra "Plane" is present. "extra_plane" indicates if an extra "Plane" is present.
+-------+------------------------------+ +-------+------------------------------+
| value | presence | | value | presence |
+=======+==============================+
| 0 | extra "Plane" is not present |
+-------+------------------------------+ +-------+------------------------------+
| 0 | extra "Plane" is not present | | 1 | extra "Plane" is present |
| 1 | extra "Plane" is present |
+-------+------------------------------+ +-------+------------------------------+
Table 12
4.1.11. num_h_slices 4.1.11. num_h_slices
"num_h_slices" indicates the number of horizontal elements of the "num_h_slices" indicates the number of horizontal elements of the
slice raster. slice raster.
Inferred to be 1 if not present. Inferred to be 1 if not present.
4.1.12. num_v_slices 4.1.12. num_v_slices
"num_v_slices" indicates the number of vertical elements of the slice "num_v_slices" indicates the number of vertical elements of the slice
raster. raster.
Inferred to be 1 if not present. Inferred to be 1 if not present.
4.1.13. quant_table_set_count 4.1.13. quant_table_set_count
"quant_table_set_count" indicates the number of Quantization "quant_table_set_count" indicates the number of Quantization
Table Sets. Table Sets.
Inferred to be 1 if not present. Inferred to be 1 if not present.
MUST NOT be 0. MUST NOT be 0.
4.1.14. states_coded 4.1.14. states_coded
"states_coded" indicates if the respective Quantization Table Set has "states_coded" indicates if the respective Quantization Table Set has
the initial states coded. the initial states coded.
Inferred to be 0 if not present. Inferred to be 0 if not present.
+-------+-----------------------------------------------------------+ +-------+--------------------------------+
| value | initial states | | value | initial states |
+-------+-----------------------------------------------------------+ +=======+================================+
| 0 | initial states are not present and are assumed to be all | | 0 | initial states are not present |
| | 128 | | | and are assumed to be all 128 |
| 1 | initial states are present | +-------+--------------------------------+
+-------+-----------------------------------------------------------+ | 1 | initial states are present |
+-------+--------------------------------+
Table 13
4.1.15. initial_state_delta 4.1.15. initial_state_delta
"initial_state_delta[ i ][ j ][ k ]" indicates the initial Range "initial_state_delta[ i ][ j ][ k ]" indicates the initial Range
coder state, it is encoded using "k" as context index and coder state, it is encoded using "k" as context index and
pred = j ? initial_states[ i ][j - 1][ k ] : 128 pred = j ? initial_states[ i ][j - 1][ k ] : 128
initial_state[ i ][ j ][ k ] = initial_state[ i ][ j ][ k ] =
( pred + initial_state_delta[ i ][ j ][ k ] ) & 255 ( pred + initial_state_delta[ i ][ j ][ k ] ) & 255
4.1.16. ec 4.1.16. ec
"ec" indicates the error detection/correction type. "ec" indicates the error detection/correction type.
+-------+--------------------------------------------+ +-------+--------------------------------------------+
| value | error detection/correction type | | value | error detection/correction type |
+=======+============================================+
| 0 | 32-bit CRC on the global header |
+-------+--------------------------------------------+
| 1 | 32-bit CRC per slice and the global header |
+-------+--------------------------------------------+ +-------+--------------------------------------------+
| 0 | 32-bit CRC on the global header |
| 1 | 32-bit CRC per slice and the global header |
| Other | reserved for future use | | Other | reserved for future use |
+-------+--------------------------------------------+ +-------+--------------------------------------------+
Table 14
4.1.17. intra 4.1.17. intra
"intra" indicates the relationship between the instances of "Frame". "intra" indicates the relationship between the instances of "Frame".
Inferred to be 0 if not present. Inferred to be 0 if not present.
+-------+-----------------------------------------------------------+ +-------+-------------------------------------+
| value | relationship | | value | relationship |
+-------+-----------------------------------------------------------+ +=======+=====================================+
| 0 | Frames are independent or dependent (keyframes and non | | 0 | Frames are independent or dependent |
| | keyframes) | | | (keyframes and non keyframes) |
| 1 | Frames are independent (keyframes only) | +-------+-------------------------------------+
| Other | reserved for future use | | 1 | Frames are independent (keyframes |
+-------+-----------------------------------------------------------+ | | only) |
+-------+-------------------------------------+
| Other | reserved for future use |
+-------+-------------------------------------+
Table 15
4.2. Configuration Record 4.2. Configuration Record
In the case of a FFV1 bitstream with "version >= 3", a "Configuration In the case of a FFV1 bitstream with "version >= 3", a "Configuration
Record" is stored in the underlying "Container", at the track header Record" is stored in the underlying "Container", at the track header
level. It contains the "Parameters" used for all instances of level. It contains the "Parameters" used for all instances of
"Frame". The size of the "Configuration Record", "NumBytes", is "Frame". The size of the "Configuration Record", "NumBytes", is
supplied by the underlying "Container". supplied by the underlying "Container".
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- ConfigurationRecord( NumBytes ) { | ConfigurationRecordIsPresent = 1 | Parameters( ) | while (remaining_symbols_in_syntax(NumBytes - 4)) { | reserved_for_future_use | br/ur/sr } | configuration_record_crc_parity | u(32) } |
ConfigurationRecord( NumBytes ) { |
ConfigurationRecordIsPresent = 1 |
Parameters( ) |
while( remaining_symbols_in_syntax( NumBytes - 4 ) ) |
reserved_for_future_use | br/ur/sr
configuration_record_crc_parity | u(32)
} |
4.2.1. reserved_for_future_use 4.2.1. reserved_for_future_use
"reserved_for_future_use" has semantics that are reserved for future "reserved_for_future_use" has semantics that are reserved for future
use. use.
Encoders conforming to this version of this specification SHALL NOT Encoders conforming to this version of this specification SHALL NOT
write this value. write this value.
Decoders conforming to this version of this specification SHALL Decoders conforming to this version of this specification SHALL
ignore its value. ignore its value.
4.2.2. configuration_record_crc_parity 4.2.2. configuration_record_crc_parity
"configuration_record_crc_parity" 32 bits that are chosen so that the "configuration_record_crc_parity" 32 bits that are chosen so that the
"Configuration Record" as a whole has a crc remainder of 0. "Configuration Record" as a whole has a crc remainder of 0.
This is equivalent to storing the crc remainder in the 32-bit parity. This is equivalent to storing the crc remainder in the 32-bit parity.
The CRC generator polynomial used is the standard IEEE CRC polynomial The CRC generator polynomial used is the standard IEEE CRC polynomial
(0x104C11DB7) with initial value 0. (0x104C11DB7) with initial value 0.
4.2.3. Mapping FFV1 into Containers 4.2.3. Mapping FFV1 into Containers
This "Configuration Record" can be placed in any file format This "Configuration Record" can be placed in any file format
supporting "Configuration Records", fitting as much as possible with supporting "Configuration Records", fitting as much as possible with
how the file format uses to store "Configuration Records". The how the file format uses to store "Configuration Records". The
"Configuration Record" storage place and "NumBytes" are currently "Configuration Record" storage place and "NumBytes" are currently
defined and supported by this version of this specification for the defined and supported by this version of this specification for the
skipping to change at page 32, line 35 skipping to change at page 32, line 17
4.3. Frame 4.3. Frame
A "Frame" is an encoded representation of a complete static image. A "Frame" is an encoded representation of a complete static image.
The whole "Frame" is provided by the underlaying container. The whole "Frame" is provided by the underlaying container.
A "Frame" consists of the keyframe field, "Parameters" (if version A "Frame" consists of the keyframe field, "Parameters" (if version
<=1), and a sequence of independent slices. The pseudo-code below <=1), and a sequence of independent slices. The pseudo-code below
describes the contents of a "Frame". describes the contents of a "Frame".
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- Frame( NumBytes ) { | keyframe | br if (keyframe && !ConfigurationRecordIsPresent { | Parameters( ) | } | while (remaining_bits_in_bitstream( NumBytes )) { | Slice( ) | } | } |
--------------------------------------------------------------|-----
Frame( NumBytes ) { |
keyframe | br
if (keyframe && !ConfigurationRecordIsPresent |
Parameters( ) |
while ( remaining_bits_in_bitstream( NumBytes ) ) |
Slice( ) |
} |
Architecture overview of slices in a "Frame": Architecture overview of slices in a "Frame":
+-----------------------------------------------------------------+ +-----------------------------------------------------------------+
+=================================================================+
| first slice header | | first slice header |
+-----------------------------------------------------------------+
| first slice content | | first slice content |
+-----------------------------------------------------------------+
| first slice footer | | first slice footer |
+-----------------------------------------------------------------+
| --------------------------------------------------------------- | | --------------------------------------------------------------- |
+-----------------------------------------------------------------+
| second slice header | | second slice header |
+-----------------------------------------------------------------+
| second slice content | | second slice content |
+-----------------------------------------------------------------+
| second slice footer | | second slice footer |
+-----------------------------------------------------------------+
| --------------------------------------------------------------- | | --------------------------------------------------------------- |
+-----------------------------------------------------------------+
| ... | | ... |
+-----------------------------------------------------------------+
| --------------------------------------------------------------- | | --------------------------------------------------------------- |
+-----------------------------------------------------------------+
| last slice header | | last slice header |
+-----------------------------------------------------------------+
| last slice content | | last slice content |
+-----------------------------------------------------------------+
| last slice footer | | last slice footer |
+-----------------------------------------------------------------+ +-----------------------------------------------------------------+
Table 16
4.4. Slice 4.4. Slice
A "Slice" is an independent spatial sub-section of a "Frame" that is A "Slice" is an independent spatial sub-section of a "Frame" that is
encoded separately from an other region of the same "Frame". The use encoded separately from an other region of the same "Frame". The use
of more than one "Slice" per "Frame" can be useful for taking of more than one "Slice" per "Frame" can be useful for taking
advantage of the opportunities of multithreaded encoding and advantage of the opportunities of multithreaded encoding and
decoding. decoding.
A "Slice" consists of a "Slice Header" (when relevant), a "Slice A "Slice" consists of a "Slice Header" (when relevant), a "Slice
Content", and a "Slice Footer" (when relevant). The pseudo-code Content", and a "Slice Footer" (when relevant). The pseudo-code
below describes the contents of a "Slice". below describes the contents of a "Slice".
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- Slice( ) { | if (version >= 3) { | SliceHeader( ) | } | SliceContent( ) | if (coder_type == 0) { | while (!byte_aligned()) { | padding | u(1) } | } | if (version <= 1) { | while (remaining_bits_in_bitstream( NumBytes ) != 0) {| reserved | u(1) } | } | if (version >= 3) { | SliceFooter( ) | } | } |
--------------------------------------------------------------|-----
Slice( ) { |
if (version >= 3) |
SliceHeader( ) |
SliceContent( ) |
if (coder_type == 0) |
while (!byte_aligned()) |
padding | u(1)
if (version <= 1) { |
while (remaining_bits_in_bitstream( NumBytes ) != 0 ) |
reserved | u(1)
} |
if (version >= 3) |
SliceFooter( ) |
} |
"padding" specifies a bit without any significance and used only for "padding" specifies a bit without any significance and used only for
byte alignment. MUST be 0. byte alignment. MUST be 0.
"reserved" specifies a bit without any significance in this revision "reserved" specifies a bit without any significance in this revision
of the specification and may have a significance in a later revision of the specification and may have a significance in a later revision
of this specification. of this specification.
Encoders SHOULD NOT fill these bits. Encoders SHOULD NOT fill these bits.
Decoders SHOULD ignore these bits. Decoders SHOULD ignore these bits.
Note in case these bits are used in a later revision of this Note in case these bits are used in a later revision of this
specification: any revision of this specification SHOULD care about specification: any revision of this specification SHOULD care about
avoiding to add 40 bits of content after "SliceContent" for version 0 avoiding to add 40 bits of content after "SliceContent" for version 0
and 1 of the bitstream. Background: due to some non conforming and 1 of the bitstream. Background: due to some non conforming
encoders, some bitstreams where found with 40 extra bits encoders, some bitstreams where found with 40 extra bits
corresponding to "error_status" and "slice_crc_parity", a decoder corresponding to "error_status" and "slice_crc_parity", a decoder
conforming to the revised specification could not do the difference conforming to the revised specification could not do the difference
between a revised bitstream and a buggy bitstream. between a revised bitstream and a buggy bitstream.
4.5. Slice Header 4.5. Slice Header
skipping to change at page 34, line 26 skipping to change at page 33, line 46
conforming to the revised specification could not do the difference conforming to the revised specification could not do the difference
between a revised bitstream and a buggy bitstream. between a revised bitstream and a buggy bitstream.
4.5. Slice Header 4.5. Slice Header
A "Slice Header" provides information about the decoding A "Slice Header" provides information about the decoding
configuration of the "Slice", such as its spatial position, size, and configuration of the "Slice", such as its spatial position, size, and
aspect ratio. The pseudo-code below describes the contents of the aspect ratio. The pseudo-code below describes the contents of the
"Slice Header". "Slice Header".
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- SliceHeader( ) { | slice_x | ur slice_y | ur slice_width - 1 | ur slice_height - 1 | ur for (i = 0; i < quant_table_set_index_count; i++) { | quant_table_set_index[ i ] | ur } | picture_structure | ur sar_num | ur sar_den | ur if (version >= 4) { | reset_contexts | br slice_coding_mode | ur } | } |
--------------------------------------------------------------|-----
SliceHeader( ) { |
slice_x | ur
slice_y | ur
slice_width - 1 | ur
slice_height - 1 | ur
for( i = 0; i < quant_table_set_index_count; i++ ) |
quant_table_set_index [ i ] | ur
picture_structure | ur
sar_num | ur
sar_den | ur
if (version >= 4) { |
reset_contexts | br
slice_coding_mode | ur
} |
} |
4.5.1. slice_x 4.5.1. slice_x
"slice_x" indicates the x position on the slice raster formed by "slice_x" indicates the x position on the slice raster formed by
num_h_slices. num_h_slices.
Inferred to be 0 if not present. Inferred to be 0 if not present.
4.5.2. slice_y 4.5.2. slice_y
"slice_y" indicates the y position on the slice raster formed by "slice_y" indicates the y position on the slice raster formed by
num_v_slices. num_v_slices.
Inferred to be 0 if not present. Inferred to be 0 if not present.
4.5.3. slice_width 4.5.3. slice_width
"slice_width" indicates the width on the slice raster formed by "slice_width" indicates the width on the slice raster formed by
num_h_slices. num_h_slices.
Inferred to be 1 if not present. Inferred to be 1 if not present.
4.5.4. slice_height 4.5.4. slice_height
"slice_height" indicates the height on the slice raster formed by "slice_height" indicates the height on the slice raster formed by
num_v_slices. num_v_slices.
Inferred to be 1 if not present. Inferred to be 1 if not present.
4.5.5. quant_table_set_index_count 4.5.5. quant_table_set_index_count
"quant_table_set_index_count" is defined as "1 + ( ( chroma_planes || "quant_table_set_index_count" is defined as "1 + ( ( chroma_planes ||
version \<= 3 ) ? 1 : 0 ) + ( extra_plane ? 1 : 0 )". version <= 3 ) ? 1 : 0 ) + ( extra_plane ? 1 : 0 )".
4.5.6. quant_table_set_index 4.5.6. quant_table_set_index
"quant_table_set_index" indicates the Quantization Table Set index to "quant_table_set_index" indicates the Quantization Table Set index to
select the Quantization Table Set and the initial states for the select the Quantization Table Set and the initial states for the
slice. slice.
Inferred to be 0 if not present. Inferred to be 0 if not present.
4.5.7. picture_structure 4.5.7. picture_structure
"picture_structure" specifies the temporal and spatial relationship "picture_structure" specifies the temporal and spatial relationship
of each "Line" of the "Frame". of each "Line" of the "Frame".
Inferred to be 0 if not present. Inferred to be 0 if not present.
+-------+-------------------------+ +-------+-------------------------+
| value | picture structure used | | value | picture structure used |
+=======+=========================+
| 0 | unknown |
+-------+-------------------------+
| 1 | top field first |
+-------+-------------------------+
| 2 | bottom field first |
+-------+-------------------------+
| 3 | progressive |
+-------+-------------------------+ +-------+-------------------------+
| 0 | unknown |
| 1 | top field first |
| 2 | bottom field first |
| 3 | progressive |
| Other | reserved for future use | | Other | reserved for future use |
+-------+-------------------------+ +-------+-------------------------+
Table 17
4.5.8. sar_num 4.5.8. sar_num
"sar_num" specifies the "Sample" aspect ratio numerator. "sar_num" specifies the "Sample" aspect ratio numerator.
Inferred to be 0 if not present. Inferred to be 0 if not present.
A value of 0 means that aspect ratio is unknown. A value of 0 means that aspect ratio is unknown.
Encoders MUST write 0 if "Sample" aspect ratio is unknown. Encoders MUST write 0 if "Sample" aspect ratio is unknown.
If "sar_den" is 0, decoders SHOULD ignore the encoded value and If "sar_den" is 0, decoders SHOULD ignore the encoded value and
consider that "sar_num" is 0. consider that "sar_num" is 0.
4.5.9. sar_den 4.5.9. sar_den
"sar_den" specifies the "Sample" aspect ratio denominator. "sar_den" specifies the "Sample" aspect ratio denominator.
Inferred to be 0 if not present. Inferred to be 0 if not present.
A value of 0 means that aspect ratio is unknown. A value of 0 means that aspect ratio is unknown.
Encoders MUST write 0 if "Sample" aspect ratio is unknown. Encoders MUST write 0 if "Sample" aspect ratio is unknown.
If "sar_num" is 0, decoders SHOULD ignore the encoded value and If "sar_num" is 0, decoders SHOULD ignore the encoded value and
consider that "sar_den" is 0. consider that "sar_den" is 0.
4.5.10. reset_contexts 4.5.10. reset_contexts
"reset_contexts" indicates if slice contexts must be reset. "reset_contexts" indicates if slice contexts must be reset.
Inferred to be 0 if not present. Inferred to be 0 if not present.
4.5.11. slice_coding_mode 4.5.11. slice_coding_mode
"slice_coding_mode" indicates the slice coding mode. "slice_coding_mode" indicates the slice coding mode.
Inferred to be 0 if not present. Inferred to be 0 if not present.
+-------+-----------------------------+ +-------+-----------------------------+
| value | slice coding mode | | value | slice coding mode |
+=======+=============================+
| 0 | Range Coding or Golomb Rice |
+-------+-----------------------------+
| 1 | raw PCM |
+-------+-----------------------------+ +-------+-----------------------------+
| 0 | Range Coding or Golomb Rice |
| 1 | raw PCM |
| Other | reserved for future use | | Other | reserved for future use |
+-------+-----------------------------+ +-------+-----------------------------+
Table 18
4.6. Slice Content 4.6. Slice Content
A "Slice Content" contains all "Line" elements part of the "Slice". A "Slice Content" contains all "Line" elements part of the "Slice".
Depending on the configuration, "Line" elements are ordered by Depending on the configuration, "Line" elements are ordered by
"Plane" then by row (YCbCr) or by row then by "Plane" (RGB). "Plane" then by row (YCbCr) or by row then by "Plane" (RGB).
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- SliceContent( ) { | if (colorspace_type == 0) { | for (p = 0; p < primary_color_count; p++) { | for (y = 0; y < plane_pixel_height[ p ]; y++) { | Line( p, y ) | } | } | } else if (colorspace_type == 1) { | for (y = 0; y < slice_pixel_height; y++) { | for (p = 0; p < primary_color_count; p++) { | Line( p, y ) | } | } | } | } |
--------------------------------------------------------------|-----
SliceContent( ) { |
if (colorspace_type == 0) { |
for( p = 0; p < primary_color_count; p++ ) |
for( y = 0; y < plane_pixel_height[ p ]; y++ ) |
Line( p, y ) |
} else if (colorspace_type == 1) { |
for( y = 0; y < slice_pixel_height; y++ ) |
for( p = 0; p < primary_color_count; p++ ) |
Line( p, y ) |
} |
} |
4.6.1. primary_color_count 4.6.1. primary_color_count
"primary_color_count" is defined as "1 + ( chroma_planes ? 2 : 0 ) + "primary_color_count" is defined as "1 + ( chroma_planes ? 2 : 0 ) +
( extra_plane ? 1 : 0 )". ( extra_plane ? 1 : 0 )".
4.6.2. plane_pixel_height 4.6.2. plane_pixel_height
"plane_pixel_height[ p ]" is the height in pixels of plane p of the "plane_pixel_height[ p ]" is the height in pixels of plane p of the
slice. slice.
skipping to change at page 37, line 28 skipping to change at page 36, line 41
4.6.1. primary_color_count 4.6.1. primary_color_count
"primary_color_count" is defined as "1 + ( chroma_planes ? 2 : 0 ) + "primary_color_count" is defined as "1 + ( chroma_planes ? 2 : 0 ) +
( extra_plane ? 1 : 0 )". ( extra_plane ? 1 : 0 )".
4.6.2. plane_pixel_height 4.6.2. plane_pixel_height
"plane_pixel_height[ p ]" is the height in pixels of plane p of the "plane_pixel_height[ p ]" is the height in pixels of plane p of the
slice. slice.
"plane_pixel_height[ 0 ]" and "plane_pixel_height[ 1 + ( "plane_pixel_height[ 0 ]" and "plane_pixel_height[ 1 + (
chroma_planes ? 2 : 0 ) ]" value is "slice_pixel_height". chroma_planes ? 2 : 0 ) ]" value is "slice_pixel_height".
If "chroma_planes" is set to 1, "plane_pixel_height[ 1 ]" and If "chroma_planes" is set to 1, "plane_pixel_height[ 1 ]" and
"plane_pixel_height[ 2 ]" value is "ceil(slice_pixel_height / "plane_pixel_height[ 2 ]" value is "ceil(slice_pixel_height /
log2_v_chroma_subsample)". log2_v_chroma_subsample)".
4.6.3. slice_pixel_height 4.6.3. slice_pixel_height
"slice_pixel_height" is the height in pixels of the slice. "slice_pixel_height" is the height in pixels of the slice.
Its value is "floor(( slice_y + slice_height ) * slice_pixel_height / Its value is "floor(( slice_y + slice_height ) * slice_pixel_height /
num_v_slices) - slice_pixel_y". num_v_slices) - slice_pixel_y".
4.6.4. slice_pixel_y 4.6.4. slice_pixel_y
"slice_pixel_y" is the slice vertical position in pixels. "slice_pixel_y" is the slice vertical position in pixels.
Its value is "floor(slice_y * frame_pixel_height / num_v_slices)". Its value is "floor(slice_y * frame_pixel_height / num_v_slices)".
4.7. Line 4.7. Line
A "Line" is a list of the sample differences (relative to the A "Line" is a list of the sample differences (relative to the
predictor) of primary color components. The pseudo-code below predictor) of primary color components. The pseudo-code below
describes the contents of the "Line". describes the contents of the "Line".
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- Line( p, y ) { | if (colorspace_type == 0) { | for (x = 0; x < plane_pixel_width[ p ]; x++) { | sample_difference[ p ][ y ][ x ] | } | } else if (colorspace_type == 1) { | for (x = 0; x < slice_pixel_width; x++) { | sample_difference[ p ][ y ][ x ] | } | } | } |
--------------------------------------------------------------|-----
Line( p, y ) { |
if (colorspace_type == 0) { |
for( x = 0; x < plane_pixel_width[ p ]; x++ ) |
sample_difference[ p ][ y ][ x ] |
} else if (colorspace_type == 1) { |
for( x = 0; x < slice_pixel_width; x++ ) |
sample_difference[ p ][ y ][ x ] |
} |
} |
4.7.1. plane_pixel_width 4.7.1. plane_pixel_width
"plane_pixel_width[ p ]" is the width in "Pixels" of "Plane" p of the "plane_pixel_width[ p ]" is the width in "Pixels" of "Plane" p of the
slice. slice.
"plane_pixel_width[ 0 ]" and "plane_pixel_width[ 1 + ( chroma_planes "plane_pixel_width[ 0 ]" and "plane_pixel_width[ 1 + ( chroma_planes
? 2 : 0 ) ]" value is "slice_pixel_width". ? 2 : 0 ) ]" value is "slice_pixel_width".
If "chroma_planes" is set to 1, "plane_pixel_width[ 1 ]" and If "chroma_planes" is set to 1, "plane_pixel_width[ 1 ]" and
"plane_pixel_width[ 2 ]" value is "ceil(slice_pixel_width / (1 << "plane_pixel_width[ 2 ]" value is "ceil(slice_pixel_width / (1 <<
log2_h_chroma_subsample))". log2_h_chroma_subsample))".
4.7.2. slice_pixel_width 4.7.2. slice_pixel_width
"slice_pixel_width" is the width in "Pixels" of the slice. "slice_pixel_width" is the width in "Pixels" of the slice.
Its value is "floor(( slice_x + slice_width ) * slice_pixel_width / Its value is "floor(( slice_x + slice_width ) * slice_pixel_width /
num_h_slices) - slice_pixel_x". num_h_slices) - slice_pixel_x".
4.7.3. slice_pixel_x 4.7.3. slice_pixel_x
"slice_pixel_x" is the slice horizontal position in "Pixels". "slice_pixel_x" is the slice horizontal position in "Pixels".
Its value is "floor(slice_x * frame_pixel_width / num_h_slices)". Its value is "floor(slice_x * frame_pixel_width / num_h_slices)".
4.7.4. sample_difference 4.7.4. sample_difference
"sample_difference[ p ][ y ][ x ]" is the sample difference for "sample_difference[ p ][ y ][ x ]" is the sample difference for
"Sample" at "Plane" "p", y position "y", and x position "x". The "Sample" at "Plane" "p", y position "y", and x position "x". The
"Sample" value is computed based on median predictor and context "Sample" value is computed based on median predictor and context
described in Section 3.2. described in the section on Samples (#samples).
4.8. Slice Footer 4.8. Slice Footer
A "Slice Footer" provides information about slice size and A "Slice Footer" provides information about slice size and
(optionally) parity. The pseudo-code below describes the contents of (optionally) parity. The pseudo-code below describes the contents of
the "Slice Header". the "Slice Footer".
Note: "Slice Footer" is always byte aligned. Note: "Slice Footer" is always byte aligned.
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- SliceFooter( ) { | slice_size | u(24) if (ec) { | error_status | u(8) slice_crc_parity | u(32) } | } |
--------------------------------------------------------------|-----
SliceFooter( ) { |
slice_size | u(24)
if (ec) { |
error_status | u(8)
slice_crc_parity | u(32)
} |
} |
4.8.1. slice_size 4.8.1. slice_size
"slice_size" indicates the size of the slice in bytes. "slice_size" indicates the size of the slice in bytes.
Note: this allows finding the start of slices before previous slices Note: this allows finding the start of slices before previous slices
have been fully decoded, and allows parallel decoding as well as have been fully decoded, and allows parallel decoding as well as
error resilience. error resilience.
4.8.2. error_status 4.8.2. error_status
"error_status" specifies the error status. "error_status" specifies the error status.
+-------+--------------------------------------+ +-------+--------------------------------------+
| value | error status | | value | error status |
skipping to change at page 39, line 28 skipping to change at page 38, line 29
Note: this allows finding the start of slices before previous slices Note: this allows finding the start of slices before previous slices
have been fully decoded, and allows parallel decoding as well as have been fully decoded, and allows parallel decoding as well as
error resilience. error resilience.
4.8.2. error_status 4.8.2. error_status
"error_status" specifies the error status. "error_status" specifies the error status.
+-------+--------------------------------------+ +-------+--------------------------------------+
| value | error status | | value | error status |
+=======+======================================+
| 0 | no error |
+-------+--------------------------------------+
| 1 | slice contains a correctable error |
+-------+--------------------------------------+
| 2 | slice contains a uncorrectable error |
+-------+--------------------------------------+ +-------+--------------------------------------+
| 0 | no error |
| 1 | slice contains a correctable error |
| 2 | slice contains a uncorrectable error |
| Other | reserved for future use | | Other | reserved for future use |
+-------+--------------------------------------+ +-------+--------------------------------------+
Table 19
4.8.3. slice_crc_parity 4.8.3. slice_crc_parity
"slice_crc_parity" 32 bits that are chosen so that the slice as a "slice_crc_parity" 32 bits that are chosen so that the slice as a
whole has a crc remainder of 0. whole has a crc remainder of 0.
This is equivalent to storing the crc remainder in the 32-bit parity. This is equivalent to storing the crc remainder in the 32-bit parity.
The CRC generator polynomial used is the standard IEEE CRC polynomial The CRC generator polynomial used is the standard IEEE CRC polynomial
(0x104C11DB7) with initial value 0. (0x104C11DB7) with initial value 0.
4.9. Quantization Table Set 4.9. Quantization Table Set
The Quantization Table Sets are stored by storing the number of equal The Quantization Table Sets are stored by storing the number of equal
entries -1 of the first half of the table (represented as "len - 1" entries -1 of the first half of the table (represented as "len - 1"
in the pseudo-code below) using the method described in in the pseudo-code below) using the method described in Range Non
Section 3.8.1.2. The second half doesn't need to be stored as it is Binary Values (#range-non-binary-values). The second half doesn't
identical to the first with flipped sign. "scale" and "len_count[ i need to be stored as it is identical to the first with flipped sign.
][ j ]" are temporary values used for the computing of "scale" and "len_count[ i ][ j ]" are temporary values used for the
"context_count[ i ]" and are not used outside Quantization Table Set computing of "context_count[ i ]" and are not used outside
pseudo-code. Quantization Table Set pseudo-code.
example: Example:
Table: 0 0 1 1 1 1 2 2 -2 -2 -2 -1 -1 -1 -1 0 Table: 0 0 1 1 1 1 2 2 -2 -2 -2 -1 -1 -1 -1 0
Stored values: 1, 3, 1 Stored values: 1, 3, 1
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- QuantizationTableSet( i ) { | scale = 1 | for (j = 0; j < MAX_CONTEXT_INPUTS; j++) { | QuantizationTable( i, j, scale ) | scale *= 2 * len_count[ i ][ j ] - 1 | } | context_count[ i ] = ceil( scale / 2 ) | } |
--------------------------------------------------------------|-----
QuantizationTableSet( i ) { |
scale = 1 |
for( j = 0; j < MAX_CONTEXT_INPUTS; j++ ) { |
QuantizationTable( i, j, scale ) |
scale *= 2 * len_count[ i ][ j ] - 1 |
} |
context_count[ i ] = ceil ( scale / 2 ) |
} |
MAX_CONTEXT_INPUTS is 5. MAX_CONTEXT_INPUTS is 5.
pseudo-code | type pseudo-code | type --------------------------------------------------------------|----- QuantizationTable(i, j, scale) { | v = 0 | for (k = 0; k < 128;) { | len - 1 | ur for (a = 0; a < len; a++) { | quant_tables[ i ][ j ][ k ] = scale * v | k++ | } | v++ | } | for (k = 1; k < 128; k++) { | quant_tables[ i ][ j ][ 256 - k ] = \ | -quant_tables[ i ][ j ][ k ] | } | quant_tables[ i ][ j ][ 128 ] = \ | -quant_tables[ i ][ j ][ 127 ] | len_count[ i ][ j ] = v | } |
--------------------------------------------------------------|-----
QuantizationTable(i, j, scale) { |
v = 0 |
for( k = 0; k < 128; ) { |
len - 1 | ur
for( a = 0; a < len; a++ ) { |
quant_tables[ i ][ j ][ k ] = scale* v |
k++ |
} |
v++ |
} |
for( k = 1; k < 128; k++ ) { |
quant_tables[ i ][ j ][ 256 - k ] = \ |
-quant_tables[ i ][ j ][ k ] |
} |
quant_tables[ i ][ j ][ 128 ] = \ |
-quant_tables[ i ][ j ][ 127 ] |
len_count[ i ][ j ] = v |
} |
4.9.1. quant_tables 4.9.1. quant_tables
"quant_tables[ i ][ j ][ k ]" indicates the quantification table "quant_tables[ i ][ j ][ k ]" indicates the quantification table
value of the Quantized Sample Difference "k" of the Quantization value of the Quantized Sample Difference "k" of the Quantization
Table "j" of the Set Quantization Table Set "i". Table "j" of the Set Quantization Table Set "i".
4.9.2. context_count 4.9.2. context_count
"context_count[ i ]" indicates the count of contexts for Quantization "context_count[ i ]" indicates the count of contexts for Quantization
Table Set "i". Table Set "i".
5. Restrictions 5. Restrictions
To ensure that fast multithreaded decoding is possible, starting To ensure that fast multithreaded decoding is possible, starting with
version 3 and if frame_pixel_width * frame_pixel_height is more than version 3 and if "frame_pixel_width * frame_pixel_height" is more
101376, slice_width * slice_height MUST be less or equal to than 101376, "slice_width * slice_height" MUST be less or equal to
num_h_slices * num_v_slices / 4. Note: 101376 is the frame size in "num_h_slices * num_v_slices / 4". Note: 101376 is the frame size in
"Pixels" of a 352x288 frame also known as CIF ("Common Intermediate "Pixels" of a 352x288 frame also known as CIF ("Common Intermediate
Format") frame size format. Format") frame size format.
For each "Frame", each position in the slice raster MUST be filled by For each "Frame", each position in the slice raster MUST be filled by
one and only one slice of the "Frame" (no missing slice position, no one and only one slice of the "Frame" (no missing slice position, no
slice overlapping). slice overlapping).
For each "Frame" with keyframe value of 0, each slice MUST have the For each "Frame" with keyframe value of 0, each slice MUST have the
same value of slice_x, slice_y, slice_width, slice_height as a slice same value of "slice_x, slice_y, slice_width, slice_height" as a
in the previous "Frame", except if reset_contexts is 1. slice in the previous "Frame", except if "reset_contexts" is 1.
6. Security Considerations 6. Security Considerations
Like any other codec, (such as [RFC6716]), FFV1 should not be used Like any other codec, (such as [RFC6716]), FFV1 should not be used
with insecure ciphers or cipher-modes that are vulnerable to known with insecure ciphers or cipher-modes that are vulnerable to known
plaintext attacks. Some of the header bits as well as the padding plaintext attacks. Some of the header bits as well as the padding
are easily predictable. are easily predictable.
Implementations of the FFV1 codec need to take appropriate security Implementations of the FFV1 codec need to take appropriate security
considerations into account, as outlined in [RFC4732]. It is considerations into account, as outlined in [RFC4732]. It is
extremely important for the decoder to be robust against malicious extremely important for the decoder to be robust against malicious
payloads. Malicious payloads must not cause the decoder to overrun payloads. Malicious payloads must not cause the decoder to overrun
its allocated memory or to take an excessive amount of resources to its allocated memory or to take an excessive amount of resources to
decode. Although problems in encoders are typically rarer, the same decode. The same applies to the encoder, even though problems in
applies to the encoder. Malicious video streams must not cause the encoders are typically rarer. Malicious video streams must not cause
encoder to misbehave because this would allow an attacker to attack the encoder to misbehave because this would allow an attacker to
transcoding gateways. A frequent security problem in image and video attack transcoding gateways. A frequent security problem in image
codecs is also to not check for integer overflows in "Pixel" count and video codecs is also to not check for integer overflows in
computations, that is to allocate width * height without considering "Pixel" count computations, that is to allocate width * height
that the multiplication result may have overflowed the arithmetic without considering that the multiplication result may have
types range. The range coder could, if implemented naively, read one overflowed the arithmetic types range. The range coder could, if
byte over the end. The implementation must ensure that no read implemented naively, read one byte over the end. The implementation
outside allocated and initialized memory occurs. must ensure that no read outside allocated and initialized memory
occurs.
The reference implementation [REFIMPL] contains no known buffer The reference implementation [REFIMPL] contains no known buffer
overflow or cases where a specially crafted packet or video segment overflow or cases where a specially crafted packet or video segment
could cause a significant increase in CPU load. could cause a significant increase in CPU load.
The reference implementation [REFIMPL] was validated in the following The reference implementation [REFIMPL] was validated in the following
conditions: conditions:
o Sending the decoder valid packets generated by the reference * Sending the decoder valid packets generated by the reference
encoder and verifying that the decoder's output matches the encoder and verifying that the decoder's output matches the
encoder's input. encoder's input.
o Sending the decoder packets generated by the reference encoder and * Sending the decoder packets generated by the reference encoder and
then subjected to random corruption. then subjected to random corruption.
o Sending the decoder random packets that are not FFV1. * Sending the decoder random packets that are not FFV1.
In all of the conditions above, the decoder and encoder was run In all of the conditions above, the decoder and encoder was run
inside the [VALGRIND] memory debugger as well as clangs address inside the [VALGRIND] memory debugger as well as clangs address
sanitizer [Address-Sanitizer], which track reads and writes to sanitizer [Address-Sanitizer], which track reads and writes to
invalid memory regions as well as the use of uninitialized memory. invalid memory regions as well as the use of uninitialized memory.
There were no errors reported on any of the tested conditions. There were no errors reported on any of the tested conditions.
7. Media Type Definition 7. Media Type Definition
This registration is done using the template defined in [RFC6838] and This registration is done using the template defined in [RFC6838] and
skipping to change at page 42, line 40 skipping to change at page 41, line 24
Subtype name: FFV1 Subtype name: FFV1
Required parameters: None. Required parameters: None.
Optional parameters: Optional parameters:
This parameter is used to signal the capabilities of a receiver This parameter is used to signal the capabilities of a receiver
implementation. This parameter MUST NOT be used for any other implementation. This parameter MUST NOT be used for any other
purpose. purpose.
version: The version of the FFV1 encoding as defined by version: The version of the FFV1 encoding as defined by the section
Section 4.1.1. on version (#version).
micro_version: The micro_version of the FFV1 encoding as defined by micro_version: The micro_version of the FFV1 encoding as defined by
Section 4.1.2. the section on micro_version (#micro-version).
coder_type: The coder_type of the FFV1 encoding as defined by coder_type: The coder_type of the FFV1 encoding as defined by the
Section 4.1.3. section on coder_type (#coder-type).
colorspace_type: The colorspace_type of the FFV1 encoding as defined colorspace_type: The colorspace_type of the FFV1 encoding as defined
by Section 4.1.5. by the section on colorspace_type (#colorspace-type).
bits_per_raw_sample: The version of the FFV1 encoding as defined by bits_per_raw_sample: The bits_per_raw_sample of the FFV1 encoding as
Section 4.1.7. defined by the section on bits_per_raw_sample (#bits-per-raw-sample).
max-slices: The value of max-slices is an integer indicating the max-slices: The value of max-slices is an integer indicating the
maximum count of slices with a frames of the FFV1 encoding. maximum count of slices with a frames of the FFV1 encoding.
Encoding considerations: Encoding considerations:
This media type is defined for encapsulation in several audiovisual This media type is defined for encapsulation in several audiovisual
container formats and contains binary data; see Section 4.2.3. This container formats and contains binary data; see the section on
"Mapping FFV1 into Containers" (#mapping-ffv1-into-containers). This
media type is framed binary data Section 4.8 of [RFC6838]. media type is framed binary data Section 4.8 of [RFC6838].
Security considerations: Security considerations:
See Section 6 of this document. See the "Security Considerations" section (#security-considerations)
of this document.
Interoperability considerations: None. Interoperability considerations: None.
Published specification: Published specification:
[I-D.ietf-cellar-ffv1] and RFC XXXX. [I-D.ietf-cellar-ffv1] and RFC XXXX.
[RFC Editor: Upon publication as an RFC, please replace "XXXX" with [RFC Editor: Upon publication as an RFC, please replace "XXXX" with
the number assigned to this document and remove this note.] the number assigned to this document and remove this note.]
skipping to change at page 43, line 41 skipping to change at page 42, line 28
Any application that requires the transport of lossless video can use Any application that requires the transport of lossless video can use
this media type. Some examples are, but not limited to screen this media type. Some examples are, but not limited to screen
recording, scientific imaging, and digital video preservation. recording, scientific imaging, and digital video preservation.
Fragment identifier considerations: N/A. Fragment identifier considerations: N/A.
Additional information: None. Additional information: None.
Person & email address to contact for further information: Michael Person & email address to contact for further information: Michael
Niedermayer <mailto:michael@niedermayer.cc> Niedermayer michael@niedermayer.cc (mailto:michael@niedermayer.cc)
Intended usage: COMMON Intended usage: COMMON
Restrictions on usage: None. Restrictions on usage: None.
Author: Dave Rice <mailto:dave@dericed.com> Author: Dave Rice dave@dericed.com (mailto:dave@dericed.com)
Change controller: IETF cellar working group delegated from the IESG. Change controller: IETF cellar working group delegated from the IESG.
8. IANA Considerations 8. IANA Considerations
The IANA is requested to register the following values: The IANA is requested to register the following values:
o Media type registration as described in Section 7. * Media type registration as described in Media Type Definition
(#media-type-definition).
9. Appendixes 9. Appendixes
9.1. Decoder implementation suggestions 9.1. Decoder implementation suggestions
9.1.1. Multi-threading Support and Independence of Slices 9.1.1. Multi-threading Support and Independence of Slices
The FFV1 bitstream is parsable in two ways: in sequential order as The FFV1 bitstream is parsable in two ways: in sequential order as
described in this document or with the pre-analysis of the footer of described in this document or with the pre-analysis of the footer of
each slice. Each slice footer contains a slice_size field so the each slice. Each slice footer contains a slice_size field so the
boundary of each slice is computable without having to parse the boundary of each slice is computable without having to parse the
slice content. That allows multi-threading as well as independence slice content. That allows multi-threading as well as independence
of slice content (a bitstream error in a slice header or slice of slice content (a bitstream error in a slice header or slice
content has no impact on the decoding of the other slices). content has no impact on the decoding of the other slices).
skipping to change at page 44, line 31 skipping to change at page 43, line 20
slice content. That allows multi-threading as well as independence slice content. That allows multi-threading as well as independence
of slice content (a bitstream error in a slice header or slice of slice content (a bitstream error in a slice header or slice
content has no impact on the decoding of the other slices). content has no impact on the decoding of the other slices).
After having checked keyframe field, a decoder SHOULD parse After having checked keyframe field, a decoder SHOULD parse
slice_size fields, from slice_size of the last slice at the end of slice_size fields, from slice_size of the last slice at the end of
the "Frame" up to slice_size of the first slice at the beginning of the "Frame" up to slice_size of the first slice at the beginning of
the "Frame", before parsing slices, in order to have slices the "Frame", before parsing slices, in order to have slices
boundaries. A decoder MAY fallback on sequential order e.g. in case boundaries. A decoder MAY fallback on sequential order e.g. in case
of a corrupted "Frame" (frame size unknown, slice_size of slices not of a corrupted "Frame" (frame size unknown, slice_size of slices not
coherent...) or if there is no possibility of seek into the stream. coherent...) or if there is no possibility of seeking into the
stream.
10. Changelog 10. Changelog
See <https://github.com/FFmpeg/FFV1/commits/master> See https://github.com/FFmpeg/FFV1/commits/master
(https://github.com/FFmpeg/FFV1/commits/master)
11. References
11.1. Normative References 11. Normative References
[I-D.ietf-cellar-ffv1] [I-D.ietf-cellar-ffv1]
Niedermayer, M., Rice, D., and J. Martinez, "FFV1 Video Niedermayer, M., Rice, D., and J. Martinez, "FFV1 Video
Coding Format Version 0, 1, and 3", draft-ietf-cellar- Coding Format Version 0, 1, and 3", draft-ietf-cellar-
ffv1-06 (work in progress), October 2018. ffv1-07 (work in progress), February 6, 2019,
<https://www.ietf.org/archive/id/draft-ietf-cellar-
ffv1-07>.
[ISO.15444-1.2016] [ISO.15444-1.2016]
International Organization for Standardization, International Organization for Standardization,
"Information technology -- JPEG 2000 image coding system: "Information technology -- JPEG 2000 image coding system:
Core coding system", October 2016. Core coding system", October 2016.
[ISO.9899.1990] [ISO.9899.1990]
International Organization for Standardization, International Organization for Standardization,
"Programming languages - C", ISO Standard 9899, 1990. "Programming languages - C", 1990.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet [RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
Denial-of-Service Considerations", RFC 4732, Denial-of-Service Considerations", RFC 4732,
DOI 10.17487/RFC4732, December 2006, DOI 10.17487/RFC4732, December 2006,
<https://www.rfc-editor.org/info/rfc4732>. <https://www.rfc-editor.org/info/rfc4732>.
skipping to change at page 45, line 32 skipping to change at page 44, line 23
[RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the [RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the
Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716, Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716,
September 2012, <https://www.rfc-editor.org/info/rfc6716>. September 2012, <https://www.rfc-editor.org/info/rfc6716>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13, Specifications and Registration Procedures", BCP 13,
RFC 6838, DOI 10.17487/RFC6838, January 2013, RFC 6838, DOI 10.17487/RFC6838, January 2013,
<https://www.rfc-editor.org/info/rfc6838>. <https://www.rfc-editor.org/info/rfc6838>.
11.2. Informative References 12. Informative References
[Address-Sanitizer] [Address-Sanitizer]
The Clang Team, "ASAN AddressSanitizer website", undated, The Clang Team, "ASAN AddressSanitizer website", August
<https://clang.llvm.org/docs/AddressSanitizer.html>. 2019, <https://clang.llvm.org/docs/AddressSanitizer.html>.
[AVI] Microsoft, "AVI RIFF File Reference", undated, [AVI] Microsoft, "AVI RIFF File Reference", August 2019,
<https://msdn.microsoft.com/en-us/library/windows/desktop/ <https://msdn.microsoft.com/en-us/library/windows/desktop/
dd318189%28v=vs.85%29.aspx>. dd318189%28v=vs.85%29.aspx>.
[HuffYUV] Rudiak-Gould, B., "HuffYUV", December 2003, [HuffYUV] Rudiak-Gould, B., "HuffYUV", December 2003,
<https://web.archive.org/web/20040402121343/ <https://web.archive.org/web/20040402121343/
http://cultact-server.novi.dk/kpo/huffyuv/huffyuv.html>. http://cultact-server.novi.dk/kpo/huffyuv/huffyuv.html>.
[ISO.14495-1.1999] [ISO.14495-1.1999]
International Organization for Standardization, International Organization for Standardization,
"Information technology -- Lossless and near-lossless "Information technology -- Lossless and near-lossless
skipping to change at page 46, line 15 skipping to change at page 45, line 5
[ISO.14496-10.2014] [ISO.14496-10.2014]
International Organization for Standardization, International Organization for Standardization,
"Information technology -- Coding of audio-visual objects "Information technology -- Coding of audio-visual objects
-- Part 10: Advanced Video Coding", September 2014. -- Part 10: Advanced Video Coding", September 2014.
[ISO.14496-12.2015] [ISO.14496-12.2015]
International Organization for Standardization, International Organization for Standardization,
"Information technology -- Coding of audio-visual objects "Information technology -- Coding of audio-visual objects
-- Part 12: ISO base media file format", December 2015. -- Part 12: ISO base media file format", December 2015.
[Matroska] [Matroska] IETF, "Matroska", 2016,
IETF, "Matroska", 2016, <https://datatracker.ietf.org/doc/ <https://datatracker.ietf.org/doc/draft-lhomme-cellar-
draft-lhomme-cellar-matroska/>. matroska/>.
[NUT] Niedermayer, M., "NUT Open Container Format", December [NUT] Niedermayer, M., "NUT Open Container Format", December
2013, <https://ffmpeg.org/~michael/nut.txt>. 2013, <https://ffmpeg.org/~michael/nut.txt>.
[range-coding] [range-coding]
Nigel, G. and N. Martin, "Range encoding: an algorithm for Nigel, G. and N. Martin, "Range encoding: an algorithm for
removing redundancy from a digitised message.", Proc. removing redundancy from a digitised message.", July 1979.
Institution of Electronic and Radio Engineers
International Conference on Video and Data Recording ,
July 1979.
[REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the [REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the
FFV1 codec in FFmpeg", undated, <https://ffmpeg.org>. FFV1 codec in FFmpeg", August 2019, <https://ffmpeg.org>.
[VALGRIND] [VALGRIND] Valgrind Developers, "Valgrind website", August 2019,
Valgrind Developers, "Valgrind website", undated,
<https://valgrind.org/>. <https://valgrind.org/>.
[YCbCr] Wikipedia, "YCbCr", undated, [YCbCr] Wikipedia, "YCbCr", August 2019,
<https://en.wikipedia.org/w/index.php?title=YCbCr>. <https://en.wikipedia.org/w/index.php?title=YCbCr>.
Authors' Addresses Authors' Addresses
Michael Niedermayer Michael Niedermayer
Email: michael@niedermayer.cc Email: michael@niedermayer.cc
Dave Rice Dave Rice
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