draft-ietf-cellar-ffv1-v4-12.txt | draft-ietf-cellar-ffv1-v4-13.txt | |||
---|---|---|---|---|
cellar M. Niedermayer | cellar M. Niedermayer | |||
Internet-Draft | Internet-Draft | |||
Intended status: Standards Track D. Rice | Intended status: Standards Track D. Rice | |||
Expires: 25 December 2020 | Expires: 3 January 2021 | |||
J. Martinez | J. Martinez | |||
23 June 2020 | 2 July 2020 | |||
FFV1 Video Coding Format Version 4 | FFV1 Video Coding Format Version 4 | |||
draft-ietf-cellar-ffv1-v4-12 | draft-ietf-cellar-ffv1-v4-13 | |||
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 36 ¶ | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
Drafts is at https://datatracker.ietf.org/drafts/current/. | Drafts is at https://datatracker.ietf.org/drafts/current/. | |||
Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
This Internet-Draft will expire on 25 December 2020. | This Internet-Draft will expire on 3 January 2021. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2020 IETF Trust and the persons identified as the | Copyright (c) 2020 IETF Trust and the persons identified as the | |||
document authors. All rights reserved. | document authors. All rights reserved. | |||
This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
Provisions Relating to IETF Documents (https://trustee.ietf.org/ | Provisions Relating to IETF Documents (https://trustee.ietf.org/ | |||
license-info) in effect on the date of publication of this document. | license-info) in effect on the date of publication of this document. | |||
Please review these documents carefully, as they describe your rights | Please review these documents carefully, as they describe your rights | |||
skipping to change at page 2, line 23 ¶ | skipping to change at page 2, line 23 ¶ | |||
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 . . . . . . . . . . . . . . . . 6 | 2.2.2. Arithmetic Operators . . . . . . . . . . . . . . . . 6 | |||
2.2.3. Assignment Operators . . . . . . . . . . . . . . . . 6 | 2.2.3. Assignment Operators . . . . . . . . . . . . . . . . 6 | |||
2.2.4. Comparison Operators . . . . . . . . . . . . . . . . 6 | 2.2.4. Comparison Operators . . . . . . . . . . . . . . . . 7 | |||
2.2.5. Mathematical Functions . . . . . . . . . . . . . . . 7 | 2.2.5. Mathematical Functions . . . . . . . . . . . . . . . 7 | |||
2.2.6. Order of Operation Precedence . . . . . . . . . . . . 8 | 2.2.6. Order of Operation Precedence . . . . . . . . . . . . 8 | |||
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 . . . . . . . . . . . . . . . . . . . . 11 | |||
3.4. Context . . . . . . . . . . . . . . . . . . . . . . . . . 11 | 3.4. Context . . . . . . . . . . . . . . . . . . . . . . . . . 11 | |||
3.5. Quantization Table Sets . . . . . . . . . . . . . . . . . 12 | 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 . . . . . . . . . . . . . . . . . . . . . . . . 13 | 3.7.1. YCbCr . . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 13 | 3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
3.8. Coding of the Sample Difference . . . . . . . . . . . . . 15 | 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 . . . . . . . . . . . . . . . . . . 20 | 3.8.2. Golomb Rice Mode . . . . . . . . . . . . . . . . . . 20 | |||
4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 25 | 4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 25 | |||
skipping to change at page 3, line 44 ¶ | skipping to change at page 3, line 44 ¶ | |||
4.7.1. primary_color_count . . . . . . . . . . . . . . . . . 44 | 4.7.1. primary_color_count . . . . . . . . . . . . . . . . . 44 | |||
4.7.2. plane_pixel_height . . . . . . . . . . . . . . . . . 44 | 4.7.2. plane_pixel_height . . . . . . . . . . . . . . . . . 44 | |||
4.7.3. slice_pixel_height . . . . . . . . . . . . . . . . . 45 | 4.7.3. slice_pixel_height . . . . . . . . . . . . . . . . . 45 | |||
4.7.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 45 | 4.7.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 45 | |||
4.8. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 45 | 4.8. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 45 | |||
4.8.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 45 | 4.8.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 45 | |||
4.8.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 46 | 4.8.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 46 | |||
4.8.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 46 | 4.8.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 46 | |||
4.8.4. sample_difference . . . . . . . . . . . . . . . . . . 46 | 4.8.4. sample_difference . . . . . . . . . . . . . . . . . . 46 | |||
4.9. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 46 | 4.9. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 46 | |||
4.9.1. slice_size . . . . . . . . . . . . . . . . . . . . . 46 | 4.9.1. slice_size . . . . . . . . . . . . . . . . . . . . . 47 | |||
4.9.2. error_status . . . . . . . . . . . . . . . . . . . . 47 | 4.9.2. error_status . . . . . . . . . . . . . . . . . . . . 47 | |||
4.9.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 47 | 4.9.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 47 | |||
5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 47 | 5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 47 | |||
6. Security Considerations . . . . . . . . . . . . . . . . . . . 48 | 6. Security Considerations . . . . . . . . . . . . . . . . . . . 48 | |||
7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 49 | 7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 49 | |||
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 50 | 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 50 | |||
9. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 50 | 9. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 50 | |||
10. Normative References . . . . . . . . . . . . . . . . . . . . 50 | 10. Normative References . . . . . . . . . . . . . . . . . . . . 50 | |||
11. Informative References . . . . . . . . . . . . . . . . . . . 51 | 11. Informative References . . . . . . . . . . . . . . . . . . . 51 | |||
Appendix A. Multi-theaded decoder implementation suggestions . . 52 | Appendix A. Multi-theaded decoder implementation suggestions . . 52 | |||
skipping to change at page 5, line 7 ¶ | skipping to change at page 5, line 7 ¶ | |||
14 [RFC2119] [RFC8174] when, and only when, they appear in all | 14 [RFC2119] [RFC8174] when, and only when, they appear in all | |||
capitals, as shown here. | capitals, as shown here. | |||
2.1. Definitions | 2.1. Definitions | |||
"Container": Format that encapsulates "Frames" (see Section 4.4) and | "Container": Format that encapsulates "Frames" (see Section 4.4) and | |||
(when required) a "Configuration Record" into a bitstream. | (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 (Y), Blue-difference Chroma (Cb), Red-difference Chroma (Cr), | |||
and Blue. | Transparency, Red, Green, 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. | |||
"Pixel": The smallest addressable representation of a color in a | "Pixel": The smallest addressable representation of a color in a | |||
"Frame". It is composed of one or more "Samples". | "Frame". It is composed of one or more "Samples". | |||
"ESC": An ESCape symbol to indicate that the symbol to be stored is | "ESC": An ESCape symbol to indicate that the symbol to be stored is | |||
too large for normal storage and that an alternate storage method is | too large for normal storage and that an alternate storage method is | |||
skipping to change at page 5, line 32 ¶ | skipping to change at page 5, line 32 ¶ | |||
change in magnitude of the symbol. | change in magnitude of the symbol. | |||
"VLC": Variable Length Code, a code that maps source symbols to a | "VLC": Variable Length Code, a code that maps source symbols to a | |||
variable number of bits. | variable number of bits. | |||
"RGB": A reference to the method of storing the value of a "Pixel" by | "RGB": A reference to the method of storing the value of a "Pixel" by | |||
using three numeric values that represent Red, Green, and Blue. | using three numeric values that represent Red, Green, and Blue. | |||
"YCbCr": A reference to the method of storing the value of a "Pixel" | "YCbCr": A reference to the method of storing the value of a "Pixel" | |||
by using three numeric values that represent the luma of the "Pixel" | by using three numeric values that represent the luma of the "Pixel" | |||
(Y) and the chrominance of the "Pixel" (Cb and Cr). YCbCr word is | (Y) and the chroma of the "Pixel" (Cb and Cr). YCbCr word is used | |||
used for historical reasons and currently references any color space | for historical reasons and currently references any color space | |||
relying on 1 luma "Sample" and 2 chrominance "Samples", e.g. YCbCr, | relying on 1 luma "Sample" and 2 chroma "Samples", e.g. YCbCr, YCgCo | |||
YCgCo or ICtCp. The exact meaning of the three numeric values is | or ICtCp. The exact meaning of the three numeric values is | |||
unspecified. | unspecified. | |||
"TBA": To Be Announced. Used in reference to the development of | "TBA": To Be Announced. Used in reference to the development of | |||
future iterations of the FFV1 specification. | future iterations of the FFV1 specification. | |||
2.2. Conventions | 2.2. Conventions | |||
2.2.1. Pseudo-code | 2.2.1. Pseudo-code | |||
The FFV1 bitstream is described in this document using pseudo-code. | The FFV1 bitstream is described in this document using pseudo-code. | |||
Note that the pseudo-code is used for clarity in order to illustrate | Note that the pseudo-code is used for clarity in order to illustrate | |||
the structure of FFV1 and not intended to specify any particular | the structure of FFV1 and not intended to specify any particular | |||
implementation. The pseudo-code used is based upon the C programming | implementation. The pseudo-code used is based upon the C programming | |||
language [ISO.9899.1990] and uses its "if/else", "while" and "for" | language [ISO.9899.1990] and uses its "if/else", "while" and "for" | |||
keywords as well as functions defined within this document. | keywords as well as functions defined within this document. | |||
In some instances, pseudo-code is presented in a two-column format | ||||
such as shown in Figure 1. In this form the "type" column provides a | ||||
symbol as defined in Table 4 that defines the storage of the data | ||||
referenced in that same line of pseudo-code. | ||||
pseudo-code | type | ||||
--------------------------------------------------------------|----- | ||||
ExamplePseudoCode( ) { | | ||||
value | ur | ||||
} | | ||||
Figure 1: A depiction of type-labelled pseudo-code used within | ||||
this document. | ||||
2.2.2. Arithmetic Operators | 2.2.2. Arithmetic Operators | |||
Note: the operators and the order of precedence are the same as used | Note: the operators and the order of precedence are the same as used | |||
in the C programming language [ISO.9899.2018], with the exception of | in the C programming language [ISO.9899.2018], with the exception of | |||
">>" (removal of implementation defined behavior) and "^" (power | ">>" (removal of implementation defined behavior) and "^" (power | |||
instead of XOR) operators which are re-defined within this section. | instead of XOR) operators which are re-defined within this section. | |||
"a + b" means a plus b. | "a + b" means a plus b. | |||
"a - b" means a minus b. | "a - b" means a minus b. | |||
skipping to change at page 9, line 44 ¶ | skipping to change at page 10, line 9 ¶ | |||
assumed to be "0" | assumed to be "0" | |||
* 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 | |||
* 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" | |||
Figure 1 depicts a slice of 9 "Samples" "a,b,c,d,e,f,g,h,i" in a 3x3 | Figure 2 depicts a slice of 9 "Samples" "a,b,c,d,e,f,g,h,i" in a 3x3 | |||
arrangement along with its assumed border. | arrangement along with its assumed 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 | | |||
+---+---+---+---+---+---+---+---+ | +---+---+---+---+---+---+---+---+ | |||
Figure 1: A depiction of FFV1's assumed border for a set example | Figure 2: A depiction of FFV1's assumed border for a set example | |||
Samples. | Samples. | |||
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 Figure 2. The labels for these | according to the labels used in Figure 3. The labels for these | |||
relatively positioned "Samples" are used within the median predictor | relatively positioned "Samples" are used within the median predictor | |||
and context. | and context. | |||
+---+---+---+---+ | +---+---+---+---+ | |||
| | | T | | | | | | T | | | |||
+---+---+---+---+ | +---+---+---+---+ | |||
| |tl | t |tr | | | |tl | t |tr | | |||
+---+---+---+---+ | +---+---+---+---+ | |||
| L | l | X | | | | L | l | X | | | |||
+---+---+---+---+ | +---+---+---+---+ | |||
Figure 2: A depiction of how relatively positions Samples are | Figure 3: A depiction of how relatively positions Samples are | |||
references within this document. | references within this document. | |||
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 15 ¶ | skipping to change at page 11, line 24 ¶ | |||
[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 top16s = t >= 32768 ? ( t - | left16s = l >= 32768 ? ( l - 65536 ) : l | |||
65536 ) : t diag16s = tl >= 32768 ? ( tl - 65536 ) : tl | top16s = t >= 32768 ? ( t - 65536 ) : t | |||
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 was discovered, the only | unsigned integer). Note that when the issue was 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 43 ¶ | skipping to change at page 12, line 4 ¶ | |||
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] | |||
Figure 4 | ||||
Figure 3 | ||||
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 one or more Quantization Table Sets. | The FFV1 bitstream contains one or more Quantization Table Sets. | |||
Each Quantization Table Set contains exactly 5 Quantization Tables | Each Quantization Table Set contains exactly 5 Quantization Tables | |||
with each Quantization Table corresponding to one of the five | with each Quantization Table corresponding to one of the five | |||
Quantized Sample Differences. For each Quantization Table, both the | Quantized Sample Differences. For each Quantization Table, both the | |||
number of quantization steps and their distribution are stored in the | number of quantization steps and their distribution are stored in the | |||
FFV1 bitstream; each Quantization Table has exactly 256 entries, and | FFV1 bitstream; each Quantization Table has exactly 256 entries, and | |||
the 8 least significant bits of the Quantized Sample Difference are | the 8 least significant bits of the Quantized Sample Difference are | |||
used as index: | used as index: | |||
Q_{j}[k] = quant_tables[i][j][k&255] | Q_{j}[k] = quant_tables[i][j][k&255] | |||
Figure 4 | Figure 5 | |||
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: | |||
* For Y "Plane", "quant_table_set_index[ 0 ]" index is used | * For Y "Plane", "quant_table_set_index[ 0 ]" index is used | |||
skipping to change at page 13, line 50 ¶ | skipping to change at page 14, line 12 ¶ | |||
[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 | Cr = r - g | |||
Y = g + (Cb + Cr) >> 2 | Y = g + (Cb + Cr) >> 2 | |||
g = Y - (Cb + Cr) >> 2 | g = Y - (Cb + Cr) >> 2 | |||
r = Cr + g | r = Cr + g | |||
b = Cb + g | b = Cb + g | |||
Figure 5 | Figure 6 | |||
Exception for the JPEG2000-RCT conversion: if "bits_per_raw_sample" | Exception for the JPEG2000-RCT conversion: if "bits_per_raw_sample" | |||
is between 9 and 15 inclusive and "extra_plane" is 0, the following | is 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 | b = Y -(Cb + Cr) >> 2 | |||
r = Cr + b | r = Cr + b | |||
g = Cb + b | g = Cb + b | |||
Figure 6 | Figure 7 | |||
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. | |||
skipping to change at page 15, line 23 ¶ | skipping to change at page 15, line 32 ¶ | |||
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 + | the equation below, the term "bits" represents "bits_per_raw_sample + | |||
1" for JPEG2000-RCT or "bits_per_raw_sample" otherwise: | 1" for JPEG2000-RCT or "bits_per_raw_sample" otherwise: | |||
coder_input = [(sample_difference + 2 ^ (bits - 1)) & | coder_input = [(sample_difference + 2 ^ (bits - 1)) & | |||
(2 ^ bits - 1)] - 2 ^ (bits - 1) | (2 ^ bits - 1)] - 2 ^ (bits - 1) | |||
Figure 7: Description of the coding of the Sample Difference in | Figure 8: Description of the coding of the Sample Difference in | |||
the bitstream. | the bitstream. | |||
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)" is | 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. "b(i)" | 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 initial | 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 symbols is | state. The length of the bytestream encoding n binary symbols is | |||
"j(n)" bytes. | "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 ) | |||
Figure 9 | ||||
Figure 8 | ||||
S_{i+1,C_{i}} = zero_state_{S_{i,C_{i}}} AND | S_{i+1,C_{i}} = zero_state_{S_{i,C_{i}}} AND | |||
l_i = L_i AND | l_i = L_i AND | |||
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}}} AND | S_{i+1,C_{i}} = one_state_{S_{i,C_{i}}} AND | |||
l_i = L_i - R_i + r_i AND | l_i = L_i - R_i + r_i AND | |||
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 | |||
Figure 9 | Figure 10 | |||
S_{i+1,k} = S_{i,k} <== C_i != k | S_{i+1,k} = S_{i,k} <== C_i != k | |||
Figure 10 | Figure 11 | |||
R_{i+1} = 2 ^ 8 * t_{i} AND | R_{i+1} = 2 ^ 8 * t_{i} AND | |||
L_{i+1} = 2 ^ 8 * l_{i} + B_{j_{i}} AND | L_{i+1} = 2 ^ 8 * l_{i} + B_{j_{i}} AND | |||
j_{i+1} = j_{i} + 1 <== | j_{i+1} = j_{i} + 1 <== | |||
t_{i} < 2 ^ 8 | t_{i} < 2 ^ 8 | |||
R_{i+1} = t_{i} AND | R_{i+1} = t_{i} AND | |||
L_{i+1} = l_{i} AND | L_{i+1} = l_{i} AND | |||
j_{i+1} = j_{i} <== | j_{i+1} = j_{i} <== | |||
t_{i} >= 2 ^ 8 | t_{i} >= 2 ^ 8 | |||
Figure 11 | Figure 12 | |||
R_{0} = 65280 | R_{0} = 65280 | |||
Figure 12 | Figure 13 | |||
L_{0} = 2 ^ 8 * B_{0} + B_{1} | L_{0} = 2 ^ 8 * B_{0} + B_{1} | |||
Figure 13 | Figure 14 | |||
j_{0} = 2 | j_{0} = 2 | |||
Figure 14 | Figure 15 | |||
3.8.1.1.1. Termination | 3.8.1.1.1. Termination | |||
The range coder can be used in three modes. | The range coder can be used in three modes. | |||
* 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. | |||
skipping to change at page 17, line 51 ¶ | skipping to change at page 17, line 51 ¶ | |||
To encode scalar integers, it would be possible to encode each bit | To encode scalar integers, it would be possible to encode each bit | |||
separately and use the past bits as context. However that would mean | separately and use the past bits as context. However that would mean | |||
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 | mantissa and sign. The exact contexts used are best described by | |||
Figure 15. | Figure 16. | |||
int get_symbol(RangeCoder *c, uint8_t *state, int is_signed) { | int get_symbol(RangeCoder *c, uint8_t *state, int is_signed) { | |||
if (get_rac(c, state + 0) { | if (get_rac(c, state + 0) { | |||
return 0; | return 0; | |||
} | } | |||
int e = 0; | int e = 0; | |||
while (get_rac(c, state + 1 + min(e, 9)) { //1..10 | while (get_rac(c, state + 1 + min(e, 9)) { //1..10 | |||
e++; | e++; | |||
} | } | |||
skipping to change at page 18, line 31 ¶ | skipping to change at page 18, line 31 ¶ | |||
return a; | return a; | |||
} | } | |||
if (get_rac(c, state + 11 + min(e, 10))) { //11..21 | if (get_rac(c, state + 11 + min(e, 10))) { //11..21 | |||
return -a; | return -a; | |||
} else { | } else { | |||
return a; | return a; | |||
} | } | |||
} | } | |||
Figure 15: A pseudo-code description of the contexts of Range Non | Figure 16: A pseudo-code description of the contexts of Range Non | |||
Binary Values. | Binary Values. | |||
"get_symbol" is used for the read out of "sample_difference" | "get_symbol" is used for the read out of "sample_difference" | |||
indicated in Figure 7. | indicated in Figure 8. | |||
"get_rac" is the process described in Section 3.8.1.1. | "get_rac" is the process described in Section 3.8.1.1. | |||
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} | |||
Figure 16 | Figure 17 | |||
zero_state_{i} = 256 - one_state_{256-i} | zero_state_{i} = 256 - one_state_{256-i} | |||
Figure 17 | Figure 18 | |||
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, | |||
skipping to change at page 19, line 47 ¶ | skipping to change at page 19, line 47 ¶ | |||
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 4.2.3) MUST be set | default. To use it, the "coder_type" (see Section 4.2.3) MUST be set | |||
to 2 and the difference to the default MUST be stored in the | to 2 and the difference to the default MUST be stored in the | |||
"Parameters", see Section 4.2. The reference implementation of FFV1 | "Parameters", see Section 4.2. The reference implementation of FFV1 | |||
in FFmpeg uses Figure 18 by default at the time of this writing when | in FFmpeg uses Figure 19 by default at the time of this writing when | |||
Range coding is used. | 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, | |||
skipping to change at page 20, line 37 ¶ | skipping to change at page 20, line 37 ¶ | |||
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, | |||
Figure 18: Alternative state transition table for Range coding. | Figure 19: Alternative state transition table for Range coding. | |||
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 two | This coding mode uses Golomb Rice codes. The VLC is split into two | |||
parts. The prefix stores the most significant bits and the suffix | parts. The prefix stores the most significant bits and the suffix | |||
skipping to change at page 21, line 14 ¶ | skipping to change at page 21, line 14 ¶ | |||
int get_ur_golomb(k) { | int get_ur_golomb(k) { | |||
for (prefix = 0; prefix < 12; prefix++) { | for (prefix = 0; prefix < 12; prefix++) { | |||
if (get_bits(1)) { | if (get_bits(1)) { | |||
return get_bits(k) + (prefix << k); | return get_bits(k) + (prefix << k); | |||
} | } | |||
} | } | |||
return get_bits(bits) + 11; | return get_bits(bits) + 11; | |||
} | } | |||
Figure 19: A pseudo-code description of the read of an unsigned | Figure 20: A pseudo-code description of the read of an unsigned | |||
integer in Golomb Rice mode. | integer in Golomb Rice mode. | |||
int get_sr_golomb(k) { | int get_sr_golomb(k) { | |||
v = get_ur_golomb(k); | v = get_ur_golomb(k); | |||
if (v & 1) return - (v >> 1) - 1; | if (v & 1) return - (v >> 1) - 1; | |||
else return (v >> 1); | else return (v >> 1); | |||
} | } | |||
Figure 20: A pseudo-code description of the read of a signed | Figure 21: A pseudo-code description of the read of a signed | |||
integer in Golomb Rice mode. | integer in Golomb Rice mode. | |||
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 01 | 9 | | | 0000 0000 01 | 9 | | |||
+----------------+-------+ | +----------------+-------+ | |||
skipping to change at page 22, line 7 ¶ | skipping to change at page 22, line 7 ¶ | |||
+----------------+-------+ | +----------------+-------+ | |||
| 0000 0000 0001 | 11 | | | 0000 0000 0001 | 11 | | |||
+----------------+-------+ | +----------------+-------+ | |||
| 0000 0000 0000 | ESC | | | 0000 0000 0000 | ESC | | |||
+----------------+-------+ | +----------------+-------+ | |||
Table 1 | Table 1 | |||
3.8.2.1.2. Suffix | 3.8.2.1.2. Suffix | |||
+---------+----------------------------------------+ | +=========+========================================+ | |||
+=========+========================================+ | +=========+========================================+ | |||
| non ESC | the k least significant bits MSB first | | | non ESC | the k least significant bits MSB first | | |||
+---------+----------------------------------------+ | +---------+----------------------------------------+ | |||
| ESC | the value - 11, in MSB first order | | | ESC | the value - 11, in MSB first order | | |||
+---------+----------------------------------------+ | +---------+----------------------------------------+ | |||
Table 2 | Table 2 | |||
"ESC" MUST NOT be used if the value can be coded as "non ESC". | "ESC" MUST NOT be used if the value can be coded as "non ESC". | |||
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 | 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 | |||
skipping to change at page 26, line 5 ¶ | skipping to change at page 26, line 5 ¶ | |||
An FFV1 bitstream is composed of a series of one or more "Frames" and | An FFV1 bitstream is composed of a series of one 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 | |||
Section 2.2.1. Table 4 lists symbols used to annotate that pseudo- | Section 2.2.1. Table 4 lists symbols used to annotate that pseudo- | |||
code in order to define the storage of the data referenced in that | code in order to define the storage of the data referenced in that | |||
line of pseudo-code. | 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 | | | sg | Golomb Rice coded signed scalar symbol coded | | |||
| | with the method described in Section 3.8.2 | | | | with the method described in Section 3.8.2 | | |||
+--------+----------------------------------------------+ | +--------+----------------------------------------------+ | |||
| br | Range coded Boolean (1-bit) symbol with the | | | br | Range coded Boolean (1-bit) symbol with the | | |||
| | method described in Section 3.8.1.1 | | | | method described in Section 3.8.1.1 | | |||
+--------+----------------------------------------------+ | +--------+----------------------------------------------+ | |||
skipping to change at page 28, line 17 ¶ | skipping to change at page 28, line 17 ¶ | |||
"context_count[ i ]" indicates the count of contexts for Quantization | "context_count[ i ]" indicates the count of contexts for Quantization | |||
Table Set "i". "context_count[ i ]" MUST be less than or equal to | Table Set "i". "context_count[ i ]" MUST be less than or equal to | |||
32768. | 32768. | |||
4.2. Parameters | 4.2. 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. Figure 21 describes the contents of the bitstream. | tables. Figure 22 describes the contents of the bitstream. | |||
"Parameters" has its own initial states, all set to 128. | "Parameters" has its own initial states, all set to 128. | |||
pseudo-code | type | pseudo-code | type | |||
--------------------------------------------------------------|----- | --------------------------------------------------------------|----- | |||
Parameters( ) { | | Parameters( ) { | | |||
version | ur | version | ur | |||
if (version >= 3) { | | if (version >= 3) { | | |||
micro_version | ur | micro_version | ur | |||
} | | } | | |||
skipping to change at page 29, line 50 ¶ | skipping to change at page 29, line 50 ¶ | |||
initial_state_delta[ i ][ j ][ k ] | sr | initial_state_delta[ i ][ j ][ k ] | sr | |||
} | | } | | |||
} | | } | | |||
} | | } | | |||
} | | } | | |||
ec | ur | ec | ur | |||
intra | ur | intra | ur | |||
} | | } | | |||
} | | } | | |||
Figure 21: A pseudo-code description of the bitstream contents. | Figure 22: A pseudo-code description of the bitstream contents. | |||
CONTEXT_SIZE is 32. | CONTEXT_SIZE is 32. | |||
4.2.1. version | 4.2.1. 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 FFV1 bitstreams due to an unknown version. | reject FFV1 bitstreams due to an unknown version. | |||
Decoders SHOULD reject FFV1 bitstreams with version <= 1 && | Decoders SHOULD reject FFV1 bitstreams with version <= 1 && | |||
ConfigurationRecordIsPresent == 1. | ConfigurationRecordIsPresent == 1. | |||
Decoders SHOULD reject FFV1 bitstreams with version >= 3 && | Decoders SHOULD reject FFV1 bitstreams 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 | | |||
+-------+-------------------------+ | +-------+-------------------------+ | |||
skipping to change at page 31, line 5 ¶ | skipping to change at page 31, line 5 ¶ | |||
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 FFV1 | the previous micro-version: decoders SHOULD NOT reject FFV1 | |||
bitstreams due to an unknown micro-version equal or above the micro- | bitstreams due to an unknown micro-version equal or above the micro- | |||
version considered as stable. | version considered 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: The definitions for | Table 6: The definitions for | |||
"micro_version" values for FFV1 | "micro_version" values for FFV1 | |||
version 3. | version 3. | |||
* 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 | Meaning of "micro_version" for "version" 4 (note: at the time of | |||
writing of this specification, version 4 is not considered stable so | writing of this specification, version 4 is not considered stable so | |||
the first stable "micro_version" value is to be announced in the | the first stable "micro_version" value is to be announced in the | |||
future): | future): | |||
+---------+-------------------------+ | +=========+=========================+ | |||
| value | micro_version | | | value | micro_version | | |||
+=========+=========================+ | +=========+=========================+ | |||
| 0...TBA | reserved* | | | 0...TBA | reserved* | | |||
+---------+-------------------------+ | +---------+-------------------------+ | |||
| TBA | first stable variant | | | TBA | first stable variant | | |||
+---------+-------------------------+ | +---------+-------------------------+ | |||
| Other | reserved for future use | | | Other | reserved for future use | | |||
+---------+-------------------------+ | +---------+-------------------------+ | |||
Table 7: The definitions for | Table 7: The definitions for | |||
"micro_version" values for FFV1 | "micro_version" values for FFV1 | |||
version 4. | version 4. | |||
* development versions which may be incompatible with the stable | * development versions which may be incompatible with the stable | |||
variants. | variants. | |||
4.2.3. coder_type | 4.2.3. coder_type | |||
"coder_type" specifies the coder used. | "coder_type" specifies the coder used. | |||
+-------+-------------------------------------------------+ | +=======+=================================================+ | |||
| value | coder used | | | value | coder used | | |||
+=======+=================================================+ | +=======+=================================================+ | |||
| 0 | Golomb Rice | | | 0 | Golomb Rice | | |||
+-------+-------------------------------------------------+ | +-------+-------------------------------------------------+ | |||
| 1 | Range Coder with default state transition table | | | 1 | Range Coder with default state transition table | | |||
+-------+-------------------------------------------------+ | +-------+-------------------------------------------------+ | |||
| 2 | Range Coder with custom state transition table | | | 2 | Range Coder with custom state transition table | | |||
+-------+-------------------------------------------------+ | +-------+-------------------------------------------------+ | |||
| Other | reserved for future use | | | Other | reserved for future use | | |||
+-------+-------------------------------------------------+ | +-------+-------------------------------------------------+ | |||
skipping to change at page 33, line 5 ¶ | skipping to change at page 33, line 5 ¶ | |||
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. | |||
4.2.5. colorspace_type | 4.2.5. 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 space | pixel | extra plane | interleave | | | value | color space | pixel | extra plane | interleave | | |||
| | encoded | transformation | content | method | | | | encoded | transformation | content | method | | |||
+=======+=============+================+==============+=============+ | +=======+=============+================+==============+=============+ | |||
| 0 | YCbCr | None | Transparency | "Plane" | | | 0 | YCbCr | None | Transparency | "Plane" | | |||
| | | | | then | | | | | | | then | | |||
| | | | | "Line" | | | | | | | "Line" | | |||
+-------+-------------+----------------+--------------+-------------+ | +-------+-------------+----------------+--------------+-------------+ | |||
| 1 | RGB | JPEG2000-RCT | Transparency | "Line" | | | 1 | RGB | JPEG2000-RCT | Transparency | "Line" | | |||
| | | | | then | | | | | | | then | | |||
| | | | | "Plane" | | | | | | | "Plane" | | |||
skipping to change at page 33, line 32 ¶ | skipping to change at page 33, line 32 ¶ | |||
Table 9 | Table 9 | |||
FFV1 bitstreams with "colorspace_type" == 1 && ("chroma_planes" != | FFV1 bitstreams with "colorspace_type" == 1 && ("chroma_planes" != | |||
1 || "log2_h_chroma_subsample" != 0 || "log2_v_chroma_subsample" != | 1 || "log2_h_chroma_subsample" != 0 || "log2_v_chroma_subsample" != | |||
0) are not part of this specification. | 0) are not part of this specification. | |||
4.2.6. chroma_planes | 4.2.6. 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 | Table 10 | |||
4.2.7. bits_per_raw_sample | 4.2.7. 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 | Table 11 | |||
* Encoders MUST NOT store "bits_per_raw_sample" = 0. Decoders SHOULD | * Encoders MUST NOT store "bits_per_raw_sample" = 0. Decoders SHOULD | |||
skipping to change at page 34, line 35 ¶ | skipping to change at page 34, line 35 ¶ | |||
"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 * | height ("chroma_height = 2 ^ -log2_v_chroma_subsample * | |||
luma_height"). | luma_height"). | |||
4.2.10. extra_plane | 4.2.10. 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 | Table 12 | |||
4.2.11. num_h_slices | 4.2.11. num_h_slices | |||
skipping to change at page 35, line 28 ¶ | skipping to change at page 35, line 28 ¶ | |||
MUST NOT be 0. | MUST NOT be 0. | |||
4.2.14. states_coded | 4.2.14. 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 | | | 0 | initial states are not present | | |||
| | and are assumed to be all 128 | | | | and are assumed to be all 128 | | |||
+-------+--------------------------------+ | +-------+--------------------------------+ | |||
| 1 | initial states are present | | | 1 | initial states are present | | |||
+-------+--------------------------------+ | +-------+--------------------------------+ | |||
Table 13 | Table 13 | |||
4.2.15. initial_state_delta | 4.2.15. 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 | |||
Figure 22 | Figure 23 | |||
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 | |||
Figure 23 | Figure 24 | |||
4.2.16. ec | 4.2.16. 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 in "ConfigurationRecord" | | | 0 | 32-bit CRC in "ConfigurationRecord" | | |||
+-------+-------------------------------------------------+ | +-------+-------------------------------------------------+ | |||
| 1 | 32-bit CRC in "Slice" and "ConfigurationRecord" | | | 1 | 32-bit CRC in "Slice" and "ConfigurationRecord" | | |||
+-------+-------------------------------------------------+ | +-------+-------------------------------------------------+ | |||
| Other | reserved for future use | | | Other | reserved for future use | | |||
+-------+-------------------------------------------------+ | +-------+-------------------------------------------------+ | |||
Table 14 | Table 14 | |||
4.2.17. intra | 4.2.17. intra | |||
"intra" indicates the constraint on "keyframe" in each instance of | "intra" indicates the constraint on "keyframe" in each instance of | |||
"Frame". | "Frame". | |||
Inferred to be 0 if not present. | Inferred to be 0 if not present. | |||
+-------+-------------------------------------------------------+ | +=======+=======================================================+ | |||
| value | relationship | | | value | relationship | | |||
+=======+=======================================================+ | +=======+=======================================================+ | |||
| 0 | "keyframe" can be 0 or 1 (non keyframes or keyframes) | | | 0 | "keyframe" can be 0 or 1 (non keyframes or keyframes) | | |||
+-------+-------------------------------------------------------+ | +-------+-------------------------------------------------------+ | |||
| 1 | "keyframe" MUST be 1 (keyframes only) | | | 1 | "keyframe" MUST be 1 (keyframes only) | | |||
+-------+-------------------------------------------------------+ | +-------+-------------------------------------------------------+ | |||
| Other | reserved for future use | | | Other | reserved for future use | | |||
+-------+-------------------------------------------------------+ | +-------+-------------------------------------------------------+ | |||
Table 15 | Table 15 | |||
skipping to change at page 39, line 19 ¶ | skipping to change at page 39, line 19 ¶ | |||
if (keyframe && !ConfigurationRecordIsPresent { | | if (keyframe && !ConfigurationRecordIsPresent { | | |||
Parameters( ) | | Parameters( ) | | |||
} | | } | | |||
while (remaining_bits_in_bitstream( NumBytes )) { | | while (remaining_bits_in_bitstream( NumBytes )) { | | |||
Slice( ) | | 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 | | |||
skipping to change at page 42, line 16 ¶ | skipping to change at page 42, line 16 ¶ | |||
"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. | |||
4.6.5. quant_table_set_index_count | 4.6.5. quant_table_set_index_count | |||
"quant_table_set_index_count" is defined as: | "quant_table_set_index_count" is defined as: | |||
1 + ( ( chroma_planes || version <= 3 ) ? 1 : 0 ) + ( extra_plane ? 1 | 1 + ( ( chroma_planes || version <= 3 ) ? 1 : 0 ) | |||
: 0 ) | + ( extra_plane ? 1 : 0 ) | |||
4.6.6. quant_table_set_index | 4.6.6. 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 Content". | "Slice Content". | |||
Inferred to be 0 if not present. | Inferred to be 0 if not present. | |||
4.6.7. picture_structure | 4.6.7. 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 | | | 0 | unknown | | |||
+-------+-------------------------+ | +-------+-------------------------+ | |||
| 1 | top field first | | | 1 | top field first | | |||
+-------+-------------------------+ | +-------+-------------------------+ | |||
| 2 | bottom field first | | | 2 | bottom field first | | |||
+-------+-------------------------+ | +-------+-------------------------+ | |||
| 3 | progressive | | | 3 | progressive | | |||
+-------+-------------------------+ | +-------+-------------------------+ | |||
skipping to change at page 44, line 5 ¶ | skipping to change at page 44, line 5 ¶ | |||
"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. | |||
4.6.11. slice_coding_mode | 4.6.11. 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 | | | 0 | Range Coding or Golomb Rice | | |||
+-------+-----------------------------+ | +-------+-----------------------------+ | |||
| 1 | raw PCM | | | 1 | raw PCM | | |||
+-------+-----------------------------+ | +-------+-----------------------------+ | |||
| Other | reserved for future use | | | Other | reserved for future use | | |||
+-------+-----------------------------+ | +-------+-----------------------------+ | |||
Table 18 | Table 18 | |||
skipping to change at page 45, line 5 ¶ | skipping to change at page 45, line 5 ¶ | |||
"primary_color_count" is defined as: | "primary_color_count" is defined as: | |||
1 + ( chroma_planes ? 2 : 0 ) + ( extra_plane ? 1 : 0 ) | 1 + ( chroma_planes ? 2 : 0 ) + ( extra_plane ? 1 : 0 ) | |||
4.7.2. plane_pixel_height | 4.7.2. plane_pixel_height | |||
"plane_pixel_height[ p ]" is the height in "Pixels" of "Plane" p of | "plane_pixel_height[ p ]" is the height in "Pixels" of "Plane" p of | |||
the "Slice". It is defined as: | the "Slice". It is defined as: | |||
(chroma_planes == 1 && (p == 1 || p == 2)) ? ceil(slice_pixel_height | chroma_planes == 1 && (p == 1 || p == 2) | |||
/ (1 << log2_v_chroma_subsample)) : slice_pixel_height | ? ceil(slice_pixel_height / (1 << log2_v_chroma_subsample)) | |||
: slice_pixel_height | ||||
4.7.3. slice_pixel_height | 4.7.3. slice_pixel_height | |||
"slice_pixel_height" is the height in pixels of the slice. It is | "slice_pixel_height" is the height in pixels of the slice. It is | |||
defined as: | defined as: | |||
floor( ( slice_y + slice_height ) * slice_pixel_height / num_v_slices | floor( | |||
) - slice_pixel_y. | ( slice_y + slice_height ) | |||
* slice_pixel_height | ||||
/ num_v_slices | ||||
) - slice_pixel_y. | ||||
4.7.4. slice_pixel_y | 4.7.4. slice_pixel_y | |||
"slice_pixel_y" is the slice vertical position in pixels. It is | "slice_pixel_y" is the slice vertical position in pixels. It is | |||
defined as: | defined as: | |||
floor( slice_y * frame_pixel_height / num_v_slices ) | floor( slice_y * frame_pixel_height / num_v_slices ) | |||
4.8. Line | 4.8. Line | |||
skipping to change at page 45, line 48 ¶ | skipping to change at page 46, line 5 ¶ | |||
sample_difference[ p ][ y ][ x ] | sd | sample_difference[ p ][ y ][ x ] | sd | |||
} | | } | | |||
} | | } | | |||
} | | } | | |||
4.8.1. plane_pixel_width | 4.8.1. 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". It is defined as: | "Slice". It is defined as: | |||
(chroma_planes == 1 && (p == 1 || p == 2)) ? ceil( slice_pixel_width | chroma\_planes == 1 && (p == 1 || p == 2) | |||
/ (1 << log2_h_chroma_subsample) ) : slice_pixel_width. | ? ceil( slice_pixel_width / (1 << log2_h_chroma_subsample) ) | |||
: slice_pixel_width. | ||||
4.8.2. slice_pixel_width | 4.8.2. slice_pixel_width | |||
"slice_pixel_width" is the width in "Pixels" of the slice. It is | "slice_pixel_width" is the width in "Pixels" of the slice. It is | |||
defined as: | defined as: | |||
floor( ( slice_x + slice_width ) * slice_pixel_width / num_h_slices ) | floor( | |||
- slice_pixel_x | ( slice_x + slice_width ) | |||
* slice_pixel_width | ||||
/ num_h_slices | ||||
) - slice_pixel_x | ||||
4.8.3. slice_pixel_x | 4.8.3. slice_pixel_x | |||
"slice_pixel_x" is the slice horizontal position in "Pixels". It is | "slice_pixel_x" is the slice horizontal position in "Pixels". It is | |||
defined as: | defined as: | |||
floor( slice_x * frame_pixel_width / num_h_slices ) | floor( slice_x * frame_pixel_width / num_h_slices ) | |||
4.8.4. sample_difference | 4.8.4. sample_difference | |||
skipping to change at page 47, line 9 ¶ | skipping to change at page 47, line 17 ¶ | |||
"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. | |||
4.9.2. error_status | 4.9.2. error_status | |||
"error_status" specifies the error status. | "error_status" specifies the error status. | |||
+-------+--------------------------------------+ | +=======+======================================+ | |||
| value | error status | | | value | error status | | |||
+=======+======================================+ | +=======+======================================+ | |||
| 0 | no error | | | 0 | no error | | |||
+-------+--------------------------------------+ | +-------+--------------------------------------+ | |||
| 1 | slice contains a correctable error | | | 1 | slice contains a correctable error | | |||
+-------+--------------------------------------+ | +-------+--------------------------------------+ | |||
| 2 | slice contains a uncorrectable error | | | 2 | slice contains a uncorrectable error | | |||
+-------+--------------------------------------+ | +-------+--------------------------------------+ | |||
| Other | reserved for future use | | | Other | reserved for future use | | |||
+-------+--------------------------------------+ | +-------+--------------------------------------+ | |||
skipping to change at page 50, line 40 ¶ | skipping to change at page 50, line 46 ¶ | |||
9. Changelog | 9. Changelog | |||
See https://github.com/FFmpeg/FFV1/commits/master | See https://github.com/FFmpeg/FFV1/commits/master | |||
(https://github.com/FFmpeg/FFV1/commits/master) | (https://github.com/FFmpeg/FFV1/commits/master) | |||
[RFC Editor: Please remove this Changelog section prior to | [RFC Editor: Please remove this Changelog section prior to | |||
publication.] | publication.] | |||
10. Normative References | 10. Normative References | |||
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC | ||||
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, | ||||
May 2017, <https://www.rfc-editor.org/info/rfc8174>. | ||||
[RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the | ||||
Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716, | ||||
September 2012, <https://www.rfc-editor.org/info/rfc6716>. | ||||
[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>. | |||
[ISO.9899.1990] | ||||
International Organization for Standardization, | ||||
"Programming languages - C", 1990. | ||||
[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. | |||
[RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the | ||||
Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716, | ||||
September 2012, <https://www.rfc-editor.org/info/rfc6716>. | ||||
[ISO.9899.2018] | ||||
International Organization for Standardization, | ||||
"Programming languages - C", 2018. | ||||
[Matroska] IETF, "Matroska", 2019, <https://datatracker.ietf.org/doc/ | [Matroska] IETF, "Matroska", 2019, <https://datatracker.ietf.org/doc/ | |||
draft-ietf-cellar-matroska/>. | draft-ietf-cellar-matroska/>. | |||
[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>. | |||
[RFC4855] Casner, S., "Media Type Registration of RTP Payload | [RFC4855] Casner, S., "Media Type Registration of RTP Payload | |||
Formats", RFC 4855, DOI 10.17487/RFC4855, February 2007, | Formats", RFC 4855, DOI 10.17487/RFC4855, February 2007, | |||
<https://www.rfc-editor.org/info/rfc4855>. | <https://www.rfc-editor.org/info/rfc4855>. | |||
[ISO.9899.2018] | [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC | |||
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, | ||||
May 2017, <https://www.rfc-editor.org/info/rfc8174>. | ||||
[ISO.9899.1990] | ||||
International Organization for Standardization, | International Organization for Standardization, | |||
"Programming languages - C", 2018. | "Programming languages - C", 1990. | |||
[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. Informative References | 11. Informative References | |||
[REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the | [YCbCr] Wikipedia, "YCbCr", undated, | |||
FFV1 codec in FFmpeg", undated, <https://ffmpeg.org>. | <https://en.wikipedia.org/w/index.php?title=YCbCr>. | |||
[ISO.14496-10.2014] | ||||
International Organization for Standardization, | ||||
"Information technology -- Coding of audio-visual objects | ||||
-- Part 10: Advanced Video Coding", September 2014. | ||||
[range-coding] | [I-D.ietf-cellar-ffv1] | |||
Nigel, G. and N. Martin, "Range encoding: an algorithm for | Niedermayer, M., Rice, D., and J. Martinez, "FFV1 Video | |||
removing redundancy from a digitised message.", July 1979. | Coding Format Version 0, 1, and 3", Work in Progress, | |||
Internet-Draft, draft-ietf-cellar-ffv1-14, 26 May 2020, | ||||
<https://tools.ietf.org/html/draft-ietf-cellar-ffv1-14>. | ||||
[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>. | |||
[AVI] Microsoft, "AVI RIFF File Reference", undated, | [AVI] Microsoft, "AVI RIFF File Reference", undated, | |||
<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>. | |||
[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. | |||
[NUT] Niedermayer, M., "NUT Open Container Format", December | ||||
2013, <https://ffmpeg.org/~michael/nut.txt>. | ||||
[YCbCr] Wikipedia, "YCbCr", undated, | ||||
<https://en.wikipedia.org/w/index.php?title=YCbCr>. | ||||
[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 | |||
compression of continuous-tone still images: Baseline", | compression of continuous-tone still images: Baseline", | |||
December 1999. | December 1999. | |||
[I-D.ietf-cellar-ffv1] | ||||
Niedermayer, M., Rice, D., and J. Martinez, "FFV1 Video | ||||
Coding Format Version 0, 1, and 3", Work in Progress, | ||||
Internet-Draft, draft-ietf-cellar-ffv1-14, 26 May 2020, | ||||
<https://tools.ietf.org/html/draft-ietf-cellar-ffv1-14>. | ||||
[VALGRIND] Valgrind Developers, "Valgrind website", undated, | [VALGRIND] Valgrind Developers, "Valgrind website", undated, | |||
<https://valgrind.org/>. | <https://valgrind.org/>. | |||
[range-coding] | ||||
Nigel, G. and N. Martin, "Range encoding: an algorithm for | ||||
removing redundancy from a digitised message.", July 1979. | ||||
[ISO.14496-10.2014] | ||||
International Organization for Standardization, | ||||
"Information technology -- Coding of audio-visual objects | ||||
-- Part 10: Advanced Video Coding", September 2014. | ||||
[REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the | ||||
FFV1 codec in FFmpeg", undated, <https://ffmpeg.org>. | ||||
[Address-Sanitizer] | [Address-Sanitizer] | |||
The Clang Team, "ASAN AddressSanitizer website", undated, | The Clang Team, "ASAN AddressSanitizer website", undated, | |||
<https://clang.llvm.org/docs/AddressSanitizer.html>. | <https://clang.llvm.org/docs/AddressSanitizer.html>. | |||
[NUT] Niedermayer, M., "NUT Open Container Format", December | ||||
2013, <https://ffmpeg.org/~michael/nut.txt>. | ||||
Appendix A. Multi-theaded decoder implementation suggestions | Appendix A. Multi-theaded decoder implementation suggestions | |||
This appendix is informative. | This appendix is informative. | |||
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 | |||
End of changes. 75 change blocks. | ||||
125 lines changed or deleted | 146 lines changed or added | |||
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