draft-ietf-cellar-ffv1-15.txt		draft-ietf-cellar-ffv1-16.txt
	cellar M. Niedermayer		cellar M. Niedermayer
	Internet-Draft		Internet-Draft
	Intended status: Informational D. Rice		Intended status: Informational 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 0, 1, and 3		FFV1 Video Coding Format Version 0, 1, and 3
	draft-ietf-cellar-ffv1-15		draft-ietf-cellar-ffv1-16
	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 22 ¶		skipping to change at page 2, line 22 ¶
	provided without warranty as described in the Simplified BSD License.		provided without warranty as described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
	2. Notation and Conventions . . . . . . . . . . . . . . . . . . 5		2. Notation and Conventions . . . . . . . . . . . . . . . . . . 5
	2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5		2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5
	2.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 5		2.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 5
	2.2.1. Pseudo-code . . . . . . . . . . . . . . . . . . . . . 6		2.2.1. Pseudo-code . . . . . . . . . . . . . . . . . . . . . 6
	2.2.2. Arithmetic Operators . . . . . . . . . . . . . . . . 6		2.2.2. Arithmetic Operators . . . . . . . . . . . . . . . . 6
	2.2.3. Assignment Operators . . . . . . . . . . . . . . . . 6		2.2.3. Assignment Operators . . . . . . . . . . . . . . . . 7
	2.2.4. Comparison Operators . . . . . . . . . . . . . . . . 7		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 . . . . . . . . . . . . . . . . . . . . . . 9
	2.2.9. Bitstream Functions . . . . . . . . . . . . . . . . . 8		2.2.9. Bitstream Functions . . . . . . . . . . . . . . . . . 9
	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 . . . . . . . . . . . . . . . . . . . . . . . . . 12
	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 . . . . . . . . . . . . . . . . . . . . . . 13
	3.7.1. YCbCr . . . . . . . . . . . . . . . . . . . . . . . . 13		3.7.1. YCbCr . . . . . . . . . . . . . . . . . . . . . . . . 13
	3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 13		3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 14
	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 . . . . . . . . . . . . . . . . . . 16
	3.8.2. Golomb Rice Mode . . . . . . . . . . . . . . . . . . 20		3.8.2. Golomb Rice Mode . . . . . . . . . . . . . . . . . . 21
	4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 25		4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 26
	4.1. Quantization Table Set . . . . . . . . . . . . . . . . . 26		4.1. Quantization Table Set . . . . . . . . . . . . . . . . . 27
	4.1.1. quant_tables . . . . . . . . . . . . . . . . . . . . 27		4.1.1. quant_tables . . . . . . . . . . . . . . . . . . . . 28
	4.1.2. context_count . . . . . . . . . . . . . . . . . . . . 28		4.1.2. context_count . . . . . . . . . . . . . . . . . . . . 29
	4.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 28		4.2. Parameters . . . . . . . . . . . . . . . . . . . . . . . 29
	4.2.1. version . . . . . . . . . . . . . . . . . . . . . . . 30		4.2.1. version . . . . . . . . . . . . . . . . . . . . . . . 31
	4.2.2. micro_version . . . . . . . . . . . . . . . . . . . . 30		4.2.2. micro_version . . . . . . . . . . . . . . . . . . . . 31
	4.2.3. coder_type . . . . . . . . . . . . . . . . . . . . . 31		4.2.3. coder_type . . . . . . . . . . . . . . . . . . . . . 32
	4.2.4. state_transition_delta . . . . . . . . . . . . . . . 31		4.2.4. state_transition_delta . . . . . . . . . . . . . . . 32
	4.2.5. colorspace_type . . . . . . . . . . . . . . . . . . . 32		4.2.5. colorspace_type . . . . . . . . . . . . . . . . . . . 33
	4.2.6. chroma_planes . . . . . . . . . . . . . . . . . . . . 32		4.2.6. chroma_planes . . . . . . . . . . . . . . . . . . . . 33
	4.2.7. bits_per_raw_sample . . . . . . . . . . . . . . . . . 33		4.2.7. bits_per_raw_sample . . . . . . . . . . . . . . . . . 34
	4.2.8. log2_h_chroma_subsample . . . . . . . . . . . . . . . 33		4.2.8. log2_h_chroma_subsample . . . . . . . . . . . . . . . 34
	4.2.9. log2_v_chroma_subsample . . . . . . . . . . . . . . . 33		4.2.9. log2_v_chroma_subsample . . . . . . . . . . . . . . . 34
	4.2.10. extra_plane . . . . . . . . . . . . . . . . . . . . . 33		4.2.10. extra_plane . . . . . . . . . . . . . . . . . . . . . 34
	4.2.11. num_h_slices . . . . . . . . . . . . . . . . . . . . 34		4.2.11. num_h_slices . . . . . . . . . . . . . . . . . . . . 35
	4.2.12. num_v_slices . . . . . . . . . . . . . . . . . . . . 34		4.2.12. num_v_slices . . . . . . . . . . . . . . . . . . . . 35
	4.2.13. quant_table_set_count . . . . . . . . . . . . . . . . 34		4.2.13. quant_table_set_count . . . . . . . . . . . . . . . . 35
	4.2.14. states_coded . . . . . . . . . . . . . . . . . . . . 34		4.2.14. states_coded . . . . . . . . . . . . . . . . . . . . 35
	4.2.15. initial_state_delta . . . . . . . . . . . . . . . . . 34		4.2.15. initial_state_delta . . . . . . . . . . . . . . . . . 35
	4.2.16. ec . . . . . . . . . . . . . . . . . . . . . . . . . 35		4.2.16. ec . . . . . . . . . . . . . . . . . . . . . . . . . 36
	4.2.17. intra . . . . . . . . . . . . . . . . . . . . . . . . 35		4.2.17. intra . . . . . . . . . . . . . . . . . . . . . . . . 36
	4.3. Configuration Record . . . . . . . . . . . . . . . . . . 36		4.3. Configuration Record . . . . . . . . . . . . . . . . . . 37
	4.3.1. reserved_for_future_use . . . . . . . . . . . . . . . 36		4.3.1. reserved_for_future_use . . . . . . . . . . . . . . . 37
	4.3.2. configuration_record_crc_parity . . . . . . . . . . . 36		4.3.2. configuration_record_crc_parity . . . . . . . . . . . 37
	4.3.3. Mapping FFV1 into Containers . . . . . . . . . . . . 36		4.3.3. Mapping FFV1 into Containers . . . . . . . . . . . . 37
	4.4. Frame . . . . . . . . . . . . . . . . . . . . . . . . . . 37		4.4. Frame . . . . . . . . . . . . . . . . . . . . . . . . . . 38
	4.5. Slice . . . . . . . . . . . . . . . . . . . . . . . . . . 39		4.5. Slice . . . . . . . . . . . . . . . . . . . . . . . . . . 40
	4.6. Slice Header . . . . . . . . . . . . . . . . . . . . . . 40		4.6. Slice Header . . . . . . . . . . . . . . . . . . . . . . 41
	4.6.1. slice_x . . . . . . . . . . . . . . . . . . . . . . . 41		4.6.1. slice_x . . . . . . . . . . . . . . . . . . . . . . . 42
	4.6.2. slice_y . . . . . . . . . . . . . . . . . . . . . . . 41		4.6.2. slice_y . . . . . . . . . . . . . . . . . . . . . . . 42
	4.6.3. slice_width . . . . . . . . . . . . . . . . . . . . . 41		4.6.3. slice_width . . . . . . . . . . . . . . . . . . . . . 42
	4.6.4. slice_height . . . . . . . . . . . . . . . . . . . . 41		4.6.4. slice_height . . . . . . . . . . . . . . . . . . . . 42
	4.6.5. quant_table_set_index_count . . . . . . . . . . . . . 41		4.6.5. quant_table_set_index_count . . . . . . . . . . . . . 42
	4.6.6. quant_table_set_index . . . . . . . . . . . . . . . . 42		4.6.6. quant_table_set_index . . . . . . . . . . . . . . . . 43
	4.6.7. picture_structure . . . . . . . . . . . . . . . . . . 42		4.6.7. picture_structure . . . . . . . . . . . . . . . . . . 43
	4.6.8. sar_num . . . . . . . . . . . . . . . . . . . . . . . 42		4.6.8. sar_num . . . . . . . . . . . . . . . . . . . . . . . 43
	4.6.9. sar_den . . . . . . . . . . . . . . . . . . . . . . . 43		4.6.9. sar_den . . . . . . . . . . . . . . . . . . . . . . . 44
	4.7. Slice Content . . . . . . . . . . . . . . . . . . . . . . 43		4.7. Slice Content . . . . . . . . . . . . . . . . . . . . . . 44
	4.7.1. primary_color_count . . . . . . . . . . . . . . . . . 43		4.7.1. primary_color_count . . . . . . . . . . . . . . . . . 44
	4.7.2. plane_pixel_height . . . . . . . . . . . . . . . . . 43		4.7.2. plane_pixel_height . . . . . . . . . . . . . . . . . 44
	4.7.3. slice_pixel_height . . . . . . . . . . . . . . . . . 44		4.7.3. slice_pixel_height . . . . . . . . . . . . . . . . . 45
	4.7.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 44		4.7.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 45
	4.8. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 44		4.8. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 45
	4.8.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 44		4.8.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 45
	4.8.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 45		4.8.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 46
	4.8.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 45		4.8.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 46
	4.8.4. sample_difference . . . . . . . . . . . . . . . . . . 45		4.8.4. sample_difference . . . . . . . . . . . . . . . . . . 46
	4.9. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 45		4.9. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 46
	4.9.1. slice_size . . . . . . . . . . . . . . . . . . . . . 45		4.9.1. slice_size . . . . . . . . . . . . . . . . . . . . . 47
	4.9.2. error_status . . . . . . . . . . . . . . . . . . . . 46		4.9.2. error_status . . . . . . . . . . . . . . . . . . . . 47
	4.9.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 46		4.9.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 47
	5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 46		5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 47
	6. Security Considerations . . . . . . . . . . . . . . . . . . . 47		6. Security Considerations . . . . . . . . . . . . . . . . . . . 48
	7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 48		7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 49
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 49		8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 50
	9. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 49		9. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 50
	10. Normative References . . . . . . . . . . . . . . . . . . . . 49		10. Normative References . . . . . . . . . . . . . . . . . . . . 50
	11. Informative References . . . . . . . . . . . . . . . . . . . 50		11. Informative References . . . . . . . . . . . . . . . . . . . 51
	Appendix A. Multi-theaded decoder implementation suggestions . . 52		Appendix A. Multi-theaded decoder implementation suggestions . . 53
	Appendix B. Future handling of some streams created by non		Appendix B. Future handling of some streams created by non
	conforming encoders . . . . . . . . . . . . . . . . . . . 52		conforming encoders . . . . . . . . . . . . . . . . . . . 53
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 52		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 53
	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
	skipping to change at page 5, line 20 ¶		skipping to change at page 5, line 20 ¶
	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 45 ¶		skipping to change at page 5, line 45 ¶
	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.
	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 49 ¶		skipping to change at page 10, line 19 ¶
	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 38 ¶
	[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 44 ¶		skipping to change at page 12, line 19 ¶
	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 3		Figure 4
	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 24 ¶
	[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 47 ¶
	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 8		Figure 9
	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 12
	Figure 11
	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 18, line 20 ¶
	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 48 ¶
	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
	3.8.1.5. default_state_transition		Figure 18
			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,
	skipping to change at page 19, line 47 ¶		skipping to change at page 20, line 43 ¶
	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 21, 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 22, 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 23, 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 27, 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 29, 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 30, 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 32, 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.
	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 32, line 15 ¶		skipping to change at page 33, line 15 ¶
	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 32, line 42 ¶		skipping to change at page 33, line 42 ¶
	Table 8		Table 8
	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 9		Table 9
	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 10		Table 10
	* 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 33, line 40 ¶		skipping to change at page 34, line 40 ¶
	"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 11		Table 11
	4.2.11. num_h_slices		4.2.11. num_h_slices
	skipping to change at page 34, line 35 ¶		skipping to change at page 35, line 35 ¶
	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 12		Table 12
	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 13		Table 13
	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 14		Table 14
	skipping to change at page 39, line 5 ¶		skipping to change at page 40, line 5 ¶
	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 5 ¶		skipping to change at page 43, line 5 ¶
	"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 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 44, 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 46, 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 49, 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
	[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
	Denial-of-Service Considerations", RFC 4732,
	DOI 10.17487/RFC4732, December 2006,
	<https://www.rfc-editor.org/info/rfc4732>.
	[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>.
	[RFC4855] Casner, S., "Media Type Registration of RTP Payload		[ISO.9899.2018]
	Formats", RFC 4855, DOI 10.17487/RFC4855, February 2007,		International Organization for Standardization,
	<https://www.rfc-editor.org/info/rfc4855>.		"Programming languages - C", 2018.
	[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC		[RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the
	2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,		Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716,
	May 2017, <https://www.rfc-editor.org/info/rfc8174>.		September 2012, <https://www.rfc-editor.org/info/rfc6716>.
	[ISO.9899.1990]		[ISO.9899.1990]
	International Organization for Standardization,		International Organization for Standardization,
	"Programming languages - C", 1990.		"Programming languages - C", 1990.
	[ISO.9899.2018]		[ISO.15444-1.2016]
	International Organization for Standardization,		International Organization for Standardization,
	"Programming languages - C", 2018.		"Information technology -- JPEG 2000 image coding system:
			Core coding system", October 2016.
			[Matroska] IETF, "Matroska", 2019, <https://datatracker.ietf.org/doc/
			draft-ietf-cellar-matroska/>.
			[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
			Denial-of-Service Considerations", RFC 4732,
			DOI 10.17487/RFC4732, December 2006,
			<https://www.rfc-editor.org/info/rfc4732>.
	[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>.
	[Matroska] IETF, "Matroska", 2019, <https://datatracker.ietf.org/doc/		[RFC4855] Casner, S., "Media Type Registration of RTP Payload
	draft-ietf-cellar-matroska/>.		Formats", RFC 4855, DOI 10.17487/RFC4855, February 2007,
			<https://www.rfc-editor.org/info/rfc4855>.
	[ISO.15444-1.2016]
	International Organization for Standardization,
	"Information technology -- JPEG 2000 image coding system:
	Core coding system", October 2016.
	[RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the		[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
	Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716,		2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
	September 2012, <https://www.rfc-editor.org/info/rfc6716>.		May 2017, <https://www.rfc-editor.org/info/rfc8174>.
	11. Informative References		11. Informative References
	[REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the		[FFV1_V3] Niedermayer, M., "Commit to mark FFV1 version 3 as non-
	FFV1 codec in FFmpeg", undated, <https://ffmpeg.org>.		experimental", August 2013, <https://git.videolan.org/?p=f
			fmpeg.git;a=commit;h=abe76b851c05eea8743f6c899cbe5f7409b0f
	[range-coding]		301>.
	Nigel, G. and N. Martin, "Range encoding: an algorithm for
	removing redundancy from a digitised message.", July 1979.
	[NUT] Niedermayer, M., "NUT Open Container Format", December
	2013, <https://ffmpeg.org/~michael/nut.txt>.
	[VALGRIND] Valgrind Developers, "Valgrind website", undated,
	<https://valgrind.org/>.
	[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>.
			[range-coding]
			Nigel, G. and N. Martin, "Range encoding: an algorithm for
			removing redundancy from a digitised message.", July 1979.
	[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>.
	[HuffYUV] Rudiak-Gould, B., "HuffYUV", December 2003,
	<https://web.archive.org/web/20040402121343/
	http://cultact-server.novi.dk/kpo/huffyuv/huffyuv.html>.
	[FFV1_V0] Niedermayer, M., "Commit to mark FFV1 version 0 as non-		[FFV1_V0] Niedermayer, M., "Commit to mark FFV1 version 0 as non-
	experimental", April 2006, <https://git.videolan.org/?p=ff		experimental", April 2006, <https://git.videolan.org/?p=ff
	mpeg.git;a=commit;h=b548f2b91b701e1235608ac882ea6df915167c		mpeg.git;a=commit;h=b548f2b91b701e1235608ac882ea6df915167c
	7e>.		7e>.
	[ISO.14496-10.2014]		[YCbCr] Wikipedia, "YCbCr", undated,
	International Organization for Standardization,		<https://en.wikipedia.org/w/index.php?title=YCbCr>.
	"Information technology -- Coding of audio-visual objects
	-- Part 10: Advanced Video Coding", September 2014.		[HuffYUV] Rudiak-Gould, B., "HuffYUV", December 2003,
			<https://web.archive.org/web/20040402121343/
			http://cultact-server.novi.dk/kpo/huffyuv/huffyuv.html>.
			[REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the
			FFV1 codec in FFmpeg", undated, <https://ffmpeg.org>.
	[FFV1_V1] Niedermayer, M., "Commit to release FFV1 version 1", April		[FFV1_V1] Niedermayer, M., "Commit to release FFV1 version 1", April
	2009, <https://git.videolan.org/?p=ffmpeg.git;a=commit;h=6		2009, <https://git.videolan.org/?p=ffmpeg.git;a=commit;h=6
	8f8d33becbd73b4d0aa277f472a6e8e72ea6849>.		8f8d33becbd73b4d0aa277f472a6e8e72ea6849>.
	[YCbCr] Wikipedia, "YCbCr", undated,		[VALGRIND] Valgrind Developers, "Valgrind website", undated,
	<https://en.wikipedia.org/w/index.php?title=YCbCr>.		<https://valgrind.org/>.
	[ISO.14495-1.1999]		[ISO.14496-10.2014]
	International Organization for Standardization,		International Organization for Standardization,
	"Information technology -- Lossless and near-lossless		"Information technology -- Coding of audio-visual objects
	compression of continuous-tone still images: Baseline",		-- Part 10: Advanced Video Coding", September 2014.
	December 1999.
	[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>.
	[FFV1_V3] Niedermayer, M., "Commit to mark FFV1 version 3 as non-		[ISO.14495-1.1999]
	experimental", August 2013, <https://git.videolan.org/?p=f		International Organization for Standardization,
	fmpeg.git;a=commit;h=abe76b851c05eea8743f6c899cbe5f7409b0f		"Information technology -- Lossless and near-lossless
	301>.		compression of continuous-tone still images: Baseline",
			December 1999.
	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
End of changes. 83 change blocks.
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