draft-ietf-cellar-ffv1-03.txt   draft-ietf-cellar-ffv1-04.txt 
cellar M. Niedermayer cellar M. Niedermayer
Internet-Draft Internet-Draft
Intended status: Informational D. Rice Intended status: Informational D. Rice
Expires: December 2, 2018 Expires: January 28, 2019
J. Martinez J. Martinez
May 31, 2018 July 27, 2018
FFV1 Video Coding Format Version 0, 1, and 3 FFV1 Video Coding Format Version 0, 1, and 3
draft-ietf-cellar-ffv1-03 draft-ietf-cellar-ffv1-04
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
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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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 December 2, 2018. This Internet-Draft will expire on January 28, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 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 Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
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. Arithmetic operators . . . . . . . . . . . . . . . . 5 2.2.1. Pseudo-code . . . . . . . . . . . . . . . . . . . . . 5
2.2.2. Assignment operators . . . . . . . . . . . . . . . . 6 2.2.2. Arithmetic Operators . . . . . . . . . . . . . . . . 6
2.2.3. Comparison operators . . . . . . . . . . . . . . . . 6 2.2.3. Assignment Operators . . . . . . . . . . . . . . . . 6
2.2.4. Mathematical functions . . . . . . . . . . . . . . . 7 2.2.4. Comparison Operators . . . . . . . . . . . . . . . . 6
2.2.5. Order of operation precedence . . . . . . . . . . . . 7 2.2.5. Mathematical Functions . . . . . . . . . . . . . . . 7
2.2.6. Pseudo-code . . . . . . . . . . . . . . . . . . . . . 8 2.2.6. Order of Operation Precedence . . . . . . . . . . . . 7
2.2.7. Range . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.7. Range . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2.8. NumBytes . . . . . . . . . . . . . . . . . . . . . . 8 2.2.8. NumBytes . . . . . . . . . . . . . . . . . . . . . . 8
2.2.9. Bitstream functions . . . . . . . . . . . . . . . . . 8 2.2.9. Bitstream Functions . . . . . . . . . . . . . . . . . 8
3. General Description . . . . . . . . . . . . . . . . . . . . . 8 3. General Description . . . . . . . . . . . . . . . . . . . . . 9
3.1. Border . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1. Border . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2. Samples . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2. Samples . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3. Median predictor . . . . . . . . . . . . . . . . . . . . 10 3.3. Median Predictor . . . . . . . . . . . . . . . . . . . . 10
3.4. Context . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.4. Context . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.5. Quantization Table Sets . . . . . . . . . . . . . . . . . 11 3.5. Quantization Table Sets . . . . . . . . . . . . . . . . . 11
3.6. Quantization Table Set indexes . . . . . . . . . . . . . 11 3.6. Quantization Table Set Indexes . . . . . . . . . . . . . 11
3.7. Color spaces . . . . . . . . . . . . . . . . . . . . . . 12 3.7. Color spaces . . . . . . . . . . . . . . . . . . . . . . 12
3.7.1. YCbCr . . . . . . . . . . . . . . . . . . . . . . . . 12 3.7.1. YCbCr . . . . . . . . . . . . . . . . . . . . . . . . 12
3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.7.2. RGB . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.8. Coding of the Sample Difference . . . . . . . . . . . . . 14 3.8. Coding of the Sample Difference . . . . . . . . . . . . . 14
3.8.1. Range coding mode . . . . . . . . . . . . . . . . . . 14 3.8.1. Range Coding Mode . . . . . . . . . . . . . . . . . . 14
3.8.2. Golomb Rice mode . . . . . . . . . . . . . . . . . . 17 3.8.2. Golomb Rice Mode . . . . . . . . . . . . . . . . . . 17
4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4. Bitstream . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.1. Configuration Record . . . . . . . . . . . . . . . . . . 20 4.1. Parameters . . . . . . . . . . . . . . . . . . . . . . . 20
4.1.1. reserved_for_future_use . . . . . . . . . . . . . . . 21 4.1.1. version . . . . . . . . . . . . . . . . . . . . . . . 21
4.1.2. configuration_record_crc_parity . . . . . . . . . . . 21 4.1.2. micro_version . . . . . . . . . . . . . . . . . . . . 22
4.1.3. Mapping FFV1 into Containers . . . . . . . . . . . . 21 4.1.3. coder_type . . . . . . . . . . . . . . . . . . . . . 22
4.2. Frame . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.1.4. state_transition_delta . . . . . . . . . . . . . . . 23
4.3. Slice . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.1.5. colorspace_type . . . . . . . . . . . . . . . . . . . 23
4.4. Slice Header . . . . . . . . . . . . . . . . . . . . . . 23 4.1.6. chroma_planes . . . . . . . . . . . . . . . . . . . . 23
4.4.1. slice_x . . . . . . . . . . . . . . . . . . . . . . . 23 4.1.7. bits_per_raw_sample . . . . . . . . . . . . . . . . . 23
4.4.2. slice_y . . . . . . . . . . . . . . . . . . . . . . . 23 4.1.8. log2_h_chroma_subsample . . . . . . . . . . . . . . . 24
4.4.3. slice_width . . . . . . . . . . . . . . . . . . . . . 24 4.1.9. log2_v_chroma_subsample . . . . . . . . . . . . . . . 24
4.4.4. slice_height . . . . . . . . . . . . . . . . . . . . 24 4.1.10. alpha_plane . . . . . . . . . . . . . . . . . . . . . 24
4.4.5. quant_table_set_index_count . . . . . . . . . . . . . 24 4.1.11. num_h_slices . . . . . . . . . . . . . . . . . . . . 24
4.4.6. quant_table_set_index . . . . . . . . . . . . . . . . 24 4.1.12. num_v_slices . . . . . . . . . . . . . . . . . . . . 24
4.4.7. picture_structure . . . . . . . . . . . . . . . . . . 24 4.1.13. quant_table_set_count . . . . . . . . . . . . . . . . 25
4.4.8. sar_num . . . . . . . . . . . . . . . . . . . . . . . 24 4.1.14. states_coded . . . . . . . . . . . . . . . . . . . . 25
4.4.9. sar_den . . . . . . . . . . . . . . . . . . . . . . . 25 4.1.15. initial_state_delta . . . . . . . . . . . . . . . . . 25
4.1.16. ec . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.5. Slice Content . . . . . . . . . . . . . . . . . . . . . . 25 4.1.17. intra . . . . . . . . . . . . . . . . . . . . . . . . 25
4.5.1. primary_color_count . . . . . . . . . . . . . . . . . 25 4.2. Configuration Record . . . . . . . . . . . . . . . . . . 26
4.5.2. plane_pixel_height . . . . . . . . . . . . . . . . . 25 4.2.1. reserved_for_future_use . . . . . . . . . . . . . . . 26
4.5.3. slice_pixel_height . . . . . . . . . . . . . . . . . 25 4.2.2. configuration_record_crc_parity . . . . . . . . . . . 26
4.5.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 25 4.2.3. Mapping FFV1 into Containers . . . . . . . . . . . . 27
4.6. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4.3. Frame . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.6.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 26 4.4. Slice . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.6.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 26 4.5. Slice Header . . . . . . . . . . . . . . . . . . . . . . 29
4.6.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 26 4.5.1. slice_x . . . . . . . . . . . . . . . . . . . . . . . 30
4.6.4. sample_difference . . . . . . . . . . . . . . . . . . 26 4.5.2. slice_y . . . . . . . . . . . . . . . . . . . . . . . 30
4.7. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 26 4.5.3. slice_width . . . . . . . . . . . . . . . . . . . . . 30
4.7.1. slice_size . . . . . . . . . . . . . . . . . . . . . 27 4.5.4. slice_height . . . . . . . . . . . . . . . . . . . . 30
4.7.2. error_status . . . . . . . . . . . . . . . . . . . . 27 4.5.5. quant_table_set_index_count . . . . . . . . . . . . . 30
4.7.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 27 4.5.6. quant_table_set_index . . . . . . . . . . . . . . . . 30
4.8. Parameters . . . . . . . . . . . . . . . . . . . . . . . 27 4.5.7. picture_structure . . . . . . . . . . . . . . . . . . 31
4.8.1. version . . . . . . . . . . . . . . . . . . . . . . . 28 4.5.8. sar_num . . . . . . . . . . . . . . . . . . . . . . . 31
4.8.2. micro_version . . . . . . . . . . . . . . . . . . . . 29 4.5.9. sar_den . . . . . . . . . . . . . . . . . . . . . . . 31
4.8.3. coder_type . . . . . . . . . . . . . . . . . . . . . 29 4.6. Slice Content . . . . . . . . . . . . . . . . . . . . . . 31
4.8.4. state_transition_delta . . . . . . . . . . . . . . . 30 4.6.1. primary_color_count . . . . . . . . . . . . . . . . . 32
4.8.5. colorspace_type . . . . . . . . . . . . . . . . . . . 30 4.6.2. plane_pixel_height . . . . . . . . . . . . . . . . . 32
4.8.6. chroma_planes . . . . . . . . . . . . . . . . . . . . 30 4.6.3. slice_pixel_height . . . . . . . . . . . . . . . . . 32
4.8.7. bits_per_raw_sample . . . . . . . . . . . . . . . . . 30 4.6.4. slice_pixel_y . . . . . . . . . . . . . . . . . . . . 32
4.8.8. log2_h_chroma_subsample . . . . . . . . . . . . . . . 31 4.7. Line . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.8.9. log2_v_chroma_subsample . . . . . . . . . . . . . . . 31 4.7.1. plane_pixel_width . . . . . . . . . . . . . . . . . . 32
4.8.10. alpha_plane . . . . . . . . . . . . . . . . . . . . . 31 4.7.2. slice_pixel_width . . . . . . . . . . . . . . . . . . 33
4.8.11. num_h_slices . . . . . . . . . . . . . . . . . . . . 31 4.7.3. slice_pixel_x . . . . . . . . . . . . . . . . . . . . 33
4.8.12. num_v_slices . . . . . . . . . . . . . . . . . . . . 31 4.7.4. sample_difference . . . . . . . . . . . . . . . . . . 33
4.8.13. quant_table_set_count . . . . . . . . . . . . . . . . 32 4.8. Slice Footer . . . . . . . . . . . . . . . . . . . . . . 33
4.8.14. states_coded . . . . . . . . . . . . . . . . . . . . 32 4.8.1. slice_size . . . . . . . . . . . . . . . . . . . . . 33
4.8.15. initial_state_delta . . . . . . . . . . . . . . . . . 32 4.8.2. error_status . . . . . . . . . . . . . . . . . . . . 33
4.8.16. ec . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.8.3. slice_crc_parity . . . . . . . . . . . . . . . . . . 34
4.8.17. intra . . . . . . . . . . . . . . . . . . . . . . . . 32 4.9. Quantization Table Set . . . . . . . . . . . . . . . . . 34
4.9. Quantization Table Set . . . . . . . . . . . . . . . . . 33 4.9.1. quant_tables . . . . . . . . . . . . . . . . . . . . 35
4.9.1. quant_tables . . . . . . . . . . . . . . . . . . . . 34 4.9.2. context_count . . . . . . . . . . . . . . . . . . . . 35
4.9.2. context_count . . . . . . . . . . . . . . . . . . . . 34 5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 35
5. Restrictions . . . . . . . . . . . . . . . . . . . . . . . . 34 6. Security Considerations . . . . . . . . . . . . . . . . . . . 36
6. Security Considerations . . . . . . . . . . . . . . . . . . . 35 7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 36
7. Media Type Definition . . . . . . . . . . . . . . . . . . . . 35 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37 9. Appendixes . . . . . . . . . . . . . . . . . . . . . . . . . 38
9. Appendixes . . . . . . . . . . . . . . . . . . . . . . . . . 37 9.1. Decoder implementation suggestions . . . . . . . . . . . 38
9.1. Decoder implementation suggestions . . . . . . . . . . . 37 9.1.1. Multi-threading Support and Independence of Slices . 38
9.1.1. Multi-threading support and independence of slices . 37 10. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 39
10. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 38 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 39
11. ToDo . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 11.1. Normative References . . . . . . . . . . . . . . . . . . 39
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 38 11.2. Informative References . . . . . . . . . . . . . . . . . 40
12.1. Normative References . . . . . . . . . . . . . . . . . . 38 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41
12.2. Informative References . . . . . . . . . . . . . . . . . 39
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40
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
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[YCbCr]. [YCbCr].
2. Notation and Conventions 2. Notation and Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
2.1. Definitions 2.1. Definitions
"Frame": An encoded representation of a complete static image.
"Slice": A spatial sub-section of a "Frame" that is encoded
separately from an other region of the same frame.
"Container": Format that encapsulates "Frames" and (when required) a "Container": Format that encapsulates "Frames" and (when required) a
"Configuration Record" into a bitstream. "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, Alpha, Red, Green, and Blue. Luma, Blue Chrominance, Red Chrominance, Alpha, Red, Green, and Blue.
"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 1 or more samples. "Frame". It is composed of 1 or more samples.
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and the chrominance of the Pixel (Cb and Cr). YCbCr word is used for and the chrominance of the Pixel (Cb and Cr). YCbCr word is used for
historical reasons and currently references any color space relying historical reasons and currently references any color space relying
on 1 luma sample and 2 chrominance samples e.g. YCbCr, YCgCo or on 1 luma sample and 2 chrominance samples e.g. YCbCr, YCgCo or
ICtCp. Exact meaning of the three numeric values is unspecified. ICtCp. Exact meaning of the three numeric values is 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
The FFV1 bitstream is described in this document using pseudo-code.
Note that the pseudo-code is used for clarity in order to illustrate
the structure of FFV1 and not intended to specify any particular
implementation. The pseudo-code used is based upon the C programming
language [ISO.9899.1990] and uses its "if/else", "while" and "for"
functions as well as functions defined within this document.
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.9899.1990]. in the C programming language [ISO.9899.1990].
2.2.1. Arithmetic operators
"a + b" means a plus b. "a + b" means a plus b.
"a - b" means a minus b. "a - b" means a minus b.
"-a" means negation of a. "-a" means negation of a.
"a * b" means a multiplied by b. "a * b" means a multiplied by b.
"a / b" means a divided by b. "a / b" means a divided by b.
"a & b" means bit-wise "and" of a and b. "a & b" means bit-wise "and" of a and b.
"a | b" means bit-wise "or" of a and b. "a | b" means bit-wise "or" of a and b.
"a >> b" means arithmetic right shift of two's complement integer "a >> b" means arithmetic right shift of two's complement integer
representation of a by b binary digits. representation of a by b binary digits.
"a << b" means arithmetic left shift of two's complement integer "a << b" means arithmetic left shift of two's complement integer
representation of a by b binary digits. representation of a by b binary digits.
2.2.2. Assignment operators 2.2.3. Assignment Operators
"a = b" means a is assigned b. "a = b" means a is assigned b.
"a++" is equivalent to a is assigned a + 1. "a++" is equivalent to a is assigned a + 1.
"a--" is equivalent to a is assigned a - 1. "a--" is equivalent to a is assigned a - 1.
"a += b" is equivalent to a is assigned a + b. "a += b" is equivalent to a is assigned a + b.
"a -= b" is equivalent to a is assigned a - b. "a -= b" is equivalent to a is assigned a - b.
"a *= b" is equivalent to a is assigned a * b. "a *= b" is equivalent to a is assigned a * b.
2.2.3. Comparison operators 2.2.4. Comparison Operators
"a > b" means a is greater than b. "a > b" means a is greater than b.
"a >= b" means a is greater than or equal to b. "a >= b" means a is greater than or equal to b.
"a < b" means a is less than b. "a < b" means a is less than b.
"a <= b" means a is less than or equal b. "a <= b" means a is less than or equal b.
"a == b" means a is equal to b. "a == b" means a is equal to b.
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"a != b" means a is not equal to b. "a != b" means a is not equal to b.
"a && b" means Boolean logical "and" of a and b. "a && b" means Boolean logical "and" of a and b.
"a || b" means Boolean logical "or" of a and b. "a || b" means Boolean logical "or" of a and b.
"!a" means Boolean logical "not" of a. "!a" means Boolean logical "not" of a.
"a ? b : c" if a is true, then b, otherwise c. "a ? b : c" if a is true, then b, otherwise c.
2.2.4. Mathematical functions 2.2.5. Mathematical Functions
floor(a) the largest integer less than or equal to a floor(a) the largest integer less than or equal to a
ceil(a) the largest integer less than or equal to a ceil(a) the smallest integer greater than or equal to a
sign(a) extracts the sign of a number, i.e. if a < 0 then -1, else if sign(a) extracts the sign of a number, i.e. if a < 0 then -1, else if
a > 0 then 1, else 0 a > 0 then 1, else 0
abs(a) the absolute value of a, i.e. abs(a) = sign(a)*a abs(a) the absolute value of a, i.e. abs(a) = sign(a)*a
log2(a) the base-two logarithm of a log2(a) the base-two logarithm of a
min(a,b) the smallest of two values a and b min(a,b) the smallest of two values a and b
max(a,b) the largest of two values a and b max(a,b) the largest of two values a and b
median(a,b,c) the numerical middle value in a data set of a, b, and median(a,b,c) the numerical middle value in a data set of a, b, and
c, i.e. a+b+c-min(a,b,c)-max(a,b,c) c, i.e. a+b+c-min(a,b,c)-max(a,b,c)
a_{b} the b-th value of a sequence of a a_{b} the b-th value of a sequence of a
a_{b,c} the 'b,c'-th value of a sequence of a a_{b,c} the 'b,c'-th value of a sequence of a
2.2.5. Order of operation precedence 2.2.6. Order of Operation Precedence
When order of precedence is not indicated explicitly by use of When order of precedence is not indicated explicitly by use of
parentheses, operations are evaluated in the following order (from parentheses, operations are evaluated in the following order (from
top to bottom, operations of same precedence being evaluated from top to bottom, operations of same precedence being evaluated from
left to right). This order of operations is based on the order of left to right). This order of operations is based on the order of
operations used in Standard C. operations used in Standard C.
a++, a-- a++, a--
!a, -a !a, -a
a * b, a / b, a % b a * b, a / b, a % b
skipping to change at page 8, line 5 skipping to change at page 8, line 19
a << b, a >> b a << b, a >> b
a < b, a <= b, a > b, a >= b a < b, a <= b, a > b, a >= b
a == b, a != b a == b, a != b
a & b a & b
a | b a | b
a && b a && b
a || b a || b
a ? b : c a ? b : c
a = b, a += b, a -= b, a *= b a = b, a += b, a -= b, a *= b
2.2.6. 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
the structure of FFV1 and not intended to specify any particular
implementation. The pseudo-code used is based upon the C programming
language [ISO.9899.1990] as uses its "if/else", "while" and "for"
functions as well as functions defined within this document.
2.2.7. Range 2.2.7. Range
"a...b" means any value starting from a to b, inclusive. "a...b" means any value starting from a to b, inclusive.
2.2.8. NumBytes 2.2.8. NumBytes
"NumBytes" is a non-negative integer that expresses the size in 8-bit "NumBytes" is a non-negative integer that expresses the size in 8-bit
octets of particular FFV1 "Configuration Record" or "Frame". FFV1 octets of particular FFV1 "Configuration Record" or "Frame". FFV1
relies on its "Container" to store the "NumBytes" values, see relies on its "Container" to store the "NumBytes" values, see
Section 4.1.3. Section 4.2.3.
2.2.9. Bitstream functions 2.2.9. Bitstream Functions
2.2.9.1. remaining_bits_in_bitstream 2.2.9.1. remaining_bits_in_bitstream
"remaining_bits_in_bitstream( )" means the count of remaining bits "remaining_bits_in_bitstream( )" means the count of remaining bits
after the pointer in that "Configuration Record" or "Frame". It is after the pointer in that "Configuration Record" or "Frame". It is
computed from the "NumBytes" value multiplied by 8 minus the count of computed from the "NumBytes" value multiplied by 8 minus the count of
bits of that "Configuration Record" or "Frame" already read by the bits of that "Configuration Record" or "Frame" already read by the
bitstream parser. bitstream parser.
2.2.9.2. byte_aligned 2.2.9.2. byte_aligned
skipping to change at page 10, line 8 skipping to change at page 10, line 16
| | | T | | | | | T | |
+---+---+---+---+ +---+---+---+---+
| |tl | t |tr | | |tl | t |tr |
+---+---+---+---+ +---+---+---+---+
| L | l | X | | | L | l | X | |
+---+---+---+---+ +---+---+---+---+
"X" is the current processed Sample. The identifiers are made of the "X" is the current processed Sample. The identifiers are made of the
first letters of the words Top, Left and Right. first letters 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:
"median(l, t, l + t - tl)". "median(l, t, l + t - tl)".
Note, this prediction template is also used in [ISO.14495-1.1999] and Note, this prediction template is also used in [ISO.14495-1.1999] and
[HuffYUV]. [HuffYUV].
skipping to change at page 10, line 40 skipping to change at page 10, line 48
Background: a two's complement signed 16-bit signed integer was used Background: a two's complement signed 16-bit signed integer was used
for storing sample values in all known implementations of FFV1 for storing sample values in all known implementations of FFV1
bitstream. So in some circumstances, the most significant bit was bitstream. So in some circumstances, the most significant bit was
wrongly interpreted (used as a sign bit instead of the 16th bit of an wrongly interpreted (used as a sign bit instead of the 16th bit of an
unsigned integer). Note that when the issue is discovered, the only unsigned integer). Note that when the issue is discovered, the only
configuration of all known implementations being impacted is 16-bit configuration of all known implementations being impacted is 16-bit
YCbCr with no Pixel transformation with Range Coder coder, as other YCbCr with no Pixel transformation with Range Coder coder, as other
potentially impacted configurations (e.g. 15/16-bit JPEG2000-RCT with potentially impacted configurations (e.g. 15/16-bit JPEG2000-RCT with
Range Coder coder, or 16-bit content with Golomb Rice coder) were Range Coder coder, or 16-bit content with Golomb Rice coder) were
implemented nowhere. In the meanwhile, 16-bit JPEG2000-RCT with implemented nowhere [ISO.15444-1.2016]. In the meanwhile, 16-bit
Range Coder coder was implemented without this issue in one JPEG2000-RCT with Range Coder coder was implemented without this
implementation and validated by one conformance checker. It is issue in one implementation and validated by one conformance checker.
expected (to be confirmed) to remove this exception for the media It is expected (to be confirmed) to remove this exception for the
predictor in the next version of the FFV1 bitstream. media predictor in the next version of the FFV1 bitstream.
3.4. Context 3.4. Context
Relative to any sample "X", the Quantized Sample Differences "L-l", Relative to any sample "X", the Quantized Sample Differences "L-l",
"l-tl", "tl-t", "T-t", and "t-tr" are used as context: "l-tl", "tl-t", "T-t", and "t-tr" are used as context:
context = Q_{0}[l - tl] + context = Q_{0}[l - tl] +
Q_{1}[tl - t] + Q_{1}[tl - t] +
Q_{2}[t - tr] + Q_{2}[t - tr] +
Q_{3}[L - l] + Q_{3}[L - l] +
skipping to change at page 11, line 32 skipping to change at page 11, line 37
quantization steps and their distribution are stored in the FFV1 quantization steps and their distribution are stored in the FFV1
bitstream; each Quantization Table has exactly 256 entries, and the 8 bitstream; each Quantization Table has exactly 256 entries, and the 8
least significant bits of the Quantized Sample Difference are used as least significant bits of the Quantized Sample Difference are used as
index: index:
Q_{j}[k] = quant_tables[i][j][k&255] Q_{j}[k] = quant_tables[i][j][k&255]
In this formula, "i" is the Quantization Table Set index, "j" is the In this formula, "i" is the Quantization Table Set index, "j" is the
Quantized Table index, "k" the Quantized Sample Difference. Quantized Table index, "k" the Quantized Sample Difference.
3.6. Quantization Table Set indexes 3.6. Quantization Table Set Indexes
For each plane of each slice, a Quantization Table Set is selected For each plane of each slice, a Quantization Table Set is selected
from an index: from an index:
o For Y plane, "quant_table_set_index [ 0 ]" index is used o For Y plane, "quant_table_set_index [ 0 ]" index is used
o For Cb and Cr planes, "quant_table_set_index [ 1 ]" index is used o For Cb and Cr planes, "quant_table_set_index [ 1 ]" index is used
o For Alpha plane, "quant_table_set_index [ (version <= 3 || o For Alpha plane, "quant_table_set_index [ (version <= 3 ||
chroma_planes) ? 2 : 1 ]" index is used chroma_planes) ? 2 : 1 ]" index is used
skipping to change at page 12, line 33 skipping to change at page 12, line 33
o Y, Cb, Cr, Alpha o Y, Cb, Cr, Alpha
The Y plane MUST be coded first. If the Cb and Cr planes are used The Y plane MUST be coded first. If the Cb and Cr planes are used
then they MUST be coded after the Y plane. If an Alpha then they MUST be coded after the Y plane. If an Alpha
(transparency) plane is used, then it MUST be coded last. (transparency) plane is used, then it MUST be coded last.
3.7.2. RGB 3.7.2. RGB
JPEG2000-RCT is a Reversible Color Transform that codes RGB (red, JPEG2000-RCT is a Reversible Color Transform that codes RGB (red,
green, blue) planes losslessly in a modified YCbCr color space. green, blue) planes losslessly in a modified YCbCr color space
Reversible Pixel transformations between YCbCr and RGB use the [ISO.15444-1.2016]. Reversible Pixel transformations between YCbCr
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
skipping to change at page 13, line 26 skipping to change at page 13, line 26
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 alpha_plane is 0, GBR planes were used as BGR planes inclusive and alpha_plane is 0, GBR planes were used as BGR planes
during both encoding and decoding. In the meanwhile, 16-bit 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.
[ISO.15444-1.2016]
When FFV1 uses the JPEG2000-RCT, the horizontal lines are interleaved When FFV1 uses the JPEG2000-RCT, the horizontal lines are interleaved
to improve caching efficiency since it is most likely that the RCT to improve caching efficiency since it is most likely that the RCT
will immediately be converted to RGB during decoding. The will immediately be converted to RGB during decoding. The
interleaved coding order is also Y, then Cb, then Cr, and then if interleaved coding order is also Y, then Cb, then Cr, and then if
used Alpha. used Alpha.
As an example, a "Frame" that is two pixels wide and two pixels high, As an example, a "Frame" that is two pixels wide and two pixels high,
could be comprised of the following structure: could be comprised of the following structure:
+------------------------+------------------------+ +------------------------+------------------------+
skipping to change at page 14, line 17 skipping to change at page 14, line 17
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 RCT), only the n (or or Range coding (or n+2 bits, in the case of RCT), only the n (or
n+1) least significant bits are used, since this is sufficient to n+1) least significant bits are used, since this is sufficient to
recover the original sample. In the equation below, the term "bits" recover the original sample. In the equation below, the term "bits"
represents bits_per_raw_sample+1 for RCT or bits_per_raw_sample represents bits_per_raw_sample+1 for RCT or bits_per_raw_sample
otherwise: otherwise:
coder_input = coder_input =
[(sample_difference + 2^(bits-1)) & (2^bits - 1)] - 2^(bits-1) [(sample_difference + 2^(bits-1)) & (2^bits - 1)] - 2^(bits-1)
3.8.1. Range coding mode 3.8.1. Range Coding Mode
Early experimental versions of FFV1 used the CABAC Arithmetic coder Early experimental versions of FFV1 used the CABAC Arithmetic coder
from H.264 as defined in [ISO.14496-10.2014] but due to the uncertain from H.264 as defined in [ISO.14496-10.2014] but due to the uncertain
patent/royalty situation, as well as its slightly worse performance, patent/royalty situation, as well as its slightly worse performance,
CABAC was replaced by a Range coder based on an algorithm defined by CABAC was replaced by a Range coder based on an algorithm defined by
_G. Nigel_ and _N. Martin_ in 1979 [range-coding]. G. Nigel and N. Martin in 1979 [range-coding].
3.8.1.1. Range binary values 3.8.1.1. Range Binary Values
To encode binary digits efficiently a Range coder is used. "C_{i}" To encode binary digits efficiently a Range coder is used. "C_{i}"
is the i-th Context. "B_{i}" is the i-th byte of the bytestream. is the i-th Context. "B_{i}" is the i-th byte of the bytestream.
"b_{i}" is the i-th Range coded binary value, "S_{0,i}" is the i-th "b_{i}" is the i-th Range coded binary value, "S_{0,i}" is the i-th
initial state, which is 128. The length of the bytestream encoding n initial state, which is 128. The length of the bytestream encoding n
binary symbols is "j_{n}" bytes. binary symbols is "j_{n}" bytes.
r_{i} = floor( ( R_{i} * S_{i,C_{i}} ) / 2^8 ) r_{i} = floor( ( R_{i} * S_{i,C_{i}} ) / 2^8 )
S_{i+1,C_{i}} = zero_state_{S_{i,C_{i}}} XOR S_{i+1,C_{i}} = zero_state_{S_{i,C_{i}}} XOR
l_i = L_i XOR l_i = L_i XOR
t_i = R_i - r_i <== t_i = R_i - r_i <==
b_i = 0 <==> b_i = 0 <==>
L_i < R_i - r_i L_i < R_i - r_i
S_{i+1,C_{i}} = one_state_{S_{i,C_{i}}} XOR S_{i+1,C_{i}} = one_state_{S_{i,C_{i}}} XOR
l_i = L_i - R_i + r_i XOR l_i = L_i - R_i + r_i XOR
t_i = r_i <== t_i = r_i <==
b_i = 1 <==> b_i = 1 <==>
L_i >= R_i - r_i L_i >= R_i - r_i
S_{i+1,k} = S_{i,k} <== C_i != k S_{i+1,k} = S_{i,k} <== C_i != k
R_{i+1} = 2^8 * t_{i} XOR R_{i+1} = 2^8 * t_{i} XOR
L_{i+1} = 2^8 * l_{i} + B_{j_{i}} XOR L_{i+1} = 2^8 * l_{i} + B_{j_{i}} XOR
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} XOR R_{i+1} = t_{i} XOR
L_{i+1} = l_{i} XOR L_{i+1} = l_{i} XOR
j_{i+1} = j_{i} <== j_{i+1} = j_{i} <==
t_{i} >= 2^8 t_{i} >= 2^8
R_{0} = 65280 R_{0} = 65280
L_{0} = 2^8 * B_{0} + B_{1} L_{0} = 2^8 * B_{0} + B_{1}
j_{0} = 2 j_{0} = 2
3.8.1.2. Range non binary values 3.8.1.2. Range Non Binary Values
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,
skipping to change at page 16, line 5 skipping to change at page 16, line 5
| |
put_rac(c, state+1+min(i,9), 0); | put_rac(c, state+1+min(i,9), 0); |
for (i=e-1; i>=0; i--) | for (i=e-1; i>=0; i--) |
put_rac(c, state+22+min(i,9), (a>>i)&1); //22..31 | put_rac(c, state+22+min(i,9), (a>>i)&1); //22..31 |
| |
if (is_signed) | if (is_signed) |
put_rac(c, state+11 + min(e, 10), v < 0); //11..21| put_rac(c, state+11 + min(e, 10), v < 0); //11..21|
} | } |
} | } |
3.8.1.3. Initial values for the context model 3.8.1.3. Initial Values for the Context Model
At keyframes all Range coder state variables are set to their initial At keyframes all Range coder state variables are set to their initial
state. state.
3.8.1.4. State transition table 3.8.1.4. State Transition Table
one_state_{i} = one_state_{i} =
default_state_transition_{i} + state_transition_delta_{i} default_state_transition_{i} + state_transition_delta_{i}
zero_state_{i} = 256 - one_state_{256-i} zero_state_{i} = 256 - one_state_{256-i}
3.8.1.5. default_state_transition 3.8.1.5. default_state_transition
0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27,
skipping to change at page 17, line 5 skipping to change at page 17, line 5
180,181,182,183,184,185,186,187,188,189,190,190,191,192,194,194, 180,181,182,183,184,185,186,187,188,189,190,190,191,192,194,194,
195,196,197,198,199,200,201,202,202,204,205,206,207,208,209,209, 195,196,197,198,199,200,201,202,202,204,205,206,207,208,209,209,
210,211,212,213,215,215,216,217,218,219,220,220,222,223,224,225, 210,211,212,213,215,215,216,217,218,219,220,220,222,223,224,225,
226,227,227,229,229,230,231,232,234,234,235,236,237,238,239,240, 226,227,227,229,229,230,231,232,234,234,235,236,237,238,239,240,
241,242,243,244,245,246,247,248,248, 0, 0, 0, 0, 0, 0, 0, 241,242,243,244,245,246,247,248,248, 0, 0, 0, 0, 0, 0, 0,
3.8.1.6. alternative state transition table 3.8.1.6. Alternative State Transition Table
The alternative state transition table has been built using iterative The alternative state transition table has been built using iterative
minimization of frame sizes and generally performs better than the minimization of frame sizes and generally performs better than the
default. To use it, the coder_type MUST be set to 2 and the default. To use it, the coder_type MUST be set to 2 and the
difference to the default MUST be stored in the parameters. The difference to the default MUST be stored in the parameters. The
reference implementation of FFV1 in FFmpeg uses this table by default reference implementation of FFV1 in FFmpeg uses this table by default
at the time of this writing when Range coding is used. at the time of this writing when Range coding is used.
0, 10, 10, 10, 10, 16, 16, 16, 28, 16, 16, 29, 42, 49, 20, 49, 0, 10, 10, 10, 10, 16, 16, 16, 28, 16, 16, 29, 42, 49, 20, 49,
skipping to change at page 17, line 46 skipping to change at page 17, line 46
175,189,179,181,186,183,192,185,200,187,191,188,190,197,193,196, 175,189,179,181,186,183,192,185,200,187,191,188,190,197,193,196,
197,194,195,196,198,202,199,201,210,203,207,204,205,206,208,214, 197,194,195,196,198,202,199,201,210,203,207,204,205,206,208,214,
209,211,221,212,213,215,224,216,217,218,219,220,222,228,223,225, 209,211,221,212,213,215,224,216,217,218,219,220,222,228,223,225,
226,224,227,229,240,230,231,232,233,234,235,236,238,239,237,242, 226,224,227,229,240,230,231,232,233,234,235,236,238,239,237,242,
241,243,242,244,245,246,247,248,249,250,251,252,252,253,254,255, 241,243,242,244,245,246,247,248,249,250,251,252,252,253,254,255,
3.8.2. Golomb Rice mode 3.8.2. Golomb Rice Mode
This coding mode uses Golomb Rice codes. The VLC is split into 2 This coding mode uses Golomb Rice codes. The VLC is split into 2
parts, the prefix stores the most significant bits and the suffix parts, the prefix stores the most significant bits and the suffix
stores the k least significant bits or stores the whole number in the stores the k least significant bits or stores the whole number in the
ESC case. The end of the bitstream of the "Frame" is filled with ESC case. The end of the bitstream of the "Frame" is filled with
0-bits until that the bitstream contains a multiple of 8 bits. 0-bits until that the bitstream contains a multiple of 8 bits.
3.8.2.1. Prefix 3.8.2.1. Prefix
+----------------+-------+ +----------------+-------+
skipping to change at page 18, line 39 skipping to change at page 18, line 39
| 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 |
+-----+-------------------------+-------+ +-----+-------------------------+-------+
3.8.2.4. Run mode 3.8.2.4. 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.
3.8.2.5. Run length coding 3.8.2.5. Run Length Coding
The run value is encoded in 2 parts, the prefix part stores the more The run value is encoded in 2 parts, the prefix part stores the more
significant part of the run as well as adjusting the run_index that significant part of the run as well as adjusting the run_index that
determines the number of bits in the less significant part of the determines the number of bits in the less significant part of the
run. The 2nd part of the value stores the less significant part of run. The 2nd part of the value stores the less significant part of
the run as it is. The run_index is reset for each plane and slice to the run as it is. The run_index is reset for each plane and slice to
0. 0.
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
skipping to change at page 19, line 34 skipping to change at page 19, line 34
else | else |
run_count = 0; | run_count = 0; |
if (run_index) | if (run_index) |
run_index--; | run_index--; |
run_mode = 2; | run_mode = 2; |
} | } |
} | } |
The log2_run function is also used within [ISO.14495-1.1999]. The log2_run function is also used within [ISO.14495-1.1999].
3.8.2.6. Level coding 3.8.2.6. Level Coding
Level coding is identical to the normal difference coding with the Level coding is identical to the normal difference coding with the
exception that the 0 value is removed as it cannot occur: exception that the 0 value is removed as it cannot occur:
if (diff>0) diff--; if (diff>0) diff--;
encode(diff); encode(diff);
Note, this is different from JPEG-LS, which doesn't use prediction in Note, this is different from JPEG-LS, which doesn't use prediction in
run mode and uses a different encoding and context model for the last run mode and uses a different encoding and context model for the last
difference On a small set of test samples the use of prediction difference On a small set of test samples the use of prediction
skipping to change at page 20, line 32 skipping to change at page 20, line 32
initialization of the decoder: initialization of the decoder:
"frame_pixel_width" is defined as "Frame" width in pixels. "frame_pixel_width" is defined as "Frame" width in pixels.
"frame_pixel_height" is defined as "Frame" height in pixels. "frame_pixel_height" is defined as "Frame" height in pixels.
Default values at the decoder initialization phase: Default values at the decoder initialization phase:
"ConfigurationRecordIsPresent" is set to 0. "ConfigurationRecordIsPresent" is set to 0.
4.1. Configuration Record 4.1. Parameters
pseudo-code | type
--------------------------------------------------------------|-----
Parameters( ) { |
version | ur
if (version >= 3) |
micro_version | ur
coder_type | ur
if (coder_type > 1) |
for (i = 1; i < 256; i++) |
state_transition_delta[ i ] | sr
colorspace_type | ur
if (version >= 1) |
bits_per_raw_sample | ur
chroma_planes | br
log2_h_chroma_subsample | ur
log2_v_chroma_subsample | ur
alpha_plane | br
if (version >= 3) { |
num_h_slices - 1 | ur
num_v_slices - 1 | ur
quant_table_set_count | ur
} |
for( i = 0; i < quant_table_set_count; i++ ) |
QuantizationTableSet( i ) |
if (version >= 3) { |
for( i = 0; i < quant_table_set_count; i++ ) { |
states_coded | br
if (states_coded) |
for( j = 0; j < context_count[ i ]; j++ ) |
for( k = 0; k < CONTEXT_SIZE; k++ ) |
initial_state_delta[ i ][ j ][ k ] | sr
} |
ec | ur
intra | ur
} |
} |
4.1.1. version
"version" specifies the version of the FFV1 bitstream.
Each version is incompatible with others versions: decoders SHOULD
reject a file due to unknown version.
Decoders SHOULD reject a file with version <= 1 &&
ConfigurationRecordIsPresent == 1.
Decoders SHOULD reject a file with version >= 3 &&
ConfigurationRecordIsPresent == 0.
+-------+-------------------------+
| value | version |
+-------+-------------------------+
| 0 | FFV1 version 0 |
| 1 | FFV1 version 1 |
| 2 | reserved* |
| 3 | FFV1 version 3 |
| Other | reserved for future use |
+-------+-------------------------+
* Version 2 was never enabled in the encoder thus version 2 files
SHOULD NOT exist, and this document does not describe them to keep
the text simpler.
4.1.2. micro_version
"micro_version" specifies the micro-version of the FFV1 bitstream.
After a version is considered stable (a micro-version value is
assigned to be the first stable variant of a specific version), each
new micro-version after this first stable variant is compatible with
the previous micro-version: decoders SHOULD NOT reject a file due to
an unknown micro-version equal or above the micro-version considered
as stable.
Meaning of micro_version for version 3:
+-------+-------------------------+
| value | micro_version |
+-------+-------------------------+
| 0...3 | reserved* |
| 4 | first stable variant |
| Other | reserved for future use |
+-------+-------------------------+
* development versions may be incompatible with the stable variants.
4.1.3. coder_type
"coder_type" specifies the coder used.
+-------+-------------------------------------------------+
| value | coder used |
+-------+-------------------------------------------------+
| 0 | Golomb Rice |
| 1 | Range Coder with default state transition table |
| 2 | Range Coder with custom state transition table |
| Other | reserved for future use |
+-------+-------------------------------------------------+
4.1.4. state_transition_delta
"state_transition_delta" specifies the Range coder custom state
transition table.
If state_transition_delta is not present in the FFV1 bitstream, all
Range coder custom state transition table elements are assumed to be
0.
4.1.5. colorspace_type
"colorspace_type" specifies color space losslessly encoded, Pixel
transformation used by the encoder, as well as interleave method.
+-------+---------------------+------------------+------------------+
| value | color space | transformation | interleave |
| | losslessly encoded | | method |
+-------+---------------------+------------------+------------------+
| 0 | YCbCr | No Pixel | plane then line |
| | | transformation | |
| 1 | RGB | JPEG2000-RCT | line then plane |
| Other | reserved for future | reserved for | reserved for |
| | use | future use | future use |
+-------+---------------------+------------------+------------------+
Restrictions:
If "colorspace_type" is 1, then "chroma_planes" MUST be 1,
"log2_h_chroma_subsample" MUST be 0, and "log2_v_chroma_subsample"
MUST be 0.
4.1.6. chroma_planes
"chroma_planes" indicates if chroma (color) planes are present.
+-------+-------------------------------+
| value | presence |
+-------+-------------------------------+
| 0 | chroma planes are not present |
| 1 | chroma planes are present |
+-------+-------------------------------+
4.1.7. bits_per_raw_sample
"bits_per_raw_sample" indicates the number of bits for each sample.
Inferred to be 8 if not present.
+-------+---------------------------------+
| value | bits for each sample |
+-------+---------------------------------+
| 0 | reserved* |
| Other | the actual bits for each sample |
+-------+---------------------------------+
* Encoders MUST NOT store bits_per_raw_sample = 0 Decoders SHOULD
accept and interpret bits_per_raw_sample = 0 as 8.
4.1.8. log2_h_chroma_subsample
"log2_h_chroma_subsample" indicates the subsample factor, stored in
powers to which the number 2 must be raised, between luma and chroma
width ("chroma_width = 2^(-log2_h_chroma_subsample) * luma_width").
4.1.9. log2_v_chroma_subsample
"log2_v_chroma_subsample" indicates the subsample factor, stored in
powers to which the number 2 must be raised, between luma and chroma
height ("chroma_height=2^(-log2_v_chroma_subsample) * luma_height").
4.1.10. alpha_plane
"alpha_plane" indicates if a transparency plane is present.
+-------+-----------------------------------+
| value | presence |
+-------+-----------------------------------+
| 0 | transparency plane is not present |
| 1 | transparency plane is present |
+-------+-----------------------------------+
4.1.11. num_h_slices
"num_h_slices" indicates the number of horizontal elements of the
slice raster.
Inferred to be 1 if not present.
4.1.12. num_v_slices
"num_v_slices" indicates the number of vertical elements of the slice
raster.
Inferred to be 1 if not present.
4.1.13. quant_table_set_count
"quant_table_set_count" indicates the number of Quantization
Table Sets.
Inferred to be 1 if not present.
MUST NOT be 0.
4.1.14. states_coded
"states_coded" indicates if the respective Quantization Table Set has
the initial states coded.
Inferred to be 0 if not present.
+-------+-----------------------------------------------------------+
| value | initial states |
+-------+-----------------------------------------------------------+
| 0 | initial states are not present and are assumed to be all |
| | 128 |
| 1 | initial states are present |
+-------+-----------------------------------------------------------+
4.1.15. initial_state_delta
"initial_state_delta[ i ][ j ][ k ]" indicates the initial Range
coder state, it is encoded using "k" as context index and
pred = j ? initial_states[ i ][j - 1][ k ] : 128
initial_state[ i ][ j ][ k ] =
( pred + initial_state_delta[ i ][ j ][ k ] ) & 255
4.1.16. ec
"ec" indicates the error detection/correction type.
+-------+--------------------------------------------+
| value | error detection/correction type |
+-------+--------------------------------------------+
| 0 | 32-bit CRC on the global header |
| 1 | 32-bit CRC per slice and the global header |
| Other | reserved for future use |
+-------+--------------------------------------------+
4.1.17. intra
"intra" indicates the relationship between the instances of "Frame".
Inferred to be 0 if not present.
+-------+-----------------------------------------------------------+
| value | relationship |
+-------+-----------------------------------------------------------+
| 0 | Frames are independent or dependent (keyframes and non |
| | keyframes) |
| 1 | Frames are independent (keyframes only) |
| Other | reserved for future use |
+-------+-----------------------------------------------------------+
4.2. Configuration Record
In the case of a FFV1 bitstream with "version >= 3", a "Configuration In the case of a FFV1 bitstream with "version >= 3", a "Configuration
Record" is stored in the underlying "Container", at the track header Record" is stored in the underlying "Container", at the track header
level. It contains the parameters used for all instances of "Frame". level. It contains the parameters used for all instances of "Frame".
The size of the "Configuration Record", "NumBytes", is supplied by The size of the "Configuration Record", "NumBytes", is supplied by
the underlying "Container". the underlying "Container".
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
ConfigurationRecord( NumBytes ) { | ConfigurationRecord( NumBytes ) { |
ConfigurationRecordIsPresent = 1 | ConfigurationRecordIsPresent = 1 |
Parameters( ) | Parameters( ) |
while( remaining_bits_in_bitstream( NumBytes ) > 32 ) | while( remaining_bits_in_bitstream( NumBytes ) > 32 ) |
reserved_for_future_use | u(1) reserved_for_future_use | u(1)
configuration_record_crc_parity | u(32) configuration_record_crc_parity | u(32)
} | } |
4.1.1. reserved_for_future_use 4.2.1. reserved_for_future_use
"reserved_for_future_use" has semantics that are reserved for future "reserved_for_future_use" has semantics that are reserved for future
use. use.
Encoders conforming to this version of this specification SHALL NOT Encoders conforming to this version of this specification SHALL NOT
write this value. write this value.
Decoders conforming to this version of this specification SHALL Decoders conforming to this version of this specification SHALL
ignore its value. ignore its value.
4.1.2. configuration_record_crc_parity 4.2.2. configuration_record_crc_parity
"configuration_record_crc_parity" 32 bits that are chosen so that the "configuration_record_crc_parity" 32 bits that are chosen so that the
"Configuration Record" as a whole has a crc remainder of 0. "Configuration Record" as a whole has a crc remainder of 0.
This is equivalent to storing the crc remainder in the 32-bit parity. This is equivalent to storing the crc remainder in the 32-bit parity.
The CRC generator polynomial used is the standard IEEE CRC polynomial The CRC generator polynomial used is the standard IEEE CRC polynomial
(0x104C11DB7) with initial value 0. (0x104C11DB7) with initial value 0.
4.1.3. Mapping FFV1 into Containers 4.2.3. Mapping FFV1 into Containers
This "Configuration Record" can be placed in any file format This "Configuration Record" can be placed in any file format
supporting "Configuration Records", fitting as much as possible with supporting "Configuration Records", fitting as much as possible with
how the file format uses to store "Configuration Records". The how the file format uses to store "Configuration Records". The
"Configuration Record" storage place and "NumBytes" are currently "Configuration Record" storage place and "NumBytes" are currently
defined and supported by this version of this specification for the defined and supported by this version of this specification for the
following formats: following formats:
4.1.3.1. AVI File Format 4.2.3.1. AVI File Format
The "Configuration Record" extends the stream format chunk ("AVI ", The "Configuration Record" extends the stream format chunk ("AVI ",
"hdlr", "strl", "strf") with the ConfigurationRecord bitstream. "hdlr", "strl", "strf") with the ConfigurationRecord bitstream.
See [AVI] for more information about chunks. See [AVI] for more information about chunks.
"NumBytes" is defined as the size, in bytes, of the strf chunk "NumBytes" is defined as the size, in bytes, of the strf chunk
indicated in the chunk header minus the size of the stream format indicated in the chunk header minus the size of the stream format
structure. structure.
4.1.3.2. ISO Base Media File Format 4.2.3.2. ISO Base Media File Format
The "Configuration Record" extends the sample description box The "Configuration Record" extends the sample description box
("moov", "trak", "mdia", "minf", "stbl", "stsd") with a "glbl" box ("moov", "trak", "mdia", "minf", "stbl", "stsd") with a "glbl" box
that contains the ConfigurationRecord bitstream. See that contains the ConfigurationRecord bitstream. See
[ISO.14496-12.2015] for more information about boxes. [ISO.14496-12.2015] for more information about boxes.
"NumBytes" is defined as the size, in bytes, of the "glbl" box "NumBytes" is defined as the size, in bytes, of the "glbl" box
indicated in the box header minus the size of the box header. indicated in the box header minus the size of the box header.
4.1.3.3. NUT File Format 4.2.3.3. NUT File Format
The codec_specific_data element (in "stream_header" packet) contains The codec_specific_data element (in "stream_header" packet) contains
the ConfigurationRecord bitstream. See [NUT] for more information the ConfigurationRecord bitstream. See [NUT] for more information
about elements. about elements.
"NumBytes" is defined as the size, in bytes, of the "NumBytes" is defined as the size, in bytes, of the
codec_specific_data element as indicated in the "length" field of codec_specific_data element as indicated in the "length" field of
codec_specific_data codec_specific_data
4.1.3.4. Matroska File Format 4.2.3.4. Matroska File Format
FFV1 SHOULD use "V_FFV1" as the Matroska "Codec ID". For FFV1 FFV1 SHOULD use "V_FFV1" as the Matroska "Codec ID". For FFV1
versions 2 or less, the Matroska "CodecPrivate" Element SHOULD NOT be versions 2 or less, the Matroska "CodecPrivate" Element SHOULD NOT be
used. For FFV1 versions 3 or greater, the Matroska "CodecPrivate" used. For FFV1 versions 3 or greater, the Matroska "CodecPrivate"
Element MUST contain the FFV1 "Configuration Record" structure and no Element MUST contain the FFV1 "Configuration Record" structure and no
other data. See [Matroska] for more information about elements. other data. See [Matroska] for more information about elements.
"NumBytes" is defined as the "Element Data Size" of the "NumBytes" is defined as the "Element Data Size" of the
"CodecPrivate" Element. "CodecPrivate" Element.
4.2. Frame 4.3. Frame
A "Frame" consists of the keyframe field, parameters (if version A "Frame" consists of the keyframe field, parameters (if version
<=1), and a sequence of independent slices. <=1), and a sequence of independent slices.
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
Frame( NumBytes ) { | Frame( NumBytes ) { |
keyframe | br keyframe | br
if (keyframe && !ConfigurationRecordIsPresent | if (keyframe && !ConfigurationRecordIsPresent |
Parameters( ) | Parameters( ) |
while ( remaining_bits_in_bitstream( NumBytes ) ) | while ( remaining_bits_in_bitstream( NumBytes ) ) |
Slice( ) | Slice( ) |
} | } |
4.3. Slice Architecture overview of slices in a "Frame":
+-----------------------------------------------------------------+
| first slice header |
| first slice content |
| first slice footer |
| --------------------------------------------------------------- |
| second slice header |
| second slice content |
| second slice footer |
| --------------------------------------------------------------- |
| ... |
| --------------------------------------------------------------- |
| last slice header |
| last slice content |
| last slice footer |
+-----------------------------------------------------------------+
4.4. Slice
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
Slice( ) { | Slice( ) { |
if (version >= 3) | if (version >= 3) |
SliceHeader( ) | SliceHeader( ) |
SliceContent( ) | SliceContent( ) |
if (coder_type == 0) | if (coder_type == 0) |
while (!byte_aligned()) | while (!byte_aligned()) |
padding | u(1) padding | u(1)
if (version <= 1) { |
while (remaining_bits_in_bitstream( NumBytes ) != 0 ) |
reserved | u(1)
} |
if (version >= 3) | if (version >= 3) |
SliceFooter( ) | SliceFooter( ) |
} | } |
"padding" specifies a bit without any significance and used only for "padding" specifies a bit without any significance and used only for
byte alignment. MUST be 0. byte alignment. MUST be 0.
4.4. Slice Header "reserved" specifies a bit without any significance in this revision
of the specification and may have a significance in a later revision
of this specification.
Encoders SHOULD NOT fill these bits.
Decoders SHOULD ignore these bits.
Note in case these bits are used in a later revision of this
specification: any revision of this specification SHOULD care about
avoiding to add 40 bits of content after "SliceContent" for version 0
and 1 of the bitstream. Background: due to some non conforming
encoders, some bitstreams where found with 40 extra bits
corresponding to "error_status" and "slice_crc_parity", a decoder
conforming to the revised specification could not do the difference
between a revised bitstream and a buggy bitstream.
4.5. Slice Header
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
SliceHeader( ) { | SliceHeader( ) { |
slice_x | ur slice_x | ur
slice_y | ur slice_y | ur
slice_width - 1 | ur slice_width - 1 | ur
slice_height - 1 | ur slice_height - 1 | ur
for( i = 0; i < quant_table_set_index_count; i++ ) | for( i = 0; i < quant_table_set_index_count; i++ ) |
quant_table_set_index [ i ] | ur quant_table_set_index [ i ] | ur
picture_structure | ur picture_structure | ur
sar_num | ur sar_num | ur
sar_den | ur sar_den | ur
} | } |
4.4.1. slice_x 4.5.1. slice_x
"slice_x" indicates the x position on the slice raster formed by "slice_x" indicates the x position on the slice raster formed by
num_h_slices. num_h_slices.
Inferred to be 0 if not present. Inferred to be 0 if not present.
4.4.2. slice_y 4.5.2. slice_y
"slice_y" indicates the y position on the slice raster formed by "slice_y" indicates the y position on the slice raster formed by
num_v_slices. num_v_slices.
Inferred to be 0 if not present. Inferred to be 0 if not present.
4.4.3. slice_width 4.5.3. slice_width
"slice_width" indicates the width on the slice raster formed by "slice_width" indicates the width on the slice raster formed by
num_h_slices. num_h_slices.
Inferred to be 1 if not present. Inferred to be 1 if not present.
4.4.4. slice_height 4.5.4. slice_height
"slice_height" indicates the height on the slice raster formed by "slice_height" indicates the height on the slice raster formed by
num_v_slices. num_v_slices.
Inferred to be 1 if not present. Inferred to be 1 if not present.
4.4.5. quant_table_set_index_count 4.5.5. quant_table_set_index_count
"quant_table_set_index_count" is defined as "1 + ( ( chroma_planes || "quant_table_set_index_count" is defined as "1 + ( ( chroma_planes ||
version \<= 3 ) ? 1 : 0 ) + ( alpha_plane ? 1 : 0 )". version \<= 3 ) ? 1 : 0 ) + ( alpha_plane ? 1 : 0 )".
4.4.6. quant_table_set_index 4.5.6. quant_table_set_index
"quant_table_set_index" indicates the Quantization Table Set index to "quant_table_set_index" indicates the Quantization Table Set index to
select the Quantization Table Set and the initial states for the select the Quantization Table Set and the initial states for the
slice. slice.
Inferred to be 0 if not present. Inferred to be 0 if not present.
4.4.7. picture_structure 4.5.7. picture_structure
"picture_structure" specifies the temporal and spatial relationship "picture_structure" specifies the temporal and spatial relationship
of each line of the "Frame". of each line of the "Frame".
Inferred to be 0 if not present. Inferred to be 0 if not present.
+-------+-------------------------+ +-------+-------------------------+
| value | picture structure used | | value | picture structure used |
+-------+-------------------------+ +-------+-------------------------+
| 0 | unknown | | 0 | unknown |
| 1 | top field first | | 1 | top field first |
| 2 | bottom field first | | 2 | bottom field first |
| 3 | progressive | | 3 | progressive |
| Other | reserved for future use | | Other | reserved for future use |
+-------+-------------------------+ +-------+-------------------------+
4.4.8. sar_num 4.5.8. sar_num
"sar_num" specifies the sample aspect ratio numerator. "sar_num" specifies the sample aspect ratio numerator.
Inferred to be 0 if not present. Inferred to be 0 if not present.
MUST be 0 if sample aspect ratio is unknown. MUST be 0 if sample aspect ratio is unknown.
4.4.9. sar_den 4.5.9. sar_den
"sar_den" specifies the sample aspect ratio numerator. "sar_den" specifies the sample aspect ratio denominator.
Inferred to be 0 if not present. Inferred to be 0 if not present.
MUST be 0 if sample aspect ratio is unknown. MUST be 0 if sample aspect ratio is unknown.
4.5. Slice Content 4.6. Slice Content
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
SliceContent( ) { | SliceContent( ) { |
if (colorspace_type == 0) { | if (colorspace_type == 0) { |
for( p = 0; p < primary_color_count; p++ ) | for( p = 0; p < primary_color_count; p++ ) |
for( y = 0; y < plane_pixel_height[ p ]; y++ ) | for( y = 0; y < plane_pixel_height[ p ]; y++ ) |
Line( p, y ) | Line( p, y ) |
} else if (colorspace_type == 1) { | } else if (colorspace_type == 1) { |
for( y = 0; y < slice_pixel_height; y++ ) | for( y = 0; y < slice_pixel_height; y++ ) |
for( p = 0; p < primary_color_count; p++ ) | for( p = 0; p < primary_color_count; p++ ) |
Line( p, y ) | Line( p, y ) |
} | } |
} | } |
4.5.1. primary_color_count 4.6.1. primary_color_count
"primary_color_count" is defined as 1 + ( chroma_planes ? 2 : 0 ) + ( "primary_color_count" is defined as "1 + ( chroma_planes ? 2 : 0 ) +
alpha_plane ? 1 : 0 ). ( alpha_plane ? 1 : 0 )".
4.5.2. plane_pixel_height 4.6.2. plane_pixel_height
"plane_pixel_height[ p ]" is the height in pixels of plane p of the "plane_pixel_height[ p ]" is the height in pixels of plane p of the
slice. slice.
"plane_pixel_height[ 0 ]" and "plane_pixel_height[ 1 + ( "plane_pixel_height[ 0 ]" and "plane_pixel_height[ 1 + (
chroma_planes ? 2 : 0 ) ]" value is "slice_pixel_height". chroma_planes ? 2 : 0 ) ]" value is "slice_pixel_height".
If "chroma_planes" is set to 1, "plane_pixel_height[ 1 ]" and If "chroma_planes" is set to 1, "plane_pixel_height[ 1 ]" and
"plane_pixel_height[ 2 ]" value is "ceil(slice_pixel_height / "plane_pixel_height[ 2 ]" value is "ceil(slice_pixel_height /
log2_v_chroma_subsample)". log2_v_chroma_subsample)".
4.5.3. slice_pixel_height 4.6.3. slice_pixel_height
"slice_pixel_height" is the height in pixels of the slice. "slice_pixel_height" is the height in pixels of the slice.
Its value is "floor(( slice_y + slice_height ) * slice_pixel_height / Its value is "floor(( slice_y + slice_height ) * slice_pixel_height /
num_v_slices) - slice_pixel_y". num_v_slices) - slice_pixel_y".
4.5.4. slice_pixel_y 4.6.4. slice_pixel_y
"slice_pixel_y" is the slice vertical position in pixels. "slice_pixel_y" is the slice vertical position in pixels.
Its value is "floor(slice_y * frame_pixel_height / num_v_slices)". Its value is "floor(slice_y * frame_pixel_height / num_v_slices)".
4.6. Line 4.7. Line
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
Line( p, y ) { | Line( p, y ) { |
if (colorspace_type == 0) { | if (colorspace_type == 0) { |
for( x = 0; x < plane_pixel_width[ p ]; x++ ) | for( x = 0; x < plane_pixel_width[ p ]; x++ ) |
sample_difference[ p ][ y ][ x ] | sample_difference[ p ][ y ][ x ] |
} else if (colorspace_type == 1) { | } else if (colorspace_type == 1) { |
for( x = 0; x < slice_pixel_width; x++ ) | for( x = 0; x < slice_pixel_width; x++ ) |
sample_difference[ p ][ y ][ x ] | sample_difference[ p ][ y ][ x ] |
} | } |
} | } |
4.6.1. plane_pixel_width 4.7.1. plane_pixel_width
"plane_pixel_width[ p ]" is the width in pixels of plane p of the "plane_pixel_width[ p ]" is the width in pixels of plane p of the
slice. slice.
"plane_pixel_width[ 0 ]" and "plane_pixel_width[ 1 + ( chroma_planes "plane_pixel_width[ 0 ]" and "plane_pixel_width[ 1 + ( chroma_planes
? 2 : 0 ) ]" value is "slice_pixel_width". ? 2 : 0 ) ]" value is "slice_pixel_width".
If "chroma_planes" is set to 1, "plane_pixel_width[ 1 ]" and If "chroma_planes" is set to 1, "plane_pixel_width[ 1 ]" and
"plane_pixel_width[ 2 ]" value is "ceil(slice_pixel_width / (1 << "plane_pixel_width[ 2 ]" value is "ceil(slice_pixel_width / (1 <<
log2_h_chroma_subsample))". log2_h_chroma_subsample))".
4.6.2. slice_pixel_width 4.7.2. slice_pixel_width
"slice_pixel_width" is the width in pixels of the slice. "slice_pixel_width" is the width in pixels of the slice.
Its value is "floor(( slice_x + slice_width ) * slice_pixel_width / Its value is "floor(( slice_x + slice_width ) * slice_pixel_width /
num_h_slices) - slice_pixel_x". num_h_slices) - slice_pixel_x".
4.6.3. slice_pixel_x 4.7.3. slice_pixel_x
"slice_pixel_x" is the slice horizontal position in pixels. "slice_pixel_x" is the slice horizontal position in pixels.
Its value is "floor(slice_x * frame_pixel_width / num_h_slices)". Its value is "floor(slice_x * frame_pixel_width / num_h_slices)".
4.6.4. sample_difference 4.7.4. sample_difference
"sample_difference[ p ][ y ][ x ]" is the sample difference for "sample_difference[ p ][ y ][ x ]" is the sample difference for
sample at plane "p", y position "y", and x position "x". The sample sample at plane "p", y position "y", and x position "x". The sample
value is computed based on prediction and context described in value is computed based on prediction and context described in
Section 3.2. Section 3.2.
4.7. Slice Footer 4.8. Slice Footer
Note: slice footer is always byte aligned. Note: slice footer is always byte aligned.
pseudo-code | type pseudo-code | type
--------------------------------------------------------------|----- --------------------------------------------------------------|-----
SliceFooter( ) { | SliceFooter( ) { |
slice_size | u(24) slice_size | u(24)
if (ec) { | if (ec) { |
error_status | u(8) error_status | u(8)
slice_crc_parity | u(32) slice_crc_parity | u(32)
} | } |
} | } |
4.7.1. slice_size 4.8.1. slice_size
"slice_size" indicates the size of the slice in bytes. "slice_size" indicates the size of the slice in bytes.
Note: this allows finding the start of slices before previous slices Note: this allows finding the start of slices before previous slices
have been fully decoded. And allows this way parallel decoding as have been fully decoded, and allows parallel decoding as well as
well as error resilience. error resilience.
4.7.2. error_status 4.8.2. error_status
"error_status" specifies the error status. "error_status" specifies the error status.
+-------+--------------------------------------+ +-------+--------------------------------------+
| value | error status | | value | error status |
+-------+--------------------------------------+ +-------+--------------------------------------+
| 0 | no error | | 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 |
+-------+--------------------------------------+ +-------+--------------------------------------+
4.7.3. slice_crc_parity 4.8.3. slice_crc_parity
"slice_crc_parity" 32 bits that are chosen so that the slice as a "slice_crc_parity" 32 bits that are chosen so that the slice as a
whole has a crc remainder of 0. whole has a crc remainder of 0.
This is equivalent to storing the crc remainder in the 32-bit parity. This is equivalent to storing the crc remainder in the 32-bit parity.
The CRC generator polynomial used is the standard IEEE CRC polynomial The CRC generator polynomial used is the standard IEEE CRC polynomial
(0x104C11DB7) with initial value 0. (0x104C11DB7) with initial value 0.
4.8. Parameters
pseudo-code | type
--------------------------------------------------------------|-----
Parameters( ) { |
version | ur
if (version >= 3) |
micro_version | ur
coder_type | ur
if (coder_type > 1) |
for (i = 1; i < 256; i++) |
state_transition_delta[ i ] | sr
colorspace_type | ur
if (version >= 1) |
bits_per_raw_sample | ur
chroma_planes | br
log2_h_chroma_subsample | ur
log2_v_chroma_subsample | ur
alpha_plane | br
if (version >= 3) { |
num_h_slices - 1 | ur
num_v_slices - 1 | ur
quant_table_set_count | ur
} |
for( i = 0; i < quant_table_set_count; i++ ) |
QuantizationTableSet( i ) |
if (version >= 3) { |
for( i = 0; i < quant_table_set_count; i++ ) { |
states_coded | br
if (states_coded) |
for( j = 0; j < context_count[ i ]; j++ ) |
for( k = 0; k < CONTEXT_SIZE; k++ ) |
initial_state_delta[ i ][ j ][ k ] | sr
} |
ec | ur
intra | ur
} |
} |
4.8.1. version
"version" specifies the version of the FFV1 bitstream.
Each version is incompatible with others versions: decoders SHOULD
reject a file due to unknown version.
Decoders SHOULD reject a file with version <= 1 &&
ConfigurationRecordIsPresent == 1.
Decoders SHOULD reject a file with version >= 3 &&
ConfigurationRecordIsPresent == 0.
+-------+-------------------------+
| value | version |
+-------+-------------------------+
| 0 | FFV1 version 0 |
| 1 | FFV1 version 1 |
| 2 | reserved* |
| 3 | FFV1 version 3 |
| Other | reserved for future use |
+-------+-------------------------+
* Version 2 was never enabled in the encoder thus version 2 files
SHOULD NOT exist, and this document does not describe them to keep
the text simpler.
4.8.2. micro_version
"micro_version" specifies the micro-version of the FFV1 bitstream.
After a version is considered stable (a micro-version value is
assigned to be the first stable variant of a specific version), each
new micro-version after this first stable variant is compatible with
the previous micro-version: decoders SHOULD NOT reject a file due to
an unknown micro-version equal or above the micro-version considered
as stable.
Meaning of micro_version for version 3:
+-------+-------------------------+
| value | micro_version |
+-------+-------------------------+
| 0...3 | reserved* |
| 4 | first stable variant |
| Other | reserved for future use |
+-------+-------------------------+
* development versions may be incompatible with the stable variants.
4.8.3. coder_type
"coder_type" specifies the coder used.
+-------+-------------------------------------------------+
| value | coder used |
+-------+-------------------------------------------------+
| 0 | Golomb Rice |
| 1 | Range Coder with default state transition table |
| 2 | Range Coder with custom state transition table |
| Other | reserved for future use |
+-------+-------------------------------------------------+
4.8.4. state_transition_delta
"state_transition_delta" specifies the Range coder custom state
transition table.
If state_transition_delta is not present in the FFV1 bitstream, all
Range coder custom state transition table elements are assumed to be
0.
4.8.5. colorspace_type
"colorspace_type" specifies color space losslessly encoded, Pixel
transformation used by the encoder, as well as interleave method.
+-------+---------------------+------------------+------------------+
| value | color space | transformation | interleave |
| | losslessly encoded | | method |
+-------+---------------------+------------------+------------------+
| 0 | YCbCr | No Pixel | plane then line |
| | | transformation | |
| 1 | RGB | JPEG2000-RCT | line then plane |
| Other | reserved for future | reserved for | reserved for |
| | use | future use | future use |
+-------+---------------------+------------------+------------------+
Restrictions:
If "colorspace_type" is 1, then "chroma_planes" MUST be 1,
"log2_h_chroma_subsample" MUST be 0, and "log2_v_chroma_subsample"
MUST be 0.
4.8.6. chroma_planes
"chroma_planes" indicates if chroma (color) planes are present.
+-------+-------------------------------+
| value | presence |
+-------+-------------------------------+
| 0 | chroma planes are not present |
| 1 | chroma planes are present |
+-------+-------------------------------+
4.8.7. bits_per_raw_sample
"bits_per_raw_sample" indicates the number of bits for each sample.
Inferred to be 8 if not present.
+-------+---------------------------------+
| value | bits for each sample |
+-------+---------------------------------+
| 0 | reserved* |
| Other | the actual bits for each sample |
+-------+---------------------------------+
* Encoders MUST NOT store bits_per_raw_sample = 0 Decoders SHOULD
accept and interpret bits_per_raw_sample = 0 as 8.
4.8.8. log2_h_chroma_subsample
"log2_h_chroma_subsample" indicates the subsample factor, stored in
powers to which the number 2 must be raised, between luma and chroma
width ("chroma_width = 2^(-log2_h_chroma_subsample) * luma_width").
4.8.9. log2_v_chroma_subsample
"log2_v_chroma_subsample" indicates the subsample factor, stored in
powers to which the number 2 must be raised, between luma and chroma
height ("chroma_height=2^(-log2_v_chroma_subsample) * luma_height").
4.8.10. alpha_plane
"alpha_plane" indicates if a transparency plane is present.
+-------+-----------------------------------+
| value | presence |
+-------+-----------------------------------+
| 0 | transparency plane is not present |
| 1 | transparency plane is present |
+-------+-----------------------------------+
4.8.11. num_h_slices
"num_h_slices" indicates the number of horizontal elements of the
slice raster.
Inferred to be 1 if not present.
4.8.12. num_v_slices
"num_v_slices" indicates the number of vertical elements of the slice
raster.
Inferred to be 1 if not present.
4.8.13. quant_table_set_count
"quant_table_set_count" indicates the number of Quantization
Table Sets.
Inferred to be 1 if not present.
MUST NOT be 0.
4.8.14. states_coded
"states_coded" indicates if the respective Quantization Table Set has
the initial states coded.
Inferred to be 0 if not present.
+-------+-----------------------------------------------------------+
| value | initial states |
+-------+-----------------------------------------------------------+
| 0 | initial states are not present and are assumed to be all |
| | 128 |
| 1 | initial states are present |
+-------+-----------------------------------------------------------+
4.8.15. initial_state_delta
"initial_state_delta[ i ][ j ][ k ]" indicates the initial Range
coder state, it is encoded using "k" as context index and
pred = j ? initial_states[ i ][j - 1][ k ] : 128
initial_state[ i ][ j ][ k ] =
( pred + initial_state_delta[ i ][ j ][ k ] ) & 255
4.8.16. ec
"ec" indicates the error detection/correction type.
+-------+--------------------------------------------+
| value | error detection/correction type |
+-------+--------------------------------------------+
| 0 | 32-bit CRC on the global header |
| 1 | 32-bit CRC per slice and the global header |
| Other | reserved for future use |
+-------+--------------------------------------------+
4.8.17. intra
"intra" indicates the relationship between the instances of "Frame".
Inferred to be 0 if not present.
+-------+-----------------------------------------------------------+
| value | relationship |
+-------+-----------------------------------------------------------+
| 0 | Frames are independent or dependent (keyframes and non |
| | keyframes) |
| 1 | Frames are independent (keyframes only) |
| Other | reserved for future use |
+-------+-----------------------------------------------------------+
4.9. Quantization Table Set 4.9. Quantization Table Set
The Quantization Table Sets are stored by storing the number of equal The Quantization Table Sets are stored by storing the number of equal
entries -1 of the first half of the table (represented as "len - 1" entries -1 of the first half of the table (represented as "len - 1"
in the pseudo-code below) using the method described in in the pseudo-code below) using the method described in
Section 3.8.1.2. The second half doesn't need to be stored as it is Section 3.8.1.2. The second half doesn't need to be stored as it is
identical to the first with flipped sign. "scale" and "len_count[ i identical to the first with flipped sign. "scale" and "len_count[ i
][ j ]" are temporary values used for the computing of ][ j ]" are temporary values used for the computing of
"context_count[ i ]" and are not used outside Quantization Table Set "context_count[ i ]" and are not used outside Quantization Table Set
pseudo-code. pseudo-code.
skipping to change at page 36, line 18 skipping to change at page 37, line 18
Required parameters: None. Required parameters: None.
Optional parameters: Optional parameters:
This parameter is used to signal the capabilities of a receiver This parameter is used to signal the capabilities of a receiver
implementation. This parameter MUST NOT be used for any other implementation. This parameter MUST NOT be used for any other
purpose. purpose.
version: The version of the FFV1 encoding as defined by version: The version of the FFV1 encoding as defined by
Section 4.8.1. Section 4.1.1.
micro_version: The micro_version of the FFV1 encoding as defined by micro_version: The micro_version of the FFV1 encoding as defined by
Section 4.8.2. Section 4.1.2.
coder_type: The coder_type of the FFV1 encoding as defined by coder_type: The coder_type of the FFV1 encoding as defined by
Section 4.8.3. Section 4.1.3.
colorspace_type: The colorspace_type of the FFV1 encoding as defined colorspace_type: The colorspace_type of the FFV1 encoding as defined
by Section 4.8.5. by Section 4.1.5.
bits_per_raw_sample: The version of the FFV1 encoding as defined by bits_per_raw_sample: The version of the FFV1 encoding as defined by
Section 4.8.7. Section 4.1.7.
max-slices: The value of max-slices is an integer indicating the max-slices: The value of max-slices is an integer indicating the
maximum count of slices with a frames of the FFV1 encoding. maximum count of slices with a frames of the FFV1 encoding.
Encoding considerations: Encoding considerations:
This media type is defined for encapsulation in several audiovisual This media type is defined for encapsulation in several audiovisual
container formats and contains binary data; see Section 4.1.3. This container formats and contains binary data; see Section 4.2.3. This
media type is framed binary data Section 4.8 of [RFC4288]. media type is framed binary data Section 4.8 of [RFC4288].
Security considerations: Security considerations:
See Section 6 of this document. See Section 6 of this document.
Interoperability considerations: None. Interoperability considerations: None.
Published specification: Published specification:
skipping to change at page 37, line 35 skipping to change at page 38, line 35
8. IANA Considerations 8. IANA Considerations
The IANA is requested to register the following values: The IANA is requested to register the following values:
o Media type registration as described in Section 7. o Media type registration as described in Section 7.
9. Appendixes 9. Appendixes
9.1. Decoder implementation suggestions 9.1. Decoder implementation suggestions
9.1.1. Multi-threading support and independence of slices 9.1.1. Multi-threading Support and Independence of Slices
The FFV1 bitstream is parsable in two ways: in sequential order as The FFV1 bitstream is parsable in two ways: in sequential order as
described in this document or with the pre-analysis of the footer of described in this document or with the pre-analysis of the footer of
each slice. Each slice footer contains a slice_size field so the each slice. Each slice footer contains a slice_size field so the
boundary of each slice is computable without having to parse the boundary of each slice is computable without having to parse the
slice content. That allows multi-threading as well as independence slice content. That allows multi-threading as well as independence
of slice content (a bitstream error in a slice header or slice of slice content (a bitstream error in a slice header or slice
content has no impact on the decoding of the other slices). content has no impact on the decoding of the other slices).
After having checked keyframe field, a decoder SHOULD parse After having checked keyframe field, a decoder SHOULD parse
slice_size fields, from slice_size of the last slice at the end of slice_size fields, from slice_size of the last slice at the end of
the "Frame" up to slice_size of the first slice at the beginning of the "Frame" up to slice_size of the first slice at the beginning of
the "Frame", before parsing slices, in order to have slices the "Frame", before parsing slices, in order to have slices
boundaries. A decoder MAY fallback on sequential order e.g. in case boundaries. A decoder MAY fallback on sequential order e.g. in case
of a corrupted "Frame" (frame size unknown, slice_size of slices not of a corrupted "Frame" (frame size unknown, slice_size of slices not
coherent...) or if there is no possibility of seek into the stream. coherent...) or if there is no possibility of seek into the stream.
Architecture overview of slices in a "Frame":
+-----------------------------------------------------------------+
| first slice header |
| first slice content |
| first slice footer |
| --------------------------------------------------------------- |
| second slice header |
| second slice content |
| second slice footer |
| --------------------------------------------------------------- |
| ... |
| --------------------------------------------------------------- |
| last slice header |
| last slice content |
| last slice footer |
+-----------------------------------------------------------------+
10. Changelog 10. Changelog
See <https://github.com/FFmpeg/FFV1/commits/master> See <https://github.com/FFmpeg/FFV1/commits/master>
11. ToDo 11. References
o mean,k estimation for the Golomb Rice codes
12. References
12.1. Normative References 11.1. Normative References
[I-D.ietf-cellar-ffv1] [I-D.ietf-cellar-ffv1]
Niedermayer, M., Rice, D., and J. Martinez, "FFV1 Video Niedermayer, M., Rice, D., and J. Martinez, "FFV1 Video
Coding Format Version 0, 1, and 3", draft-ietf-cellar- Coding Format Version 0, 1, and 3", draft-ietf-cellar-
ffv1-02 (work in progress), April 2018. ffv1-03 (work in progress), June 2018.
[ISO.15444-1.2016] [ISO.15444-1.2016]
International Organization for Standardization, International Organization for Standardization,
"Information technology -- JPEG 2000 image coding system: "Information technology -- JPEG 2000 image coding system:
Core coding system", October 2016. Core coding system", October 2016.
[ISO.9899.1990] [ISO.9899.1990]
International Organization for Standardization, International Organization for Standardization,
"Programming languages - C", ISO Standard 9899, 1990. "Programming languages - C", ISO Standard 9899, 1990.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", RFC 4288, DOI 10.17487/RFC4288, Registration Procedures", RFC 4288, DOI 10.17487/RFC4288,
December 2005, <https://www.rfc-editor.org/info/rfc4288>. December 2005, <https://www.rfc-editor.org/info/rfc4288>.
[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>.
[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>.
[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>.
[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>.
12.2. Informative References 11.2. Informative References
[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>.
[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>.
[FFV1_V0] Niedermayer, M., "Commit to mark FFV1 version 0 as non- [FFV1_V0] Niedermayer, M., "Commit to mark FFV1 version 0 as non-
skipping to change at page 40, line 32 skipping to change at page 41, line 18
[range-coding] [range-coding]
Nigel, G. and N. Martin, "Range encoding: an algorithm for Nigel, G. and N. Martin, "Range encoding: an algorithm for
removing redundancy from a digitised message.", Proc. removing redundancy from a digitised message.", Proc.
Institution of Electronic and Radio Engineers Institution of Electronic and Radio Engineers
International Conference on Video and Data Recording , International Conference on Video and Data Recording ,
July 1979. July 1979.
[REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the [REFIMPL] Niedermayer, M., "The reference FFV1 implementation / the
FFV1 codec in FFmpeg", undated, <https://ffmpeg.org>. FFV1 codec in FFmpeg", undated, <https://ffmpeg.org>.
[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>.
[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>.
[VALGRIND] [VALGRIND]
Valgrind Developers, "Valgrind website", undated, Valgrind Developers, "Valgrind website", undated,
<https://valgrind.org/>. <https://valgrind.org/>.
[YCbCr] Wikipedia, "YCbCr", undated, [YCbCr] Wikipedia, "YCbCr", undated,
<https://en.wikipedia.org/w/index.php?title=YCbCr>. <https://en.wikipedia.org/w/index.php?title=YCbCr>.
Authors' Addresses Authors' Addresses
Michael Niedermayer Michael Niedermayer
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