[FFmpeg-devel] [Cellar] [Matroska-devel] Colour Format proposal
Dave Rice
dave at dericed.com
Fri Feb 19 20:59:41 CET 2016
Hi all,
Working with the IETF Cellar Working Group, https://datatracker.ietf.org/wg/cellar/charter/, Frank Galligan has drafted a proposal for the management of metadata in Matroska to accommodate information on color, full/broadcast range, HDR metadata, chroma subsampling patterns and other information. I'm forwarding it to ffmpeg-devel and libav-devel to encourage any additional comments. The background discussion thus far is visible at https://mailarchive.ietf.org/arch/search/?email_list=cellar&gbt=1&q=Colour+Format+proposal <https://mailarchive.ietf.org/arch/search/?email_list=cellar&gbt=1&q=Colour+Format+proposal>. For context, the structure for Matroska element definitions is currently in draft here: https://github.com/Matroska-Org/ebml-specification/blob/master/specification.markdown#ebml-schema-element-attributes <https://github.com/Matroska-Org/ebml-specification/blob/master/specification.markdown#ebml-schema-element-attributes>.
> Begin forwarded message:
>
> From: Frank Galligan <frankgalligan at gmail.com>
> Subject: Re: [Cellar] [Matroska-devel] Colour Format proposal
> Date: February 18, 2016 at 2:50:27 PM EST
> To: Dave Rice <dave at dericed.com>
> Cc: Jerome Martinez <jerome at mediaarea.net>, Discussion about the current and future development of Matroska <matroska-devel at lists.matroska.org>, cellar at ietf.org
>
> Here is the current proposal, minus the reference to the 265 doc.
>
> The parent element would be Video [E0].
>
>
> Element Name: Colour
> Level: 4
> ID: [55][B0]
> Mandatory: -
> Multiple: -
> Default: -
> Type: m
> Description: Settings describing the colour format.
>
>
> Element Name: MatrixCoefficients
> Level: 5
> ID: [55][B1]
> Mandatory: -
> Multiple: -
> Default: 2
> Type: u
> Description: The Matrix Coefficients of the video used to derive luma and
> chroma values from reg, green, and blue color primaries. For
> clarity, the value and meanings for MatrixCoefficients are adopted
> from Table 4 of ISO/IEC 23001-8:2013/DCOR1. (0:GBR, 1: BT709,
> 2: Unspecified, 3: Reserved, 4: FCC, 5: BT470BG, 6: SMPTE 170M,
> 7: SMPTE 240M, 8: YCOCG, 9: BT2020 Non-constant Luminance,
> 10: BT2020 Constant Luminance)
>
>
> Element Name: BitsPerChannel
> Level: 5
> ID: [55][B2]
> Mandatory: -
> Multiple: -
> Default: 0
> Type: u
> Description: Number of decoded bits per channel. A value of 0 indicates that
> the BitsPerChannel is unspecified.
>
>
> Element Name: ChromaSubsamplingHorz
> Level: 5
> ID: [55][B3]
> Mandatory: -
> Multiple: -
> Default: -
> Type: u
> Description: The amount of pixels to remove in the Cr and Cb channels for every
> pixel not removed horizontally. Example: For video with 4:2:0
> chroma subsampling, the ChromaSubsamplingHorz should be set to 1.
>
>
> Element Name: ChromaSubsamplingVert
> Level: 5
> ID: [55][B4]
> Mandatory: -
> Multiple: -
> Default: -
> Type: u
> Description: The amount of pixels to remove in the Cr and Cb channels for every
> pixel not removed vertically. Example: For video with 4:2:0 chroma
> subsampling, the ChromaSubsamplingVert should be set to 1.
>
> Element Name: CbSubsamplingHorz
> Level: 5
> ID: [55][B5]
> Mandatory: -
> Multiple: -
> Default: -
> Type: u
> Description: The amount of pixels to remove in the Cb channel for every pixel
> not removed horizontally. This is additive with
> ChromaSubsamplingHorz. Example: For video with 4:2:1 chroma
> subsampling, the ChromaSubsamplingHorz should be set to 1 and
> CbSubsamplingHorz should be set to 1.
>
>
> Element Name: CbSubsamplingVert
> Level: 5
> ID: [55][B6]
> Mandatory: -
> Multiple: -
> Default: -
> Type: u
> Description: The amount of pixels to remove in the Cb channel for every pixel
> not removed vertically. This is additive with
> ChromaSubsamplingVert.
>
>
> Element Name: ChromaSitingHorz
> Level: 5
> ID: [55][B7]
> Mandatory: -
> Multiple: -
> Default: 0
> Type: u
> Description: How Chroma is subsampled horizontally. (0: Unspecified, 1: Left
> collocated , 2: Half)
>
> Element Name: ChromaSitingVert
> Level: 5
> ID: [55][B8]
> Mandatory: -
> Multiple: -
> Default: 0
> Type: u
> Description: How Chroma is subsampled vertically. (0: Unspecified, 1: Top
> collocated , 2: Half)
>
>
> Element Name: Range
> Level: 5
> ID: [55][B9]
> Mandatory: -
> Multiple: -
> Default: 0
> Type: u
> Description: Clipping of the color ranges. (0: Unspecified, 1: Broadcast range,
> 2: Full range (no clipping), 3: Defined by
> MatrixCoefficients/TransferCharacteristics)
>
>
> Element Name: TransferCharacteristics
> Level: 5
> ID: [55][BA]
> Mandatory: -
> Multiple: -
> Default: 2
> Type: u
> Description: The transfer characteristics of the video. For clarity, the value
> and meanings for TransferCharacteristics 1-15 are adopted from
> Table 3 of ISO/IEC 23001-8:2013/DCOR1. TransferCharacteristics
> 16-17 are adopted from <265 doc> and 18 is the proposed value of
> ARIB STD-B67. (0: Reserved, 1: ITU-R BT.709, 2: Unspecified,
> 3: Reserved, 4: Gamma 2.2 curve, 5: Gamma 2.8 curve,
> 6: SMPTE 170M, 7: SMPTE 240M, 8: Linear, 9: Log, 10: Log Sqrt,
> 11: IEC 61966-2-4, 12: ITU-R BT.1361 Extended Colour Gamut,
> 13: IEC 61966-2-1, 14: ITU-R BT.2020 10 bit,
> 15: ITU-R BT.2020 12 bit, 16: SMPTE ST 2084, 17: SMPTE ST 428-1
> 18: ARIB STD-B67 (HLG))
>
>
> Element Name: Primaries
> Level: 5
> Mandatory: -
> Multiple: -
> ID: [55][BB]
> Default: 2
> Type: u
> Description: The colour primaries of the video. For clarity, the value and
> meanings for Primaries are adopted from Table 2 of
> ISO/IEC 23001-8:2013/DCOR1. (0: Reserved, 1: ITU-R BT.709,
> 2: Unspecified, 3: Reserved, 4: ITU-R BT.470M, 5: ITU-R BT.470BG,
> 6: SMPTE 170M, 7: SMPTE 240M, 8: FILM, 9: ITU-R BT.2020,
> 10: SMPTE ST 428-1, 22: JEDEC P22 phosphors)
>
>
> Element Name: MaxCLL
> Level: 5
> ID: [55][BC]
> Mandatory: -
> Multiple: -
> Default: -
> Type: u
> Description: Maximum brightness of a single pixel (Maximum Content Light Level)
> in candelas per square meter (cd/m²).
>
>
> Element Name: MaxFALL
> Level: 5
> ID: [55][BD]
> Mandatory: -
> Multiple: -
> Default: -
> Type: u
> Description: Maximum brightness of a single full frame (Maximum Frame-Average
> Light Level) in candelas per square meter (cd/m²).
>
>
> Element Name: MasteringMetadata
> Level: 5
> ID: [55][D0]
> Mandatory: -
> Multiple: -
> Default: -
> Type: m
> Description: SMPTE 2086 mastering data.
>
>
> Element Name: PrimaryRChromaticityX
> Level: 6
> ID: [55][D1]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> Type: f
> Description: Red X chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: PrimaryRChromaticityY
> Level: 6
> ID: [55][D2]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> Type: f
> Description: Red Y chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: PrimaryGChromaticityX
> Level: 6
> ID: [55][D3]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> f
> Description: Green X chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: PrimaryGChromaticityY
> Level: 6
> ID: [55][D4]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> Type: f
> Description: Green Y chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: PrimaryBChromaticityX
> Level: 6
> ID: [55][D5]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> Type: f
> Description: Blue X chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: PrimaryBChromaticityY
> Level: 6
> ID: [55][D6]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> Type: f
> Description: Blue Y chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: WhitePointChromaticityX
> Level: 6
> ID: [55][D7]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> Type: f
> Description: White point X chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: WhitePointChromaticityY
> Level: 6
> ID: [55][D8]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 1.0
> Default: -
> Type: f
> Description: White point Y chromaticity coordinate as defined by CIE 1931.
>
>
> Element Name: LuminanceMax
> Level: 6
> ID: [55][D9]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 9999.99
> Default: -
> Type: f
> Description: Maximum luminance. Shall be represented in candelas per square
> meter (cd/m²).
>
>
> Element Name: LuminanceMin
> Level: 6
> ID: [55][DA]
> Mandatory: -
> Multiple: -
> Range: 0.0 <= f <= 999.9999
> Default: -
> Type: f
> Description: Minimum luminance. Shall be represented in candelas per square
> meter (cd/m²).
>
>
> [IEC23001-8] ISO/IEC 23001-8:2013/DCOR1, "Coding independent media description code points", 2013, <http://standards.iso.org/ittf/PubliclyAvailableStandards/c062088_ISO_IEC_23001-8_2013.zip <http://standards.iso.org/ittf/PubliclyAvailableStandards/c062088_ISO_IEC_23001-8_2013.zip>>.
>
> <reference to h265 doc)
[...]
Those interested in standardization efforts for EBML, Matroska, and FFV1 are encouraged to join the CELLAR Working Group. https://datatracker.ietf.org/wg/cellar/charter/ <https://datatracker.ietf.org/wg/cellar/charter/>.
Best Regards,
Dave Rice
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