Re: [Cellar] [Matroska-devel] Colour Format proposal

[Jerome Martinez <[e-mail]>]

Le 05/01/2016 22:54, Dave Rice a écrit :
> [...]
>> Element Name: ColourMatrix
>> Level:        5
>> ID:           [55][A1]
>> Mandatory:    ma
>> Multiple:     -
>> Default:      2
>> Type:         u
>> Description:  ColourMatrix of the video. (0: IEC 61966-2-1 (sRGB), 1: 
>> BT709,
>>             2: Unspecified,
>
> Any reason for "Unspecified" to be #2 rather than #0? Do these numbers 
> align with a FFmpeg/libav enumeration?

Similar to Apple QuickTime nclc specs, ISO/MPEG Video / AVC / HEVC, ITU 
H.26x.
I recommend to not change that.

>
> [...]
>
>> Element Name: ChromaSubsampling
>> Level:        5
>> ID:           [55][A3]
>> Mandatory:    ma
>> Multiple:     -
>> Default:      0
>> Type:         u
>> Description:  (0: 4:2:0, 2: 4:2:2, 4: 4:4:4)
>
> This is mandatory, but there is no Unspecified option. If I want to 
> clarify that a contained 4:1:1 DV stream uses bt.601 there is no valid 
> way to say this, since if ColourMatrix is used then ChromaSubsampling 
> must also be used, but there is no options that fit 4:1:1.

+1 (must be optional or unknown possibility, and more cases)

Jérôme