[FFmpeg-devel] [PATCH v1 1/2] lavc/vp9: set yuvj pixel format for full range decode

[Leo Izen]

On 6/17/23 10:26, Thilo Borgmann wrote:
> Am 17.06.23 um 16:02 schrieb Leo Izen:
>> On 6/17/23 04:11, Thilo Borgmann wrote:
>>> While the yuvj pixel formats are deprecated lots of code still relies
>>> on them to be set. Without setting a yuvj420p pixel format VP9
>>> decoding ends up incorrectly due to auto conversion.
>>>
>>
>> I oppose this on principle. If there's code that relies on YUVJ being 
>> set, then *that code* needs to be changed so it respects the 
>> AVFrame->color_range field. Which code is working improperly with this?
> 
> I don't like adding YUVJ stuff either. If I do
> 
>   ./ffmpeg -i full-range-in.mp4 -c:v libvpx-vp9 -lossless 1 
> lossless-out.mp4
> 
> and then comparing the frames, they are not equal. E.g. by
> 
>   ./ffmpeg -i full-range-in.mp4 -i lossless-out.mp4 -filter_complex ssim 
> -f crc -
> 
> they are not 1.0 in ssim terms.
> 

Are you sure? I just tested a sample and found that I got exactly 1.0 in 
ssim terms. Do you have a link to a sample for which this fails?

- Leo Izen