[FFmpeg-user] ProRes XQ 12-bit support

[Paul B Mahol]

On 4/24/18, Elliott Balsley <elliottbalsley at gmail.com> wrote:
>>> Can it be possible for ffmpeg to misinterpret the image as 10-bit instead
>>> of
>>> 12, and still make the image look correct?
>>
>> No.
>
>
> I think this actually could be possible.  If you ignore the two least
> significant bits, then the image would still look correct, just lacking
> precision.
>
> Looking at the source code here, I see that PRORES_BITS_PER_SAMPLE is
> defined as 10.  So it sounds like ffmpeg simply decodes all ProRes as
> 10-bit.  I would like to request the option to decode ProRes with 12-bit
> precision, but unfortunately I do not have any programming knowledge to
> contribute.
>
> https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/proresdsp.h
> <https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/proresdsp.h>
>
> Sample footage is here if anybody is interested:
> http://www.arri.com/camera/alexa/learn/alexa_sample_footage/

There is no 12 bit codec.

There is only possible 16 bit alpha, which is downconverted to 10 bit.