[FFmpeg-devel] [PATCH 1/2] lavu/pixfmt: add AYUV pixel format

[Carl Eugen Hoyos]

Am 29.08.2019 um 03:34 schrieb Fu, Linjie <linjie.fu at intel.com>:

>> -----Original Message-----
>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
>> Of Carl Eugen Hoyos
>> Sent: Thursday, August 29, 2019 05:17
>> To: FFmpeg development discussions and patches <ffmpeg-
>> devel at ffmpeg.org>
>> Subject: Re: [FFmpeg-devel] [PATCH 1/2] lavu/pixfmt: add AYUV pixel format
>> 
>>>> Am Mi., 28. Aug. 2019 um 09:34 Uhr schrieb Fu, Linjie <linjie.fu at intel.com>:
>>>> 
>>>> -----Original Message-----
>>>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On
>> Behalf
>>>> Of Carl Eugen Hoyos
>>>> Sent: Wednesday, August 28, 2019 14:51
>>>> To: FFmpeg development discussions and patches <ffmpeg-
>>>> devel at ffmpeg.org>
>>>> Subject: Re: [FFmpeg-devel] [PATCH 1/2] lavu/pixfmt: add AYUV pixel
>> format
>>>> 
>>>> 
>>>> 
>>>>> Am 28.08.2019 um 08:22 schrieb Linjie Fu <linjie.fu at intel.com>:
>>>>> 
>>>>> Add support for packed 4:4:4 pixel format AYUV.
>>>>> 
>>>>> It is the format that VAAPI/QSV uses when coping with 4:4:4
>>>>> surfaces.
>>>> 
>>>>> Alpha channel will be set to default value for HEVC REXT
>>>>> hw decode.
>>>> 
>>>> What is the „default value“?
>>> 
>>> Default zero. (and it should be 255 for display)
>> 
>> If this is not a bug in the driver, there is no alpha channel that can be used.
>> Rename it to 0YUV and remove the alpha usage.
> 
> From the pixel format level, adding AYUV format is for a more fundamental/common usage.

Yes, but the new pixel format will only be accepted if it is needed for hardware compatibility.
If the hardware only supports 0YUV, it cannot be used to argue in favour of a new AYUV format.

Carl Eugen