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

[Carl Eugen Hoyos]

> Am 29.08.2019 um 14:30 schrieb Hendrik Leppkes <h.leppkes at gmail.com>:
> 
>> On Thu, Aug 29, 2019 at 1:47 PM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>> 
>> 
>> 
>> 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.
>> 
> 
> AYUV is a standard format used on Windows and documented by Microsoft
> as the recommended 4:4:4 8-bit format for all purposes. Its hardly a
> niche format. Its perfectly appropriate to support it.

For which use case?

Carl Eugen