[FFmpeg-user] vaapi: Impossible to convert between the formats

[Carl Eugen Hoyos]

2018-06-17 22:44 GMT+02:00, Mark Thompson <sw at jkqxz.net>:
> On 17/06/18 21:30, Carl Eugen Hoyos wrote:
>> 2018-06-17 22:00 GMT+02:00, Mark Thompson <sw at jkqxz.net>:
>>
>>> Intel devices do not support MPEG-4 part 2 at all.  If you are using
>>> the Mesa driver on an AMD device, some MPEG-4 part 2 streams
>>> may be supported if you set the environment variable
>>> VAAPI_MPEG4_ENABLED to 1, but it's not enabled by default
>>> because the implementation is incomplete due to API constraints.
>>
>> I know this mail isn't helpful but reading above and remembering how
>> nice vdpau worked (already) many years ago and remembering how
>> people said at the time that vaapi is much superior over vdpau I still
>> wonder if we (FFmpeg) shouldn't have fought vaapi much stronger...
>
> I doubt it would be particularly hard to make it work.  Since Intel didn't
> implement MPEG-4 part 2 on their supported devices they just cobbled
> together some set of stream/frame properties which looked sufficient for
> decoding and made that the API.  When AMD / Mesa tried to implement
> it they made some of it work but found that the API was incomplete, and
> then they gave up. If you (or anyone else, including AMD) wants it to
> work then it would be straightforward (if somewhat tedious) to add the
> necessary properties to VAAPI / libva to get to the point that it matches
> the working VDPAU behaviour.

Sadly that would be far above my capabilities.

Again, sorry for the rant, I am happy for everybody who can use vaapi.

Carl Eugen