[vlc-devel] [PATCH 08/16] avcodec: vdpau: do not rely on avctx->refs for VP9

[Steve Lhomme]

On 2019-10-24 21:21, Rémi Denis-Courmont wrote:
> Le torstaina 24. lokakuuta 2019, 17.20.22 EEST Steve Lhomme a écrit :
>> It gives one when it should be 8. Other codecs seem to be OK.
> 
> Isn't that a bug in upstream libavcodec ?

It might be. But the ffmpeg hardware handlers and ours except for VDPAU 
rely on the codec ID rather than the AVContext refs to find the number 
of surfaces needed.

At least for VP9 it gives a value of 2 even though 8 are needed. 
Software decoding works but it might be because it can allocate more 
pictures than originally expected.

> Forcing 2 refs does not seem to match the patch description.

This also follows other implementations where the default amount needed 
is 2 (MPEG1/2, VC1, for example).