[FFmpeg-devel] [PATCH] avcodec/mfenc: set frame size for audio encoders.

[Anton Khirnov]

Quoting Gyan Doshi (2022-06-18 10:28:38)
> 
> 
> On 2022-06-18 12:19 pm, Andreas Rheinhardt wrote:
> > Gyan Doshi:
> >> Default avctx->frame_size is 0 which leads to init failure for
> >> audio MediaFoundation encoders.
> >> ---
> >>   libavcodec/mfenc.c | 3 +++
> >>   1 file changed, 3 insertions(+)
> >>
> >> diff --git a/libavcodec/mfenc.c b/libavcodec/mfenc.c
> >> index 13ed7b3e11..ff9ffe4827 100644
> >> --- a/libavcodec/mfenc.c
> >> +++ b/libavcodec/mfenc.c
> >> @@ -1066,6 +1066,9 @@ static int mf_init_encoder(AVCodecContext *avctx)
> >>   
> >>       c->main_subtype = *subtype;
> >>   
> >> +    if (c->is_audio && !avctx->frame_size)
> >> +        avctx->frame_size = 1024;
> >> +
> >>       if ((ret = mf_create(avctx, &c->functions, &c->mft, avctx->codec, use_hw)) < 0)
> >>           return ret;
> >>   
> > 1. You forgot to mention the ticket that this is supposed to fix; you
> > should also add that this a regression and the commit
> > (827d6fe73d2f5472c1c2128eb14fab6a4db29032) that supposedly introduced
> > the regression (if this is indeed true).
>   I initially became aware due to a user query. Saw ticket later. Will 
> add details.
> 
> > 2. Where does this number come from (apart from the user-provided error
> > message)? How did it work before said commit?
> > (It seems that frame_size was unset before this commit, but did it
> > somehow just not matter?)
> 
> The MF encoders accept any number of samples per frame. They reframe as 
> necessary for DSP.

So set AV_CODEC_CAP_VARIABLE_FRAME_SIZE instead? Or does it have to be
constant?

-- 
Anton Khirnov