[FFmpeg-devel] [PATCH] avcodec/utils: initialize delay in avcodec_parameters_to_context()

[Hendrik Leppkes]

On Sat, Jun 4, 2016 at 12:09 PM, Michael Niedermayer
<michael at niedermayer.cc> wrote:
> On Sat, Jun 04, 2016 at 09:47:47AM +0200, Hendrik Leppkes wrote:
>> On Sat, Jun 4, 2016 at 4:55 AM, Michael Niedermayer
>> <michael at niedermayer.cc> wrote:
>> > Fixes lost codec delayy
>> > Should fix Ticket5509
>> >
>> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>> > ---
>> >  libavcodec/utils.c |    1 +
>> >  1 file changed, 1 insertion(+)
>> >
>> > diff --git a/libavcodec/utils.c b/libavcodec/utils.c
>> > index 7b99526..4016583 100644
>> > --- a/libavcodec/utils.c
>> > +++ b/libavcodec/utils.c
>> > @@ -4157,6 +4157,7 @@ int avcodec_parameters_to_context(AVCodecContext *codec,
>> >          codec->sample_rate     = par->sample_rate;
>> >          codec->block_align     = par->block_align;
>> >          codec->frame_size      = par->frame_size;
>> > +        codec->delay           =
>> >          codec->initial_padding = par->initial_padding;
>> >          codec->seek_preroll    = par->seek_preroll;
>> >          break;
>> > --
>> > 1.7.9.5
>> >
>>
>> Its probably fine to set it, but delay is not the correct field for
>> ffmpeg.c and/or whichever muxer is involved to be using then.
>
> delay must be set for the demuxer (required by API and used by
> applications), avcodec_parameters_to_context()
> has no knowledge about working on demuxer or muxer side
> contexts unless i miss something. (i tried avctx->codec but its never
> set)
> I can add a parameter to avcodec_parameters_to_context() that
> indicates if its for the demuxer or muxer or add a
> avcodec_parameters_to_context2() or a
> avcodec_parameters_to_context_demuxer()
> ff_parameters_to_context_demuxer()
> do you agree to add such function ?
> (iam asking as changes to AVCodecParameters API tend to receive
>  a lot of opposition)

Adding more weird API sounds silly, this patch is likely the better option.
Once ffmpeg.c is updated to use codecpar properly, this whole
double-field issue goes away anyway.

- Hendrik