[FFmpeg-devel] [PATCH 2/2] avcodec/liblc3enc: don't force unspec channel layouts

[Stefano Sabatini]

On date Thursday 2024-04-04 18:59:09 +0200, Andreas Rheinhardt wrote:
> James Almer:
> > We only care about channel count. Layout details will be ignored either way.
> > 
> > Signed-off-by: James Almer <jamrial at gmail.com>
> > ---
> >  libavcodec/liblc3enc.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/libavcodec/liblc3enc.c b/libavcodec/liblc3enc.c
> > index 63d1645b10..5f8169a0cf 100644
> > --- a/libavcodec/liblc3enc.c
> > +++ b/libavcodec/liblc3enc.c
> > @@ -61,6 +61,11 @@ static av_cold int liblc3_encode_init(AVCodecContext *avctx)
> >                 "Unsupported frame duration %.1f ms.\n", frame_us / 1000.f);
> >          return AVERROR(EINVAL);
> >      }
> > +    if (channels < 0 || channels > ENCODER_MAX_CHANNELS) {
> > +        av_log(avctx, AV_LOG_ERROR,
> > +               "Unsupported channel count %d. Should be 1 or 2\n", channels);
> > +        return AVERROR(EINVAL);
> > +    }
> >  
> >      hr_mode |= srate_hz > 48000;
> >      hr_mode &= srate_hz >= 48000;
> > @@ -195,9 +200,6 @@ const FFCodec ff_liblc3_encoder = {
> >      .p.type         = AVMEDIA_TYPE_AUDIO,
> >      .p.id           = AV_CODEC_ID_LC3,
> >      .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
> > -    .p.ch_layouts = (const AVChannelLayout[])
> > -        { { AV_CHANNEL_ORDER_UNSPEC, 1 },
> > -          { AV_CHANNEL_ORDER_UNSPEC, 2 }, { 0 } },
> >      .p.supported_samplerates = (const int [])
> >          { 96000, 48000, 32000, 24000, 16000, 8000, 0 },
> >      .p.sample_fmts = (const enum AVSampleFormat[])
> 

> I think we should rather change encode.c to mean that an UNSPEC channel
> layout (in AVCodec.ch_layouts) works with every channel layout with the
> same number of channels.

This was my naive interpretation of the code, without checking the
code. This would probably save some boilerplate (OTOH it should also
be fine to apply the hotfix).