[FFmpeg-devel] [PATCH] Make Immersive Audio Model optional for MOV demuxing

[Eugene Zemtsov]

> Can you elaborate why you need this? In configure the mov demuxer
> selects iamfdec, so it will always be present and compiled.

Chromium doesn't use Immersive Audio, but the code for handling it
bloats Android binaries,
that's why we disabled it.

I have a second patch that disables iamfdec by default for mov demuxer,
but I had a feeling that maintainers will be less inclined to accept
it and that's why I split it from this one.
I will still try to send it if this patch is accepted.


On Wed, Mar 27, 2024 at 4:59 PM James Almer <jamrial at gmail.com> wrote:
>
> On 3/27/2024 8:55 PM, Eugene Zemtsov via ffmpeg-devel wrote:
> > From: Eugene Zemtsov <eugene at chromium.org>
> >
> > Signed-off-by: Eugene Zemtsov <eugene at chromium.org>
> > ---
> >   libavformat/mov.c | 15 ++++++++++++++-
> >   1 file changed, 14 insertions(+), 1 deletion(-)
> >
> > diff --git a/libavformat/mov.c b/libavformat/mov.c
> > index c55778f3ef..662301bf67 100644
> > --- a/libavformat/mov.c
> > +++ b/libavformat/mov.c
> > @@ -839,6 +839,7 @@ static int mov_read_dac3(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >       return 0;
> >   }
> >
> > +#if CONFIG_IAMFDEC
> >   static int mov_read_iacb(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >   {
> >       AVStream *st;
> > @@ -1015,6 +1016,7 @@ fail:
> >
> >       return ret;
> >   }
> > +#endif
> >
> >   static int mov_read_dec3(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >   {
> > @@ -4797,6 +4799,7 @@ static void fix_timescale(MOVContext *c, MOVStreamContext *sc)
> >       }
> >   }
> >
> > +#if CONFIG_IAMFDEC
> >   static int mov_update_iamf_streams(MOVContext *c, const AVStream *st)
> >   {
> >       const MOVStreamContext *sc = st->priv_data;
> > @@ -4840,6 +4843,7 @@ static int mov_update_iamf_streams(MOVContext *c, const AVStream *st)
> >
> >       return 0;
> >   }
> > +#endif
> >
> >   static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >   {
> > @@ -4921,11 +4925,13 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >
> >       mov_build_index(c, st);
> >
> > +#if CONFIG_IAMFDEC
> >       if (sc->iamf) {
> >           ret = mov_update_iamf_streams(c, st);
> >           if (ret < 0)
> >               return ret;
> >       }
> > +#endif
> >
> >       if (sc->dref_id-1 < sc->drefs_count && sc->drefs[sc->dref_id-1].path) {
> >           MOVDref *dref = &sc->drefs[sc->dref_id - 1];
> > @@ -8457,7 +8463,9 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
> >   { MKTAG('i','p','r','p'), mov_read_iprp },
> >   { MKTAG('i','i','n','f'), mov_read_iinf },
> >   { MKTAG('a','m','v','e'), mov_read_amve }, /* ambient viewing environment box */
> > +#if CONFIG_IAMFDEC
> >   { MKTAG('i','a','c','b'), mov_read_iacb },
> > +#endif
> >   { 0, NULL }
> >   };
> >
> > @@ -8929,8 +8937,10 @@ static void mov_free_stream_context(AVFormatContext *s, AVStream *st)
> >       av_freep(&sc->coll);
> >       av_freep(&sc->ambient);
> >
> > +#if CONFIG_IAMFDEC
> >       if (sc->iamf)
> >           ff_iamf_read_deinit(sc->iamf);
> > +#endif
> >       av_freep(&sc->iamf);
> >   }
> >
> > @@ -9570,6 +9580,7 @@ static int mov_read_packet(AVFormatContext *s, AVPacket *pkt)
> >
> >           if (st->codecpar->codec_id == AV_CODEC_ID_EIA_608 && sample->size > 8)
> >               ret = get_eia608_packet(sc->pb, pkt, sample->size);
> > +#if CONFIG_IAMFDEC
> >           else if (sc->iamf) {
> >               int64_t pts, dts, pos, duration;
> >               int flags, size = sample->size;
> > @@ -9592,7 +9603,9 @@ static int mov_read_packet(AVFormatContext *s, AVPacket *pkt)
> >               }
> >               if (!ret)
> >                   return FFERROR_REDO;
> > -        } else
> > +        }
> > +#endif
> > +        else
> >               ret = av_get_packet(sc->pb, pkt, sample->size);
> >           if (ret < 0) {
> >               if (should_retry(sc->pb, ret)) {
>
> Can you elaborate why you need this? In configure the mov demuxer
> selects iamfdec, so it will always be present and compiled.
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-- 
Thanks,
Eugene Zemtsov.