[FFmpeg-devel] [PATCH 1/2] avformat/movenc: Add movie_timescale option to AVIF

[Vignesh Venkatasubramanian]

On Thu, Jan 5, 2023 at 1:34 AM "zhilizhao(赵志立)" <quinkblack at foxmail.com> wrote:
>
>
>
> > On Jan 5, 2023, at 06:16, Vignesh Venkatasubramanian <vigneshv-at-google.com at ffmpeg.org> wrote:
> >
> > Allow specifying the movie_timescale options to AVIF ouptut.
> >
> > This also makes sure that when movie_timescale is not specified,
> > the default value of 1000 is used instead of 0. Animated AVIF
> > files which don't specify the movie_timescale will have the
> > correct duration written in the track and movie headers after this
> > change (instead of writing 0).
> >
> > Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
> > ---
> > libavformat/movenc.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/libavformat/movenc.c b/libavformat/movenc.c
> > index 7d49892283..36c76f7f60 100644
> > --- a/libavformat/movenc.c
> > +++ b/libavformat/movenc.c
> > @@ -7758,6 +7758,11 @@ static const AVCodecTag codec_f4v_tags[] = {
> > };
> >
> > #if CONFIG_AVIF_MUXER
> > +
> > +static const AVOption avif_options[] = {
> > +    { "movie_timescale", "set movie timescale", offsetof(MOVMuxContext, movie_timescale), AV_OPT_TYPE_INT, {.i64 = MOV_TIMESCALE}, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
> > +    { NULL },
> > +};
>
> If there is a chance to add more options which is shared with
> mov_isobmff_muxer_class, define a common option to avoid
> duplication. Otherwise keep it as this.
>

As of now, this is the only one that's being repeated. I think we can
make a common option if we decide to copy over more from the
mov_isobmff_muxer_class.

> > static const AVCodecTag codec_avif_tags[] = {
> >     { AV_CODEC_ID_AV1,     MKTAG('a','v','0','1') },
> >     { AV_CODEC_ID_NONE, 0 },
> > @@ -7767,6 +7772,7 @@ static const AVCodecTag *const codec_avif_tags_list[] = { codec_avif_tags, NULL
> > static const AVClass mov_avif_muxer_class = {
> >     .class_name = "avif muxer",
> >     .item_name  = av_default_item_name,
> > +    .option     = avif_options,
> >     .version    = LIBAVUTIL_VERSION_INT,
> > };
> > #endif
> > --
> > 2.39.0.314.g84b9a713c41-goog
> >
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>


-- 
Vignesh