[FFmpeg-devel] [PATCH] avformat: add av_format_inject_global_side_data(), and disable it by default

[Michael Niedermayer]

On Sun, Apr 13, 2014 at 07:42:49PM +0200, wm4 wrote:
> On Sun, 13 Apr 2014 19:35:21 +0200
> Michael Niedermayer <michaelni at gmx.at> wrote:
> 
> > After this commit applications needs to call av_format_inject_global_side_data()
> > or handle AVStream side data by some other means if they want it not to be lost.
> > 
> > This fixes a API incompatibility with libav.
> > libav API does not allow the data to be passed through AVPackets
> > 
> > Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> > ---
> 
> Sounds somewhat ok.
> 
> >  doc/APIchanges         |    3 +++
> >  ffplay.c               |    2 ++
> >  libavformat/avformat.h |   10 +++++++++-
> >  libavformat/internal.h |    2 ++
> >  libavformat/utils.c    |   17 ++++++++++++++---
> >  5 files changed, 30 insertions(+), 4 deletions(-)
> > 
> > diff --git a/doc/APIchanges b/doc/APIchanges
> > index a53647f..4cf922b 100644
> > --- a/doc/APIchanges
> > +++ b/doc/APIchanges
> > @@ -15,6 +15,9 @@ libavutil:     2012-10-22
> >  
> >  API changes, most recent first:
> >  
> > +2014-04-XX - xxxxxxx - lavf xx.xx.1xx - avformat.h
> > +  Add av_format_inject_global_side_data()
> > +
> >  2014-04-12 - xxxxxxx - lavu 52.76.100 - log.h
> >    Add av_log_get_flags()
> >  
> > diff --git a/ffplay.c b/ffplay.c
> > index c86f94f..86b9126 100644
> > --- a/ffplay.c
> > +++ b/ffplay.c
> > @@ -2752,6 +2752,8 @@ static int read_thread(void *arg)
> >      if (genpts)
> >          ic->flags |= AVFMT_FLAG_GENPTS;
> >  
> > +    av_format_inject_global_side_data(ic);
> > +
> >      opts = setup_find_stream_info_opts(ic, codec_opts);
> >      orig_nb_streams = ic->nb_streams;
> >  
> > diff --git a/libavformat/avformat.h b/libavformat/avformat.h
> > index ebebb3f..a1185ca 100644
> > --- a/libavformat/avformat.h
> > +++ b/libavformat/avformat.h
> > @@ -862,6 +862,8 @@ typedef struct AVStream {
> >       * - muxing: May be set by the caller before avformat_write_header().
> >       *
> >       * Freed by libavformat in avformat_free_context().
> > +     *
> > +     * @see av_format_inject_global_side_data()
> >       */
> >      AVPacketSideData *side_data;
> >      /**
> > @@ -1043,7 +1045,7 @@ typedef struct AVStream {
> >      /**
> >       * Internal data to inject global side data
> >       */
> > -    int global_side_data_injected;
> > +    int inject_global_side_data;
> >  
> >  } AVStream;
> >  
> > @@ -1613,6 +1615,12 @@ av_format_control_message av_format_get_control_message_cb(const AVFormatContext
> >  void      av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
> >  
> >  /**
> > + * This function will cause global side data to be injected in the next packet
> > + * of each stream as well as after any subsequent seek.
> > + */
> > +void av_format_inject_global_side_data(AVFormatContext *s);
> > +
> > +/**
> >   * Returns the method used to set ctx->duration.
> >   *
> >   * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
> > diff --git a/libavformat/internal.h b/libavformat/internal.h
> > index f19cebf..e9e9293 100644
> > --- a/libavformat/internal.h
> > +++ b/libavformat/internal.h
> > @@ -52,6 +52,8 @@ struct AVFormatInternal {
> >       * Muxing only.
> >       */
> >      int nb_interleaved_streams;
> > +
> > +    int inject_global_side_data;
> >  };
> >  
> >  #ifdef __GNUC__
> > diff --git a/libavformat/utils.c b/libavformat/utils.c
> > index 2014577..8105ecf 100644
> > --- a/libavformat/utils.c
> > +++ b/libavformat/utils.c
> > @@ -110,6 +110,16 @@ MAKE_ACCESSORS(AVFormatContext, format, int, metadata_header_padding)
> >  MAKE_ACCESSORS(AVFormatContext, format, void *, opaque)
> >  MAKE_ACCESSORS(AVFormatContext, format, av_format_control_message, control_message_cb)
> >  
> > +void av_format_inject_global_side_data(AVFormatContext *s)
> > +{
> > +    int i;
> > +    s->internal->inject_global_side_data = 1;
> > +    for (i = 0; i < s->nb_streams; i++) {
> > +        AVStream *st = s->streams[i];
> > +        st->inject_global_side_data = 1;
> > +    }
> > +}
> 
> What about streams that are added later? Or is ff_read_frame_flush
> called on new streams?

fixed locally but i suspect this case never occurs
that is containers which add streams later probably dont have
global headers

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When you are offended at any man's fault, turn to yourself and study your
own failings. Then you will forget your anger. -- Epictetus
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