[FFmpeg-devel] [PATCH] examples/filtering_audio: update to new API

[Stefano Sabatini]

On date Thursday 2013-03-14 01:40:33 +0100, Clément Bœsch encoded:
> On Wed, Mar 13, 2013 at 10:09:10PM +0100, Stefano Sabatini wrote:
> > In particular, fix crash.
> > ---
> >  doc/examples/filtering_audio.c |   26 ++++++++++++--------------
> >  1 file changed, 12 insertions(+), 14 deletions(-)
> > 
> > diff --git a/doc/examples/filtering_audio.c b/doc/examples/filtering_audio.c
> > index ad69d32..01e6926 100644
> > --- a/doc/examples/filtering_audio.c
> > +++ b/doc/examples/filtering_audio.c
> > @@ -150,11 +150,10 @@ static int init_filters(const char *filters_descr)
> >      return 0;
> >  }
> >  
> > -static void print_samplesref(AVFilterBufferRef *samplesref)
> > +static void print_frame(AVFrame *frame)
> 
> Note: I think this could be made const.
> 
> >  {
> > -    const AVFilterBufferRefAudioProps *props = samplesref->audio;
> > -    const int n = props->nb_samples * av_get_channel_layout_nb_channels(props->channel_layout);
> > -    const uint16_t *p     = (uint16_t*)samplesref->data[0];
> > +    const int n = frame->nb_samples * av_get_channel_layout_nb_channels(av_frame_get_channel_layout(frame));
> > +    const uint16_t *p     = (uint16_t*)frame->data[0];
> >      const uint16_t *p_end = p + n;
> >  
> >      while (p < p_end) {
> > @@ -169,10 +168,11 @@ int main(int argc, char **argv)
> >  {
> >      int ret;
> >      AVPacket packet;
> > -    AVFrame *frame = avcodec_alloc_frame();
> > +    AVFrame *frame = av_frame_alloc();
> > +    AVFrame *filt_frame = av_frame_alloc();
> >      int got_frame;
> >  
> > -    if (!frame) {
> > +    if (!frame || !filt_frame) {
> >          perror("Could not allocate frame");
> >          exit(1);
> >      }
> > @@ -192,7 +192,6 @@ int main(int argc, char **argv)
> >  
> >      /* read all packets */
> >      while (1) {
> > -        AVFilterBufferRef *samplesref;
> >          if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
> >              break;
> >  
> > @@ -207,22 +206,20 @@ int main(int argc, char **argv)
> >  
> >              if (got_frame) {
> >                  /* push the audio data from decoded frame into the filtergraph */
> > -                if (av_buffersrc_add_frame(buffersrc_ctx, frame) < 0) {
> > +                if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0) {
> >                      av_log(NULL, AV_LOG_ERROR, "Error while feeding the audio filtergraph\n");
> >                      break;
> >                  }
> >  
> >                  /* pull filtered audio from the filtergraph */
> >                  while (1) {
> > -                    ret = av_buffersink_get_buffer_ref(buffersink_ctx, &samplesref, 0);
> > +                    ret = av_buffersink_get_frame(buffersink_ctx, filt_frame);
> >                      if(ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
> >                          break;
> >                      if(ret < 0)
> >                          goto end;
> > -                    if (samplesref) {
> > -                        print_samplesref(samplesref);
> > -                        avfilter_unref_bufferp(&samplesref);
> > -                    }
> > +                    print_frame(filt_frame);
> > +                    av_frame_unref(filt_frame);
> >                  }
> >              }
> >          }
> > @@ -233,7 +230,8 @@ end:
> >      if (dec_ctx)
> >          avcodec_close(dec_ctx);
> >      avformat_close_input(&fmt_ctx);
> > -    av_freep(&frame);
> > +    av_frame_free(&frame);
> > +    av_frame_free(&filt_frame);
> >  
> >      if (ret < 0 && ret != AVERROR_EOF) {
> >          char buf[1024];
> 
> I wonder if a in_frame/out_frame naming wouldn't be more easy to
> understand (or at least just a note along with each alloc).

The problem with in/out is that they are always relative to something
and tend to be confusing as far as that something is not very well
specified (is it the decoder? is it the filtergraph). Feel free to
suggest a better naming.

Will push this soon, thanks.
-- 
FFmpeg = Fascinating Freak Mean Puristic Extensive Guru