[FFmpeg-trac] #375(avfilter:new): earwax audio filter generates wrong pts and af_sox filter can not be applied.

FFmpeg trac at avcodec.org
Mon Aug 1 02:50:27 CEST 2011

#375: earwax audio filter generates wrong pts and af_sox filter can not be
 Reporter:  chinshou  |        Type:  defect
   Status:  new       |    Priority:  normal
Component:  avfilter  |     Version:  unspecified
 Keywords:            |  Blocked By:
 Blocking:            |  Reproduced:  0
 Analyzed:  0         |
 Sorry, I do not know is it appropriate to report bug for audio filter
 branch at https://github.com/mnzaki/FFmpeg/commits/audio-filters-20110726

 I just try the audio filter branch for a while and noticed that when i set
 -af earwax , the generated audio data pts always 0.
 I added the  avfilter_copy_buffer_ref_props(outref, insamples); call to
 copy original pts to new samplesref and it seems to fix the problem.

 static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef
     int16_t *taps, *endin, *in, *out;
     AVFilterBufferRef *outref =
         avfilter_get_audio_buffer(inlink, AV_PERM_WRITE,
 +   avfilter_copy_buffer_ref_props(outref, insamples);//<<--copy pts

     taps  = ((EarwaxContext*)inlink->dst->priv)->taps;
     out   = (int16_t*)outref->data[0];
     in    = (int16_t*)insamples->data[0];

 second, I guess we should add packing negotiate code to af_sox filter's
 query_formats ,
 static int query_formats(AVFilterContext *ctx)
     AVFilterFormats *formats = NULL;
     avfilter_add_format(&formats, AV_SAMPLE_FMT_S32);
     avfilter_set_common_sample_formats(ctx, formats);
 +    avfilter_set_common_packing_formats(ctx,
 avfilter_all_packing_formats());// << ---- packing negotiation

     return 0;

 otherwise avfilter_graph_config call will fail at
 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
             else if (link->type == AVMEDIA_TYPE_AUDIO) {
                 if (!link->in_chlayouts || !link->out_chlayouts ||
                     !link->in_packing   || !link->out_packing)
                     return AVERROR(EINVAL); <<------fail at here

                 if (!avfilter_merge_formats(link->in_formats,
                                             link->out_formats)    ||
                                             link->out_chlayouts)  ||

 best regards

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/375>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker

More information about the FFmpeg-trac mailing list