func: void avfilter_link_free(AVFilterLink **link)
  
  {
  
      if (!*link)
  
          return;
  
  
  
      if ((*link)->pool) {
  
          int i;
  
          for (i = 0; i < POOL_SIZE; i++) {
  
              if ((*link)->pool->pic[i]) {
  
                  AVFilterBufferRef *picref = (*link)->pool->pic[i];
  
                  /* free buffer: picrefs stored in the pool are not
  
                   * supposed to contain a free callback */
  
                  av_freep(&picref->buf->data[0]);
  
                  av_freep(&picref->buf);
  
  
  
                  av_freep(&picref->audio);
  
                  av_freep(&picref->video);
  
                  av_freep(&picref);
  
              }
  
          }
  
          av_freep(&(*link)->pool);
  
      }
  
      av_freep(link);
  
  }
  