@@ -121,6 +121,8 @@ int av_buffersrc_add_ref(AVFilterContext *s, AVFilterBufferRef *buf, int flags)

             CHECK_VIDEO_PARAM_CHANGE(s, c, buf->video->w, buf->video->h, buf->format);

             break;

         case AVMEDIA_TYPE_AUDIO:

+            if (!buf->audio->channel_layout)

+                buf->audio->channel_layout = c->channel_layout;

             CHECK_AUDIO_PARAM_CHANGE(s, c, buf->audio->sample_rate, buf->audio->channel_layout,

                                      buf->format);

             break;

@@ -370,6 +372,8 @@ static int config_props(AVFilterLink *link)

         link->sample_aspect_ratio = c->pixel_aspect;

         break;

     case AVMEDIA_TYPE_AUDIO:

+        if (!c->channel_layout)

+            c->channel_layout = link->channel_layout;

         break;

     default:

         return AVERROR(EINVAL);