@@ -162,6 +162,29 @@ static int open_stream(void *log, MovieStream *st)

     return 0;

 }

+static int guess_channel_layout(MovieStream *st, int st_index, void *log_ctx)

+{

+    AVCodecContext *dec_ctx = st->st->codec;

+    char buf[256];

+    int64_t chl = av_get_default_channel_layout(dec_ctx->channels);

+

+    if (!chl) {

+        av_log(log_ctx, AV_LOG_ERROR,

+               "Channel layout is not set in stream %d, and could not "

+               "be guessed from the number of channels (%d)\n",

+               st_index, dec_ctx->channels);

+        return AVERROR(EINVAL);

+    }

+

+    av_get_channel_layout_string(buf, sizeof(buf), dec_ctx->channels, chl);

+    av_log(log_ctx, AV_LOG_WARNING,

+           "Channel layout is not set in output stream %d, "

+           "guessed channel layout is '%s'\n",

+           st_index, buf);

+    dec_ctx->channel_layout = chl;

+    return 0;

+}

+

 static av_cold int movie_init(AVFilterContext *ctx, const char *args)

 {

     MovieContext *movie = ctx->priv;

@@ -282,6 +305,12 @@ static av_cold int movie_init(AVFilterContext *ctx, const char *args)

         ret = open_stream(ctx, &movie->st[i]);

         if (ret < 0)

             return ret;

+        if ( movie->st[i].st->codec->codec->type == AVMEDIA_TYPE_AUDIO &&

+            !movie->st[i].st->codec->channel_layout) {

+            ret = guess_channel_layout(&movie->st[i], i, ctx);

+            if (ret < 0)

+                return ret;

+        }

     }

     if (!(movie->frame = avcodec_alloc_frame()) ) {

@@ -337,8 +366,7 @@ static int movie_query_formats(AVFilterContext *ctx)

             ff_formats_ref(ff_make_format_list(list), &outlink->in_formats);

             list[0] = c->sample_rate;

             ff_formats_ref(ff_make_format_list(list), &outlink->in_samplerates);

-            list64[0] = c->channel_layout ? c->channel_layout :

-                        av_get_default_channel_layout(c->channels);

+            list64[0] = c->channel_layout;

             ff_channel_layouts_ref(avfilter_make_format64_list(list64),

                                    &outlink->in_channel_layouts);

             break;