@@ -395,6 +395,19 @@ void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)

 /** Default handler for query_formats() */

 int avfilter_default_query_formats(AVFilterContext *ctx);

+/** start_frame() handler for filters which simply pass video along */

+void avfilter_null_start_frame(AVFilterLink *link, AVFilterPicRef *picref);

+

+/** draw_slice() handler for filters which simply pass video along */

+void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir);

+

+/** end_frame() handler for filters which simply pass video along */

+void avfilter_null_end_frame(AVFilterLink *link);

+

+/** get_video_buffer() handler for filters which simply pass video along */

+AVFilterPicRef *avfilter_null_get_video_buffer(AVFilterLink *link,

+                                                  int perms, int w, int h);

+

 /**

  * Filter definition. This defines the pads a filter contains, and all the

  * callback functions used to interact with the filter.

@@ -165,3 +165,23 @@ int avfilter_default_query_formats(AVFilterContext *ctx)

     return 0;

 }

+void avfilter_null_start_frame(AVFilterLink *link, AVFilterPicRef *picref)

+{

+    avfilter_start_frame(link->dst->outputs[0], picref);

+}

+

+void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)

+{

+    avfilter_draw_slice(link->dst->outputs[0], y, h, slice_dir);

+}

+

+void avfilter_null_end_frame(AVFilterLink *link)

+{

+    avfilter_end_frame(link->dst->outputs[0]);

+}

+

+AVFilterPicRef *avfilter_null_get_video_buffer(AVFilterLink *link, int perms, int w, int h)

+{

+    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);

+}

+