@@ -638,6 +638,7 @@ void choose_sample_fmt(AVStream *st, AVCodec *codec);

 int configure_filtergraph(FilterGraph *fg);

 int configure_output_filter(FilterGraph *fg, OutputFilter *ofilter, AVFilterInOut *out);

+void check_filter_outputs(void);

 int ist_in_filtergraph(FilterGraph *fg, InputStream *ist);

 int filtergraph_is_simple(FilterGraph *fg);

 int init_simple_filtergraph(InputStream *ist, OutputStream *ost);

@@ -678,6 +678,21 @@ int configure_output_filter(FilterGraph *fg, OutputFilter *ofilter, AVFilterInOu

     }

 }

+void check_filter_outputs(void)

+{

+    int i;

+    for (i = 0; i < nb_filtergraphs; i++) {

+        int n;

+        for (n = 0; n < filtergraphs[i]->nb_outputs; n++) {

+            OutputFilter *output = filtergraphs[i]->outputs[n];

+            if (!output->ost) {

+                av_log(NULL, AV_LOG_FATAL, "Filter %s has an unconnected output\n", output->name);

+                exit_program(1);

+            }

+        }

+    }

+}

+

 static int sub2video_prepare(InputStream *ist, InputFilter *ifilter)

 {

     AVFormatContext *avf = input_files[ist->file_index]->ctx;

@@ -3260,6 +3260,8 @@ int ffmpeg_parse_options(int argc, char **argv)

         goto fail;

     }

+    check_filter_outputs();

+

 fail:

     uninit_parse_context(&octx);

     if (ret < 0) {