@@ -2852,7 +2852,10 @@ static void opt_input_file(const char *filename)

     int64_t timestamp;

     if (last_asked_format) {

-        file_iformat = av_find_input_format(last_asked_format);

+        if (!(file_iformat = av_find_input_format(last_asked_format))) {

+            fprintf(stderr, "Unknown input format: '%s'\n", last_asked_format);

+            av_exit(1);

+        }

         last_asked_format = NULL;

     }