Fix problems with FFmpeg files that have all-zero stream IDs.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/lib/ffmpeg.cc b/src/lib/ffmpeg.cc
index e85a2c44e..e5e5f317a 100644
--- a/src/lib/ffmpeg.cc
+++ b/src/lib/ffmpeg.cc
@@ -118,6 +118,24 @@ FFmpeg::setup_general ()
 		throw DecodeError (N_("could not find video stream"));
 	}
 
+	/* Hack: if the AVStreams have zero IDs, put some in.  We
+	   use the IDs so that we can cope with VOBs, in which streams
+	   move about in index but remain with the same ID in different
+	   VOBs.  However, some files have all-zero IDs, hence this hack.
+	*/
+	   
+	uint32_t i = 0;
+	while (i < _format_context->nb_streams && _format_context->streams[i]->id == 0) {
+		++i;
+	}
+
+	if (i == _format_context->nb_streams) {
+		/* Put in our own IDs */
+		for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
+			_format_context->streams[i]->id = i;
+		}
+	}
+
 	_frame = avcodec_alloc_frame ();
 	if (_frame == 0) {
 		throw DecodeError (N_("could not allocate frame"));