Ensure codec_id = CODEC_ID_NONE for unknown codecs (don't reuse previous one).

Patch by Steve Lhomme % slhomme A divxcorp P com %
Original thread:
Date: Mon, 06 Nov 2006 21:20:14 +0100
Subject: [Ffmpeg-devel] [PATCH] Matroska known/unknown codec

Originally committed as revision 6923 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/matroska.c

@@ -2138,11 +2138,11 @@ matroska_read_header (AVFormatContext    *s,
     /* Have we found a cluster? */
     if (res == 1) {
         int i, j;
-        enum CodecID codec_id= CODEC_ID_NONE;
         MatroskaTrack *track;
         AVStream *st;
 
         for (i = 0; i < matroska->num_tracks; i++) {
+            enum CodecID codec_id = CODEC_ID_NONE;
             void *extradata = NULL;
             int extradata_size = 0;
             track = matroska->tracks[i];