Correct tag is m2v1

Originally committed as revision 25271 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/isom.c

@@ -132,7 +132,7 @@ const AVCodecTag codec_movvideo_tags[] = {
 
     { CODEC_ID_MPEG1VIDEO, MKTAG('m', '1', 'v', '1') }, /* Apple MPEG-1 Camcorder */
     { CODEC_ID_MPEG1VIDEO, MKTAG('m', 'p', 'e', 'g') }, /* MPEG */
-    { CODEC_ID_MPEG2VIDEO, MKTAG('m', '2', 'v', '2') }, /* Apple MPEG-2 Camcorder */
+    { CODEC_ID_MPEG2VIDEO, MKTAG('m', '2', 'v', '1') }, /* Apple MPEG-2 Camcorder */
     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '1') }, /* MPEG2 HDV 720p30 */
     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '2') }, /* MPEG2 HDV 1080i60 */
     { CODEC_ID_MPEG2VIDEO, MKTAG('h', 'd', 'v', '3') }, /* MPEG2 HDV 1080i50 */