m4v/m4a are usual itunes/ipod/iphone extensions

Originally committed as revision 13737 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/movenc.c

@@ -1690,7 +1690,7 @@ AVOutputFormat mp4_muxer = {
     "mp4",
     NULL_IF_CONFIG_SMALL("MP4 format"),
     "application/mp4",
-    "mp4,m4a",
+    "mp4",
     sizeof(MOVContext),
     CODEC_ID_AAC,
     CODEC_ID_MPEG4,
@@ -1738,7 +1738,7 @@ AVOutputFormat ipod_muxer = {
     "ipod",
     NULL_IF_CONFIG_SMALL("iPod H.264 MP4 format"),
     "application/mp4",
-    NULL,
+    "m4v,m4a",
     sizeof(MOVContext),
     CODEC_ID_AAC,
     CODEC_ID_H264,