Drop the unofficial extension prefix for MPEG and MPEG-TS formats

As per the RFCs:
http://tools.ietf.org/html/rfc3555#page-38
http://tools.ietf.org/html/rfc3003

CC: libav-stable@libav.org

libavformat/mp3enc.c

@@ -435,7 +435,7 @@ static int mp3_write_trailer(struct AVFormatContext *s)
 AVOutputFormat ff_mp2_muxer = {
     .name              = "mp2",
     .long_name         = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
-    .mime_type         = "audio/x-mpeg",
+    .mime_type         = "audio/mpeg",
     .extensions        = "mp2,m2a,mpa",
     .audio_codec       = AV_CODEC_ID_MP2,
     .video_codec       = AV_CODEC_ID_NONE,
@@ -577,7 +577,7 @@ static int mp3_write_header(struct AVFormatContext *s)
 AVOutputFormat ff_mp3_muxer = {
     .name              = "mp3",
     .long_name         = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
-    .mime_type         = "audio/x-mpeg",
+    .mime_type         = "audio/mpeg",
     .extensions        = "mp3",
     .priv_data_size    = sizeof(MP3Context),
     .audio_codec       = AV_CODEC_ID_MP3,

libavformat/mpegtsenc.c

@@ -1269,7 +1269,7 @@ static const AVClass mpegts_muxer_class = {
 AVOutputFormat ff_mpegts_muxer = {
     .name           = "mpegts",
     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-TS (MPEG-2 Transport Stream)"),
-    .mime_type      = "video/x-mpegts",
+    .mime_type      = "video/MP2T",
     .extensions     = "ts,m2t,m2ts,mts",
     .priv_data_size = sizeof(MpegTSWrite),
     .audio_codec    = AV_CODEC_ID_MP2,

libavformat/rawenc.c

@@ -222,7 +222,7 @@ AVOutputFormat ff_mlp_muxer = {
 AVOutputFormat ff_mpeg1video_muxer = {
     .name              = "mpeg1video",
     .long_name         = NULL_IF_CONFIG_SMALL("raw MPEG-1 video"),
-    .mime_type         = "video/x-mpeg",
+    .mime_type         = "video/mpeg",
     .extensions        = "mpg,mpeg,m1v",
     .audio_codec       = AV_CODEC_ID_NONE,
     .video_codec       = AV_CODEC_ID_MPEG1VIDEO,