add mpeg2 fourcc and aac format tag from asf

Originally committed as revision 16036 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/riff.c

@@ -100,6 +100,7 @@ const AVCodecTag codec_bmp_tags[] = {
     { CODEC_ID_MPEG2VIDEO,   MKTAG( 2 ,  0 ,  0 ,  16) },
     { CODEC_ID_MPEG2VIDEO,   MKTAG('D', 'V', 'R', ' ') },
     { CODEC_ID_MPEG2VIDEO,   MKTAG('M', 'M', 'E', 'S') },
+    { CODEC_ID_MPEG2VIDEO,   MKTAG('L', 'M', 'P', '2') }, /* Lead MPEG2 in avi */
     { CODEC_ID_MJPEG,        MKTAG('M', 'J', 'P', 'G') },
     { CODEC_ID_MJPEG,        MKTAG('L', 'J', 'P', 'G') },
     { CODEC_ID_MJPEG,        MKTAG('d', 'm', 'b', '1') },
@@ -220,6 +221,7 @@ const AVCodecTag codec_wav_tags[] = {
     { CODEC_ID_SONIC,           0x2048 },
     { CODEC_ID_SONIC_LS,        0x2048 },
     { CODEC_ID_AAC,             0x706d },
+    { CODEC_ID_AAC,             0x4143 },
     { CODEC_ID_FLAC,            0xF1AC },
     { CODEC_ID_ADPCM_SWF,       ('S'<<8)+'F' },
     { CODEC_ID_VORBIS,          ('V'<<8)+'o' }, //HACK/FIXME, does vorbis in WAV/AVI have an (in)official id?