add T263. works on samples/V-codecs/T263/

Originally committed as revision 16685 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/riff.c

@@ -34,6 +34,7 @@ const AVCodecTag codec_bmp_tags[] = {
     { CODEC_ID_H264,         MKTAG('V', 'S', 'S', 'H') },
     { CODEC_ID_H263,         MKTAG('H', '2', '6', '3') },
     { CODEC_ID_H263,         MKTAG('X', '2', '6', '3') },
+    { CODEC_ID_H263,         MKTAG('T', '2', '6', '3') },
     { CODEC_ID_H263,         MKTAG('L', '2', '6', '3') },
     { CODEC_ID_H263,         MKTAG('V', 'X', '1', 'K') },
     { CODEC_ID_H263P,        MKTAG('H', '2', '6', '3') },