sn40 avi fourcc decodes with ffodivx

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@17928 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/riff.c

@@ -74,6 +74,7 @@ const AVCodecTag codec_bmp_tags[] = {
     { CODEC_ID_MPEG4,        MKTAG('E', 'P', 'H', 'V') }, /* Ephv MPEG-4 */
     { CODEC_ID_MPEG4,        MKTAG('E', 'M', '4', 'A') },
     { CODEC_ID_MPEG4,        MKTAG('M', '4', 'C', 'C') }, /* Divio MPEG-4 */
+    { CODEC_ID_MPEG4,        MKTAG('S', 'N', '4', '0') },
     { CODEC_ID_MSMPEG4V3,    MKTAG('D', 'I', 'V', '3') }, /* default signature when using MSMPEG4 */
     { CODEC_ID_MSMPEG4V3,    MKTAG('M', 'P', '4', '3') },
     { CODEC_ID_MSMPEG4V3,    MKTAG('M', 'P', 'G', '3') },