riff: add dvis/pdvc FourCCs

samples:

http://www.datafilehost.com/download-4b49270d.htmlSigned-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/riff.c

@@ -120,6 +120,8 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { CODEC_ID_DVVIDEO,      MKTAG('d', 'v', 'c', ' ') },
     { CODEC_ID_DVVIDEO,      MKTAG('d', 'v', 'c', 's') },
     { CODEC_ID_DVVIDEO,      MKTAG('d', 'v', 'h', '1') },
+    { CODEC_ID_DVVIDEO,      MKTAG('d', 'v', 'i', 's') },
+    { CODEC_ID_DVVIDEO,      MKTAG('p', 'd', 'v', 'c') },
     { CODEC_ID_DVVIDEO,      MKTAG('S', 'L', '2', '5') },
     { CODEC_ID_DVVIDEO,      MKTAG('S', 'L', 'D', 'V') },
     { CODEC_ID_MPEG1VIDEO,   MKTAG('m', 'p', 'g', '1') },