riff: Add "S263" FourCC

libavformat/riff.c

@@ -275,6 +275,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_ZLIB,         MKTAG('Z', 'L', 'I', 'B') },
     { AV_CODEC_ID_4XM,          MKTAG('4', 'X', 'M', 'V') },
     { AV_CODEC_ID_FLV1,         MKTAG('F', 'L', 'V', '1') },
+    { AV_CODEC_ID_FLV1,         MKTAG('S', '2', '6', '3') },
     { AV_CODEC_ID_FLASHSV,      MKTAG('F', 'S', 'V', '1') },
     { AV_CODEC_ID_SVQ1,         MKTAG('s', 'v', 'q', '1') },
     { AV_CODEC_ID_TSCC,         MKTAG('t', 's', 'c', 'c') },