support SVQ1 in AVI files, just for fun

Originally committed as revision 3112 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/avienc.c

@@ -160,6 +160,7 @@ const CodecTag codec_bmp_tags[] = {
     { CODEC_ID_ZLIB, MKTAG('Z', 'L', 'I', 'B') },
     { CODEC_ID_4XM, MKTAG('4', 'X', 'M', 'V') },
     { CODEC_ID_FLV1, MKTAG('F', 'L', 'V', '1') },
+    { CODEC_ID_SVQ1, MKTAG('s', 'v', 'q', '1') },
     { 0, 0 },
 };