Add FourCC MJPG for CODEC_ID_JPEGLS.

Patch by Francesco Lavra, francescolavra interfree it

Originally committed as revision 23076 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/riff.c

@@ -129,6 +129,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { CODEC_ID_LJPEG,        MKTAG('L', 'J', 'P', 'G') },
     { CODEC_ID_MJPEG,        MKTAG('J', 'P', 'G', 'L') }, /* Pegasus lossless JPEG */
     { CODEC_ID_JPEGLS,       MKTAG('M', 'J', 'L', 'S') }, /* JPEG-LS custom FOURCC for avi - encoder */
+    { CODEC_ID_JPEGLS,       MKTAG('M', 'J', 'P', 'G') },
     { CODEC_ID_MJPEG,        MKTAG('M', 'J', 'L', 'S') }, /* JPEG-LS custom FOURCC for avi - decoder */
     { CODEC_ID_MJPEG,        MKTAG('j', 'p', 'e', 'g') },
     { CODEC_ID_MJPEG,        MKTAG('I', 'J', 'P', 'G') },