rawvideo codec: support PIX_FMT_BGR48LE and PIX_FMT_BGR48BE

Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavcodec/raw.c

@@ -102,6 +102,8 @@ const PixelFormatTag ff_raw_pix_fmt_tags[] = {
     { PIX_FMT_BGR4_BYTE,MKTAG('R', '4', 'B', 'Y') },
     { PIX_FMT_RGB48LE,  MKTAG('R', 'G', 'B', 48 ) },
     { PIX_FMT_RGB48BE,  MKTAG( 48, 'R', 'G', 'B') },
+    { PIX_FMT_BGR48LE,  MKTAG('B', 'G', 'R', 48 ) },
+    { PIX_FMT_BGR48BE,  MKTAG( 48, 'B', 'G', 'R') },
     { PIX_FMT_GRAY16LE,    MKTAG('Y', '1',  0 , 16 ) },
     { PIX_FMT_GRAY16BE,    MKTAG(16 ,  0 , '1', 'Y') },
     { PIX_FMT_YUV420P16LE, MKTAG('Y', '3', 11 , 16 ) },