Support decoding Avid 1:1x codec, (partially) fixes issue1684.

Originally committed as revision 21222 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/raw.c

@@ -52,6 +52,7 @@ const PixelFormatTag ff_raw_pixelFormatTags[] = {
     { PIX_FMT_UYVY422, MKTAG('u', 'y', 'v', '1') },
     { PIX_FMT_UYVY422, MKTAG('2', 'V', 'u', '1') },
     { PIX_FMT_UYVY422, MKTAG('A', 'V', 'R', 'n') }, /* Avid AVI Codec 1:1 */
+    { PIX_FMT_UYVY422, MKTAG('A', 'V', '1', 'x') }, /* Avid 1:1x */
     { PIX_FMT_GRAY8,   MKTAG('G', 'R', 'E', 'Y') },
     { PIX_FMT_RGB555,  MKTAG('R', 'G', 'B', 15) },
     { PIX_FMT_BGR555,  MKTAG('B', 'G', 'R', 15) },

libavformat/isom.c

@@ -171,6 +171,7 @@ const AVCodecTag codec_movvideo_tags[] = {
 
     { CODEC_ID_DIRAC, MKTAG('d', 'r', 'a', 'c') },
     { CODEC_ID_DNXHD, MKTAG('A', 'V', 'd', 'n') }, /* AVID DNxHD */
+    { CODEC_ID_RAWVIDEO, MKTAG('A', 'V', '1', 'x') }, /* AVID 1:1x */
     { CODEC_ID_SGI,   MKTAG('s', 'g', 'i', ' ') }, /* SGI  */
     { CODEC_ID_DPX,   MKTAG('d', 'p', 'x', ' ') }, /* DPX */