riff: support ProRes in avi (APCN fourcc)

libavformat/riff.c

@@ -347,6 +347,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_G2M,          MKTAG('G', '2', 'M', '3') },
     { AV_CODEC_ID_G2M,          MKTAG('G', '2', 'M', '4') },
     { AV_CODEC_ID_FIC,          MKTAG('F', 'I', 'C', 'V') },
+    { AV_CODEC_ID_PRORES,       MKTAG('A', 'P', 'C', 'N') },
     { AV_CODEC_ID_NONE,         0 }
 };