rgba in .mov muxing

Originally committed as revision 18787 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/movenc.c

@@ -616,6 +616,7 @@ static const struct {
     { PIX_FMT_BGR555,  MKTAG('r','a','w',' '), 16 },
     { PIX_FMT_RGB24,   MKTAG('r','a','w',' '), 24 },
     { PIX_FMT_BGR32_1, MKTAG('r','a','w',' '), 32 },
+    { PIX_FMT_RGBA,    MKTAG('R','G','B','A'), 32 },
 };
 
 static int mov_get_rawvideo_codec_tag(AVFormatContext *s, MOVTrack *track)