Support biCompression I420

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@12821 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavdevice/vfwcap.c

@@ -96,6 +96,8 @@ static enum PixelFormat vfw_pixfmt(DWORD biCompression, WORD biBitCount)
     switch(biCompression) {
     case MKTAG('Y', 'U', 'Y', '2'):
         return PIX_FMT_YUYV422;
+    case MKTAG('I', '4', '2', '0'):
+        return PIX_FMT_YUV420P;
     case BI_RGB:
         switch(biBitCount) { /* 1-8 are untested */
             case 1: