Doxy for ff_match_2uint16().

Originally committed as revision 21115 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/internal.h

@@ -42,6 +42,10 @@ int ff_is_hwaccel_pix_fmt(enum PixelFormat pix_fmt);
  */
 AVHWAccel *ff_find_hwaccel(enum CodecID codec_id, enum PixelFormat pix_fmt);
 
+/**
+ * Return the index into tab at which {a,b} match elements {[0],[1]} of tab.
+ * If there is no such matching pair then size is returned.
+ */
 int ff_match_2uint16(const uint16_t (*tab)[2], int size, int a, int b);
 
 #endif /* AVCODEC_INTERNAL_H */