Fix implicit declaration warning.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@21114 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/internal.h

@@ -42,4 +42,6 @@ int ff_is_hwaccel_pix_fmt(enum PixelFormat pix_fmt);
  */
 AVHWAccel *ff_find_hwaccel(enum CodecID codec_id, enum PixelFormat pix_fmt);
 
+int ff_match_2uint16(const uint16_t (*tab)[2], int size, int a, int b);
+
 #endif /* AVCODEC_INTERNAL_H */