avcodec/libopenjpegdec: Set key frame metadata

Signed-off-by: Michael Bradshaw <mjbshaw@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/libopenjpegdec.c

@@ -546,6 +546,8 @@ static int libopenjpeg_decode_frame(AVCodecContext *avctx,
     }
 
     *got_frame = 1;
+    picture->pict_type = AV_PICTURE_TYPE_I;
+    picture->key_frame = 1;
     ret        = buf_size;
 
 done: