smacker video decoder uses reget_buffer, set CODEC_CAP_DR1

Originally committed as revision 19103 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/smacker.c

@@ -701,6 +701,7 @@ AVCodec smacker_decoder = {
     NULL,
     decode_end,
     decode_frame,
+    CODEC_CAP_DR1,
     .long_name = NULL_IF_CONFIG_SMALL("Smacker video"),
 };