gif decoder use get_buffer, so set DR1

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@18990 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/gifdec.c

@@ -335,5 +335,6 @@ AVCodec gif_decoder = {
     NULL,
     gif_decode_close,
     gif_decode_frame,
+    CODEC_CAP_DR1,
     .long_name = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
 };