[FFmpeg-cvslog] mpeg4: use a self-explanatory #define MAX_NVOP_SIZE

[Andreas Cadhalpun]

ffmpeg | branch: master | Andreas Cadhalpun <andreas.cadhalpun at googlemail.com> | Fri Apr  3 19:14:16 2015 +0200| [f62880bfb8c72ccbfdce4dd9daf93af691060ddd] | committer: Michael Niedermayer

mpeg4: use a self-explanatory #define MAX_NVOP_SIZE

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f62880bfb8c72ccbfdce4dd9daf93af691060ddd
---

 libavcodec/h263dec.c    |    2 +-
 libavcodec/mpeg4video.h |    3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index a1981a3..c28a465 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -459,7 +459,7 @@ retry:
         }
     }
 
-    if (s->bitstream_buffer_size && (s->divx_packed || buf_size < 20)) // divx 5.01+/xvid frame reorder
+    if (s->bitstream_buffer_size && (s->divx_packed || buf_size <= MAX_NVOP_SIZE)) // divx 5.01+/xvid frame reorder
         ret = init_get_bits8(&s->gb, s->bitstream_buffer,
                              s->bitstream_buffer_size);
     else
diff --git a/libavcodec/mpeg4video.h b/libavcodec/mpeg4video.h
index e83692c..43650bb 100644
--- a/libavcodec/mpeg4video.h
+++ b/libavcodec/mpeg4video.h
@@ -59,6 +59,9 @@
 #define VISUAL_OBJ_STARTCODE 0x1B5
 #define VOP_STARTCODE        0x1B6
 
+/* smaller packets likely don't contain a real frame */
+#define MAX_NVOP_SIZE 19
+
 typedef struct Mpeg4DecContext {
     MpegEncContext m;