rv10: check size of s->mb_width * s->mb_height

If it doesn't fit into 12 bits it triggers an assertion.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 7 insertions, 1 deletions

diff --git a/libavcodec/rv10enc.c b/libavcodec/rv10enc.c
index ca760524a8..2eca9c3c88 100644
--- a/libavcodec/rv10enc.c
+++ b/libavcodec/rv10enc.c
@@ -28,7 +28,7 @@
 #include "mpegvideo.h"
 #include "put_bits.h"
 
-void ff_rv10_encode_picture_header(MpegEncContext *s, int picture_number)
+int ff_rv10_encode_picture_header(MpegEncContext *s, int picture_number)
 {
     int full_frame= 0;
 
@@ -48,12 +48,18 @@ void ff_rv10_encode_picture_header(MpegEncContext *s, int picture_number)
     /* if multiple packets per frame are sent, the position at which
        to display the macroblocks is coded here */
     if(!full_frame){
+        if (s->mb_width * s->mb_height >= (1U << 12)) {
+            avpriv_report_missing_feature(s->avctx, "Encoding frames with %d (>= 4096) macroblocks",
+                                          s->mb_width * s->mb_height);
+            return AVERROR(ENOSYS);
+        }
         put_bits(&s->pb, 6, 0); /* mb_x */
         put_bits(&s->pb, 6, 0); /* mb_y */
         put_bits(&s->pb, 12, s->mb_width * s->mb_height);
     }
 
     put_bits(&s->pb, 3, 0);     /* ignored */
+    return 0;
 }
 
 FF_MPV_GENERIC_CLASS(rv10)