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| author | Laurent Aimar <fenrir@videolan.org> | 2011-09-24 23:16:19 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2011-10-01 20:24:46 +0200 |
| commit | d92bfc98f9f64fa891ee4a3640ba6c55e90540ef (patch) | |
| tree | 08543d9381f06d559e20da6d32228c2968a8a84c | |
| parent | 1ed90c84f6ab75af91b08436cefb8ea464f8495b (diff) | |
| download | ffmpeg-d92bfc98f9f64fa891ee4a3640ba6c55e90540ef.tar.gz | |
Prevent NULL dereferences when the previous frame is missing in vmd video decoder.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 6a6383bebcb03a785797007031ad1c9786a508a5)
| -rw-r--r-- | libavcodec/vmdav.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/libavcodec/vmdav.c b/libavcodec/vmdav.c index d7cd3bbb87..f5f8598919 100644 --- a/libavcodec/vmdav.c +++ b/libavcodec/vmdav.c @@ -226,8 +226,9 @@ static void vmd_decode(VmdVideoContext *s) /* if only a certain region will be updated, copy the entire previous * frame before the decode */ - if (frame_x || frame_y || (frame_width != s->avctx->width) || - (frame_height != s->avctx->height)) { + if (s->prev_frame.data[0] && + (frame_x || frame_y || (frame_width != s->avctx->width) || + (frame_height != s->avctx->height))) { memcpy(s->frame.data[0], s->prev_frame.data[0], s->avctx->height * s->frame.linesize[0]); @@ -272,7 +273,7 @@ static void vmd_decode(VmdVideoContext *s) ofs += len; } else { /* interframe pixel copy */ - if (ofs + len + 1 > frame_width) + if (ofs + len + 1 > frame_width || !s->prev_frame.data[0]) return; memcpy(&dp[ofs], &pp[ofs], len + 1); ofs += len + 1; @@ -312,7 +313,7 @@ static void vmd_decode(VmdVideoContext *s) ofs += len; } else { /* interframe pixel copy */ - if (ofs + len + 1 > frame_width) + if (ofs + len + 1 > frame_width || !s->prev_frame.data[0]) return; memcpy(&dp[ofs], &pp[ofs], len + 1); ofs += len + 1; |