Prevent NULL dereferences when the previous frame is missing in vmd video decoder.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Laurent Aimar 2011-09-24 23:16:19 +02:00 committed by Michael Niedermayer
parent e7aed1280e
commit 6a6383bebc

View File

@ -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;