[FFmpeg-cvslog] lagarith: pad RGB buffer by 1 byte.

Ronald S. Bultje git at videolan.org
Sat Aug 4 23:54:12 CEST 2012


ffmpeg | branch: master | Ronald S. Bultje <rsbultje at gmail.com> | Thu Aug  2 20:46:09 2012 -0700| [98d0d19208959766a58f13dd6a678d1f765a26ac] | committer: Ronald S. Bultje

lagarith: pad RGB buffer by 1 byte.

For left HFYU prediction, we predict from the buffer buf+1 using 8- or
16-byte reads. This means that aligning the buffer by 16 bytes is in
itself not sufficient, because if the width itself is 16- or 8-byte
aligned, the buffer will not be padded, and thus a read of size 16 at
buf+1 will overflow boundaries at the right edge. Padding the buffer by
1 byte is sufficient to not overflow its boundaries.

Fixes bug 342.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=98d0d19208959766a58f13dd6a678d1f765a26ac
---

 libavcodec/lagarith.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c
index 35f5a07..e72674c 100644
--- a/libavcodec/lagarith.c
+++ b/libavcodec/lagarith.c
@@ -553,7 +553,7 @@ static int lag_decode_frame(AVCodecContext *avctx,
 
         if (!l->rgb_planes) {
             l->rgb_stride = FFALIGN(avctx->width, 16);
-            l->rgb_planes = av_malloc(l->rgb_stride * avctx->height * planes);
+            l->rgb_planes = av_malloc(l->rgb_stride * avctx->height * planes + 1);
             if (!l->rgb_planes) {
                 av_log(avctx, AV_LOG_ERROR, "cannot allocate temporary buffer\n");
                 return AVERROR(ENOMEM);



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