[FFmpeg-cvslog] lcl: don't overwrite input memory.

[Ronald S. Bultje]

ffmpeg | branch: master | Ronald S. Bultje <rsbultje at gmail.com> | Wed Feb 22 14:22:56 2012 -0800| [01cb62aba2503b4173f101154f9f840f04f9c7f8] | committer: Ronald S. Bultje

lcl: don't overwrite input memory.

If the PNG filter is enabled, a PNG-style filter will run over the
input buffer, writing into the buffer. Therefore, if no zlib compression
was used, ensure that we copy into a temporary buffer, otherwise we
overwrite user-provided input data.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=01cb62aba2503b4173f101154f9f840f04f9c7f8
---

 libavcodec/lcldec.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/libavcodec/lcldec.c b/libavcodec/lcldec.c
index b66a3ce..a7f0bde 100644
--- a/libavcodec/lcldec.c
+++ b/libavcodec/lcldec.c
@@ -236,9 +236,14 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPac
          * gives a file with ZLIB fourcc, but frame is really uncompressed.
          * To be sure that's true check also frame size */
         if (c->compression == COMP_ZLIB_NORMAL && c->imgtype == IMGTYPE_RGB24 &&
-            len == width * height * 3)
-            break;
-        if (c->flags & FLAG_MULTITHREAD) {
+            len == width * height * 3) {
+            if (c->flags & FLAG_PNGFILTER) {
+                memcpy(c->decomp_buf, encoded, len);
+                encoded = c->decomp_buf;
+            } else {
+                break;
+            }
+        } else if (c->flags & FLAG_MULTITHREAD) {
             int ret;
             mthread_inlen = AV_RL32(encoded);
             mthread_inlen = FFMIN(mthread_inlen, len - 8);