[FFmpeg-cvslog] lavf: compute probe buffer size more reliably.

[Nicolas George]

ffmpeg | branch: release/0.11 | Nicolas George <nicolas.george at normalesup.org> | Tue Dec  4 19:49:51 2012 +0100| [d3835cb87714bece30e6ce748c9f11ca640859da] | committer: Carl Eugen Hoyos

lavf: compute probe buffer size more reliably.

The previous code computes the offset by reversing the growth
of the allocated buffer size: it is complex and did lead to
inconsistencies when the size limit is reached.

Fix trac ticket #1991.
(cherry picked from commit 03847eb8259291b4ff1bd840bd779d0699d71f96)

Conflicts:
	libavformat/utils.c
(cherry picked from commit e74cd2f4706f71da5e9205003c1d8263b54ed3fb)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d3835cb87714bece30e6ce748c9f11ca640859da
---

 libavformat/utils.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index ca97b91..fd0b10b 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -460,7 +460,7 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
 {
     AVProbeData pd = { filename ? filename : "", NULL, -offset };
     unsigned char *buf = NULL;
-    int ret = 0, probe_size;
+    int ret = 0, probe_size, buf_offset = 0;
 
     if (!max_probe_size) {
         max_probe_size = PROBE_BUF_MAX;
@@ -500,7 +500,7 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
             score = 0;
             ret = 0;            /* error was end of file, nothing read */
         }
-        pd.buf_size += ret;
+        pd.buf_size = buf_offset += ret;
         pd.buf = &buf[offset];
 
         memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);