[FFmpeg-cvslog] flvdec: Check index for being valid

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Thu Dec 29 23:22:41 2011 +0100| [df0bff6643cadbd9c07bbe2b0536a7c9d0dfe0c6] | committer: Michael Niedermayer

flvdec: Check index for being valid
Fixes seeking in Enigma_Principles_of_Lust.flv

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=df0bff6643cadbd9c07bbe2b0536a7c9d0dfe0c6
---

 libavformat/flvdec.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index 57ef061..2e50320 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -200,7 +200,16 @@ static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, AVStream
         }
     }
 
-    if (timeslen == fileposlen && fileposlen && max_pos <= filepositions[0]) {
+    if (timeslen == fileposlen && fileposlen>1 && max_pos <= filepositions[0]) {
+        int64_t dts, size0, size1;
+        avio_seek(ioc, filepositions[1]-4, SEEK_SET);
+        size0 = avio_rb32(ioc);
+                avio_r8(ioc);
+        size1 = avio_rb24(ioc);
+        dts   = avio_rb24(ioc);
+        dts  |= avio_r8(ioc) << 24;
+        if (size0 > filepositions[1] || FFABS(dts - times[1]*1000)>5000)
+            goto finish;
          for(i = 0; i < timeslen; i++)
              av_add_index_entry(vstream, filepositions[i], times[i]*1000, 0, 0, AVINDEX_KEYFRAME);
     } else