[FFmpeg-cvslog] avformat/movenc: Limit ism_lookahead to a sane value

[Andreas Rheinhardt]

ffmpeg | branch: release/4.4 | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Wed Sep 22 20:36:21 2021 +0200| [8c1899a71bc92387afa38f8438cfd05a33ffb48f] | committer: Andreas Rheinhardt

avformat/movenc: Limit ism_lookahead to a sane value

There can only be a maximum of 255 entries in a tfrf tag, so using
more makes no sense; moreover, several size computations can overflow
in this case. Fix this by limiting it to 255.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
(cherry picked from commit 1cf3c59b58f4380d5ce166a67331777891d06eef)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8c1899a71bc92387afa38f8438cfd05a33ffb48f
---

 libavformat/movenc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 2cd5773dc5..8a06de2fd2 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -91,7 +91,7 @@ static const AVOption options[] = {
     { "frag_duration", "Maximum fragment duration", offsetof(MOVMuxContext, max_fragment_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
     { "min_frag_duration", "Minimum fragment duration", offsetof(MOVMuxContext, min_fragment_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
     { "frag_size", "Maximum fragment size", offsetof(MOVMuxContext, max_fragment_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
-    { "ism_lookahead", "Number of lookahead entries for ISM files", offsetof(MOVMuxContext, ism_lookahead), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
+    { "ism_lookahead", "Number of lookahead entries for ISM files", offsetof(MOVMuxContext, ism_lookahead), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 255, AV_OPT_FLAG_ENCODING_PARAM},
     { "video_track_timescale", "set timescale of all video tracks", offsetof(MOVMuxContext, video_track_timescale), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
     { "brand",    "Override major brand", offsetof(MOVMuxContext, major_brand),   AV_OPT_TYPE_STRING, {.str = NULL}, .flags = AV_OPT_FLAG_ENCODING_PARAM },
     { "use_editlist", "use edit list", offsetof(MOVMuxContext, use_editlist), AV_OPT_TYPE_BOOL, {.i64 = -1}, -1, 1, AV_OPT_FLAG_ENCODING_PARAM},