[FFmpeg-cvslog] lavf/matroskaenc: Force the minimum value for -reserve_index_space to 2.

[Carl Eugen Hoyos]

ffmpeg | branch: master | Carl Eugen Hoyos <ceffmpeg at gmail.com> | Sun Feb 11 20:41:32 2018 +0100| [d401ba6b3d86091dff2fae326c610f0120ee8853] | committer: Carl Eugen Hoyos

lavf/matroskaenc: Force the minimum value for -reserve_index_space to 2.

Fixes an assertion failure:
Assertion size >= 2 failed at libavformat/matroskaenc.c:298

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d401ba6b3d86091dff2fae326c610f0120ee8853
---

 libavformat/matroskaenc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index f22c2ab70c..5950b4de44 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -2001,6 +2001,8 @@ static int mkv_write_header(AVFormatContext *s)
     }
     if ((pb->seekable & AVIO_SEEKABLE_NORMAL) && mkv->reserve_cues_space) {
         mkv->cues_pos = avio_tell(pb);
+        if (mkv->reserve_cues_space == 1)
+            mkv->reserve_cues_space++;
         put_ebml_void(pb, mkv->reserve_cues_space);
     }