[FFmpeg-cvslog] avformat/vobsub: do not attempt to check duplicate subtitles

[wm4]

ffmpeg | branch: master | wm4 <nfxjfg at googlemail.com> | Mon Sep 21 13:43:32 2015 +0200| [5c93e57f5c07b52f04363c178c4fc1892c0d71aa] | committer: wm4

avformat/vobsub: do not attempt to check duplicate subtitles

Some .idx files actually contain duplicate subtitle events:

timestamp: 00:07:52:600, filepos: 00004e800
timestamp: 00:07:52:600, filepos: 00004f800

The second will be dropped, because it has same pts, duration, and text
(the text is just a dummy empty string; the real data is retrieved when
actually reading vobsub subtitle packets).

Dropping this is probably not intended/safe, so avoid it.

See trac issue #4872 for a sample. This patch doesn't fix decoding of
the sample, though.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5c93e57f5c07b52f04363c178c4fc1892c0d71aa
---

 libavformat/mpeg.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index a63b567..55f2b3f 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -857,6 +857,7 @@ static int vobsub_read_header(AVFormatContext *s)
 
     for (i = 0; i < s->nb_streams; i++) {
         vobsub->q[i].sort = SUB_SORT_POS_TS;
+        vobsub->q[i].keep_duplicates = 1;
         ff_subtitles_queue_finalize(s, &vobsub->q[i]);
     }