[FFmpeg-cvslog] avformat/mov: prevent duplication of first fragment's ctts_data

[Daniel Glöckner]

ffmpeg | branch: master | Daniel Glöckner <daniel-gl at gmx.net> | Sun Aug  6 03:04:53 2017 +0200| [feb1dbc7bd4c395400c48055c563ac23d5251716] | committer: Michael Niedermayer

avformat/mov: prevent duplication of first fragment's ctts_data

MP4 files with fragments might have the first moof box that is mentioned
in a fragment index before the first mdat box. Since it is then already
parsed by mov_read_header, we have to make sure that mov_switch_root
will not parse it again when seeking by setting the headers_read flag in
the index. Parsing it a second time would cause the ctts_data array to
receive a second copy of the information from the trun box, leading to
wrong PTS values for the second and following fragments in presence of
B-frames.

Fixes ticket 6560.

Signed-off-by: Daniel Glöckner <daniel-gl at gmx.net>
Reviewed-by: Dale Curtis <dalecurtis at chromium.org>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=feb1dbc7bd4c395400c48055c563ac23d5251716
---

 libavformat/mov.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 89b2af7597..994e9c6eba 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -6363,6 +6363,13 @@ static int mov_read_header(AVFormatContext *s)
     }
     ff_configure_buffers_for_index(s, AV_TIME_BASE);
 
+    for (i = 0; i < mov->fragment_index_count; i++) {
+        MOVFragmentIndex *idx = mov->fragment_index_data[i];
+        for (j = 0; j < idx->item_count; j++)
+            if (idx->items[j].moof_offset <= mov->fragment.moof_offset)
+                idx->items[j].headers_read = 1;
+    }
+
     return 0;
 }