path: root/demux/demux_mkv.c
diff options
authorwm4 <wm4@nowhere>2013-11-28 15:10:45 +0100
committerwm4 <wm4@nowhere>2013-11-28 15:20:33 +0100
commitdc0b2046cdeb0bbf78e7012d9eafa29a2888b1ec (patch)
treee8fdb97e22f2ef067ded7f53a9b21153432b998e /demux/demux_mkv.c
parentd9b5dedfe95dc9b24e6c59c33044396187918bc2 (diff)
video: add insane hack to work around FFmpeg/Libav insanity
So, FFmpeg/Libav requires us to figure out video timestamps ourselves (see last 10 commits or so), but the methods it provides for this aren't even sufficient. In particular, everything that uses AVI-style DTS (avi, vfw-muxed mkv, possibly mpeg4-in-ogm) with a codec that has an internal frame delay is broken. In this case, libavcodec will shift the packet- to-image correspondence by the codec delay, meaning that with a delay=1, the first AVFrame.pkt_dts is not 0, but that of the second packet. All timestamps will appear shifted. The start time (e.g. the time displayed when doing "mpv file.avi --pause") will not be exactly 0. (According to Libav developers, this is how it's supposed to work; just that the first DTS values are normally negative with formats that use DTS "properly". Who cares if it doesn't work at all with very common video formats? There's no indication that they'll fix this soon, either. An elegant workaround is missing too.) Add a hack to re-enable the old PTS code for AVI and vfw-muxed MKV. Since these timestamps are not reorderd, we wouldn't need to sort them, but it's less code this way (and possibly more robust, should a demuxer unexpectedly output PTS). The original intention of all the timestamp changes recently was actually to get rid of demuxer-specific hacks and the old timestamp sorting code, but it looks like this didn't work out. Yet another case where trying to replace native MPlayer functionality with FFmpeg/Libav led to disadvantages and bugs. (Note that the old PTS sorting code doesn't and can't handle frame dropping correctly, though.) Bug reports:
Diffstat (limited to 'demux/demux_mkv.c')
1 files changed, 1 insertions, 0 deletions
diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index b0e7ed0ac2..f4f78bc70c 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -1338,6 +1338,7 @@ static int demux_mkv_open_video(demuxer_t *demuxer, mkv_track_t *track)
sh_v->disp_h = track->v_dheight;
mp_msg(MSGT_DEMUX, MSGL_V, "[mkv] Aspect: %f\n", sh_v->aspect);
+ sh_v->avi_dts = track->ms_compat;
return 0;