[vlc-commits] demux: mp4: avoid audio cuts on seek

[Francois Cartegnie]

vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Fri Oct  6 11:43:17 2017 +0200| [168bd3f8e7283f72250d8753ddb3ad63bc7dd54b] | committer: Francois Cartegnie

demux: mp4: avoid audio cuts on seek

mostly with fast seek

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=168bd3f8e7283f72250d8753ddb3ad63bc7dd54b
---

 modules/demux/mp4/mp4.c | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/modules/demux/mp4/mp4.c b/modules/demux/mp4/mp4.c
index 4a7561cd40..10a98c03cc 100644
--- a/modules/demux/mp4/mp4.c
+++ b/modules/demux/mp4/mp4.c
@@ -1460,19 +1460,40 @@ static int Seek( demux_t *p_demux, mtime_t i_date, bool b_accurate )
     demux_sys_t *p_sys = p_demux->p_sys;
     unsigned int i_track;
 
-    /* First update global time */
-    p_sys->i_time = MP4_rescale( i_date, CLOCK_FREQ, p_sys->i_timescale );
-    p_sys->i_pcr  = VLC_TS_INVALID;
-
     /* Now for each stream try to go to this time */
+    mtime_t i_start = i_date;
     for( i_track = 0; i_track < p_sys->i_tracks; i_track++ )
     {
         mp4_track_t *tk = &p_sys->track[i_track];
-        MP4_TrackSeek( p_demux, tk, i_date );
+        /* FIXME: we should find the lowest time from tracks with indexes.
+           considering only video for now */
+        if( tk->fmt.i_cat != VIDEO_ES )
+            continue;
+        if( MP4_TrackSeek( p_demux, tk, i_date ) == VLC_SUCCESS )
+        {
+            mtime_t i_seeked = MP4_TrackGetDTS( p_demux, tk );
+            if( i_seeked < i_start )
+                i_start = i_seeked;
+        }
+    }
+
+    msg_Dbg( p_demux, "seeking with %"PRId64 "ms %s", (i_date - i_start) / 1000,
+            !b_accurate ? "alignment" : "preroll (use input-fast-seek to avoid)" );
+
+    for( i_track = 0; i_track < p_sys->i_tracks; i_track++ )
+    {
+        mp4_track_t *tk = &p_sys->track[i_track];
+        if( tk->fmt.i_cat == VIDEO_ES )
+            continue;
+        MP4_TrackSeek( p_demux, tk, i_start );
     }
-    MP4_UpdateSeekpoint( p_demux, i_date );
 
+    MP4_UpdateSeekpoint( p_demux, i_date );
     MP4ASF_ResetFrames( p_sys );
+    /* update global time */
+    p_sys->i_time = MP4_rescale( i_start, CLOCK_FREQ, p_sys->i_timescale );
+    p_sys->i_pcr  = VLC_TS_INVALID;
+
     if( b_accurate )
         es_out_Control( p_demux->out, ES_OUT_SET_NEXT_DISPLAY_TIME, i_date );