Properly aligned export (Stem + Session)

[ardour.git] / libs / ardour / session_export.cc

diff --git a/libs/ardour/session_export.cc b/libs/ardour/session_export.cc
index 33ede3cadcdad58fe6e7f695a577d0717a48e238..879f34020af63004387fe0314a118004c9e54fc7 100644 (file)
--- a/libs/ardour/session_export.cc
+++ b/libs/ardour/session_export.cc
@@ -104,7 +104,7 @@ Session::pre_export ()
 
 /** Called for each range that is being exported */
 int
-Session::start_audio_export (samplepos_t position, bool realtime, bool region_export, bool comensate_master_latency)
+Session::start_audio_export (samplepos_t position, bool realtime, bool region_export)
 {
        if (!_exporting) {
                pre_export ();
@@ -127,31 +127,6 @@ Session::start_audio_export (samplepos_t position, bool realtime, bool region_ex
                _export_preroll = 1;
        }
 
-       /* "worst_track_latency" is the correct value for stem-exports
-        * see to Route::add_export_point(),
-        *
-        * For master-bus export, we also need to add the master's latency.
-        * (or actually longest-total-session-latency - worst-track-latency)
-        * to align the export to 00:00:00:00.
-        *
-        * We must not use worst_playback_latency because that
-        * includes external (hardware) latencies and would overcompensate
-        * during file-export.
-        *
-        * (this is all still very [w]hacky. Individual Bus and Track outputs
-        * are not aligned but one can select them in the PortExportChannelSelector)
-        */
-       _export_latency = worst_track_out_latency ();
-
-       boost::shared_ptr<Route> master = master_out ();
-       if (master && comensate_master_latency) {
-               _export_latency += master->signal_latency ();
-       }
-
-       if (region_export) {
-               _export_latency = 0;
-       }
-
        /* We're about to call Track::seek, so the butler must have finished everything
           up otherwise it could be doing do_refill in its thread while we are doing
           it here.
@@ -181,6 +156,12 @@ Session::start_audio_export (samplepos_t position, bool realtime, bool region_ex
        */
 
        _transport_sample = position;
+
+       if (!region_export) {
+               _remaining_latency_preroll = worst_latency_preroll ();
+       } else {
+               _remaining_latency_preroll = 0;
+       }
        export_status->stop = false;
 
        /* get transport ready. note how this is calling butler functions
@@ -277,18 +258,21 @@ Session::process_export_fw (pframes_t nframes)
                return;
        }
 
-       if (_export_latency > 0) {
-               samplepos_t remain = std::min ((samplepos_t)nframes, _export_latency);
+       if (_remaining_latency_preroll > 0) {
+               samplepos_t remain = std::min ((samplepos_t)nframes, _remaining_latency_preroll);
 
                if (need_buffers) {
                        _engine.main_thread()->get_buffers ();
                }
+
                process_without_events (remain);
+
                if (need_buffers) {
                        _engine.main_thread()->drop_buffers ();
                }
 
-               _export_latency -= remain;
+               _remaining_latency_preroll -= remain;
+               _transport_sample -= remain;
                nframes -= remain;
 
                if (nframes == 0) {