fast region export -- don't call process()

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

diff --git a/libs/ardour/session_export.cc b/libs/ardour/session_export.cc
index 7234411ce4ee6496ecc2c4a924f7ae8bb5da45b4..23172838d075c7726dcfd8d02f413c5c2927a1db 100644 (file)
--- a/libs/ardour/session_export.cc
+++ b/libs/ardour/session_export.cc
@@ -104,15 +104,19 @@ Session::pre_export ()
 
 /** Called for each range that is being exported */
 int
-Session::start_audio_export (framepos_t position, bool realtime)
+Session::start_audio_export (framepos_t position, bool realtime, bool region_export)
 {
        if (!_exporting) {
                pre_export ();
        }
 
        _realtime_export = realtime;
+       _region_export = region_export;
 
-       if (realtime) {
+       if (region_export) {
+               _export_preroll = 0;
+       }
+       else if (realtime) {
                _export_preroll = nominal_frame_rate ();
        } else {
                _export_preroll = Config->get_export_preroll() * nominal_frame_rate ();
@@ -134,6 +138,10 @@ Session::start_audio_export (framepos_t position, bool realtime)
         */
        _export_latency = worst_track_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.
@@ -177,13 +185,14 @@ Session::start_audio_export (framepos_t position, bool realtime)
                return -1;
        }
 
+       _engine.Freewheel.connect_same_thread (export_freewheel_connection, boost::bind (&Session::process_export_fw, this, _1));
+
        if (_realtime_export) {
                Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
                _export_rolling = true;
                process_function = &Session::process_export_fw;
                return 0;
        } else {
-               _engine.Freewheel.connect_same_thread (export_freewheel_connection, boost::bind (&Session::process_export_fw, this, _1));
                _export_rolling = true;
                return _engine.freewheel (true);
        }
@@ -196,15 +205,26 @@ Session::process_export (pframes_t nframes)
                stop_audio_export ();
        }
 
-       if (_export_rolling) {
-               /* make sure we've caught up with disk i/o, since
-               we're running faster than realtime c/o JACK.
-               */
-               _butler->wait_until_finished ();
+       /* for Region Raw or Fades, we can skip this
+        * RegionExportChannelFactory::update_buffers() does not care
+        * about anything done here
+        */
+       if (!_region_export) {
+               if (_export_rolling) {
+                       if (!_realtime_export)  {
+                               /* make sure we've caught up with disk i/o, since
+                                * we're running faster than realtime c/o JACK.
+                                */
+                               _butler->wait_until_finished ();
+                       }
+
+                       /* do the usual stuff */
 
-               /* do the usual stuff */
+                       process_without_events (nframes);
 
-               process_without_events (nframes);
+               } else if (_realtime_export) {
+                       fail_roll (nframes); // somehow we need to silence _ALL_ output buffers
+               }
        }
 
        try {
@@ -221,13 +241,14 @@ Session::process_export (pframes_t nframes)
 void
 Session::process_export_fw (pframes_t nframes)
 {
+       const bool need_buffers = _engine.freewheeling ();
        if (_export_preroll > 0) {
 
-               if (!_realtime_export) {
+               if (need_buffers) {
                        _engine.main_thread()->get_buffers ();
                }
                fail_roll (nframes);
-               if (!_realtime_export) {
+               if (need_buffers) {
                        _engine.main_thread()->drop_buffers ();
                }
 
@@ -249,11 +270,11 @@ Session::process_export_fw (pframes_t nframes)
        if (_export_latency > 0) {
                framepos_t remain = std::min ((framepos_t)nframes, _export_latency);
 
-               if (!_realtime_export) {
+               if (need_buffers) {
                        _engine.main_thread()->get_buffers ();
                }
                process_without_events (remain);
-               if (!_realtime_export) {
+               if (need_buffers) {
                        _engine.main_thread()->drop_buffers ();
                }
 
@@ -264,11 +285,12 @@ Session::process_export_fw (pframes_t nframes)
                        return;
                }
        }
-       if (!_realtime_export) {
+
+       if (need_buffers) {
                _engine.main_thread()->get_buffers ();
        }
        process_export (nframes);
-       if (!_realtime_export) {
+       if (need_buffers) {
                _engine.main_thread()->drop_buffers ();
        }
 
@@ -304,10 +326,9 @@ Session::finalize_audio_export ()
        if (_realtime_export) {
                Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
                process_function = &Session::process_with_events;
-       } else {
-               _engine.freewheel (false);
-               export_freewheel_connection.disconnect();
        }
+       _engine.freewheel (false);
+       export_freewheel_connection.disconnect();
 
        _mmc->enable_send (_pre_export_mmc_enabled);