switch from std::auto_ptr<> (deprecated) to boost::scoped_ptr<>
[ardour.git] / libs / ardour / route.cc
index f0bd724e4467e52de4f085434050ee27d8cbb391..df708bbd30be78cca1dff6f36ec686e7e95b4423 100644 (file)
@@ -57,6 +57,7 @@
 #include "ardour/delayline.h"
 #include "ardour/midi_buffer.h"
 #include "ardour/midi_port.h"
+#include "ardour/monitor_control.h"
 #include "ardour/monitor_processor.h"
 #include "ardour/pannable.h"
 #include "ardour/panner.h"
@@ -94,8 +95,6 @@ Route::Route (Session& sess, string name, PresentationInfo::Flag flag, DataType
        , Muteable (sess, name)
        , _active (true)
        , _signal_latency (0)
-       , _initial_delay (0)
-       , _roll_delay (0)
        , _disk_io_point (DiskIOPreFader)
        , _pending_process_reorder (0)
        , _pending_signals (0)
@@ -105,15 +104,14 @@ Route::Route (Session& sess, string name, PresentationInfo::Flag flag, DataType
        , _meter_type (MeterPeak)
        , _denormal_protection (false)
        , _recordable (true)
-       , _silent (false)
        , _declickable (false)
        , _have_internal_generator (false)
        , _default_type (default_type)
        , _track_number (0)
+       , _strict_io (false)
        , _in_configure_processors (false)
        , _initial_io_setup (false)
        , _in_sidechain_setup (false)
-       , _strict_io (false)
        , _custom_meter_position_noted (false)
        , _pinmgr_proxy (0)
        , _patch_selector_dialog (0)
@@ -193,12 +191,9 @@ Route::init ()
                _amp->set_display_name (_("Monitor"));
        }
 
-#if 0 // not used - just yet
        if (!is_master() && !is_monitor() && !is_auditioner()) {
-               _delayline.reset (new DelayLine (_session, _name));
-               add_processor (_delayline, PreFader);
+               _delayline.reset (new DelayLine (_session, name ()));
        }
-#endif
 
        /* and input trim */
 
@@ -311,19 +306,27 @@ Route::maybe_declick (BufferSet&, samplecnt_t, int)
 void
 Route::process_output_buffers (BufferSet& bufs,
                               samplepos_t start_sample, samplepos_t end_sample, pframes_t nframes,
-                              int declick, bool gain_automation_ok)
+                              int declick, bool gain_automation_ok, bool run_disk_reader)
 {
        /* Caller must hold process lock */
        assert (!AudioEngine::instance()->process_lock().trylock());
 
        Glib::Threads::RWLock::ReaderLock lm (_processor_lock, Glib::Threads::TRY_LOCK);
        if (!lm.locked()) {
-               // can this actually happen? functions calling process_output_buffers()
-               // already take a reader-lock.
+               // can this actually happen?
+               // Places that need a WriterLock on (_processor_lock) must also take the process-lock.
                bufs.silence (nframes, 0);
+               assert (0); // ...one way to find out.
                return;
        }
 
+       /* We should offset the route-owned ctrls by the given latency, however
+        * this only affects Mute. Other route-owned controls (solo, polarity..)
+        * are not automatable.
+        *
+        * Mute has its own issues since there's not a single mute-point,
+        * but in general
+        */
        automation_run (start_sample, nframes);
 
        /* figure out if we're going to use gain automation */
@@ -339,19 +342,68 @@ Route::process_output_buffers (BufferSet& bufs,
                                start_sample + _trim->output_latency (),
                                end_sample + _trim->output_latency (),
                                nframes);
-       } else {
-               _amp->apply_gain_automation (false);
-               _trim->apply_gain_automation (false);
        }
 
-       /* Tell main outs what to do about monitoring.  We do this so that
-          on a transition between monitoring states we get a de-clicking gain
-          change in the _main_outs delivery, if config.get_use_monitor_fades()
-          is true.
+       /* We align the playhead to output. The user hears what the clock says:
+        * When the playhead/clock says 1:00:00:00 the user will hear the audio sample
+        * at 1:00:00:00. sample_start will be [sample at] 1:00:00:00
+        *
+        * e.g. clock says Time T = 0,  sample_start = 0
+        * Disk-read(play) -> latent-plugin (+10) -> fader-automation -> output (+5)
+        * -> total playback latency "disk -> out" is 15.
+        * -> at Time T= -15, the disk-reader reads sample T=0.
+        * By the Time T=0 is reached (dt=15 later) that sample is audible.
+        */
 
-          We override this in the case where we have an internal generator.
-       */
-       bool silence = _have_internal_generator ? false : (monitoring_state () == MonitoringSilence);
+       start_sample += _signal_latency;
+       end_sample += _signal_latency;
+
+       start_sample += _output->latency ();
+       end_sample += _output->latency ();
+
+       const double speed = (is_auditioner() ? 1.0 : _session.transport_speed ());
+
+       /* Note: during intial pre-roll 'start_sample' as passed as argument can be negative.
+        * Functions calling process_output_buffers() will set  "run_disk_reader"
+        * to false if the pre-roll count-down is larger than playback_latency ().
+        *
+        * playback_latency() is guarnteed to be <= _signal_latency + _output->latency ()
+        */
+       assert (!_disk_reader || !run_disk_reader || start_sample >= 0);
+
+       /* however the disk-writer may need to pick up output from other tracks
+        * during pre-roll (in particular if this route has latent effects after the disk).
+        *
+        * e.g. track 1 play -> latency A --port--> track2 capture -> latency B ---> out
+        * total pre-roll = A + B.
+        *
+        * Note the disk-writer has built-in overlap detection (it's safe to run it early)
+        * given that
+        */
+       bool run_disk_writer = false;
+       if (_disk_writer && speed != 0) {
+               samplecnt_t latency_preroll = _session.remaining_latency_preroll ();
+               run_disk_writer = latency_preroll < nframes + (_signal_latency + _output->latency ());
+               if (end_sample - _disk_writer->input_latency () < _session.transport_sample ()) {
+                       run_disk_writer = true;
+               }
+       }
+
+       /* Tell main outs what to do about monitoring.  We do this so that
+        * on a transition between monitoring states we get a de-clicking gain
+        * change in the _main_outs delivery, if config.get_use_monitor_fades()
+        * is true.
+        *
+        * We override this in the case where we have an internal generator.
+        *
+        * FIXME: when punching in/out this also depends on latency compensated time
+        * for this route. monitoring_state() does not currently handle that correctly,.
+        *
+        * Also during remaining_latency_preroll, transport_rolling () is false, but
+        * we may need to monitor disk instead.
+        */
+       MonitorState ms = monitoring_state ();
+       bool silence = _have_internal_generator ? false : (ms == MonitoringSilence);
 
        _main_outs->no_outs_cuz_we_no_monitor (silence);
 
@@ -359,6 +411,8 @@ Route::process_output_buffers (BufferSet& bufs,
           GLOBAL DECLICK (for transport changes etc.)
           ----------------------------------------------------------------------------------------- */
 
+       // XXX not latency compensated. calls Amp::declick, but there may be
+       // plugins between disk and Fader.
        maybe_declick (bufs, nframes, declick);
        _pending_declick = 0;
 
@@ -366,6 +420,14 @@ Route::process_output_buffers (BufferSet& bufs,
           DENORMAL CONTROL/PHASE INVERT
           ----------------------------------------------------------------------------------------- */
 
+       /* TODO phase-control should become a processor, or rather a Stub-processor:
+        * a point in the chain which calls a special-cased private Route method.
+        * _phase_control is route-owned and dynamic.)
+        * and we should rename it to polarity.
+        *
+        * denormals: we'll need to protect silent inputs as well as silent disk
+        * (when not monitoring input).  Or simply drop that feature.
+        */
        if (!_phase_control->none()) {
 
                int chn = 0;
@@ -410,26 +472,23 @@ Route::process_output_buffers (BufferSet& bufs,
                                        sp[nx] += 1.0e-27f;
                                }
                        }
-
                }
+
        }
 
        /* -------------------------------------------------------------------------------------------
           and go ....
           ----------------------------------------------------------------------------------------- */
 
-       /* set this to be true if the meter will already have been ::run() earlier */
-       bool const meter_already_run = metering_state() == MeteringInput;
-
        samplecnt_t latency = 0;
-       const double speed = (is_auditioner() ? 1.0 : _session.transport_speed ());
 
        for (ProcessorList::const_iterator i = _processors.begin(); i != _processors.end(); ++i) {
 
-               if (meter_already_run && boost::dynamic_pointer_cast<PeakMeter> (*i)) {
-                       /* don't ::run() the meter, otherwise it will have its previous peak corrupted */
-                       continue;
-               }
+               /* TODO check for split cycles here.
+                *
+                * start_frame, end_frame is adjusted by latency and may
+                * cross loop points.
+                */
 
 #ifndef NDEBUG
                /* if it has any inputs, make sure they match */
@@ -445,26 +504,74 @@ Route::process_output_buffers (BufferSet& bufs,
                }
 #endif
 
-               /* should we NOT run plugins here if the route is inactive?
-                  do we catch route != active somewhere higher?
-               */
-
-               if (boost::dynamic_pointer_cast<Send>(*i) != 0) {
-                       boost::dynamic_pointer_cast<Send>(*i)->set_delay_in(_signal_latency - latency);
-               }
                if (boost::dynamic_pointer_cast<PluginInsert>(*i) != 0) {
-                       const samplecnt_t longest_session_latency = _initial_delay + _signal_latency;
+                       /* set potential sidechain ports, capture and playback latency.
+                        * This effectively sets jack port latency which should include
+                        * up/downstream latencies.
+                        *
+                        * However, the value is not used by Ardour (2017-09-20) and calling
+                        * IO::latency() is expensive, so we punt.
+                        *
+                        * capture should be
+                        *      input()->latenct + latency,
+                        * playback should be
+                        *      output->latency() + _signal_latency - latency
+                        *
+                        * Also see note below, _signal_latency may be smaller than latency
+                        * if a plugin's latency increases while it's running.
+                        */
+                       const samplecnt_t playback_latency = std::max ((samplecnt_t)0, _signal_latency - latency);
                        boost::dynamic_pointer_cast<PluginInsert>(*i)->set_sidechain_latency (
-                                       _initial_delay + latency, longest_session_latency - latency);
+                                       /* input->latency() + */ latency, /* output->latency() + */ playback_latency);
+               }
+
+               bool re_inject_oob_data = false;
+               if ((*i) == _disk_reader) {
+                       /* Well now, we've made it past the disk-writer and to the disk-reader.
+                        * Time to decide what to do about monitoring.
+                        *
+                        * Even when not doing MonitoringDisk, we need to run the processors,
+                        * so that it advances its internal buffers (IFF run_disk_reader is true).
+                        *
+                        */
+                       if (ms == MonitoringDisk || ms == MonitoringSilence) {
+                               /* this will clear out-of-band data, too (e.g. MIDI-PC, Panic etc.
+                                * OOB data is written at the end of the cycle (nframes - 1),
+                                * and jack does not re-order events, so we push them back later */
+                               re_inject_oob_data = true;
+                               bufs.silence (nframes, 0);
+                       }
                }
 
-               //cerr << name() << " run " << (*i)->name() << endl;
-               (*i)->run (bufs, start_sample - latency, end_sample - latency, speed, nframes, *i != _processors.back());
+               double pspeed = speed;
+               if ((!run_disk_reader && (*i) == _disk_reader) || (!run_disk_writer && (*i) == _disk_writer)) {
+                       /* run with speed 0, no-roll */
+                       pspeed = 0;
+               }
+
+               (*i)->run (bufs, start_sample - latency, end_sample - latency, pspeed, nframes, *i != _processors.back());
+
                bufs.set_count ((*i)->output_streams());
 
+               /* Note: plugin latency may change. While the plugin does inform the session via
+                * processor_latency_changed(). But the session may not yet have gotten around to
+                * update the actual worste-case and update this track's _signal_latency.
+                *
+                * So there can be cases where adding up all latencies may not equal _signal_latency.
+                */
                if ((*i)->active ()) {
                        latency += (*i)->signal_latency ();
                }
+
+               if (re_inject_oob_data) {
+                       write_out_of_band_data (bufs, nframes);
+               }
+
+#if 0
+               if ((*i) == _delayline) {
+                       latency += _delayline->get_delay ();
+               }
+#endif
        }
 }
 
@@ -596,15 +703,19 @@ void
 Route::monitor_run (samplepos_t start_sample, samplepos_t end_sample, pframes_t nframes, int declick)
 {
        assert (is_monitor());
-       BufferSet& bufs (_session.get_route_buffers (n_process_buffers()));
-       fill_buffers_with_input (bufs, _input, nframes);
-       passthru (bufs, start_sample, end_sample, nframes, declick);
+       Glib::Threads::RWLock::ReaderLock lm (_processor_lock, Glib::Threads::TRY_LOCK);
+       run_route (start_sample, end_sample, nframes, declick, true, false);
 }
 
 void
-Route::passthru (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, pframes_t nframes, int declick)
+Route::run_route (samplepos_t start_sample, samplepos_t end_sample, pframes_t nframes, int declick, bool gain_automation_ok, bool run_disk_reader)
 {
-       _silent = false;
+       BufferSet& bufs (_session.get_route_buffers (n_process_buffers()));
+
+       fill_buffers_with_input (bufs, _input, nframes);
+
+       /* filter captured data before meter sees it */
+       filter_input (bufs);
 
        if (is_monitor() && _session.listening() && !_session.is_auditioning()) {
 
@@ -616,18 +727,19 @@ Route::passthru (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
                bufs.silence (nframes, 0);
        }
 
-       write_out_of_band_data (bufs, start_sample, end_sample, nframes);
-       process_output_buffers (bufs, start_sample, end_sample, nframes, declick, true);
-}
+       snapshot_out_of_band_data (nframes);
+       /* append immediate messages to the first MIDI buffer (thus sending it to the first output port) */
 
-void
-Route::passthru_silence (samplepos_t start_sample, samplepos_t end_sample, pframes_t nframes, int declick)
-{
-       BufferSet& bufs (_session.get_route_buffers (n_process_buffers(), true));
+       write_out_of_band_data (bufs, nframes);
+
+       /* run processor chain */
 
-       bufs.set_count (_input->n_ports());
-       write_out_of_band_data (bufs, start_sample, end_sample, nframes);
-       process_output_buffers (bufs, start_sample, end_sample, nframes, declick, false);
+       process_output_buffers (bufs, start_sample, end_sample, nframes, declick, gain_automation_ok, run_disk_reader);
+
+       /* map events (e.g. MIDI-CC) back to control-parameters */
+       update_controls (bufs);
+
+       flush_processor_buffers_locked (nframes);
 }
 
 void
@@ -1249,7 +1361,7 @@ Route::clear_processors (Placement p)
                                seen_amp = true;
                        }
 
-                       if ((*i) == _amp || (*i) == _meter || (*i) == _main_outs || (*i) == _delayline || (*i) == _trim) {
+                       if (is_internal_processor (*i)) {
 
                                /* you can't remove these */
 
@@ -1299,6 +1411,15 @@ Route::clear_processors (Placement p)
        }
 }
 
+bool
+Route::is_internal_processor (boost::shared_ptr<Processor> p) const
+{
+       if (p == _amp || p == _meter || p == _main_outs || p == _delayline || p == _trim) {
+               return true;
+       }
+       return false;
+}
+
 int
 Route::remove_processor (boost::shared_ptr<Processor> processor, ProcessorStreams* err, bool need_process_lock)
 {
@@ -1318,7 +1439,7 @@ Route::remove_processor (boost::shared_ptr<Processor> processor, ProcessorStream
 
        /* these can never be removed */
 
-       if (processor == _amp || processor == _meter || processor == _main_outs || processor == _delayline || processor == _trim) {
+       if (is_internal_processor (processor)) {
                return 0;
        }
 
@@ -1420,11 +1541,11 @@ int
 Route::replace_processor (boost::shared_ptr<Processor> old, boost::shared_ptr<Processor> sub, ProcessorStreams* err)
 {
        /* these can never be removed */
-       if (old == _amp || old == _meter || old == _main_outs || old == _delayline || old == _trim) {
+       if (is_internal_processor (old)) {
                return 1;
        }
        /* and can't be used as substitute, either */
-       if (sub == _amp || sub == _meter || sub == _main_outs || sub == _delayline || sub == _trim) {
+       if (is_internal_processor (sub)) {
                return 1;
        }
 
@@ -1539,7 +1660,7 @@ Route::remove_processors (const ProcessorList& to_be_deleted, ProcessorStreams*
 
                        /* these can never be removed */
 
-                       if (processor == _amp || processor == _meter || processor == _main_outs || processor == _delayline || processor == _trim) {
+                       if (is_internal_processor (processor)) {
                                ++i;
                                continue;
                        }
@@ -2308,17 +2429,17 @@ Route::set_strict_io (const bool enable)
 XMLNode&
 Route::get_state()
 {
-       return state(true);
+       return state (false);
 }
 
 XMLNode&
 Route::get_template()
 {
-       return state(false);
+       return state (true);
 }
 
 XMLNode&
-Route::state(bool full_state)
+Route::state (bool save_template)
 {
        if (!_session._template_state_dir.empty()) {
                foreach_processor (sigc::bind (sigc::mem_fun (*this, &Route::set_plugin_state_dir), _session._template_state_dir));
@@ -2349,14 +2470,14 @@ Route::state(bool full_state)
        node->add_child_nocopy (_solo_isolate_control->get_state ());
        node->add_child_nocopy (_solo_safe_control->get_state ());
 
-       node->add_child_nocopy (_input->state (full_state));
-       node->add_child_nocopy (_output->state (full_state));
+       node->add_child_nocopy (_input->get_state ());
+       node->add_child_nocopy (_output->get_state ());
        node->add_child_nocopy (_mute_master->get_state ());
 
        node->add_child_nocopy (_mute_control->get_state ());
        node->add_child_nocopy (_phase_control->get_state ());
 
-       if (full_state) {
+       if (!skip_saving_automation) {
                node->add_child_nocopy (Automatable::get_automation_xml_state ());
        }
 
@@ -2366,13 +2487,16 @@ Route::state(bool full_state)
        }
 
        if (_pannable) {
-               node->add_child_nocopy (_pannable->state (full_state));
+               node->add_child_nocopy (_pannable->get_state ());
        }
 
        {
                Glib::Threads::RWLock::ReaderLock lm (_processor_lock);
                for (i = _processors.begin(); i != _processors.end(); ++i) {
-                       if (!full_state) {
+                       if (*i == _delayline) {
+                               continue;
+                       }
+                       if (save_template) {
                                /* template save: do not include internal sends functioning as
                                         aux sends because the chance of the target ID
                                         in the session where this template is used
@@ -2390,7 +2514,7 @@ Route::state(bool full_state)
                                        }
                                }
                        }
-                       node->add_child_nocopy((*i)->state (full_state));
+                       node->add_child_nocopy((*i)->get_state ());
                }
        }
 
@@ -2588,6 +2712,10 @@ Route::set_state (const XMLNode& node, int version)
                }
        }
 
+       if (_delayline) {
+               _delayline->set_name (name ());
+       }
+
        return 0;
 }
 
@@ -2781,7 +2909,7 @@ Route::get_processor_state ()
 {
        XMLNode* root = new XMLNode (X_("redirects"));
        for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
-               root->add_child_nocopy ((*i)->state (true));
+               root->add_child_nocopy ((*i)->get_state ());
        }
 
        return *root;
@@ -2823,10 +2951,7 @@ Route::set_processor_state (const XMLNode& node)
                        _meter->set_state (**niter, Stateful::current_state_version);
                        new_order.push_back (_meter);
                } else if (prop->value() == "delay") {
-                       if (_delayline) {
-                               _delayline->set_state (**niter, Stateful::current_state_version);
-                               new_order.push_back (_delayline);
-                       }
+                       // skip -- internal
                } else if (prop->value() == "main-outs") {
                        _main_outs->set_state (**niter, Stateful::current_state_version);
                } else if (prop->value() == "intreturn") {
@@ -3005,29 +3130,22 @@ Route::silence_unlocked (samplecnt_t nframes)
 
        const samplepos_t now = _session.transport_sample ();
 
-       if (!_silent) {
+       _output->silence (nframes);
 
-               _output->silence (nframes);
+       // update owned automated controllables
+       automation_run (now, nframes);
 
-               // update owned automated controllables
-               automation_run (now, nframes);
-
-               for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
-                       boost::shared_ptr<PluginInsert> pi;
-
-                       if (!_active && (pi = boost::dynamic_pointer_cast<PluginInsert> (*i)) != 0) {
-                               /* evaluate automated automation controls */
-                               pi->automation_run (now, nframes);
-                               /* skip plugins, they don't need anything when we're not active */
-                               continue;
-                       }
+       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
+               boost::shared_ptr<PluginInsert> pi;
 
-                       (*i)->silence (nframes, now);
+               if (!_active && (pi = boost::dynamic_pointer_cast<PluginInsert> (*i)) != 0) {
+                       /* evaluate automated automation controls */
+                       pi->automation_run (now, nframes);
+                       /* skip plugins, they don't need anything when we're not active */
+                       continue;
                }
 
-               if (nframes == _session.get_block_size()) {
-                       // _silent = true;
-               }
+               (*i)->silence (nframes, now);
        }
 }
 
@@ -3335,22 +3453,18 @@ Route::feeds_according_to_graph (boost::shared_ptr<Route> other)
 void
 Route::non_realtime_transport_stop (samplepos_t now, bool flush)
 {
-       {
-               Glib::Threads::RWLock::ReaderLock lm (_processor_lock);
+       Glib::Threads::RWLock::ReaderLock lm (_processor_lock);
 
-               Automatable::non_realtime_transport_stop (now, flush);
+       Automatable::non_realtime_transport_stop (now, flush);
 
-               for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
-
-                       if (!_have_internal_generator && (Config->get_plugins_stop_with_transport() && flush)) {
-                               (*i)->flush ();
-                       }
+       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
 
-                       (*i)->non_realtime_transport_stop (now, flush);
+               if (!_have_internal_generator && (Config->get_plugins_stop_with_transport() && flush)) {
+                       (*i)->flush ();
                }
-       }
 
-       _roll_delay = _initial_delay;
+               (*i)->non_realtime_transport_stop (now, flush);
+       }
 }
 
 void
@@ -3542,8 +3656,58 @@ Route::flush_processor_buffers_locked (samplecnt_t nframes)
        }
 }
 
+void
+Route::flush_processors ()
+{
+       Glib::Threads::RWLock::ReaderLock lm (_processor_lock);
+
+       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
+               (*i)->flush ();
+       }
+}
+
+samplecnt_t
+Route::playback_latency (bool incl_downstream) const
+{
+       samplecnt_t rv;
+       if (_disk_reader) {
+               rv = _disk_reader->output_latency ();
+       } else {
+               rv = _signal_latency;
+       }
+       if (incl_downstream) {
+               rv += _output->connected_latency (true);
+       } else {
+               rv += _output->latency ();
+       }
+       return rv;
+}
+
+pframes_t
+Route::latency_preroll (pframes_t nframes, samplepos_t& start_sample, samplepos_t& end_sample)
+{
+       samplecnt_t latency_preroll = _session.remaining_latency_preroll ();
+       if (latency_preroll == 0) {
+               return nframes;
+       }
+       if (!_disk_reader) {
+               start_sample -= latency_preroll;
+               end_sample   -= latency_preroll;
+               return nframes;
+       }
+
+       if (latency_preroll > playback_latency ()) {
+               no_roll_unlocked (nframes, start_sample - latency_preroll, end_sample - latency_preroll, false);
+               return 0;
+       }
+
+       start_sample -= latency_preroll;
+       end_sample -= latency_preroll;
+       return nframes;
+}
+
 int
-Route::no_roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, bool session_state_changing)
+Route::roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, int declick, bool& need_butler)
 {
        Glib::Threads::RWLock::ReaderLock lm (_processor_lock, Glib::Threads::TRY_LOCK);
 
@@ -3553,74 +3717,62 @@ Route::no_roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sam
 
        if (!_active) {
                silence_unlocked (nframes);
+               _meter->reset();
                return 0;
        }
 
-       if (session_state_changing) {
-               if (_session.transport_speed() != 0.0f) {
-                       /* we're rolling but some state is changing (e.g. our diskstream contents)
-                          so we cannot use them. Be silent till this is over.
-
-                          XXX note the absurdity of ::no_roll() being called when we ARE rolling!
-                       */
-                       silence_unlocked (nframes);
-                       return 0;
-               }
-               /* we're really not rolling, so we're either delivery silence or actually
-                  monitoring, both of which are safe to do while session_state_changing is true.
-               */
+       if ((nframes = latency_preroll (nframes, start_sample, end_sample)) == 0) {
+               return 0;
        }
 
-       BufferSet& bufs = _session.get_route_buffers (n_process_buffers());
-
-       fill_buffers_with_input (bufs, _input, nframes);
+       run_route (start_sample, end_sample, nframes, declick, (!_disk_writer || !_disk_writer->record_enabled()) && _session.transport_rolling(), true);
 
-       if (_meter_point == MeterInput) {
-               _meter->run (bufs, start_sample, end_sample, 0.0, nframes, true);
+       if ((_disk_reader && _disk_reader->need_butler()) || (_disk_writer && _disk_writer->need_butler())) {
+               need_butler = true;
        }
-
-       _amp->apply_gain_automation (false);
-       _trim->apply_gain_automation (false);
-       passthru (bufs, start_sample, end_sample, nframes, 0);
-
-       flush_processor_buffers_locked (nframes);
-
        return 0;
 }
 
 int
-Route::roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, int declick, bool& /* need_butler */)
+Route::no_roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, bool session_state_changing)
 {
        Glib::Threads::RWLock::ReaderLock lm (_processor_lock, Glib::Threads::TRY_LOCK);
+
        if (!lm.locked()) {
                return 0;
        }
 
-       if (!_active) {
-               silence_unlocked (nframes);
-               return 0;
-       }
+       return no_roll_unlocked (nframes, start_sample, end_sample, session_state_changing);
+}
 
-       samplepos_t unused = 0;
+int
+Route::no_roll_unlocked (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, bool session_state_changing)
+{
+       /* Must be called with the processor lock held */
 
-       if ((nframes = check_initial_delay (nframes, unused)) == 0) {
+       if (!_active) {
+               silence_unlocked (nframes);
+               _meter->reset();
                return 0;
        }
 
-       _silent = false;
-
-       BufferSet& bufs = _session.get_route_buffers (n_process_buffers());
-
-       fill_buffers_with_input (bufs, _input, nframes);
+       if (session_state_changing) {
+               if (_session.transport_speed() != 0.0f) {
+                       /* we're rolling but some state is changing (e.g. our diskstream contents)
+                          so we cannot use them. Be silent till this is over.
 
-       if (_meter_point == MeterInput) {
-               _meter->run (bufs, start_sample, end_sample, 1.0, nframes, true);
+                          XXX note the absurdity of ::no_roll() being called when we ARE rolling!
+                       */
+                       silence_unlocked (nframes);
+                       _meter->reset();
+                       return 0;
+               }
+               /* we're really not rolling, so we're either delivery silence or actually
+                  monitoring, both of which are safe to do while session_state_changing is true.
+               */
        }
 
-       passthru (bufs, start_sample, end_sample, nframes, declick);
-
-       flush_processor_buffers_locked (nframes);
-
+       run_route (start_sample, end_sample, nframes, 0, false, false);
        return 0;
 }
 
@@ -3632,16 +3784,6 @@ Route::silent_roll (pframes_t nframes, samplepos_t /*start_sample*/, samplepos_t
        return 0;
 }
 
-void
-Route::flush_processors ()
-{
-       Glib::Threads::RWLock::ReaderLock lm (_processor_lock);
-
-       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
-               (*i)->flush ();
-       }
-}
-
 #ifdef __clang__
 __attribute__((annotate("realtime")))
 #endif
@@ -3852,51 +3994,57 @@ Route::add_export_point()
                Glib::Threads::Mutex::Lock lx (AudioEngine::instance()->process_lock ());
                Glib::Threads::RWLock::WriterLock lw (_processor_lock);
 
-               // this aligns all tracks; but not tracks + busses
-               samplecnt_t latency = _session.worst_track_roll_delay ();
-               assert (latency >= _initial_delay);
-               _capturing_processor.reset (new CapturingProcessor (_session, latency - _initial_delay));
-               _capturing_processor->activate ();
-
+               /* Align all tracks for stem-export w/o processing.
+                * Compensate for all plugins between the this route's disk-reader
+                * and the common final downstream output (ie alignment point for playback).
+                */
+               _capturing_processor.reset (new CapturingProcessor (_session, playback_latency (true)));
                configure_processors_unlocked (0, &lw);
-
+               _capturing_processor->activate ();
        }
 
        return _capturing_processor;
 }
 
 samplecnt_t
-Route::update_signal_latency (bool set_initial_delay)
+Route::update_signal_latency (bool apply_to_delayline)
 {
-       Glib::Threads::RWLock::ReaderLock lm (_processor_lock);
+       // TODO: bail out if !active() and set/assume _signal_latency = 0,
+       // here or in Session::* ? -> also zero send latencies,
+       // and make sure that re-enabling a route updates things again...
 
-       samplecnt_t l_in  = _input->latency ();
-       samplecnt_t l_out = 0;
+       Glib::Threads::RWLock::ReaderLock lm (_processor_lock);
 
-       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
+       samplecnt_t l_in  = 0;
+       samplecnt_t l_out = _output->user_latency();
+       for (ProcessorList::reverse_iterator i = _processors.rbegin(); i != _processors.rend(); ++i) {
+               if (boost::shared_ptr<Send> snd = boost::dynamic_pointer_cast<Send> (*i)) {
+                       snd->set_delay_in (l_out + _output->latency());
+               }
+               (*i)->set_output_latency (l_out);
                if ((*i)->active ()) {
                        l_out += (*i)->signal_latency ();
-                       l_in += (*i)->signal_latency ();
                }
-               (*i)->set_input_latency (l_in);
-               (*i)->set_output_latency (l_out);
-       }
-
-       l_out += _output->user_latency();
-
-       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
-               (*i)->set_output_latency (l_out - (*i)->output_latency ());
        }
 
        DEBUG_TRACE (DEBUG::Latency, string_compose ("%1: internal signal latency = %2\n", _name, l_out));
 
        _signal_latency = l_out;
 
+       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
+               (*i)->set_input_latency (l_in);
+               (*i)->set_playback_offset (_signal_latency + _output->latency ());
+               (*i)->set_capture_offset (_input->latency ());
+               if ((*i)->active ()) {
+                       l_in += (*i)->signal_latency ();
+               }
+       }
+
        lm.release ();
 
-       if (set_initial_delay) {
+       if (apply_to_delayline) {
                /* see also Session::post_playback_latency() */
-               set_latency_compensation (_session.worst_track_latency () + _session.worst_track_out_latency () - output ()->latency ());
+               apply_latency_compensation ();
        }
 
        if (_signal_latency != l_out) {
@@ -3914,28 +4062,28 @@ Route::set_user_latency (samplecnt_t nframes)
 }
 
 void
-Route::set_latency_compensation (samplecnt_t longest_session_latency)
+Route::apply_latency_compensation ()
 {
-       samplecnt_t old = _initial_delay;
-       assert (!_disk_reader || _disk_reader->output_latency () <= _signal_latency);
+       if (_delayline) {
+               samplecnt_t old = _delayline->get_delay ();
 
-       if (_disk_reader &&  _signal_latency < longest_session_latency) {
-               _initial_delay = longest_session_latency - (_signal_latency - _disk_reader->input_latency ());
-       } else {
-               _initial_delay = 0;
-       }
+               samplecnt_t play_lat_in = _input->connected_latency (true);
+               samplecnt_t play_lat_out = _output->connected_latency (true);
+               samplecnt_t latcomp = play_lat_in - play_lat_out - _signal_latency;
 
-       DEBUG_TRACE (DEBUG::Latency, string_compose (
-                            "%1: compensate for maximum latency of %2,"
-                            "given own latency of %3, using initial delay of %4\n",
-                            name(), longest_session_latency, _signal_latency, _initial_delay));
+#if 0 // DEBUG
+               samplecnt_t capt_lat_in = _input->connected_latency (false);
+               samplecnt_t capt_lat_out = _output->connected_latency (false);
+               samplecnt_t latcomp_capt = capt_lat_out - capt_lat_in - _signal_latency;
 
-       if (_initial_delay != old) {
-               initial_delay_changed (); /* EMIT SIGNAL */
-       }
+               cout << "ROUTE " << name() << " delay for " << latcomp << " (c: " << latcomp_capt << ")" << endl;
+#endif
+
+               _delayline->set_delay (latcomp > 0 ? latcomp : 0);
 
-       if (_session.transport_stopped()) {
-               _roll_delay = _initial_delay;
+               if (old !=  _delayline->get_delay ()) {
+                       signal_latency_updated (); /* EMIT SIGNAL */
+               }
        }
 }
 
@@ -4558,28 +4706,12 @@ Route::setup_invisible_processors ()
        ProcessorList::iterator after_amp = amp;
        ++after_amp;
 
-       /* METER */
+       /* Pre-fader METER */
 
-       if (_meter) {
-               switch (_meter_point) {
-               case MeterInput:
-                       assert (!_meter->display_to_user ());
-                       new_processors.push_front (_meter);
-                       break;
-               case MeterPreFader:
-                       assert (!_meter->display_to_user ());
-                       new_processors.insert (amp, _meter);
-                       break;
-               case MeterPostFader:
-                       /* do nothing here */
-                       break;
-               case MeterOutput:
-                       /* do nothing here */
-                       break;
-               case MeterCustom:
-                       /* the meter is visible, so we don't touch it here */
-                       break;
-               }
+       if (_meter && _meter_point == MeterPreFader) {
+               /* add meter just before the fader */
+               assert (!_meter->display_to_user ());
+               new_processors.insert (amp, _meter);
        }
 
        /* MAIN OUTS */
@@ -4638,12 +4770,6 @@ Route::setup_invisible_processors ()
                }
        }
 
-#if 0 // not used - just yet
-       if (!is_master() && !is_monitor() && !is_auditioner()) {
-               new_processors.push_front (_delayline);
-       }
-#endif
-
        /* MONITOR CONTROL */
 
        if (_monitor_control && is_monitor ()) {
@@ -4672,8 +4798,6 @@ Route::setup_invisible_processors ()
                new_processors.push_front (_intreturn);
        }
 
-       /* EXPORT PROCESSOR */
-
        /* DISK READER & WRITER (for Track objects) */
 
        if (_disk_reader || _disk_writer) {
@@ -4713,6 +4837,21 @@ Route::setup_invisible_processors ()
                }
        }
 
+       /* ensure dist-writer is before disk-reader */
+       if (_disk_reader && _disk_writer) {
+               ProcessorList::iterator reader_pos = find (new_processors.begin(), new_processors.end(), _disk_reader);
+               ProcessorList::iterator writer_pos = find (new_processors.begin(), new_processors.end(), _disk_writer);
+               assert (reader_pos != new_processors.end ());
+               assert (writer_pos != new_processors.end ());
+               if (std::distance (new_processors.begin(), reader_pos) < std::distance (new_processors.begin(), writer_pos)) {
+                       new_processors.erase (reader_pos);
+                       assert (writer_pos == find (new_processors.begin(), new_processors.end(), _disk_writer));
+                       new_processors.insert (++writer_pos, _disk_reader);
+               }
+       }
+
+
+       /* EXPORT PROCESSOR */
        if (_capturing_processor) {
                assert (!_capturing_processor->display_to_user ());
                ProcessorList::iterator reader_pos = find (new_processors.begin(), new_processors.end(), _disk_reader);
@@ -4724,6 +4863,30 @@ Route::setup_invisible_processors ()
                }
        }
 
+       /* Input meter */
+       if (_meter && _meter_point == MeterInput) {
+               /* add meter just before the disk-writer (if any)
+                * otherwise at the top, but after the latency delayline
+                * (perhaps it should also be after intreturn on busses ??)
+                */
+               assert (!_meter->display_to_user ());
+               ProcessorList::iterator writer_pos = find (new_processors.begin(), new_processors.end(), _disk_writer);
+               if (writer_pos != new_processors.end()) {
+                       new_processors.insert (writer_pos, _meter);
+               } else {
+                       new_processors.push_front (_meter);
+               }
+       }
+
+       if (!is_master() && !is_monitor() && !is_auditioner()) {
+               ProcessorList::iterator reader_pos = find (new_processors.begin(), new_processors.end(), _disk_reader);
+               if (reader_pos != new_processors.end()) {
+                       /* insert before disk-reader */
+                       new_processors.insert (reader_pos, _delayline);
+               } else {
+                       new_processors.push_front (_delayline);
+               }
+       }
 
        _processors = new_processors;
 
@@ -4811,15 +4974,6 @@ Route::processor_by_id (PBD::ID id) const
        return boost::shared_ptr<Processor> ();
 }
 
-/** @return the monitoring state, or in other words what data we are pushing
- *  into the route (data from the inputs, data from disk or silence)
- */
-MonitorState
-Route::monitoring_state () const
-{
-       return MonitoringInput;
-}
-
 /** @return what we should be metering; either the data coming from the input
  *  IO or the data that is flowing through the route.
  */
@@ -4876,9 +5030,11 @@ Route::non_realtime_locate (samplepos_t pos)
                _pannable->non_realtime_locate (pos);
        }
 
-       if (_delayline.get()) {
-               _delayline.get()->flush();
+#if 0 // XXX mayhaps clear delayline here (and at stop?)
+       if (_delayline) {
+               _delayline->flush ();
        }
+#endif
 
        {
                //Glib::Threads::Mutex::Lock lx (AudioEngine::instance()->process_lock ());
@@ -4888,7 +5044,6 @@ Route::non_realtime_locate (samplepos_t pos)
                        (*i)->non_realtime_locate (pos);
                }
        }
-       _roll_delay = _initial_delay;
 }
 
 void
@@ -5265,6 +5420,19 @@ Route::filter_enable_controllable (bool) const
 #endif
 }
 
+boost::shared_ptr<AutomationControl>
+Route::tape_drive_controllable () const
+{
+#ifdef MIXBUS
+
+       if ( _ch_pre && (is_master() || mixbus()) ) {
+               return boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (_ch_pre->control (Evoral::Parameter (ARDOUR::PluginAutomation, 0, 4)));
+       }
+#endif
+
+       return boost::shared_ptr<AutomationControl>();
+}
+
 string
 Route::eq_band_name (uint32_t band) const
 {
@@ -5430,6 +5598,43 @@ Route::comp_speed_name (uint32_t mode) const
 #endif
 }
 
+boost::shared_ptr<AutomationControl>
+Route::send_pan_azi_controllable (uint32_t n) const
+{
+#ifdef  MIXBUS
+# undef MIXBUS_PORTS_H
+# include "../../gtk2_ardour/mixbus_ports.h"
+       boost::shared_ptr<ARDOUR::PluginInsert> plug = ch_post();
+       if (plug && !mixbus()) {
+               uint32_t port_id = 0;
+               switch (n) {
+# ifdef MIXBUS32C
+                       case  0: port_id = port_channel_post_aux0_pan; break;  //32c mb "pan" controls use zero-based names, unlike levels. ugh
+                       case  1: port_id = port_channel_post_aux1_pan; break;
+                       case  2: port_id = port_channel_post_aux2_pan; break;
+                       case  3: port_id = port_channel_post_aux3_pan; break;
+                       case  4: port_id = port_channel_post_aux4_pan; break;
+                       case  5: port_id = port_channel_post_aux5_pan; break;
+                       case  6: port_id = port_channel_post_aux6_pan; break;
+                       case  7: port_id = port_channel_post_aux7_pan; break;
+                       case  8: port_id = port_channel_post_aux8_pan; break;
+                       case  9: port_id = port_channel_post_aux9_pan; break;
+                       case 10: port_id = port_channel_post_aux10_pan; break;
+                       case 11: port_id = port_channel_post_aux11_pan; break;
+# endif
+                       default:
+                               break;
+               }
+
+               if (port_id > 0) {
+                       return boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (plug->control (Evoral::Parameter (ARDOUR::PluginAutomation, 0, port_id)));
+               }
+       }
+#endif
+       
+       return boost::shared_ptr<AutomationControl>();
+}
+
 boost::shared_ptr<AutomationControl>
 Route::send_level_controllable (uint32_t n) const
 {
@@ -5670,3 +5875,164 @@ Route::set_disk_io_point (DiskIOPoint diop)
 
        processors_changed (RouteProcessorChange ()); /* EMIT SIGNAL */
 }
+
+#ifdef USE_TRACKS_CODE_FEATURES
+
+/* This is the Tracks version of Track::monitoring_state().
+ *
+ * Ardour developers: try to flag or fix issues if parts of the libardour API
+ * change in ways that invalidate this
+ */
+
+MonitorState
+Route::monitoring_state () const
+{
+       /* Explicit requests */
+
+       if (_monitoring != MonitorInput) {
+               return MonitoringInput;
+       }
+
+       if (_monitoring & MonitorDisk) {
+               return MonitoringDisk;
+       }
+
+       /* This is an implementation of the truth table in doc/monitor_modes.pdf;
+          I don't think it's ever going to be too pretty too look at.
+       */
+
+       // GZ: NOT USED IN TRACKS
+       //bool const auto_input = _session.config.get_auto_input ();
+       //bool const software_monitor = Config->get_monitoring_model() == SoftwareMonitoring;
+       //bool const tape_machine_mode = Config->get_tape_machine_mode ();
+
+       bool const roll = _session.transport_rolling ();
+       bool const track_rec = _diskstream->record_enabled ();
+       bool session_rec = _session.actively_recording ();
+
+       if (track_rec) {
+
+               if (!session_rec && roll) {
+                       return MonitoringDisk;
+               } else {
+                       return MonitoringInput;
+               }
+
+       } else {
+
+               if (roll) {
+                       return MonitoringDisk;
+               }
+       }
+
+       return MonitoringSilence;
+}
+
+#else
+
+/* This is the Ardour/Mixbus version of Track::monitoring_state().
+ *
+ * Tracks developers: do NOT modify this method under any circumstances.
+ */
+
+MonitorState
+Route::monitoring_state () const
+{
+       if (!_disk_reader) {
+               return MonitoringInput;
+       }
+
+       /* Explicit requests */
+       MonitorChoice m (_monitoring_control->monitoring_choice());
+
+       if (m != MonitorAuto) {
+
+               MonitorState ms ((MonitorState) 0);
+
+               if (m & MonitorInput) {
+                       ms = MonitoringInput;
+               }
+
+               if (m & MonitorDisk) {
+                       ms = MonitorState (ms | MonitoringDisk);
+               }
+
+               return ms;
+       }
+
+       switch (_session.config.get_session_monitoring ()) {
+               case MonitorDisk:
+                       return MonitoringDisk;
+                       break;
+               case MonitorInput:
+                       return MonitoringInput;
+                       break;
+               default:
+                       break;
+       }
+
+       /* This is an implementation of the truth table in doc/monitor_modes.pdf;
+          I don't think it's ever going to be too pretty too look at.
+       */
+
+       bool const roll = _session.transport_rolling ();
+       bool const track_rec = _disk_writer->record_enabled ();
+       bool const auto_input = _session.config.get_auto_input ();
+       bool const software_monitor = Config->get_monitoring_model() == SoftwareMonitoring;
+       bool const tape_machine_mode = Config->get_tape_machine_mode ();
+       bool session_rec;
+
+       /* I suspect that just use actively_recording() is good enough all the
+        * time, but just to keep the semantics the same as they were before
+        * sept 26th 2012, we differentiate between the cases where punch is
+        * enabled and those where it is not.
+        *
+        * rg: sept 30 2017: Above is not the case: punch-in/out location is
+        * global session playhead position.
+        * When this method is called from process_output_buffers() we need
+        * to use delay-compensated route's process-position.
+        *
+        * NB. Disk reader/writer may also be offset by a same amount of time.
+        *
+        * Also keep in mind that _session.transport_rolling() is false during
+        * pre-roll but the disk already produces output.
+        *
+        * TODO: FIXME
+        */
+
+       if (_session.config.get_punch_in() || _session.config.get_punch_out()) {
+               session_rec = _session.actively_recording ();
+       } else {
+               session_rec = _session.get_record_enabled();
+       }
+
+       if (track_rec) {
+
+               if (!session_rec && roll && auto_input) {
+                       return MonitoringDisk;
+               } else {
+                       return software_monitor ? MonitoringInput : MonitoringSilence;
+               }
+
+       } else {
+
+               if (tape_machine_mode) {
+
+                       return MonitoringDisk;
+
+               } else {
+
+                       if (!roll && auto_input) {
+                               return software_monitor ? MonitoringInput : MonitoringSilence;
+                       } else {
+                               return MonitoringDisk;
+                       }
+
+               }
+       }
+
+       abort(); /* NOTREACHED */
+       return MonitoringSilence;
+}
+
+#endif