more MTC stuff, including toggleable use of torben's PI controller

git-svn-id: svn://localhost/ardour2/branches/3.0@6265 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 140 insertions, 85 deletions

diff --git a/libs/ardour/mtc_slave.cc b/libs/ardour/mtc_slave.cc
index 4ca86236b7..9e566367bc 100644
--- a/libs/ardour/mtc_slave.cc
+++ b/libs/ardour/mtc_slave.cc
@@ -22,6 +22,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include "pbd/error.h"
+#include "pbd/enumwriter.h"
 #include "pbd/failed_constructor.h"
 #include "pbd/pthread_utils.h"
 
@@ -30,7 +31,7 @@
 #include "ardour/slave.h"
 #include "ardour/session.h"
 #include "ardour/audioengine.h"
-#include "ardour/cycles.h"
+#include "ardour/pi_controller.h"
 
 #include "i18n.h"
 
@@ -45,8 +46,14 @@ MTC_Slave::MTC_Slave (Session& s, MIDI::Port& p)
 {
 	can_notify_on_unknown_rate = true;
 	did_reset_tc_format = false;
+
+	pic = new PIController (1.0, 8);
 	
 	last_mtc_fps_byte = session.get_mtc_timecode_bits ();
+	mtc_frame = 0;
+
+	speed_accumulator_size = 16;
+	speed_accumulator = new double[speed_accumulator_size];
 
 	rebind (p);
 	reset ();
@@ -57,6 +64,15 @@ MTC_Slave::~MTC_Slave()
 	if (did_reset_tc_format) {
 		session.config.set_timecode_format (saved_tc_format);
 	}
+	delete pic;
+	delete [] speed_accumulator;
+}
+
+bool 
+MTC_Slave::give_slave_full_control_over_transport_speed() const
+{
+	return true; // for PiC control */
+	// return false; // for Session-level computed varispeed
 }
 
 void
@@ -68,6 +84,8 @@ MTC_Slave::rebind (MIDI::Port& p)
 
 	port = &p;
 
+	cerr << "Bind to port MTC messages\n";
+
 	connections.push_back (port->input()->mtc_time.connect (mem_fun (*this, &MTC_Slave::update_mtc_time)));
 	connections.push_back (port->input()->mtc_qtr.connect (mem_fun (*this, &MTC_Slave::update_mtc_qtr)));
 	connections.push_back (port->input()->mtc_status.connect (mem_fun (*this, &MTC_Slave::update_mtc_status)));
@@ -76,34 +94,8 @@ MTC_Slave::rebind (MIDI::Port& p)
 void
 MTC_Slave::update_mtc_qtr (Parser& /*p*/, int which_qtr, nframes_t now)
 {
-	DEBUG_TRACE (DEBUG::MTC, string_compose ("qtr frame %1 at %2, valid-for-time? %3\n", which_qtr, now, qtr_frame_messages_valid_for_time));
-
-	if (qtr_frame_messages_valid_for_time) {
-
-		if (which_qtr != 7) {
-
-			/* leave position and speed updates for the last
-			   qtr frame message of the 8 to be taken
-			   care of in update_mtc_time(), invoked
-			   by the Parser right after this.
-			*/
-
-			nframes_t qtr;
-			
-			qtr = (long) (session.frames_per_timecode_frame() / 4);
-			mtc_frame += qtr;
-			
-			double speed = compute_apparent_speed (now);
-			
-			current.guard1++;
-			current.position = mtc_frame;
-			current.timestamp = now;
-			current.speed = speed;
-			current.guard2++;
-		}
-
-		last_inbound_frame = now;
-	}
+	DEBUG_TRACE (DEBUG::MTC, string_compose ("qtr frame %1 at %2\n", which_qtr, now));
+	last_inbound_frame = now;
 }
 
 void
@@ -116,7 +108,8 @@ MTC_Slave::update_mtc_time (const byte *msg, bool was_full, nframes_t now)
 	Timecode::Time timecode;
 	TimecodeFormat tc_format;
 	bool reset_tc = true;
-	
+	nframes64_t window_root = -1;
+
 	DEBUG_TRACE (DEBUG::MTC, string_compose ("full mtc time known at %1, full ? %2\n", now, was_full));
 	
 	timecode.hours = msg[3];
@@ -175,24 +168,28 @@ MTC_Slave::update_mtc_time (const byte *msg, bool was_full, nframes_t now)
 	DEBUG_TRACE (DEBUG::MTC, string_compose ("MTC time timestamp = %1 TC %2 = frame %3 (from full message ? %4)\n", 
 						 now, timecode, mtc_frame, was_full));
 
-	if (was_full) {
+	if (was_full || outside_window (mtc_frame)) {
 
 		session.timecode_to_sample (timecode, mtc_frame, true, false);
 		session.request_locate (mtc_frame, false);
 		session.request_transport_speed (0);
-		update_mtc_status (MIDI::Parser::MTC_Stopped);
-
+		update_mtc_status (MIDI::MTC_Stopped);
+		window_root = mtc_frame;
+		
 		reset ();
 
 	} else {
-
 			
 		/* we've had the first set of 8 qtr frame messages, determine position
-			   and allow continuing qtr frame messages to provide position
-			   and speed information.
+		   and allow continuing qtr frame messages to provide position
+		   and speed information.
 		*/
 		
-		qtr_frame_messages_valid_for_time = true;
+		/* do a careful conversion of the timecode value to a position
+		   so that we take drop/nondrop and all that nonsense into 
+		   consideration.
+		*/
+
 		session.timecode_to_sample (timecode, mtc_frame, true, false);
 		
 		/* We received the last quarter frame 7 quarter frames (1.75 mtc
@@ -203,56 +200,84 @@ MTC_Slave::update_mtc_time (const byte *msg, bool was_full, nframes_t now)
 		
 		mtc_frame += (long) (1.75 * session.frames_per_timecode_frame()) + session.worst_output_latency();
 
+
 		if (now) {
-			double speed = compute_apparent_speed (now);
-			
+
+			if (last_mtc_timestamp == 0) {
+
+				last_mtc_timestamp = now;
+				last_mtc_frame = mtc_frame;
+
+			} else {
+
+				if (give_slave_full_control_over_transport_speed()) {
+					/* PIC 
+					 * 
+					 * its not the average, but we will assign it to current.speed below
+					 */
+					
+					average_speed = pic->get_ratio (session.audible_frame() - mtc_frame);
+					
+				} else {
+
+					/* Non-PiC 
+					 */
+
+					nframes64_t time_delta = (now - last_mtc_timestamp);
+					
+					if (time_delta != 0) {
+						double apparent_speed = (mtc_frame - last_mtc_frame) / (double) (time_delta);
+						
+						process_apparent_speed (apparent_speed);
+						DEBUG_TRACE (DEBUG::Slave, string_compose ("apparent speed was %1 average is now %2\n", apparent_speed, average_speed));
+					} else {
+						DEBUG_TRACE (DEBUG::Slave, string_compose ("no apparent calc, average is %1\n", average_speed));
+					}
+					
+					/* every second, recalibrate the starting point for the speed measurement */
+					if (mtc_frame - last_mtc_frame > session.frame_rate()) {
+						last_mtc_timestamp = now;
+						last_mtc_frame = mtc_frame;
+					}
+				}
+			}
+
 			current.guard1++;
 			current.position = mtc_frame;
 			current.timestamp = now;
-			current.speed = speed;
+			current.speed = average_speed;
 			current.guard2++;
+			window_root = mtc_frame;
 		}
 	}
 
 	if (now) {
 		last_inbound_frame = now;
 	}
+
+	if (window_root >= 0) {
+		reset_window (window_root);
+	}
 }
 
-double
-MTC_Slave::compute_apparent_speed (nframes64_t now)
+void
+MTC_Slave::process_apparent_speed (double this_speed)
 {
-	if (current.timestamp != 0) {
-		
-		double speed = (double) ((mtc_frame - current.position) / (double) (now - current.timestamp));
-		DEBUG_TRACE (DEBUG::MTC, string_compose ("instantaneous speed = %1 from %2 / %3\n",
-							 speed, mtc_frame - current.position, now - current.timestamp));
-		
-		/* crude low pass filter/smoother for speed */
+	DEBUG_TRACE (DEBUG::MTC, string_compose ("speed cnt %1 sz %2 have %3\n", speed_accumulator_cnt, speed_accumulator_size, have_first_speed_accumulator));
 
-		accumulator[accumulator_index++] = speed;
-		
-		if (accumulator_index >= accumulator_size) {
-			have_first_accumulated_speed = true;
-			accumulator_index = 0;
-		}
-		
-		if (have_first_accumulated_speed) {
-			double total = 0;
-			
-			for (int32_t i = 0; i < accumulator_size; ++i) {
-				total += accumulator[i];
-			}
-			
-			speed = total / accumulator_size;
-			DEBUG_TRACE (DEBUG::MTC, string_compose ("speed smoothed to %1\n", speed));
-		} 
+	if (speed_accumulator_cnt >= speed_accumulator_size) {
+		have_first_speed_accumulator = true;
+		speed_accumulator_cnt = 0;
+	}
 
-		return speed;
-		
-	} else {
-		
-		return 0;
+	speed_accumulator[speed_accumulator_cnt++] = this_speed;
+
+	if (have_first_speed_accumulator) {
+		average_speed = 0.0;
+		for (size_t i = 0; i < speed_accumulator_size; ++i) {
+			average_speed += speed_accumulator[i];
+		}
+		average_speed /= speed_accumulator_size;
 	}
 }
 
@@ -271,16 +296,16 @@ MTC_Slave::handle_locate (const MIDI::byte* mmc_tc)
 }
 
 void
-MTC_Slave::update_mtc_status (MIDI::Parser::MTC_Status status)
+MTC_Slave::update_mtc_status (MIDI::MTC_Status status)
 {
 	/* XXX !!! thread safety ... called from MIDI I/O context
 	   and process() context (via ::speed_and_position())
 	*/
 
+
+	DEBUG_TRACE (DEBUG::MTC, string_compose ("new MTC status %1\n", enum_2_string (status)));
 	switch (status) {
 	case MTC_Stopped:
-		mtc_frame = 0;
-
 		current.guard1++;
 		current.position = mtc_frame;
 		current.timestamp = 0;
@@ -290,27 +315,22 @@ MTC_Slave::update_mtc_status (MIDI::Parser::MTC_Status status)
 		break;
 
 	case MTC_Forward:
-		mtc_frame = 0;
-
 		current.guard1++;
 		current.position = mtc_frame;
 		current.timestamp = 0;
 		current.speed = 0;
 		current.guard2++;
-
 		break;
 
 	case MTC_Backward:
-		mtc_frame = 0;
-
 		current.guard1++;
 		current.position = mtc_frame;
 		current.timestamp = 0;
 		current.speed = 0;
 		current.guard2++;
-
 		break;
 	}
+	
 }
 
 void
@@ -365,7 +385,7 @@ MTC_Slave::speed_and_position (double& speed, nframes64_t& pos)
 		pos = last.position;
 		session.request_locate (pos, false);
 		session.request_transport_speed (0);
-		update_mtc_status (MIDI::Parser::MTC_Stopped);
+		update_mtc_status (MIDI::MTC_Stopped);
 		reset();
 		DEBUG_TRACE (DEBUG::MTC, "MTC not seen for 1/4 second - reset\n");
 		return false;
@@ -384,7 +404,7 @@ MTC_Slave::speed_and_position (double& speed, nframes64_t& pos)
 		if (last.timestamp && (now > last.timestamp)) {
 			elapsed = (nframes_t) floor (last.speed * (now - last.timestamp));
 			DEBUG_TRACE (DEBUG::MTC, string_compose ("last timecode received @ %1, now = %2, elapsed frames = %3 w/speed= %4\n",
-								 last.timestamp, now, elapsed, speed));
+								 last.timestamp, now, elapsed, last.speed));
 		} else {
 			elapsed = 0; /* XXX is this right? */
 		}
@@ -422,7 +442,42 @@ MTC_Slave::reset ()
 	current.timestamp = 0;
 	current.speed = 0;
 	current.guard2++;
-	accumulator_index = 0;
-	have_first_accumulated_speed = false;
-	qtr_frame_messages_valid_for_time = false;
+
+	window_begin = 0;
+	window_end = 0;
+	last_mtc_frame = 0;
+	last_mtc_timestamp = 0;
+
+	average_speed = 0;
+	have_first_speed_accumulator = false;
+	speed_accumulator_cnt = 0;
+
+	pic->out_of_bounds();
+}
+
+void
+MTC_Slave::reset_window (nframes64_t root)
+{
+	window_begin = root;
+
+	if (session.slave_state() == Session::Running) {
+		window_end = root + (session.frames_per_timecode_frame() * 2);
+	} else {
+		window_end = root + seekahead_distance ();
+	}
+
+	DEBUG_TRACE (DEBUG::MTC, string_compose ("legal MTC window now %1 .. %2\n", window_begin, window_end));
+}
+
+nframes64_t
+MTC_Slave::seekahead_distance () const
+{
+	/* 1 second */
+	return session.frame_rate();
+}
+
+bool
+MTC_Slave::outside_window (nframes64_t pos) const
+{
+	return ((pos < window_begin) || (pos > window_end));
 }