From 0047b87e3dba286906097d5b15ca73b5b529b0eb Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Fri, 26 Oct 2012 11:39:10 +0000
Subject: [PATCH] LTC Slave - re-init on xrun or graph change

git-svn-id: svn://localhost/ardour2/branches/3.0@13350 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 libs/ardour/ardour/session.h |  3 +++
 libs/ardour/ardour/slave.h   |  3 +++
 libs/ardour/ltc_slave.cc     | 26 ++++++++++++++++++++++----
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 33fadcd6bd..c5172c337d 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -850,6 +850,9 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
         boost::shared_ptr<Port> ltc_input_port() const;
         boost::shared_ptr<Port> ltc_output_port() const;
 
+	boost::shared_ptr<IO> ltc_input_io() { return _ltc_input; }
+	boost::shared_ptr<IO> ltc_output_io() { return _ltc_output; }
+
   protected:
 	friend class AudioEngine;
 	void set_block_size (pframes_t nframes);
diff --git a/libs/ardour/ardour/slave.h b/libs/ardour/ardour/slave.h
index e96a90fc76..0ff1da7884 100644
--- a/libs/ardour/ardour/slave.h
+++ b/libs/ardour/ardour/slave.h
@@ -380,6 +380,9 @@ public:
 	Timecode::TimecodeFormat ltc_timecode;
 	Timecode::TimecodeFormat a3e_timecode;
 
+	PBD::ScopedConnectionList port_connections;
+	jack_latency_range_t      ltc_slave_latency;
+
 	/* DLL - chase LTC */
 	int    transport_direction;
 	int    engine_dll_initstate;
diff --git a/libs/ardour/ltc_slave.cc b/libs/ardour/ltc_slave.cc
index 3be0ce6c82..12386eeb18 100644
--- a/libs/ardour/ltc_slave.cc
+++ b/libs/ardour/ltc_slave.cc
@@ -61,10 +61,14 @@ LTC_Slave::LTC_Slave (Session& s)
 
 	decoder = ltc_decoder_create((int) frames_per_ltc_frame, 128 /*queue size*/);
 	reset();
+	session.Xrun.connect_same_thread (port_connections, boost::bind (&LTC_Slave::reset, this));
+	session.engine().GraphReordered.connect_same_thread (port_connections, boost::bind (&LTC_Slave::reset, this));
 }
 
 LTC_Slave::~LTC_Slave()
 {
+	port_connections.drop_connections();
+
 	if (did_reset_tc_format) {
 		session.config.set_timecode_format (saved_tc_format);
 	}
@@ -99,6 +103,11 @@ LTC_Slave::reset()
 	transport_direction = 0;
 	ltc_speed = 0;
 	engine_dll_initstate = 0;
+
+	if (session.ltc_output_io()) { /* check if Port exits */
+		boost::shared_ptr<Port> ltcport = session.ltc_input_port();
+		ltcport->get_connected_latency_range(ltc_slave_latency, false);
+	}
 }
 
 void
@@ -351,15 +360,24 @@ LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 	framecnt_t nframes = session.engine().frames_per_cycle();
 
 	jack_default_audio_sample_t *in;
-	jack_latency_range_t ltc_latency;
 
 	boost::shared_ptr<Port> ltcport = session.ltc_input_port();
-	ltcport->get_connected_latency_range(ltc_latency, false);
+
+#if 1
+	/* TODO read layency only on demand -> ::reset()
+	 * this is already prepared.
+	 *
+	 * ..but first fix jack2 issue with re-computing latency
+	 * in the correct order. Until then, querying it in the
+	 * process-callback is the only way to get the current value
+	 */
+	ltcport->get_connected_latency_range(ltc_slave_latency, false);
+#endif
 	in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 
 	frameoffset_t skip = now - (monotonic_cnt + nframes);
 	monotonic_cnt = now;
-	DEBUG_TRACE (DEBUG::LTC, string_compose ("speed_and_position - TID:%1 | latency: %2 | skip %3\n", ::pthread_self(), ltc_latency.max, skip));
+	DEBUG_TRACE (DEBUG::LTC, string_compose ("speed_and_position - TID:%1 | latency: %2 | skip %3\n", ::pthread_self(), ltc_slave_latency.max, skip));
 
 	if (last_timestamp == 0) {
 		engine_dll_initstate = 0;
@@ -390,7 +408,7 @@ LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 			reset();
 		}
 
-		parse_ltc(nframes, in, now + ltc_latency.max );
+		parse_ltc(nframes, in, now + ltc_slave_latency.max );
 		process_ltc(now);
 	}