From 79abf3dfa6d649fbf1fb6fd16cd489f434d0b909 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Fri, 23 Jun 2017 14:19:04 -0400
Subject: [PATCH] set + store signal chain latency for all processors;
 DiskWriter sets its capture_offset appropriately

---
 libs/ardour/ardour/disk_writer.h | 2 --
 libs/ardour/ardour/processor.h   | 4 ++++
 libs/ardour/disk_writer.cc       | 7 +++----
 libs/ardour/processor.cc         | 9 +++++++++
 libs/ardour/route.cc             | 6 ++++++
 5 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/libs/ardour/ardour/disk_writer.h b/libs/ardour/ardour/disk_writer.h
index 72882e86fb..218d1fc1fa 100644
--- a/libs/ardour/ardour/disk_writer.h
+++ b/libs/ardour/ardour/disk_writer.h
@@ -90,7 +90,6 @@ class LIBARDOUR_API DiskWriter : public DiskIOProcessor
 	PBD::Signal0<void> AlignmentStyleChanged;
 
 	void set_input_latency (framecnt_t);
-	framecnt_t input_latency () const { return _input_latency; }
 
 	bool configure_io (ChanCount in, ChanCount out);
 
@@ -170,7 +169,6 @@ class LIBARDOUR_API DiskWriter : public DiskIOProcessor
 	CaptureInfos capture_info;
 
   private:
-	framecnt_t   _input_latency;
 	gint         _record_enabled;
 	gint         _record_safe;
 	framepos_t    capture_start_frame;
diff --git a/libs/ardour/ardour/processor.h b/libs/ardour/ardour/processor.h
index 1898b6cb60..095ab7fadf 100644
--- a/libs/ardour/ardour/processor.h
+++ b/libs/ardour/ardour/processor.h
@@ -70,6 +70,9 @@ class LIBARDOUR_API Processor : public SessionObject, public Automatable, public
 
 	virtual framecnt_t signal_latency() const { return 0; }
 
+	virtual void set_input_latency (framecnt_t);
+	framecnt_t input_latency () const { return _input_latency; }
+
 	virtual int set_block_size (pframes_t /*nframes*/) { return 0; }
 	virtual bool requires_fixed_sized_buffers() const { return false; }
 
@@ -149,6 +152,7 @@ protected:
 	ProcessorWindowProxy *_window_proxy;
 	PluginPinWindowProxy *_pinmgr_proxy;
 	SessionObject* _owner;
+	framecnt_t _input_latency;
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/disk_writer.cc b/libs/ardour/disk_writer.cc
index 4eb4393861..82f9324d5b 100644
--- a/libs/ardour/disk_writer.cc
+++ b/libs/ardour/disk_writer.cc
@@ -45,7 +45,6 @@ PBD::Signal0<void> DiskWriter::Overrun;
 
 DiskWriter::DiskWriter (Session& s, string const & str, DiskIOProcessor::Flag f)
 	: DiskIOProcessor (s, str, f)
-	, _input_latency (0)
 	, _record_enabled (0)
 	, _record_safe (0)
 	, capture_start_frame (0)
@@ -292,7 +291,8 @@ DiskWriter::get_captured_frames (uint32_t n) const
 void
 DiskWriter::set_input_latency (framecnt_t l)
 {
-	_input_latency = l;
+	Processor::set_input_latency (l);
+	set_capture_offset ();
 }
 
 void
@@ -309,7 +309,7 @@ DiskWriter::set_capture_offset ()
 		break;
 	}
 
-        DEBUG_TRACE (DEBUG::CaptureAlignment, string_compose ("%1: using IO latency, capture offset set to %2 with style = %3\n", name(), _capture_offset, enum_2_string (_alignment_style)));
+	DEBUG_TRACE (DEBUG::CaptureAlignment, string_compose ("%1: using input latency %4, capture offset set to %2 with style = %3\n", name(), _capture_offset, enum_2_string (_alignment_style), _input_latency));
 }
 
 
@@ -322,7 +322,6 @@ DiskWriter::set_align_style (AlignStyle a, bool force)
 
 	if ((a != _alignment_style) || force) {
 		_alignment_style = a;
-		cerr << name() << " using align style " << enum_2_string (_alignment_style) << endl;
 		set_capture_offset ();
 		AlignmentStyleChanged ();
 	}
diff --git a/libs/ardour/processor.cc b/libs/ardour/processor.cc
index 23e55f91ae..335bb0f019 100644
--- a/libs/ardour/processor.cc
+++ b/libs/ardour/processor.cc
@@ -68,6 +68,7 @@ Processor::Processor(Session& session, const string& name)
 	, _window_proxy (0)
 	, _pinmgr_proxy (0)
 	, _owner (0)
+	, _input_latency (0)
 {
 }
 
@@ -86,6 +87,7 @@ Processor::Processor (const Processor& other)
 	, _window_proxy (0)
 	, _pinmgr_proxy (0)
 	, _owner (0)
+	, _input_latency (0)
 {
 }
 
@@ -288,3 +290,10 @@ Processor::owner() const
 {
 	return _owner;
 }
+
+void
+Processor::set_input_latency (framecnt_t cnt)
+{
+	_input_latency = cnt;
+}
+
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index 352d36a2c5..b7a57fd3f1 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -1806,6 +1806,8 @@ Route::configure_processors_unlocked (ProcessorStreams* err, Glib::Threads::RWLo
 	// TODO check for a potential ReaderLock after ReaderLock ??
 	Glib::Threads::RWLock::ReaderLock lr (_processor_lock);
 
+	framecnt_t chain_latency = _input->latency ();
+
 	list< pair<ChanCount,ChanCount> >::iterator c = configuration.begin();
 	for (ProcessorList::iterator p = _processors.begin(); p != _processors.end(); ++p, ++c) {
 
@@ -1816,6 +1818,10 @@ Route::configure_processors_unlocked (ProcessorStreams* err, Glib::Threads::RWLo
 			lm->acquire ();
 			return -1;
 		}
+
+		(*p)->set_input_latency (chain_latency);
+		chain_latency += (*p)->signal_latency ();
+
 		processor_max_streams = ChanCount::max(processor_max_streams, c->first);
 		processor_max_streams = ChanCount::max(processor_max_streams, c->second);
 
-- 
2.30.2