forward port 2.X various changes (not all, but i have a list) ending with 6928

git-svn-id: svn://localhost/ardour2/branches/3.0@7643 d708f5d6-7413-0410-9779-e7cbd77b26cf

4 files changed, 33 insertions, 1 deletions

diff --git a/libs/ardour/ardour/audiosource.h b/libs/ardour/ardour/audiosource.h
index 2d749dd673..249757f9b4 100644
--- a/libs/ardour/ardour/audiosource.h
+++ b/libs/ardour/ardour/audiosource.h
@@ -70,6 +70,7 @@ class AudioSource : virtual public Source,
 
 	uint32_t read_data_count() const { return _read_data_count; }
 	uint32_t write_data_count() const { return _write_data_count; }
+	void dec_read_data_count(nframes_t);
 
 	int read_peaks (PeakData *peaks, framecnt_t npeaks,
 			framepos_t start, framecnt_t cnt, double samples_per_visual_peak) const;
diff --git a/libs/ardour/ardour/rc_configuration_vars.h b/libs/ardour/ardour/rc_configuration_vars.h
index 244744cfe2..a637ac4bb8 100644
--- a/libs/ardour/ardour/rc_configuration_vars.h
+++ b/libs/ardour/ardour/rc_configuration_vars.h
@@ -123,6 +123,7 @@ CONFIG_VARIABLE (float, meter_falloff, "meter-falloff", 32.0f)
 
 /* miscellany */
 
+CONFIG_VARIABLE (bool, replicate_missing_region_channels, "replicate-missing-region-channels", false)
 CONFIG_VARIABLE (bool, hiding_groups_deactivates_groups, "hiding-groups-deactivates-groups", true)
 CONFIG_VARIABLE (bool, verify_remove_last_capture, "verify-remove-last-capture", true)
 CONFIG_VARIABLE (bool, no_new_session_dialog, "no-new-session-dialog", false)
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index a1cb58458b..992ae7fab2 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -356,6 +356,10 @@ AudioRegion::_read_at (const SourceList& /*srcs*/, framecnt_t limit,
 	framecnt_t to_read;
 	bool raw = (rops == ReadOpsNone);
 
+        if (n_channels() == 0) {
+                return 0;
+        }
+
 	if (muted() && !raw) {
 		return 0; /* read nothing */
 	}
@@ -407,7 +411,22 @@ AudioRegion::_read_at (const SourceList& /*srcs*/, framecnt_t limit,
 		   we don't have.
 		*/
 
-		memset (mixdown_buffer, 0, sizeof (Sample) * cnt);
+                if (Config->get_replicate_missing_region_channels()) {
+                       /* track is N-channel, this region has less channels, so use a relevant channel
+                        */
+                        
+                        uint32_t channel = n_channels() % chan_n;
+                        boost::shared_ptr<AudioSource> src = audio_source (channel);
+
+                        if (src->read (mixdown_buffer, _start + internal_offset, to_read) != to_read) {
+                                return 0; /* "read nothing" */
+                        }
+
+                        /* adjust read data count appropriately since this was a duplicate read */
+                        src->dec_read_data_count (to_read);
+                } else {
+                        memset (mixdown_buffer, 0, sizeof (Sample) * cnt);
+                }
 	}
 
 	if (rops & ReadOpsFades) {
diff --git a/libs/ardour/audiosource.cc b/libs/ardour/audiosource.cc
index f309f599c5..083cf3bea9 100644
--- a/libs/ardour/audiosource.cc
+++ b/libs/ardour/audiosource.cc
@@ -945,3 +945,14 @@ AudioSource::available_peaks (double zoom_factor) const
 	return (end/sizeof(PeakData)) * _FPP;
 }
 
+void
+AudioSource::dec_read_data_count (nframes_t cnt)
+{
+        uint32_t val = cnt * sizeof (Sample);
+
+        if (val < _read_data_count) {
+                _read_data_count -= val;
+        } else { 
+                _read_data_count = 0;
+        }
+}