Prevent selection of too few DCP channels (#611).

This makes Film::audio_channels() return a minimum of any active
processor's output channel count, even if fewer DCP channels have
been selected.  It may have been neater code-wise to make Player cope
if such a setting is made, but it would probably confuse people
if we don't auto-fix it (like this commit does).

5 files changed, 55 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index 688e933b4..2b0f1fef6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-16  c.hetherington  <cth@carlh.net>
+
+	* Prevent selection of fewer DCP channels than
+	are present in the output of an active processor (#611).
+
 2015-06-15  Carl Hetherington  <cth@carlh.net>
 
 	* Select newly-added content (#455).
diff --git a/src/lib/film.cc b/src/lib/film.cc
index d67182022..98b921029 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -72,6 +72,7 @@ using std::map;
 using std::vector;
 using std::setfill;
 using std::min;
+using std::max;
 using std::make_pair;
 using std::endl;
 using std::cout;
@@ -805,6 +806,7 @@ Film::set_audio_processor (AudioProcessor const * processor)
 {
 	_audio_processor = processor;
 	signal_changed (AUDIO_PROCESSOR);
+	signal_changed (AUDIO_CHANNELS);
 }
 
 void
@@ -1230,3 +1232,18 @@ Film::audio_output_names () const
 
 	return vector<string> (n.begin(), n.begin() + audio_channels ());
 }
+
+int
+Film::audio_channels () const
+{
+	int minimum = 0;
+	if (_audio_processor) {
+		minimum = _audio_processor->out_channels ();
+	}
+
+	if (minimum % 2 == 1) {
+		++minimum;
+	}
+
+	return max (minimum, _audio_channels);
+}
diff --git a/src/lib/film.h b/src/lib/film.h
index f9dc0ed9c..a1daebe78 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -223,9 +223,7 @@ public:
 		return _video_frame_rate;
 	}
 
-	int audio_channels () const {
-		return _audio_channels;
-	}
+	int audio_channels () const;
 
 	bool three_d () const {
 		return _three_d;
@@ -326,7 +324,9 @@ private:
 	int _video_frame_rate;
 	/** The date that we should use in a ISDCF name */
 	boost::gregorian::date _isdcf_date;
-	/** Number of audio channels to put in the DCP */
+	/** Number of audio channels requested for the DCP; this will be overridden
+	    if we are using an audio processor which outputs more channels.
+	*/
 	int _audio_channels;
 	/** If true, the DCP will be written in 3D mode; otherwise in 2D.
 	    This will be regardless of what content is on the playlist.
diff --git a/src/wx/dcp_panel.cc b/src/wx/dcp_panel.cc
index 24c678c57..0759694f8 100644
--- a/src/wx/dcp_panel.cc
+++ b/src/wx/dcp_panel.cc
@@ -30,6 +30,7 @@
 #include "lib/ffmpeg_content.h"
 #include "lib/audio_processor.h"
 #include <dcp/key.h>
+#include <dcp/raw_convert.h>
 #include <wx/wx.h>
 #include <wx/notebook.h>
 #include <wx/gbsizer.h>
@@ -41,6 +42,8 @@ using std::cout;
 using std::list;
 using std::string;
 using std::vector;
+using std::pair;
+using std::make_pair;
 using boost::lexical_cast;
 using boost::shared_ptr;
 
@@ -245,7 +248,7 @@ DCPPanel::audio_channels_changed ()
 		return;
 	}
 
-	_film->set_audio_channels ((_audio_channels->GetSelection () + 1) * 2);
+	_film->set_audio_channels (dcp::raw_convert<int> (string_client_data (_audio_channels->GetClientObject (_audio_channels->GetSelection ()))));
 }
 
 void
@@ -346,7 +349,7 @@ DCPPanel::film_changed (int p)
 		break;
 	}
 	case Film::AUDIO_CHANNELS:
-		checked_set (_audio_channels, (_film->audio_channels () / 2) - 1);
+		checked_set (_audio_channels, dcp::raw_convert<string> (_film->audio_channels ()));
 		setup_dcp_name ();
 		break;
 	case Film::THREE_D:
@@ -363,6 +366,8 @@ DCPPanel::film_changed (int p)
 		} else {
 			checked_set (_audio_processor, 0);
 		}
+		setup_audio_channels_choice ();
+		film_changed (Film::AUDIO_CHANNELS);
 		break;
 	default:
 		break;
@@ -648,6 +653,26 @@ DCPPanel::make_video_panel ()
 	return panel;
 }
 
+void
+DCPPanel::setup_audio_channels_choice ()
+{
+	int min = 2;
+	if (_film && _film->audio_processor ()) {
+		min = _film->audio_processor()->out_channels ();
+	}
+
+	if (min % 2 == 1) {
+		++min;
+	}
+
+	vector<pair<string, string> > items;
+	for (int i = min; i <= 12; i += 2) {
+		items.push_back (make_pair (dcp::raw_convert<string> (i), dcp::raw_convert<string> (i)));
+	}
+
+	checked_set (_audio_channels, items);
+}
+
 wxPanel *
 DCPPanel::make_audio_panel ()
 {
@@ -661,9 +686,7 @@ DCPPanel::make_audio_panel ()
 	
 	add_label_to_grid_bag_sizer (grid, panel, _("Channels"), true, wxGBPosition (r, 0));
 	_audio_channels = new wxChoice (panel, wxID_ANY);
-	for (int i = 2; i <= 12; i += 2) {
-		_audio_channels->Append (wxString::Format ("%d", i));
-	}
+	setup_audio_channels_choice ();
 	grid->Add (_audio_channels, wxGBPosition (r, 1));
 	++r;
 
diff --git a/src/wx/dcp_panel.h b/src/wx/dcp_panel.h
index 3179ad73a..ab4e7f1d3 100644
--- a/src/wx/dcp_panel.h
+++ b/src/wx/dcp_panel.h
@@ -76,6 +76,7 @@ private:
 	void setup_frame_rate_widget ();
 	void setup_container ();
 	void setup_dcp_name ();
+	void setup_audio_channels_choice ();
 
 	wxPanel* make_general_panel ();
 	wxPanel* make_video_panel ();