Pad silence for things that already have at least some audio.

7 files changed, 50 insertions, 9 deletions

diff --git a/src/lib/encoder.cc b/src/lib/encoder.cc
index 2c989452d..6a99132fd 100644
--- a/src/lib/encoder.cc
+++ b/src/lib/encoder.cc
@@ -433,10 +433,10 @@ Encoder::encoder_thread (ServerDescription* server)
 void
 Encoder::write_audio (shared_ptr<const AudioBuffers> data)
 {
-	AudioMapping m (_film->audio_channels ());
+	AudioMapping m (_film);
 	if (m.dcp_channels() != _film->audio_channels()) {
 
-		/* Remap (currently just for mono -> 5.1) */
+		/* Remap and pad with silence */
 
 		shared_ptr<AudioBuffers> b (new AudioBuffers (m.dcp_channels(), data->frames ()));
 		for (int i = 0; i < m.dcp_channels(); ++i) {
diff --git a/src/lib/film.cc b/src/lib/film.cc
index d92d7a977..ce555ac8b 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -108,6 +108,7 @@ Film::Film (string d, bool must_exist)
 	, _j2k_bandwidth (200000000)
 	, _dci_metadata (Config::instance()->default_dci_metadata ())
 	, _dcp_frame_rate (0)
+	, _minimum_audio_channels (0)
 	, _source_frame_rate (0)
 	, _dirty (false)
 {
@@ -185,6 +186,7 @@ Film::Film (Film const & o)
 	, _dci_metadata      (o._dci_metadata)
 	, _dci_date          (o._dci_date)
 	, _dcp_frame_rate    (o._dcp_frame_rate)
+	, _minimum_audio_channels (o._minimum_audio_channels)
 	, _size              (o._size)
 	, _length            (o._length)
 	, _content_digest    (o._content_digest)
@@ -506,6 +508,7 @@ Film::write_metadata () const
 	_dci_metadata.write (f);
 	f << "dci_date " << boost::gregorian::to_iso_string (_dci_date) << endl;
 	f << "dcp_frame_rate " << _dcp_frame_rate << endl;
+	f << "minimum_audio_channels " << _minimum_audio_channels << endl;
 	f << "width " << _size.width << endl;
 	f << "height " << _size.height << endl;
 	f << "length " << _length.get_value_or(0) << endl;
@@ -642,6 +645,8 @@ Film::read_metadata ()
 			_dci_date = boost::gregorian::from_undelimited_string (v);
 		} else if (k == "dcp_frame_rate") {
 			_dcp_frame_rate = atoi (v.c_str ());
+		} else if (k == "minimum_audio_channels") {
+			_minimum_audio_channels = atoi (v.c_str ());
 		}
 
 		_dci_metadata.read (k, v);
@@ -1324,6 +1329,16 @@ Film::set_dcp_frame_rate (int f)
 }
 
 void
+Film::set_minimum_audio_channels (int c)
+{
+	{
+		boost::mutex::scoped_lock lm (_state_mutex);
+		_minimum_audio_channels = c;
+	}
+	signal_changed (MINIMUM_AUDIO_CHANNELS);
+}
+			
+void
 Film::set_size (libdcp::Size s)
 {
 	{
diff --git a/src/lib/film.h b/src/lib/film.h
index dd0a83d94..ca9bd57f4 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -153,7 +153,8 @@ public:
 		CONTENT_AUDIO_STREAMS,
 		SUBTITLE_STREAMS,
 		SOURCE_FRAME_RATE,
-		DCP_FRAME_RATE
+		DCP_FRAME_RATE,
+		MINIMUM_AUDIO_CHANNELS
 	};
 
 
@@ -335,6 +336,11 @@ public:
 		return _source_frame_rate;
 	}
 
+	int minimum_audio_channels () const {
+		boost::mutex::scoped_lock lm (_state_mutex);
+		return _minimum_audio_channels;
+	}
+
 	boost::shared_ptr<AudioStream> audio_stream () const;
 	bool has_audio () const;
 	
@@ -379,6 +385,7 @@ public:
 	void set_content_audio_streams (std::vector<boost::shared_ptr<AudioStream> >);
 	void set_subtitle_streams (std::vector<boost::shared_ptr<SubtitleStream> >);
 	void set_source_frame_rate (float);
+	void set_minimum_audio_channels (int);
 
 	/** Emitted when some property has changed */
 	mutable boost::signals2::signal<void (Property)> Changed;
@@ -481,6 +488,7 @@ private:
 	boost::gregorian::date _dci_date;
 	/** Frames per second to run our DCP at */
 	int _dcp_frame_rate;
+	int _minimum_audio_channels;
 
 	/* Data which are cached to speed things up */
 
diff --git a/src/lib/transcoder.cc b/src/lib/transcoder.cc
index 48cf402d7..a202d440c 100644
--- a/src/lib/transcoder.cc
+++ b/src/lib/transcoder.cc
@@ -73,7 +73,7 @@ Transcoder::Transcoder (shared_ptr<Film> f, DecodeOptions o, Job* j, shared_ptr<
 	/* Set up the decoder to use the film's set streams */
 	_decoders.video->set_subtitle_stream (f->subtitle_stream ());
 	if (f->audio_stream ()) {
-	    _decoders.audio->set_audio_stream (f->audio_stream ());
+		_decoders.audio->set_audio_stream (f->audio_stream ());
 	}
 
 	_decoders.video->connect_video (_delay_line);
diff --git a/src/lib/util.cc b/src/lib/util.cc
index 4cf57368a..83980f828 100644
--- a/src/lib/util.cc
+++ b/src/lib/util.cc
@@ -61,6 +61,7 @@ extern "C" {
 #include "filter.h"
 #include "sound_processor.h"
 #include "config.h"
+#include "film.h"
 #ifdef DVDOMATIC_WINDOWS
 #include "stack.hpp"
 #endif
@@ -962,8 +963,9 @@ audio_channel_name (int c)
 	return channels[c];
 }
 
-AudioMapping::AudioMapping (int c)
-	: _source_channels (c)
+AudioMapping::AudioMapping (shared_ptr<const Film> f)
+	: _source_channels (f->audio_stream() ? f->audio_stream()->channels() : 0)
+	, _minimum_channels (f->minimum_audio_channels ())
 {
 
 }
@@ -1001,8 +1003,11 @@ AudioMapping::dcp_to_source (libdcp::Channel c) const
 	return static_cast<int> (c);
 }
 
+/** @return minimum number of DCP channels that we can allow in this
+    DCP, given the nature of the source.
+*/
 int
-AudioMapping::dcp_channels () const
+AudioMapping::minimum_dcp_channels () const
 {
 	if (_source_channels == 1) {
 		/* The source is mono, so to put the mono channel into
@@ -1014,6 +1019,15 @@ AudioMapping::dcp_channels () const
 	return _source_channels;
 }
 
+/** @return number of channels that there should be in the DCP, including
+ *  any silent padded ones.
+ */
+int
+AudioMapping::dcp_channels () const
+{
+	return max (_source_channels, _minimum_channels);
+}
+
 FrameRateConversion::FrameRateConversion (float source, int dcp)
 	: skip (false)
 	, repeat (false)
diff --git a/src/lib/util.h b/src/lib/util.h
index 0d745e50c..c9e5bef16 100644
--- a/src/lib/util.h
+++ b/src/lib/util.h
@@ -50,6 +50,7 @@ extern "C" {
 #define MAX_AUDIO_CHANNELS 6
 
 class Scaler;
+class Film;
 
 extern std::string seconds_to_hms (int);
 extern std::string seconds_to_approximate_hms (int);
@@ -287,14 +288,17 @@ private:
 class AudioMapping
 {
 public:
-	AudioMapping (int);
+	AudioMapping (boost::shared_ptr<const Film>);
 
 	boost::optional<libdcp::Channel> source_to_dcp (int c) const;
 	boost::optional<int> dcp_to_source (libdcp::Channel c) const;
+
+	int minimum_dcp_channels () const;
 	int dcp_channels () const;
 
 private:
 	int _source_channels;
+	int _minimum_channels;
 };
 
 extern int64_t video_frames_to_audio_frames (SourceFrame v, float audio_sample_rate, float frames_per_second);
diff --git a/src/lib/writer.cc b/src/lib/writer.cc
index 1a6daa1db..cff0b5be2 100644
--- a/src/lib/writer.cc
+++ b/src/lib/writer.cc
@@ -77,7 +77,7 @@ Writer::Writer (shared_ptr<Film> f)
 
 	_picture_asset_writer = _picture_asset->start_write (_first_nonexistant_frame > 0);
 
-	AudioMapping m (_film->audio_channels ());
+	AudioMapping m (_film);
 	
 	if (m.dcp_channels() > 0) {
 		_sound_asset.reset (