Fix another bit of incorrect logic (this_is_first_audio was inverted). Also try to add _audio_starts_with_video mode to Matcher.

2 files changed, 28 insertions, 6 deletions

diff --git a/src/lib/matcher.cc b/src/lib/matcher.cc
index 2723f2a2d..3776d4fbc 100644
--- a/src/lib/matcher.cc
+++ b/src/lib/matcher.cc
@@ -34,7 +34,6 @@ Matcher::Matcher (shared_ptr<Log> log, int sample_rate, float frames_per_second)
 	, _frames_per_second (frames_per_second)
 	, _video_frames (0)
 	, _audio_frames (0)
-	, _had_first_video (false)
 	, _had_first_audio (false)
 {
 
@@ -52,8 +51,11 @@ Matcher::process_video (boost::shared_ptr<const Image> image, bool same, boost::
 		_first_input = t;
 	}
 
-	bool const this_is_first_video = !_had_first_video;
-	_had_first_video = true;
+	bool const this_is_first_video = !_first_video;
+	
+	if (!_first_video) {
+		_first_video = t;
+	}
 
 	if (this_is_first_video && _had_first_audio) {
 		/* First video since we got audio */
@@ -104,13 +106,13 @@ Matcher::process_audio (boost::shared_ptr<const AudioBuffers> b, double t)
 		_first_input = t;
 	}
 
-	bool const this_is_first_audio = _had_first_audio;
+	bool const this_is_first_audio = !_had_first_audio;
 	_had_first_audio = true;
 	
-	if (!_had_first_video) {
+	if (!_first_video) {
 		/* No video yet; we must postpone these data until we have some */
 		_pending_audio.push_back (AudioRecord (b, t));
-	} else if (this_is_first_audio && _had_first_video) {
+	} else if (this_is_first_audio && _first_video) {
 		/* First audio since we got video */
 		_pending_audio.push_back (AudioRecord (b, t));
 		fix_start (_first_input.get ());
@@ -145,6 +147,11 @@ Matcher::fix_start (double first_video)
 	match (first_video - _pending_audio.front().time);
 
 	for (list<AudioRecord>::iterator i = _pending_audio.begin(); i != _pending_audio.end(); ++i) {
+		if (_audio_starts_with_video) {
+			assert (_first_video);
+			assert (_first_audio);
+			i->time += _first_video.get() - _first_audio.get();
+		}
 		process_audio (i->audio, i->time);
 	}
 	
@@ -211,3 +218,12 @@ Matcher::repeat_last_video ()
 	++_video_frames;
 }
 
+/** Set `audio starts with video' behaviour.  If this is enabled,
+ *  audio time stamps are adjusted so that the first audio is synced
+ *  with the first video.
+ */
+void
+Matcher::set_audio_starts_with_video (bool a)
+{
+	_audio_starts_with_video = a;
+}
diff --git a/src/lib/matcher.h b/src/lib/matcher.h
index 41aa373a4..aab6adad9 100644
--- a/src/lib/matcher.h
+++ b/src/lib/matcher.h
@@ -25,6 +25,9 @@ class Matcher : public Processor, public TimedAudioSink, public TimedVideoSink,
 {
 public:
 	Matcher (boost::shared_ptr<Log> log, int sample_rate, float frames_per_second);
+
+	void set_audio_starts_with_video (bool);
+	
 	void process_video (boost::shared_ptr<const Image> i, bool, boost::shared_ptr<Subtitle> s, double);
 	void process_audio (boost::shared_ptr<const AudioBuffers>, double);
 	void process_end ();
@@ -55,9 +58,12 @@ private:
 	std::list<AudioRecord> _pending_audio;
 
 	boost::optional<double> _first_input;
+	boost::optional<double> _first_video;
 	boost::shared_ptr<const Image> _last_image;
 	boost::shared_ptr<Subtitle> _last_subtitle;
 
 	bool _had_first_video;
 	bool _had_first_audio;
+
+	bool _audio_starts_with_video;
 };