3 files changed, 36 insertions, 22 deletions

diff --git a/servers/audio/effects/audio_effect_spectrum_analyzer.cpp b/servers/audio/effects/audio_effect_spectrum_analyzer.cpp
index 01a52aa01f..46d92336f3 100644
--- a/servers/audio/effects/audio_effect_spectrum_analyzer.cpp
+++ b/servers/audio/effects/audio_effect_spectrum_analyzer.cpp
@@ -130,7 +130,7 @@ Vector2 AudioEffectSpectrumAnalyzerInstance::get_magnitude_for_frequency_range(f
 	}
 	uint64_t time = OS::get_singleton()->get_ticks_usec();
 	float diff = double(time - last_fft_time) / 1000000.0 + base->get_tap_back_pos();
-	diff -= AudioServer::get_singleton()->get_output_delay();
+	diff -= AudioServer::get_singleton()->get_output_latency();
 	float fft_time_size = float(fft_size) / mix_rate;
 
 	int fft_index = fft_pos;
diff --git a/servers/audio_server.cpp b/servers/audio_server.cpp
index c83c3029f3..fc3ecedd03 100644
--- a/servers/audio_server.cpp
+++ b/servers/audio_server.cpp
@@ -68,16 +68,21 @@ void AudioDriver::audio_server_process(int p_frames, int32_t *p_buffer, bool p_u
 
 void AudioDriver::update_mix_time(int p_frames) {
 
-	_mix_amount += p_frames;
+	_last_mix_frames = p_frames;
 	if (OS::get_singleton())
 		_last_mix_time = OS::get_singleton()->get_ticks_usec();
 }
 
-double AudioDriver::get_mix_time() const {
+double AudioDriver::get_time_since_last_mix() const {
+
+	return (OS::get_singleton()->get_ticks_usec() - _last_mix_time) / 1000000.0;
+}
+
+double AudioDriver::get_time_to_next_mix() const {
 
 	double total = (OS::get_singleton()->get_ticks_usec() - _last_mix_time) / 1000000.0;
-	total += _mix_amount / (double)get_mix_rate();
-	return total;
+	double mix_buffer = _last_mix_frames / (double)get_mix_rate();
+	return mix_buffer - total;
 }
 
 void AudioDriver::input_buffer_init(int driver_buffer_frames) {
@@ -148,7 +153,7 @@ Array AudioDriver::capture_get_device_list() {
 AudioDriver::AudioDriver() {
 
 	_last_mix_time = 0;
-	_mix_amount = 0;
+	_last_mix_frames = 0;
 	input_position = 0;
 	input_size = 0;
 
@@ -281,13 +286,6 @@ void AudioServer::_driver_process(int p_frames, int32_t *p_buffer) {
 		to_mix -= to_copy;
 	}
 
-	// Calculate latency for Performance.AUDIO_OUTPUT_LATENCY
-	if (OS::get_singleton()) {
-		uint64_t ticks = OS::get_singleton()->get_ticks_usec();
-		output_latency = (ticks - output_latency_ticks) / 1000000.f;
-		output_latency_ticks = ticks;
-	}
-
 #ifdef DEBUG_ENABLED
 	prof_time += OS::get_singleton()->get_ticks_usec() - prof_ticks;
 #endif
@@ -1107,13 +1105,19 @@ AudioServer *AudioServer::get_singleton() {
 	return singleton;
 }
 
-double AudioServer::get_mix_time() const {
+double AudioServer::get_output_latency() const {
 
-	return 0;
+	return AudioDriver::get_singleton()->get_latency();
 }
-double AudioServer::get_output_delay() const {
 
-	return 0;
+double AudioServer::get_time_to_next_mix() const {
+
+	return AudioDriver::get_singleton()->get_time_to_next_mix();
+}
+
+double AudioServer::get_time_since_last_mix() const {
+
+	return AudioDriver::get_singleton()->get_time_since_last_mix();
 }
 
 AudioServer *AudioServer::singleton = NULL;
@@ -1357,6 +1361,10 @@ void AudioServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_device"), &AudioServer::get_device);
 	ClassDB::bind_method(D_METHOD("set_device", "device"), &AudioServer::set_device);
 
+	ClassDB::bind_method(D_METHOD("get_time_to_next_mix"), &AudioServer::get_time_to_next_mix);
+	ClassDB::bind_method(D_METHOD("get_time_since_last_mix"), &AudioServer::get_time_since_last_mix);
+	ClassDB::bind_method(D_METHOD("get_output_latency"), &AudioServer::get_output_latency);
+
 	ClassDB::bind_method(D_METHOD("capture_get_device_list"), &AudioServer::capture_get_device_list);
 	ClassDB::bind_method(D_METHOD("capture_get_device"), &AudioServer::capture_get_device);
 	ClassDB::bind_method(D_METHOD("capture_set_device", "name"), &AudioServer::capture_set_device);
@@ -1386,6 +1394,8 @@ AudioServer::AudioServer() {
 #ifdef DEBUG_ENABLED
 	prof_time = 0;
 #endif
+	mix_time = 0;
+	mix_size = 0;
 }
 
 AudioServer::~AudioServer() {
diff --git a/servers/audio_server.h b/servers/audio_server.h
index 3b69cb1b88..e56d87ce84 100644
--- a/servers/audio_server.h
+++ b/servers/audio_server.h
@@ -45,7 +45,7 @@ class AudioDriver {
 
 	static AudioDriver *singleton;
 	uint64_t _last_mix_time;
-	uint64_t _mix_amount;
+	uint64_t _last_mix_frames;
 
 #ifdef DEBUG_ENABLED
 	uint64_t prof_ticks;
@@ -71,7 +71,8 @@ protected:
 #endif
 
 public:
-	double get_mix_time() const; //useful for video -> audio sync
+	double get_time_since_last_mix() const; //useful for video -> audio sync
+	double get_time_to_next_mix() const;
 
 	enum SpeakerMode {
 		SPEAKER_MODE_STEREO,
@@ -163,6 +164,9 @@ public:
 	typedef void (*AudioCallback)(void *p_userdata);
 
 private:
+	uint64_t mix_time;
+	int mix_size;
+
 	uint32_t buffer_size;
 	uint64_t mix_count;
 	uint64_t mix_frames;
@@ -351,8 +355,9 @@ public:
 
 	static AudioServer *get_singleton();
 
-	virtual double get_mix_time() const; //useful for video -> audio sync
-	virtual double get_output_delay() const;
+	virtual double get_output_latency() const;
+	virtual double get_time_to_next_mix() const;
+	virtual double get_time_since_last_mix() const;
 
 	void *audio_data_alloc(uint32_t p_data_len, const uint8_t *p_from_data = NULL);
 	void audio_data_free(void *p_data);
@@ -377,7 +382,6 @@ public:
 	String capture_get_device();
 	void capture_set_device(const String &p_name);
 
-	float get_output_latency() { return output_latency; }
 	AudioServer();
 	virtual ~AudioServer();
 };