From 341cd455d8f5b0f01e33aaa0fd675eeb396b4355 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 21 Jun 2023 23:54:55 +0200
Subject: [PATCH] CoreAudio: unconditionally apply device latency

---
 libs/backends/coreaudio/coreaudio_backend.cc | 22 ++++++++++++++++----
 libs/backends/coreaudio/coreaudio_backend.h  |  3 +++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/libs/backends/coreaudio/coreaudio_backend.cc b/libs/backends/coreaudio/coreaudio_backend.cc
index 15e8c9f8b9..fd28b76ad0 100644
--- a/libs/backends/coreaudio/coreaudio_backend.cc
+++ b/libs/backends/coreaudio/coreaudio_backend.cc
@@ -112,6 +112,8 @@ CoreAudioBackend::CoreAudioBackend (AudioEngine& e, AudioBackendInfo& info)
 	, _n_outputs (0)
 	, _systemic_audio_input_latency (0)
 	, _systemic_audio_output_latency (0)
+	, _hw_audio_input_latency (0)
+	, _hw_audio_output_latency (0)
 	, _dsp_load (0)
 	, _processed_samples (0)
 {
@@ -451,6 +453,7 @@ CoreAudioBackend::systemic_output_latency () const
 uint32_t
 CoreAudioBackend::systemic_hw_input_latency () const
 {
+	return 0;
 	if (name_to_id (_input_audio_device) != UINT32_MAX) {
 		return _pcmio->get_latency(name_to_id(_input_audio_device, Input), true);
 	}
@@ -460,6 +463,7 @@ CoreAudioBackend::systemic_hw_input_latency () const
 uint32_t
 CoreAudioBackend::systemic_hw_output_latency () const
 {
+	return 0;
 	if (name_to_id (_output_audio_device) != UINT32_MAX) {
 		return _pcmio->get_latency(name_to_id(_output_audio_device, Output), false);
 	}
@@ -642,6 +646,16 @@ CoreAudioBackend::_start (bool for_latency_measurement)
 		PBD::warning << _("CoreAudioBackend: sample rate does not match.") << endmsg;
 	}
 
+	_hw_audio_input_latency = _hw_audio_output_latency = 0;
+
+	if (device1 != UINT32_MAX) {
+		_hw_audio_input_latency = _pcmio->get_latency(device1, true);
+	}
+
+	if (device2 != UINT32_MAX) {
+		_hw_audio_output_latency = _pcmio->get_latency(device2, false);
+	}
+
 	_measure_latency = for_latency_measurement;
 
 	_preinit = true;
@@ -1244,12 +1258,12 @@ CoreAudioBackend::get_latency_range (PortEngine::PortHandle port_handle, bool fo
 	r = port->latency_range (for_playback);
 	if (port->is_physical() && port->is_terminal() && port->type() == DataType::AUDIO) {
 		if (port->is_input() && for_playback) {
-			r.min += _samples_per_period;
-			r.max += _samples_per_period;
+			r.min += _samples_per_period + _hw_audio_input_latency;
+			r.max += _samples_per_period + _hw_audio_input_latency;
 		}
 		if (port->is_output() && !for_playback) {
-			r.min += _samples_per_period;
-			r.max += _samples_per_period;
+			r.min += _samples_per_period + _hw_audio_output_latency;
+			r.max += _samples_per_period + _hw_audio_output_latency;
 		}
 	}
 	return r;
diff --git a/libs/backends/coreaudio/coreaudio_backend.h b/libs/backends/coreaudio/coreaudio_backend.h
index 05cff39d6d..e3daeec26e 100644
--- a/libs/backends/coreaudio/coreaudio_backend.h
+++ b/libs/backends/coreaudio/coreaudio_backend.h
@@ -368,6 +368,9 @@ class CoreAudioBackend : public AudioBackend, public PortEngineSharedImpl {
 	uint32_t _systemic_audio_input_latency;
 	uint32_t _systemic_audio_output_latency;
 
+	uint32_t _hw_audio_input_latency;
+	uint32_t _hw_audio_output_latency;
+
 	/* coreaudio specific  */
 	enum DeviceFilter { All, Input, Output, Duplex };
 	uint32_t name_to_id(std::string, DeviceFilter filter = All) const;