Implement a setting in the sound preferences, to apply a manual sync latency offset

Author: JoergAtGithub

src/engine/enginemixer.cpp

@@ -93,6 +93,14 @@ EngineMixer::EngineMixer(UserSettingsPointer pConfig,
                   ConfigKey(group, "boothDelay"))),
           m_pLatencyCompensationDelay(std::make_unique<EngineDelay>(
                   ConfigKey(group, "microphoneLatencyCompensation"))),
+          m_pExternalSyncLatencyCompensation(std::make_unique<ControlPotmeter>(
+                  ConfigKey(group, "externalSyncLatencyCompensation"),
+                  -100.0, // min
+                  100.0,  // max
+                  true,   // allowOutOfBounds
+                  true,   // bIgnoreNops
+                  false,  // bTrack
+                  true)), // bPersist
           m_pVumeter(std::make_unique<EngineVuMeter>(kMainGroup, kLegacyGroup)),
           // Starts a thread for recording and broadcast
           m_pEngineSideChain(bEnableSidechain

src/engine/enginemixer.h

@@ -313,6 +313,7 @@ class EngineMixer : public QObject, public AudioSource {
     std::unique_ptr<EngineDelay> m_pHeadDelay;
     std::unique_ptr<EngineDelay> m_pBoothDelay;
     std::unique_ptr<EngineDelay> m_pLatencyCompensationDelay;
+    std::unique_ptr<ControlPotmeter> m_pExternalSyncLatencyCompensation;
 
     std::unique_ptr<EngineVuMeter> m_pVumeter;
     std::unique_ptr<EngineSideChain> m_pEngineSideChain;

src/preferences/dialog/dlgprefsound.cpp

@@ -75,6 +75,8 @@ DlgPrefSound::DlgPrefSound(QWidget* pParent,
           m_pSettings(pSettings),
           m_config(pSoundManager.get()),
           m_pLatencyCompensation(kMasterGroup, QStringLiteral("microphoneLatencyCompensation")),
+          m_pExternalSyncLatencyCompensation(
+                  kMasterGroup, QStringLiteral("externalSyncLatencyCompensation")),
           m_pMainDelay(kMasterGroup, QStringLiteral("delay")),
           m_pHeadDelay(kMasterGroup, QStringLiteral("headDelay")),
           m_pBoothDelay(kMasterGroup, QStringLiteral("boothDelay")),
@@ -155,6 +157,8 @@ DlgPrefSound::DlgPrefSound(QWidget* pParent,
     }
 
     latencyCompensationSpinBox->setValue(m_pLatencyCompensation.get());
+    externalSyncLatencyCompensationSpinBox->setValue(
+            m_pExternalSyncLatencyCompensation.get());
     latencyCompensationWarningLabel->setWordWrap(true);
     mainDelaySpinBox->setValue(m_pMainDelay.get());
     headDelaySpinBox->setValue(m_pHeadDelay.get());
@@ -167,6 +171,10 @@ DlgPrefSound::DlgPrefSound(QWidget* pParent,
             QOverload<double>::of(&QDoubleSpinBox::valueChanged),
             this,
             &DlgPrefSound::latencyCompensationSpinboxChanged);
+    connect(externalSyncLatencyCompensationSpinBox,
+            QOverload<double>::of(&QDoubleSpinBox::valueChanged),
+            this,
+            &DlgPrefSound::externalSyncLatencyCompensationSpinboxChanged);
     connect(mainDelaySpinBox,
             QOverload<double>::of(&QDoubleSpinBox::valueChanged),
             this,
@@ -953,6 +961,8 @@ void DlgPrefSound::slotResetToDefaults() {
                     static_cast<int>(EngineMixer::MicMonitorMode::Main)));
 
     latencyCompensationSpinBox->setValue(latencyCompensationSpinBox->minimum());
+    externalSyncLatencyCompensationSpinBox->setValue(0.0);
+    m_pExternalSyncLatencyCompensation.set(0.0);
 
     settingChanged();
 #ifdef __RUBBERBAND__
@@ -975,6 +985,10 @@ void DlgPrefSound::latencyCompensationSpinboxChanged(double value) {
     checkLatencyCompensation();
 }
 
+void DlgPrefSound::externalSyncLatencyCompensationSpinboxChanged(double value) {
+    m_pExternalSyncLatencyCompensation.set(value);
+}
+
 void DlgPrefSound::mainDelaySpinboxChanged(double value) {
     m_pMainDelay.set(value);
 }

src/preferences/dialog/dlgprefsound.h

@@ -52,6 +52,7 @@ class DlgPrefSound : public DlgPreferencePage, public Ui::DlgPrefSoundDlg  {
     void bufferUnderflow(double count);
     void outputLatencyChanged(double latency);
     void latencyCompensationSpinboxChanged(double value);
+    void externalSyncLatencyCompensationSpinboxChanged(double value);
     void mainDelaySpinboxChanged(double value);
     void headDelaySpinboxChanged(double value);
     void boothDelaySpinboxChanged(double value);
@@ -95,6 +96,7 @@ class DlgPrefSound : public DlgPreferencePage, public Ui::DlgPrefSoundDlg  {
     SoundManagerConfig m_config;
 
     PollingControlProxy m_pLatencyCompensation;
+    PollingControlProxy m_pExternalSyncLatencyCompensation;
     PollingControlProxy m_pMainDelay;
     PollingControlProxy m_pHeadDelay;
     PollingControlProxy m_pBoothDelay;

src/preferences/dialog/dlgprefsounddlg.ui

@@ -151,14 +151,43 @@
        </property>
       </widget>
      </item>
-     <item row="11" column="0">
+     <item row="10" column="0">
+      <widget class="QLabel" name="externalSyncLatencyCompensationLabel">
+       <property name="text">
+        <string>External Sync Latency Compensation</string>
+       </property>
+       <property name="buddy">
+        <cstring>externalSyncLatencyCompensationSpinBox</cstring>
+       </property>
+      </widget>
+     </item>
+     <item row="10" column="1">
+      <widget class="QDoubleSpinBox" name="externalSyncLatencyCompensationSpinBox">
+       <property name="suffix">
+        <string> ms</string>
+       </property>
+       <property name="decimals">
+        <number>3</number>
+       </property>
+       <property name="minimum">
+        <double>-100.000000000000000</double>
+       </property>
+       <property name="maximum">
+        <double>100.000000000000000</double>
+       </property>
+       <property name="singleStep">
+        <double>0.100000000000000</double>
+       </property>
+      </widget>
+     </item>
+     <item row="12" column="0">
       <widget class="QLabel" name="mainDelayLabel">
        <property name="text">
         <string>Main Output Delay</string>
        </property>
       </widget>
      </item>
-     <item row="11" column="1">
+     <item row="12" column="1">
       <widget class="QDoubleSpinBox" name="mainDelaySpinBox">
        <property name="suffix">
         <string extracomment="milliseconds"> ms</string>
@@ -174,14 +203,14 @@
        </property>
       </widget>
      </item>
-     <item row="12" column="0">
+     <item row="13" column="0">
       <widget class="QLabel" name="headDelayLabel">
        <property name="text">
         <string>Headphone Output Delay</string>
        </property>
       </widget>
      </item>
-     <item row="12" column="1">
+     <item row="13" column="1">
       <widget class="QDoubleSpinBox" name="headDelaySpinBox">
        <property name="suffix">
         <string extracomment="milliseconds"> ms</string>
@@ -197,14 +226,14 @@
        </property>
       </widget>
      </item>
-     <item row="13" column="0">
+     <item row="14" column="0">
       <widget class="QLabel" name="boothDelayLabel">
        <property name="text">
         <string>Booth Output Delay</string>
        </property>
       </widget>
      </item>
-     <item row="13" column="1">
+     <item row="14" column="1">
       <widget class="QDoubleSpinBox" name="boothDelaySpinBox">
        <property name="suffix">
         <string extracomment="milliseconds"> ms</string>
@@ -213,14 +242,17 @@
         <number>3</number>
        </property>
        <property name="maximum">
-        <double>500.000000000000000</double>
+        <double>-100.000000000000000</double>
+       </property>
+       <property name="maximum">
+        <double>100.000000000000000</double>
        </property>
        <property name="singleStep">
         <double>0.100000000000000</double>
        </property>
       </widget>
      </item>
-     <item row="14" column="0" colspan="2">
+     <item row="15" column="0" colspan="2">
       <widget class="QLabel" name="latencyCompensationWarningLabel">
        <property name="text">
         <string notr="true">warning goes here</string>

src/soundio/sounddeviceportaudio.cpp

@@ -8,6 +8,7 @@
 #include <cstddef>
 
 #include "control/controlobject.h"
+#include "control/controlproxy.h"
 #include "sounddevicenetwork.h"
 #include "soundio/sounddevice.h"
 #include "soundio/soundmanager.h"
@@ -120,7 +121,10 @@ SoundDevicePortAudio::SoundDevicePortAudio(UserSettingsPointer config,
           m_callbackResult(paAbort),
           m_hostTimeFilter(kNumPointsInHostTimeFilter),
           m_cummulatedBufferTime(0),
-          m_meanOutputLatency(MovingInterquartileMean(128)) {
+          m_meanOutputLatency(MovingInterquartileMean(128)),
+          m_pExternalSyncLatencyCompensation(std::make_unique<ControlProxy>(
+                  QStringLiteral("[Master]"),
+                  QStringLiteral("externalSyncLatencyCompensation"))) {
     // Setting parent class members:
     m_hostAPI = Pa_GetHostApiInfo(deviceInfo->hostApi)->name;
     m_sampleRate = mixxx::audio::SampleRate::fromDouble(deviceInfo->defaultSampleRate);
@@ -1182,17 +1186,22 @@ void SoundDevicePortAudio::updateCallbackEntryToDacTime(
 
     // Only use latency from PortAudios timeInfo, if it's in reasonable range,
     // otherwise use latency value from PortAudios streamInfo
+    auto externalSyncLatencyUs = std::chrono::duration_cast<std::chrono::microseconds>(
+            std::chrono::duration<double, std::milli>(m_pExternalSyncLatencyCompensation->get()));
+
     if (callbackEntrytoDacSecs > kMinReasonableAudioLatencySecs &&
             timeSinceLastCbSecs < bufferSizeSec * 2) {
         m_meanOutputLatency.insert(timeInfo->outputBufferDacTime - soundCardTimeNow);
 
         m_absTimeWhenPrevOutputBufferReachesDac = filteredHostTimeNow +
-                std::chrono::microseconds(static_cast<long long>(
-                        m_meanOutputLatency.mean() * 1000000));
+                std::chrono::duration_cast<std::chrono::microseconds>(
+                        std::chrono::duration<double>(m_meanOutputLatency.mean())) +
+                externalSyncLatencyUs;
     } else {
         m_absTimeWhenPrevOutputBufferReachesDac = filteredHostTimeNow +
-                std::chrono::microseconds(
-                        static_cast<long long>(m_outputLatencyMillis * 1000));
+                std::chrono::duration_cast<std::chrono::microseconds>(
+                        std::chrono::duration<double, std::milli>(m_outputLatencyMillis)) +
+                externalSyncLatencyUs;
     }
 
     double diff = (timeSinceLastCbSecs + callbackEntrytoDacSecs) -

src/soundio/sounddeviceportaudio.h

@@ -100,4 +100,6 @@ class SoundDevicePortAudio : public SoundDevice {
     HostTimeFilter m_hostTimeFilter;
     double m_cummulatedBufferTime;
     MovingInterquartileMean m_meanOutputLatency;
+
+    std::unique_ptr<ControlProxy> m_pExternalSyncLatencyCompensation;
 };