Merge pull request #14307 from Sam-Belliveau/granular-audio-stretching

Add an option to preserve audio pitch when emulation speed changes

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/model/BooleanSetting.kt

@@ -31,6 +31,7 @@ enum class BooleanSetting(
         false
     ),
     MAIN_AUDIO_FILL_GAPS(Settings.FILE_DOLPHIN, Settings.SECTION_INI_CORE, "AudioFillGaps", true),
+    MAIN_AUDIO_PRESERVE_PITCH(Settings.FILE_DOLPHIN, Settings.SECTION_INI_CORE, "AudioPreservePitch", false),
     MAIN_BBA_XLINK_CHAT_OSD(
         Settings.FILE_DOLPHIN,
         Settings.SECTION_INI_CORE,

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -556,6 +556,14 @@ class SettingsFragmentPresenter(
                 R.string.audio_fill_gaps_description
             )
         )
+        sl.add(
+            SwitchSetting(
+                context,
+                BooleanSetting.MAIN_AUDIO_PRESERVE_PITCH,
+                R.string.audio_preserve_pitch,
+                R.string.audio_preserve_pitch_description
+            )
+        )
         sl.add(
             IntSliderSetting(
                 context,

Source/Android/app/src/main/res/values/strings.xml

@@ -188,6 +188,8 @@
     <string name="audio_buffer_size_description">Controls the number of audio samples buffered. Lower values reduce latency but may cause more crackling or stuttering. If unsure, set this to 80 ms.</string>
     <string name="audio_fill_gaps">Fill Audio Gaps</string>
     <string name="audio_fill_gaps_description">Repeat existing audio during lag spikes to prevent stuttering. If unsure, leave this checked.</string>
+    <string name="audio_preserve_pitch">Preserve Audio Pitch</string>
+    <string name="audio_preserve_pitch_description">Keeps audio at normal pitch when changing emulation speed. Without this, audio pitch changes proportionally with speed. If unsure, leave this unchecked.</string>
     <string name="audio_volume">Audio Volume</string>
 
     <!-- Path Settings -->

Source/Core/AudioCommon/Mixer.cpp

@@ -71,7 +71,7 @@ void Mixer::MixerFifo::Mix(s16* samples, std::size_t num_samples)
       static_cast<double>(FIXED_SAMPLE_RATE_DIVIDEND) / m_input_sample_rate_divisor;
 
   const double emulation_speed = m_mixer->m_config_emulation_speed;
-  if (0 < emulation_speed && emulation_speed != 1.0)
+  if (!m_mixer->m_config_audio_preserve_pitch && 0 < emulation_speed && emulation_speed != 1.0)
     in_sample_rate *= emulation_speed;
 
   const double base = static_cast<double>(1 << GRANULE_FRAC_BITS);
@@ -430,6 +430,7 @@ void Mixer::StopLogDSPAudio()
 void Mixer::RefreshConfig()
 {
   m_config_emulation_speed = Config::Get(Config::MAIN_EMULATION_SPEED);
+  m_config_audio_preserve_pitch = Config::Get(Config::MAIN_AUDIO_PRESERVE_PITCH);
   m_config_fill_audio_gaps = Config::Get(Config::MAIN_AUDIO_FILL_GAPS);
   m_config_audio_buffer_ms = Config::Get(Config::MAIN_AUDIO_BUFFER_SIZE);
 }

Source/Core/AudioCommon/Mixer.h

@@ -163,6 +163,7 @@ private:
   bool m_log_dsp_audio = false;
 
   float m_config_emulation_speed;
+  bool m_config_audio_preserve_pitch;
   bool m_config_fill_audio_gaps;
   int m_config_audio_buffer_ms;
 

Source/Core/Core/Config/MainSettings.cpp

@@ -71,6 +71,7 @@ const Info<AudioCommon::DPL2Quality> MAIN_DPL2_QUALITY{{System::Main, "Core", "D
 const Info<int> MAIN_AUDIO_LATENCY{{System::Main, "Core", "AudioLatency"}, 20};
 const Info<int> MAIN_AUDIO_BUFFER_SIZE{{System::Main, "Core", "AudioBufferSize"}, 80};
 const Info<bool> MAIN_AUDIO_FILL_GAPS{{System::Main, "Core", "AudioFillGaps"}, true};
+const Info<bool> MAIN_AUDIO_PRESERVE_PITCH{{System::Main, "Core", "AudioPreservePitch"}, false};
 const Info<std::string> MAIN_MEMCARD_A_PATH{{System::Main, "Core", "MemcardAPath"}, ""};
 const Info<std::string> MAIN_MEMCARD_B_PATH{{System::Main, "Core", "MemcardBPath"}, ""};
 const Info<std::string>& GetInfoForMemcardPath(ExpansionInterface::Slot slot)

Source/Core/Core/Config/MainSettings.h

@@ -79,6 +79,7 @@ extern const Info<AudioCommon::DPL2Quality> MAIN_DPL2_QUALITY;
 extern const Info<int> MAIN_AUDIO_LATENCY;
 extern const Info<int> MAIN_AUDIO_BUFFER_SIZE;
 extern const Info<bool> MAIN_AUDIO_FILL_GAPS;
+extern const Info<bool> MAIN_AUDIO_PRESERVE_PITCH;
 extern const Info<std::string> MAIN_MEMCARD_A_PATH;
 extern const Info<std::string> MAIN_MEMCARD_B_PATH;
 const Info<std::string>& GetInfoForMemcardPath(ExpansionInterface::Slot slot);

Source/Core/DolphinQt/Settings/AudioPane.cpp

@@ -181,6 +181,9 @@ void AudioPane::CreateWidgets()
 
   m_audio_fill_gaps = new ConfigBool(tr("Fill Audio Gaps"), Config::MAIN_AUDIO_FILL_GAPS);
 
+  m_audio_preserve_pitch =
+      new ConfigBool(tr("Preserve Audio Pitch"), Config::MAIN_AUDIO_PRESERVE_PITCH);
+
   m_speed_up_mute_enable = new ConfigBool(tr("Mute When Disabling Speed Limit"),
                                           Config::MAIN_AUDIO_MUTE_ON_DISABLED_SPEED_LIMIT);
 
@@ -192,8 +195,9 @@ void AudioPane::CreateWidgets()
 
   playback_layout->addLayout(buffer_layout, 0, 0);
   playback_layout->addWidget(m_audio_fill_gaps, 1, 0);
-  playback_layout->addWidget(m_speed_up_mute_enable, 2, 0);
-  playback_layout->setRowStretch(3, 1);
+  playback_layout->addWidget(m_audio_preserve_pitch, 2, 0);
+  playback_layout->addWidget(m_speed_up_mute_enable, 3, 0);
+  playback_layout->setRowStretch(4, 1);
   playback_box->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
 
   auto* const main_vbox_layout = new QVBoxLayout;
@@ -317,6 +321,10 @@ void AudioPane::AddDescriptions()
   static const char TR_FILL_AUDIO_GAPS_DESCRIPTION[] = QT_TR_NOOP(
       "Repeat existing audio during lag spikes to prevent stuttering.<br><br><dolphin_emphasis>If "
       "unsure, leave this checked.</dolphin_emphasis>");
+  static const char TR_PRESERVE_AUDIO_PITCH_DESCRIPTION[] = QT_TR_NOOP(
+      "Keeps audio at normal pitch when changing emulation speed. Without this, audio pitch "
+      "changes proportionally with speed.<br><br><dolphin_emphasis>If unsure, leave this "
+      "unchecked.</dolphin_emphasis>");
   static const char TR_SPEED_UP_MUTE_DESCRIPTION[] =
       QT_TR_NOOP("Mutes the audio when overriding the emulation speed limit (default hotkey: Tab). "
                  "<br><br><dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>");
@@ -357,4 +365,7 @@ void AudioPane::AddDescriptions()
 
   m_audio_fill_gaps->SetTitle(tr("Fill Audio Gaps"));
   m_audio_fill_gaps->SetDescription(tr(TR_FILL_AUDIO_GAPS_DESCRIPTION));
+
+  m_audio_preserve_pitch->SetTitle(tr("Preserve Audio Pitch"));
+  m_audio_preserve_pitch->SetDescription(tr(TR_PRESERVE_AUDIO_PITCH_DESCRIPTION));
 }

Source/Core/DolphinQt/Settings/AudioPane.h

@@ -66,5 +66,6 @@ private:
 
   // Misc Settings
   ConfigBool* m_audio_fill_gaps;
+  ConfigBool* m_audio_preserve_pitch;
   ConfigBool* m_speed_up_mute_enable;
 };