SideLeft

SideLeft

#Overview

name: SideLeft

The value of this variable can be defined or overridden in .ini config files. 2 .ini config files referencing this setting variable.

It is referenced in 34 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of SideLeft is to represent the side left channel in a multi-channel audio setup. This variable is part of the EAudioMixerChannel enumeration, which defines various channel types for audio mixing and processing in Unreal Engine 5.

SideLeft is primarily used in the audio subsystem of Unreal Engine, specifically in the AudioMixer module and related audio processing components. It’s also utilized in plugins like the Synthesis plugin for audio effects and processing.

The value of this variable is typically set as part of the audio channel configuration, either programmatically or through engine settings. It’s often used in conjunction with other channel types to define speaker layouts and audio routing.

SideLeft frequently interacts with other channel types, particularly SideRight, as they form a pair of side channels in surround sound setups. It’s also commonly used alongside other channel types like FrontLeft, FrontRight, Center, LowFrequency, BackLeft, and BackRight to create various multi-channel configurations (e.g., 5.1, 7.1).

Developers should be aware that the SideLeft channel is not present in all audio configurations. Its availability depends on the specific audio setup and the number of channels supported by the audio device or format being used.

Best practices when using this variable include:

  1. Always check for the presence of the SideLeft channel before attempting to use it.
  2. Consider fallback options for audio systems that don’t support side channels.
  3. Ensure proper channel mapping when converting between different audio formats or channel configurations.
  4. Use it in conjunction with other channel types to create immersive surround sound experiences.

#Setting Variables

#References In INI files

Location: <Workspace>/Engine/Config/BaseEngine.ini:1580, section: [AudioChannelAzimuthMap]

Location: <Workspace>/Engine/Config/BaseEngine.ini:1589, section: [AudioDefaultChannelOrder]

#References in C++ code

#Callsites

This variable is referenced in the following C++ source code:

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/ConvolutionReverb.cpp:31

Scope (from outer to inner):

file
namespace    Audio
namespace    ConvolutionReverbIntrinsics

Source code excerpt:

				EAudioMixerChannel::Type::FrontLeft,
				EAudioMixerChannel::Type::FrontRight,
				EAudioMixerChannel::Type::SideLeft,
				EAudioMixerChannel::Type::SideRight
			},

			// Five channels (5.0)
			{
				EAudioMixerChannel::Type::FrontLeft,
				EAudioMixerChannel::Type::FrontRight,
				EAudioMixerChannel::Type::FrontCenter,
				EAudioMixerChannel::Type::SideLeft,
				EAudioMixerChannel::Type::SideRight
			},

			// Six channels (5.1)
			{
				EAudioMixerChannel::Type::FrontLeft,

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/ConvolutionReverb.cpp:50

Scope (from outer to inner):

file
namespace    Audio
namespace    ConvolutionReverbIntrinsics

Source code excerpt:

				EAudioMixerChannel::Type::FrontCenter,
				EAudioMixerChannel::Type::LowFrequency,
				EAudioMixerChannel::Type::SideLeft,
				EAudioMixerChannel::Type::SideRight
			},

			// Seven channels (7.0)
			{
				EAudioMixerChannel::Type::FrontLeft,

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/ConvolutionReverb.cpp:61

Scope (from outer to inner):

file
namespace    Audio
namespace    ConvolutionReverbIntrinsics

Source code excerpt:

				EAudioMixerChannel::Type::BackLeft,
				EAudioMixerChannel::Type::BackRight,
				EAudioMixerChannel::Type::SideLeft,
				EAudioMixerChannel::Type::SideRight
			},

			// Eight channels (7.1)
			{
				EAudioMixerChannel::Type::FrontLeft,

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/ConvolutionReverb.cpp:73

Scope (from outer to inner):

file
namespace    Audio
namespace    ConvolutionReverbIntrinsics

Source code excerpt:

				EAudioMixerChannel::Type::BackLeft,
				EAudioMixerChannel::Type::BackRight,
				EAudioMixerChannel::Type::SideLeft,
				EAudioMixerChannel::Type::SideRight
			}
		};

		bool GetReverbOutputChannelTypesForNumChannels(int32 InNumChannels, TArray<EAudioMixerChannel::Type>& OutChannelTypes)
		{

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/SubmixChannelFormatConverter.cpp:27

Scope (from outer to inner):

file
namespace    Audio
namespace    SubmixChannelFormatConverterPrivate

Source code excerpt:

		static const TMap<EAudioMixerChannel::Type, TArray<EAudioMixerChannel::Type>> PairedRearChannelTypes =
		{
			{ EAudioMixerChannel::FrontLeft, { EAudioMixerChannel::BackLeft, EAudioMixerChannel::SideLeft, EAudioMixerChannel::TopBackLeft } },
			{ EAudioMixerChannel::FrontRight, { EAudioMixerChannel::BackRight, EAudioMixerChannel::SideRight, EAudioMixerChannel::TopBackRight } },
			{ EAudioMixerChannel::FrontCenter, { EAudioMixerChannel::BackCenter, EAudioMixerChannel::TopCenter, EAudioMixerChannel::TopBackCenter } },
			{ EAudioMixerChannel::FrontLeftOfCenter, { EAudioMixerChannel::BackLeft, EAudioMixerChannel::SideLeft, EAudioMixerChannel::TopBackLeft } },
			{ EAudioMixerChannel::FrontRightOfCenter, { EAudioMixerChannel::BackRight, EAudioMixerChannel::SideRight, EAudioMixerChannel::TopBackRight } },
			{ EAudioMixerChannel::TopFrontLeft, { EAudioMixerChannel::BackLeft, EAudioMixerChannel::SideLeft, EAudioMixerChannel::TopBackLeft } },
			{ EAudioMixerChannel::TopFrontRight, { EAudioMixerChannel::BackRight, EAudioMixerChannel::SideRight, EAudioMixerChannel::TopBackRight } },
			{ EAudioMixerChannel::TopFrontCenter, { EAudioMixerChannel::BackCenter, EAudioMixerChannel::TopCenter, EAudioMixerChannel::TopBackCenter } }
		};

		// For a _flipped_ rear-channel-bleed, this map pairs all front channels with all
		// associated rear channels that should receive bled audio.

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/SubmixChannelFormatConverter.cpp:79

Scope (from outer to inner):

file
namespace    Audio
function     bool GetSubmixChannelOrderForNumChannels

Source code excerpt:

						EAudioMixerChannel::Type::FrontLeft,
						EAudioMixerChannel::Type::FrontRight,
						EAudioMixerChannel::Type::SideLeft,
						EAudioMixerChannel::Type::SideRight
					}
				);

				return true;

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/SubmixChannelFormatConverter.cpp:95

Scope (from outer to inner):

file
namespace    Audio
function     bool GetSubmixChannelOrderForNumChannels

Source code excerpt:

						EAudioMixerChannel::Type::FrontCenter,
						EAudioMixerChannel::Type::LowFrequency,
						EAudioMixerChannel::Type::SideLeft,
						EAudioMixerChannel::Type::SideRight
					}
				);

				return true;

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/SubmixChannelFormatConverter.cpp:113

Scope (from outer to inner):

file
namespace    Audio
function     bool GetSubmixChannelOrderForNumChannels

Source code excerpt:

						EAudioMixerChannel::Type::BackLeft,
						EAudioMixerChannel::Type::BackRight,
						EAudioMixerChannel::Type::SideLeft,
						EAudioMixerChannel::Type::SideRight
					}
				);

				return true;
		}

#Loc: <Workspace>/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Private/SubmixChannelFormatConverter.cpp:382

Scope (from outer to inner):

file
namespace    Audio
function     bool FSimpleUpmixer::GetSimpleUpmixerStaticMixEntries

Source code excerpt:

		const int32 InputFrontLeftIndex = InInputChannelTypes.Find(EAudioMixerChannel::Type::FrontLeft);
		const int32 InputFrontRightIndex = InInputChannelTypes.Find(EAudioMixerChannel::Type::FrontRight);
		const int32 InputSideLeftIndex = InInputChannelTypes.Find(EAudioMixerChannel::Type::SideLeft);
		const int32 InputSideRightIndex = InInputChannelTypes.Find(EAudioMixerChannel::Type::SideRight);
		const int32 InputBackLeftIndex = InInputChannelTypes.Find(EAudioMixerChannel::Type::BackLeft);
		const int32 InputBackRightIndex = InInputChannelTypes.Find(EAudioMixerChannel::Type::BackRight);

		// Query which output channels exist
		const int32 OutputFrontLeftIndex = InOutputChannelTypes.Find(EAudioMixerChannel::Type::FrontLeft);
		const int32 OutputFrontRightIndex = InOutputChannelTypes.Find(EAudioMixerChannel::Type::FrontRight);
		const int32 OutputSideLeftIndex = InOutputChannelTypes.Find(EAudioMixerChannel::Type::SideLeft);
		const int32 OutputSideRightIndex = InOutputChannelTypes.Find(EAudioMixerChannel::Type::SideRight);
		const int32 OutputBackLeftIndex = InOutputChannelTypes.Find(EAudioMixerChannel::Type::BackLeft);
		const int32 OutputBackRightIndex = InOutputChannelTypes.Find(EAudioMixerChannel::Type::BackRight);

		// Check for mono input and stereo output.
		const bool bInputIsMono = (1 == InInputChannelTypes.Num()) && (InInputChannelTypes[0] == EAudioMixerChannel::Type::FrontCenter);

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerChannelMaps.cpp:26

Scope (from outer to inner):

file
namespace    Audio

Source code excerpt:

			EAudioMixerChannel::FrontLeft,
			EAudioMixerChannel::FrontRight,
			EAudioMixerChannel::SideLeft,
			EAudioMixerChannel::SideRight
		},

		// ESubmixChannelFormat::FiveDotOne
		{
			EAudioMixerChannel::FrontLeft,

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerChannelMaps.cpp:36

Scope (from outer to inner):

file
namespace    Audio

Source code excerpt:

			EAudioMixerChannel::FrontCenter,
			EAudioMixerChannel::LowFrequency,
			EAudioMixerChannel::SideLeft,
			EAudioMixerChannel::SideRight
		},

		// ESubmixChannelFormat::SevenDotOne
		{
			EAudioMixerChannel::FrontLeft,

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerChannelMaps.cpp:48

Scope (from outer to inner):

file
namespace    Audio

Source code excerpt:

			EAudioMixerChannel::BackLeft,
			EAudioMixerChannel::BackRight,
			EAudioMixerChannel::SideLeft,
			EAudioMixerChannel::SideRight
		},

		// ESubmixChannelFormat::Ambisonics
		// Ambisonics output is encoded to max encoded channel (i.e. 7.1).
		// To support ambisonic encoded output, will need to convert to

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerChannelMaps.cpp:63

Scope (from outer to inner):

file
namespace    Audio

Source code excerpt:

			EAudioMixerChannel::BackLeft,
			EAudioMixerChannel::BackRight,
			EAudioMixerChannel::SideLeft,
			EAudioMixerChannel::SideRight
		}, 
	};

	// Make a channel map cache
	static TArray<TArray<float>> ChannelMapCache;

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerChannelMaps.cpp:240

Scope (from outer to inner):

file
namespace    Audio
function     void FMixerDevice::InitializeChannelAzimuthMap

Source code excerpt:

		DefaultChannelAzimuthPositions[EAudioMixerChannel::FrontRightOfCenter] = { EAudioMixerChannel::FrontRightOfCenter, 345 };
		DefaultChannelAzimuthPositions[EAudioMixerChannel::BackCenter] = { EAudioMixerChannel::BackCenter, 180 };
		DefaultChannelAzimuthPositions[EAudioMixerChannel::SideLeft] = { EAudioMixerChannel::SideLeft, 250 };
		DefaultChannelAzimuthPositions[EAudioMixerChannel::SideRight] = { EAudioMixerChannel::SideRight, 110 };

		// Check any engine ini overrides for these default positions
		if (NumChannels != 2)
		{
			int32 AzimuthPositionOverride = 0;

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerDevice.cpp:431

Scope (from outer to inner):

file
namespace    Audio
function     TArray<Audio::FChannelPositionInfo>* FMixerDevice::GetDefaultPositionMap

Source code excerpt:

														 SpeakerPositions[EAudioMixerChannel::FrontLeft] //left
														,SpeakerPositions[EAudioMixerChannel::FrontRight] // right
														,SpeakerPositions[EAudioMixerChannel::SideLeft] //Left Surround
														,SpeakerPositions[EAudioMixerChannel::SideRight] //Right Surround
				};
				return &QuadMap;
			}

			// 5.1 speakers.

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerDevice.cpp:445

Scope (from outer to inner):

file
namespace    Audio
function     TArray<Audio::FChannelPositionInfo>* FMixerDevice::GetDefaultPositionMap

Source code excerpt:

														,SpeakerPositions[EAudioMixerChannel::FrontCenter] //center
														,SpeakerPositions[EAudioMixerChannel::LowFrequency] //LFE
														,SpeakerPositions[EAudioMixerChannel::SideLeft] //Left Rear
														,SpeakerPositions[EAudioMixerChannel::SideRight] //Right Rear
				};
				return &FiveDotOneMap;
			}

			// 7.1 speakers.

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerDevice.cpp:461

Scope (from outer to inner):

file
namespace    Audio
function     TArray<Audio::FChannelPositionInfo>* FMixerDevice::GetDefaultPositionMap

Source code excerpt:

														,SpeakerPositions[EAudioMixerChannel::BackLeft] // Left Rear
														,SpeakerPositions[EAudioMixerChannel::BackRight] // Right Rear
														,SpeakerPositions[EAudioMixerChannel::SideLeft] // Left Surround
														,SpeakerPositions[EAudioMixerChannel::SideRight] // Right Surround
				};


				return &SevenDotOneMap;
			}

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Private/AudioMixerSource.cpp:2169

Scope (from outer to inner):

file
lambda-function

Source code excerpt:

							TMap<EAudioMixerChannel::Type, float> LeftOmniMap;
							LeftOmniMap.Add(EAudioMixerChannel::FrontLeft, 1.0f);
							LeftOmniMap.Add(EAudioMixerChannel::SideLeft, 1.0f);

							return LeftOmniMap;
						};

						auto CreateRightOmniMap = []() -> TMap<EAudioMixerChannel::Type, float>
						{

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Public/AudioMixerBlueprintLibrary.h:66

Scope: file

Source code excerpt:

	FrontRightOfCenter,
	BackCenter,
	SideLeft,
	SideRight,
	TopCenter,
	TopFrontLeft,
	TopFrontCenter,
	TopFrontRight,
	TopBackLeft,

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixer/Public/AudioMixerBlueprintLibrary.h:93

Scope (from outer to inner):

file
function     inline const TCHAR* ToString

Source code excerpt:

		case EAudioMixerChannelType::FrontRightOfCenter:	return TEXT("FrontRightOfCenter");
		case EAudioMixerChannelType::BackCenter:			return TEXT("BackCenter");
		case EAudioMixerChannelType::SideLeft:				return TEXT("SideLeft");
		case EAudioMixerChannelType::SideRight:				return TEXT("SideRight");
		case EAudioMixerChannelType::TopCenter:				return TEXT("TopCenter");
		case EAudioMixerChannelType::TopFrontLeft:			return TEXT("TopFrontLeft");
		case EAudioMixerChannelType::TopFrontCenter:		return TEXT("TopFrontCenter");
		case EAudioMixerChannelType::TopFrontRight:			return TEXT("TopFrontRight");
		case EAudioMixerChannelType::TopBackLeft:			return TEXT("TopBackLeft");

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixerCore/Private/AudioMixer.cpp:813

Scope (from outer to inner):

file
namespace    Audio
function     static void InitializeDefaultChannelOrder

Source code excerpt:

		DefaultChannelOrder[2] = EAudioMixerChannel::FrontCenter;
		DefaultChannelOrder[3] = EAudioMixerChannel::LowFrequency;
		DefaultChannelOrder[4] = EAudioMixerChannel::SideLeft;
		DefaultChannelOrder[5] = EAudioMixerChannel::SideRight;
		DefaultChannelOrder[6] = EAudioMixerChannel::BackLeft;
		DefaultChannelOrder[7] = EAudioMixerChannel::BackRight;

		bool bOverridden = false;
		EAudioMixerChannel::Type ChannelMapOverride[AUDIO_MIXER_MAX_OUTPUT_CHANNELS];

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixerCore/Public/AudioMixer.h:88

Scope (from outer to inner):

file
namespace    EAudioMixerChannel

Source code excerpt:

		FrontRightOfCenter,
		BackCenter,
		SideLeft,
		SideRight,
		TopCenter,
		TopFrontLeft,
		TopFrontCenter,
		TopFrontRight,
		TopBackLeft,

#Loc: <Workspace>/Engine/Source/Runtime/AudioMixerCore/Public/AudioMixer.h:117

Scope (from outer to inner):

file
namespace    EAudioMixerChannel
function     inline const TCHAR* ToString

Source code excerpt:

		case FrontRightOfCenter:	return TEXT("FrontRightOfCenter");
		case BackCenter:			return TEXT("BackCenter");
		case SideLeft:				return TEXT("SideLeft");
		case SideRight:				return TEXT("SideRight");
		case TopCenter:				return TEXT("TopCenter");
		case TopFrontLeft:			return TEXT("TopFrontLeft");
		case TopFrontCenter:		return TEXT("TopFrontCenter");
		case TopFrontRight:			return TEXT("TopFrontRight");
		case TopBackLeft:			return TEXT("TopBackLeft");

#Loc: <Workspace>/Engine/Source/Runtime/MediaUtils/Private/MediaAudioResampler.cpp:33

Scope (from outer to inner):

file
namespace    MediaAudioResampler

Source code excerpt:


	static const float Matrix_4_1[] = {
		// FrontLeft	FrontRight	SideLeft	SideRight
		0.707f,			0.707f,		0.5f,		0.5f,		// Mono
	};

	static const float Matrix_5_1[] = {
		// FrontLeft	FrontRight	Center		SideLeft	SideRight
		0.707f,			0.707f,		0.5f,		0.5f,		0.5f,		// Mono
	};

	static const float Matrix_6_1[] = {
		// FrontLeft	FrontRight	Center		LowFreq		SideLeft	SideRight
		0.707f,			0.707f,		0.5f,		0.0f,		0.5f,		0.5f,		// Mono
	};

	static const float Matrix_7_1[] = {
		// FrontLeft	FrontRight	BackLeft	LFE			BackRight	SideLeft	SideRight
		0.707f,			0.707f,		0.5f,		0.0f,		0.5f,		0.5f,		0.5f,		// Mono
	};

	static const float Matrix_8_1[] = {
		// FrontLeft	FrontRight	Center		LowFreq		SideLeft	SideRight	BackLeft	BackRight
		0.707f,			0.707f,		1.0f,		0.0f,		0.5f,		0.5f,		0.5f,		0.5f,		// Mono
	};

	static const float* ToMono[8] = {
		Matrix_1_1,
		Matrix_2_1,

#Loc: <Workspace>/Engine/Source/Runtime/MediaUtils/Private/MediaAudioResampler.cpp:89

Scope (from outer to inner):

file
namespace    MediaAudioResampler

Source code excerpt:


	static const float Matrix_4_2[] = {
		// FrontLeft	FrontRight	SideLeft	SideRight
		1.0f,			0.0f,		0.707f,		0.0f,		// Left
		0.0f,			1.0f,		0.0f,		0.707f,		// Right
	};

	static const float Matrix_5_2[] = {
		// FrontLeft	FrontRight	Center		SideLeft	SideRight
		1.0f,			0.0f,		0.707f,		0.707f,		0.0f,		// Left
		0.0f,			1.0f,		0.707f,		0.0f,		0.707f,		// Right
	};

	static const float Matrix_6_2[] = {
		// FrontLeft	FrontRight	Center		LowFreq		SideLeft	SideRight
		1.0f,			0.0f,		0.707f,		0.0f,		0.707f,		0.0f,		// Left
		0.0f,			1.0f,		0.707f,		0.0f,		0.0f,		0.707f,		// Right
	};

	static const float Matrix_7_2[] = {
		// FrontLeft	FrontRight	BackLeft	LFE			BackRight	SideLeft	SideRight
		1.0f,			0.0f,		0.707f,		0.0f,		0.0f,		0.707f,		0.0f,		// Left
		0.0f,			1.0f,		0.0f,		0.0f,		0.707f,		0.0f,		0.707f,		// Right
	};

	static const float Matrix_8_2[] = {
		// FrontLeft	FrontRight	Center		LowFreq		SideLeft	SideRight	BackLeft	BackRight
		1.0f,			0.0f,		0.707f,		0.0f,		0.707f,		0.0f,		0.707f,		0.0f,		// Left
		0.0f,			1.0f,		0.707f,		0.0f,		0.0f,		0.707f,		0.0f,		0.707f,		// Right
	};

	static const float* ToStereo[8] = {
		Matrix_1_2,

#Loc: <Workspace>/Engine/Source/Runtime/MediaUtils/Private/MediaAudioResampler.cpp:138

Scope (from outer to inner):

file
namespace    MediaAudioResampler

Source code excerpt:

		1.0f,		// Center
		0.0f,		// LowFrequency
		0.0f,		// SideLeft
		0.0f,		// SideRight
		0.0f,		// BackLeft
		0.0f,		// BackRight
	};

	static const float Matrix_2_8[] = {

#Loc: <Workspace>/Engine/Source/Runtime/MediaUtils/Private/MediaAudioResampler.cpp:150

Scope (from outer to inner):

file
namespace    MediaAudioResampler

Source code excerpt:

		0.0f,			0.0f,			// Center
		0.0f,			0.0f,			// LowFrequency
		0.0f,			0.0f,			// SideLeft
		0.0f,			0.0f,			// SideRight
		0.0f,			0.0f,			// BackLeft
		0.0f,			0.0f,			// BackRight
	};

	static const float Matrix_3_8[] = {

#Loc: <Workspace>/Engine/Source/Runtime/MediaUtils/Private/MediaAudioResampler.cpp:162

Scope (from outer to inner):

file
namespace    MediaAudioResampler

Source code excerpt:

		0.0f,			0.0f,		1.0f,	// Center
		0.0f,			0.0f,		0.0f,	// LowFrequency
		0.0f,			0.0f,		0.0f,	// SideLeft
		0.0f,			0.0f,		0.0f,	// SideRight
		0.0f,			0.0f,		0.0f,	// BackLeft
		0.0f,			0.0f,		0.0f,	// BackRight
	};

	static const float Matrix_4_8[] = {
		// FrontLeft	FrontRight	SideLeft	SideRight
		1.0f,			0.0f,		0.0f,		0.0f,		// FrontLeft
		0.0f,			1.0f,		0.0f,		0.0f,		// FrontRight
		0.0f,			0.0f,		0.0f,		0.0f,		// Center
		0.0f,			0.0f,		0.0f,		0.0f,		// LowFrequency
		0.0f,			0.0f,		1.0f,		0.0f,		// SideLeft
		0.0f,			0.0f,		0.0f,		1.0f,		// SideRight
		0.0f,			0.0f,		0.0f,		0.0f,		// BackLeft
		0.0f,			0.0f,		0.0f,		0.0f,		// BackRight
	};

	static const float Matrix_5_8[] = {
		// FrontLeft	FrontRight	Center		SideLeft	SideRight
		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
		0.0f,			1.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
		0.0f,			0.0f,		1.0f,		0.0f,		0.0f,		// Center
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// LowFrequency
		0.0f,			0.0f,		0.0f,		1.0f,		0.0f,		// SideLeft
		0.0f,			0.0f,		0.0f,		0.0f,		1.0f,		// SideRight
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// BackLeft
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// BackRight
	};

	static const float Matrix_6_8[] = {
		// FrontLeft	FrontRight	Center		LowFreq		SideLeft	SideRight
		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
		0.0f,			1.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
		0.0f,			0.0f,		1.0f,		0.0f,		0.0f,		0.0f,		// Center
		0.0f,			0.0f,		0.0f,		1.0f,		0.0f,		0.0f,		// LowFrequency
		0.0f,			0.0f,		0.0f,		0.0f,		1.0f,		0.0f,		// SideLeft
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		1.0f,		// SideRight
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// BackLeft
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// BackRight
	};

	static const float Matrix_7_8[] = {
		// FrontLeft	FrontRight	BackLeft	LFE			BackRight	SideLeft	SideRight
		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
		0.0f,			1.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// Center
		0.0f,			0.0f,		0.0f,		1.0f,		0.0f,		0.0f,		0.0f,		// LowFrequency
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		1.0f,		0.0f,		// SideLeft
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		1.0f,		// SideRight
		0.0f,			0.0f,		1.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// BackLeft
		0.0f,			0.0f,		0.0f,		0.0f,		1.0f,		0.0f,		0.0f,		// BackRight
	};

	static const float Matrix_8_8[] = {
		// FrontLeft	FrontRight	Center		LowFreq		SideLeft	SideRight	BackLeft	BackRight
		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
		0.0f,			1.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
		0.0f,			0.0f,		1.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// Center
		0.0f,			0.0f,		0.0f,		1.0f,		0.0f,		0.0f,		0.0f,		0.0f,		// LowFrequency
		0.0f,			0.0f,		0.0f,		0.0f,		1.0f,		0.0f,		0.0f,		0.0f,		// SideLeft
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		1.0f,		0.0f,		0.0f,		// SideRight
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		1.0f,		0.0f,		// BackLeft
		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		0.0f,		1.0f,		// BackRight
	};

	static const float* ToSurround[8] = {

#Loc: <Workspace>/Engine/Source/Runtime/NonRealtimeAudioRenderer/Private/AudioMixerPlatformNonRealtime.cpp:170

Scope (from outer to inner):

file
namespace    Audio
function     bool FMixerPlatformNonRealtime::GetOutputDeviceInfo

Source code excerpt:

		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::BackLeft);
		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::BackRight);
		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::SideLeft);
		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::SideRight);

		return true;
	}

	bool FMixerPlatformNonRealtime::GetDefaultOutputDeviceIndex(uint32& OutDefaultDeviceIndex) const

#Loc: <Workspace>/Engine/Source/Runtime/SignalProcessing/Private/ChannelMap.cpp:12

Scope (from outer to inner):

file
namespace    Audio
namespace    ChannelMapPrivate

Source code excerpt:

		static constexpr float ToMonoMatrix[ChannelMapMaxNumChannels * 1] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight  
			0.707f,			0.707f,		1.0f,		0.0f,			0.5f,		0.5f,		0.5f,		0.5f,		// FrontLeft
		};

		static constexpr float VorbisToMonoMatrix[ChannelMapVorbisNumChannels * 1] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency		
			0.707f,			1.0f,		0.707f,		0.5f,			0.5f,		0.0f,		// FrontLeft
		};

		static constexpr float ToStereoMatrix[ChannelMapMaxNumChannels * 2] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight  
			1.0f,			0.0f,		0.707f,		0.0f,			0.707f,		0.0f,		0.707f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.707f,		0.0f,			0.0f,		0.707f,		0.0f,		0.707f,		// FrontRight
		};

		static constexpr float VorbisToStereoMatrix[ChannelMapVorbisNumChannels * 2] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency		
			1.0f,			0.707f,		0.0f,		0.707f,			0.0f,		0.0f,		// FrontLeft
			0.0f,			0.707f,		1.0f,		0.0f,			0.707f,		0.0f,		// FrontRight
		};

		static constexpr float ToTriMatrix[ChannelMapMaxNumChannels * 3] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight  
			1.0f,			0.0f,		0.0f,		0.0f,			0.707f,		0.0f,		0.707f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.707f,		0.0f,		0.707f,		// FrontRight
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// Center
		};

		static constexpr float VorbisToTriMatrix[ChannelMapVorbisNumChannels * 3] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency		
			1.0f,			0.0f,		0.0f,		0.707f,			0.0f,		0.0f,		// FrontLeft
			0.0f,			0.0f,		1.0f,		0.0f,			0.707f,		0.0f,		// FrontRight
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// Center
		};

		static constexpr float ToQuadMatrix[ChannelMapMaxNumChannels * 4] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight	
			1.0f,			0.0f,		0.707f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.707f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		1.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		0.0f,		1.0f,		// SideRight
		};

		static constexpr float VorbisToQuadMatrix[ChannelMapVorbisNumChannels * 4] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency		
			1.0f,			0.707f,		0.0f,		0.0f,			0.0f,		0.0f,		// FrontLeft
			0.0f,			0.707f,		1.0f,		0.0f,			0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		// SideRight
		};

		static constexpr float To5Matrix[ChannelMapMaxNumChannels * 5] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight	
			1.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// Center
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		1.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		0.0f,		1.0f,		// SideRight
		};

		static constexpr float VorbisTo5Matrix[ChannelMapVorbisNumChannels * 5] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency		
			1.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// FrontLeft
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		// FrontRight
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// Center
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		// SideRight
		};

		static constexpr float To5Point1Matrix[ChannelMapMaxNumChannels * 6] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight	
			1.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// Center
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// LowFrequency
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		1.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		0.0f,		1.0f,		// SideRight
		};

		static constexpr float VorbisTo5Point1Matrix[ChannelMapVorbisNumChannels * 6] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency	
			1.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// FrontLeft
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		// FrontRight
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// Center
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		// LowFrequency
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		// SideRight
		};

		static constexpr float ToHexMatrix[ChannelMapMaxNumChannels * 7] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight	
			1.0f,			0.0f,		0.707f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.707f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		1.0f,		0.0f,		// BackLeft
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// LFE
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		1.0f,		// BackRight
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		0.0f,		0.0f,		// SideRight
		};

		static constexpr float VorbisToHexMatrix[ChannelMapVorbisNumChannels * 7] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency	
			1.0f,			0.707f,		0.0f,		0.0f,			0.0f,		0.0f,		// FrontLeft
			0.0f,			0.707f,		1.0f,		0.0f,			0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// BackLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		// LFE
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// BackRight
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		// SideRight
		};

#if PLATFORM_MICROSOFT

		static constexpr float To7Point1Matrix[ChannelMapMaxNumChannels * 8] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight
			1.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontCenter
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// LowFrequency
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		0.0f,		0.0f,		// SideRight
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		1.0f,		0.0f,		// BackLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		1.0f,		// BackRight
		};

#else //PLATFORM_MICROSOFT

		// NOTE: the BackLeft/BackRight and SideLeft/SideRight are reversed than they should be since our 7.1 importer code has it backward
		static constexpr float To7Point1Matrix[ChannelMapMaxNumChannels * 8] =
		{
			// FrontLeft	FrontRight	Center		LowFrequency	SideLeft	SideRight	BackLeft	BackRight
			1.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontLeft
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontRight
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// FrontCenter
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		0.0f,		0.0f,		// LowFrequency
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		1.0f,		0.0f,		// BackLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		0.0f,		1.0f,		// BackRight
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		0.0f,		0.0f,		// SideRight
		};

#endif//PLATFORM_MICROSOFT

		static constexpr float VorbisTo7Point1Matrix[ChannelMapVorbisNumChannels * 8] =
		{
			// FrontLeft	Center		FrontRight	SideLeft		SideRight	LowFrequency		
			1.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// FrontLeft
			0.0f,			0.0f,		1.0f,		0.0f,			0.0f,		0.0f,		// FrontRight
			0.0f,			1.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// FrontCenter
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		1.0f,		// LowFrequency
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// SideLeft
			0.0f,			0.0f,		0.0f,		0.0f,			0.0f,		0.0f,		// SideRight
			0.0f,			0.0f,		0.0f,		1.0f,			0.0f,		0.0f,		// BackLeft
			0.0f,			0.0f,		0.0f,		0.0f,			1.0f,		0.0f,		// BackRight
		};

		static float const * const OutputChannelMaps[ChannelMapMaxNumChannels] =

#Loc: <Workspace>/Engine/Source/Runtime/SoundFieldRendering/Private/SoundFieldRendering.cpp:690

Scope: file

Source code excerpt:

	,{EAudioMixerChannel::BackLeft, 210, 0} 
	,{EAudioMixerChannel::BackRight, 150, 0}
	,{EAudioMixerChannel::SideLeft, 250, 0}
	,{EAudioMixerChannel::SideRight, 110, 0}
	,{EAudioMixerChannel::BackCenter, 180,0}
};

FSoundFieldEncoder::FSoundFieldEncoder()
{

#Loc: <Workspace>/Engine/Source/Runtime/Windows/AudioMixerXAudio2/Private/AudioMixerPlatformXAudio2.cpp:858

Scope (from outer to inner):

file
namespace    Audio
function     static bool GetMMDeviceInfo

Source code excerpt:

					EAudioMixerChannel::FrontCenter,
					EAudioMixerChannel::LowFrequency,
					EAudioMixerChannel::SideLeft,
					EAudioMixerChannel::SideRight,
					EAudioMixerChannel::BackLeft,
					EAudioMixerChannel::BackRight,
				};

				EAudioMixerChannel::Type* ChannelOrdering = DefaultChannelOrdering;

#Loc: <Workspace>/Engine/Source/Runtime/Windows/AudioMixerXAudio2/Private/AudioMixerPlatformXAudio2.cpp:1038

Scope (from outer to inner):

file
namespace    Audio
function     bool FMixerPlatformXAudio2::GetOutputDeviceInfo

Source code excerpt:

		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::BackLeft);
		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::BackRight);
		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::SideLeft);
		OutInfo.OutputChannelArray.Add(EAudioMixerChannel::SideRight);
		return true;
#endif 
	}

	bool FMixerPlatformXAudio2::GetDefaultOutputDeviceIndex(uint32& OutDefaultDeviceIndex) const

#Loc: <Workspace>/Engine/Source/Runtime/Windows/AudioMixerXAudio2/Private/WindowsMMDeviceInfoCache.cpp:134

Scope (from outer to inner):

file
namespace    Audio
function     bool FWindowsMMDeviceCache::EnumerateChannelMask

Source code excerpt:

			EAudioMixerChannel::FrontCenter,
			EAudioMixerChannel::LowFrequency,
			EAudioMixerChannel::SideLeft,
			EAudioMixerChannel::SideRight,
			EAudioMixerChannel::BackLeft,
			EAudioMixerChannel::BackRight,
		};

		const EAudioMixerChannel::Type* ChannelOrdering = DefaultChannelOrdering;