Files
UnrealEngine/Engine/Source/Runtime/Apple/AudioMixerAudioUnit/Private/AudioMixerPlatformAudioUnit.h
2025-05-18 13:04:45 +08:00

100 lines
3.7 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
#include "AudioMixer.h"
#include "DSP/Dsp.h"
#include <AudioToolbox/AudioToolbox.h>
#include <AudioUnit/AudioUnit.h>
// Any platform defines
namespace Audio
{
class FMixerPlatformAudioUnit : public IAudioMixerPlatformInterface
{
public:
FMixerPlatformAudioUnit();
~FMixerPlatformAudioUnit();
//~ Begin IAudioMixerPlatformInterface
virtual FString GetPlatformApi() const override { return TEXT("AudioUnit"); }
virtual bool InitializeHardware() override;
virtual bool CheckAudioDeviceChange() override;
virtual bool TeardownHardware() override;
virtual bool IsInitialized() const override;
virtual bool GetNumOutputDevices(uint32& OutNumOutputDevices) override;
virtual bool GetOutputDeviceInfo(const uint32 InDeviceIndex, FAudioPlatformDeviceInfo& OutInfo) override;
virtual bool GetDefaultOutputDeviceIndex(uint32& OutDefaultDeviceIndex) const override;
virtual bool OpenAudioStream(const FAudioMixerOpenStreamParams& Params) override;
virtual bool CloseAudioStream() override;
virtual bool StartAudioStream() override;
virtual bool StopAudioStream() override;
virtual bool MoveAudioStreamToNewAudioDevice(const FString& InNewDeviceId) override;
virtual FAudioPlatformDeviceInfo GetPlatformDeviceInfo() const override;
virtual void SubmitBuffer(const uint8* Buffer) override;
virtual FString GetDefaultDeviceName() override;
virtual FAudioPlatformSettings GetPlatformSettings() const override;
virtual int32 GetNumFrames(const int32 InNumReqestedFrames) override;
virtual void ResumeContext() override;
virtual void SuspendContext() override;
/** Whether or not the platform disables caching of decompressed PCM data (i.e. to save memory on fixed memory platforms) */
virtual bool DisablePCMAudioCaching() const override { return true; }
//~ End IAudioMixerPlatformInterface
static void IncrementSuspendCounter();
static void DecrementSuspendCounter();
private:
AudioStreamBasicDescription OutputFormat;
bool bSuspended;
/** True if the connection to the device has been initialized */
bool bInitialized;
/** True if execution is in the callback */
bool bInCallback;
AUGraph AudioUnitGraph;
AUNode OutputNode;
AudioUnit OutputUnit;
uint8* SubmittedBufferPtr;
int32 SubmittedBytes = 0;
int32 RemainingBytesInCurrentSubmittedBuffer;
int32 BytesPerSubmittedBuffer;
double GraphSampleRate;
bool bSupportsBackgroundAudio;
// We may have to grow the circular buffer capacity since Audio Unit callback size is not guaranteed to be constant
// Currently, this just zero's-out and reallocates, so it will pop. (We always keep largest capacity)
void GrowCircularBufferIfNeeded(const int32 InNumSamplesPerRenderCallback, const int32 InNumSamplesPerDeviceCallback);
// This buffer is pushed to and popped from in the SubmitBuffer callback.
// This is required for devices that require frame counts per callback that are not powers of two.
Audio::TCircularAudioBuffer<int8> CircularOutputBuffer;
int32 NumSamplesPerRenderCallback;
int32 NumSamplesPerDeviceCallback;
mutable bool bInternalPlatformSettingsInitialized{ false };
mutable FAudioPlatformSettings InternalPlatformSettings;
void InterruptContext(bool Interrupted);
bool PerformCallback(AudioBufferList* OutputBufferData);
void HandleError(const TCHAR* InLogOutput, bool bTeardown = true);
static OSStatus AudioRenderCallback(void* RefCon, AudioUnitRenderActionFlags* ActionFlags,
const AudioTimeStamp* TimeStamp, UInt32 BusNumber,
UInt32 NumFrames, AudioBufferList* IOData);
};
}