AudioMixerWasapiRenderStream.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "AudioMixer.h" 
#include "IAudioMixerWasapiDeviceManager.h"
#include "WasapiAudioFormat.h"
 
#include <atomic>
 
#include "Windows/AllowWindowsPlatformTypes.h"
#include "Windows/AllowWindowsPlatformAtomics.h"
 
#include "Microsoft/COMPointer.h"
 
THIRD_PARTY_INCLUDES_START
#include <mmdeviceapi.h>            // IMMNotificationClient
#include <audiopolicy.h>            // IAudioSessionEvents
THIRD_PARTY_INCLUDES_END
 
#include "Windows/HideWindowsPlatformAtomics.h"
#include "Windows/HideWindowsPlatformTypes.h"
 
DECLARE_DELEGATE(FAudioMixerReadNextBufferDelegate);
 
namespace Audio
{
    class FAudioMixerWasapiRenderStream : public IDeviceRenderCallback
    {
    public:
 
        FAudioMixerWasapiRenderStream();
        virtual ~FAudioMixerWasapiRenderStream();
 
        virtual bool InitializeHardware(const FWasapiRenderStreamParams& InParams);
        virtual bool TeardownHardware();
        virtual bool IsInitialized() const;
        virtual int32 GetNumFrames(const int32 InNumRequestedFrames) const;
        virtual bool OpenAudioStream(const FWasapiRenderStreamParams& InParams, HANDLE InEventHandle);
        virtual bool CloseAudioStream();
        virtual bool StartAudioStream();
        virtual bool StopAudioStream();
        virtual void SubmitBuffer(const uint8* Buffer, const SIZE_T InNumFrames) { }
        virtual void SubmitDirectOutBuffer(const int32 InChannelIndex, const FAlignedFloatBuffer& InBuffer) { }
 
        UE_DEPRECATED(5.7, "GetMinimumBufferSize() is deprecated. Please use GetDefaultDevicePeriod() in the future.")
        static uint32 GetMinimumBufferSize(const uint32 InSampleRate);
 
    protected:
        
        uint32 GetDefaultDevicePeriod() const { return DefaultDevicePeriod; }
 
        TComPtr<IAudioClient2> AudioClient;
 
        TComPtr<IAudioRenderClient> RenderClient;
 
        FWasapiAudioFormat AudioFormat;
 
        std::atomic<bool> bIsInitialized = false;
 
        std::atomic<EAudioOutputStreamState::Type> StreamState = EAudioOutputStreamState::Closed;
 
        FWasapiRenderStreamParams RenderStreamParams;
 
        uint32 DefaultDevicePeriod = 0;
 
        uint32 NumFramesPerDeviceBuffer = 0;
 
        uint32 CallbackBufferErrors = 0;
 
        FAlignedFloatBuffer DownmixScratchBuffer;
        
        TArray<float> MixdownGainsMap;
 
    private:
        
        void InitializeDownmixBuffers(const int32 InNumInputChannels, const int32 InNumFrames, const FWasapiAudioFormat& InAudioOutputFormat);
    };
}