IXAudio2 - 0xC0000005: Access violation writing location 0x00000000

Question

I'm having a strange problem with my DirectX XAudio2 program. Everything should work fine, but I'm getting 0xC0000005: Access violation error here:

if(FAILED(hr = xAudio2Engine->CreateSourceVoice(&pAudioTrack->mAudioSource, lWaveFileFormat)))

Here is XAudio2Manager.cpp:

#include "XAudio2Manager.h"
#include <exception>

class XAudio2InitException: public std::exception
{
    virtual const char* what() const throw()
    {
        return "XAudio2 Initialiation failed";
    }
} XAudio2ex;

template <class T> void SafeRelease(T **ppT)
{
    if(*ppT)
    {
        (*ppT)->Release();
        *ppT = NULL;
    }
}

cAudioTrack::cAudioTrack()
{
    mIsPlaying = false;
}

//cAudioTrack::~cAudioTrack();
//{

//}

void cAudioTrack::Play()
{
    if(!mIsPlaying)
    {
        mAudioSource->Start();
        mIsPlaying = true;
    }
}

void cAudioTrack::Pause()
{
    if(mIsPlaying)
    {
        mAudioSource->Stop();
        mIsPlaying = false;
    }
}

void cAudioTrack::Reset()
{
    mAudioSource->FlushSourceBuffers();
    mAudioSource->SubmitSourceBuffer(&buffer);
    mIsPlaying = false;
}

cXAudio2Manager::cXAudio2Manager()
{
    xAudio2Engine = NULL;
    masterVoice = NULL;

    HRESULT hr = S_OK;

    // Create audio engine
    if(SUCCEEDED(hr))
    {
        hr = XAudio2Create(&xAudio2Engine);
    }

    // Create mastering voice
    if(SUCCEEDED(hr))
    {
        hr = xAudio2Engine->CreateMasteringVoice(&masterVoice,
            XAUDIO2_DEFAULT_CHANNELS, XAUDIO2_DEFAULT_SAMPLERATE,
            0,0, NULL);
    }

    // If failed, throw exception
    if(!SUCCEEDED(hr))
    {
        throw XAudio2ex;
    }
}

bool cXAudio2Manager::LoadPCMFile(LPWSTR filename, cAudioTrack *pAudioTrack, bool pLooping)
{
    HRESULT hr = S_OK;

    // Read wave file
    CWaveFile lWaveFile;

    if(FAILED(hr = lWaveFile.Open(const_cast<LPWSTR>(filename), nullptr, WAVEFILE_READ)))
    {
        return false;
    }

    // Get file format
    WAVEFORMATEX* lWaveFileFormat = lWaveFile.GetFormat();

    // Calculate bytes and samples 
    DWORD lWaveFileSize = lWaveFile.GetSize();

    // Read sample data from wave file in to memory
    BYTE* lWaveData = new BYTE[lWaveFileSize];
    if(FAILED(hr = lWaveFile.Read(lWaveData, lWaveFileSize, &lWaveFileSize)))
    {
        if (lWaveData)
            delete[] lWaveData;
        return false;
    }  

    if(FAILED(hr = xAudio2Engine->CreateSourceVoice(&pAudioTrack->mAudioSource, lWaveFileFormat)))
    {
        if(lWaveData)
            delete [] lWaveData;
        return false;
    }

    XAUDIO2_BUFFER buffer = {0};
    pAudioTrack->buffer = buffer;
    pAudioTrack->buffer.pAudioData = lWaveData;
    pAudioTrack->buffer.Flags = XAUDIO2_END_OF_STREAM;
    pAudioTrack->buffer.AudioBytes = lWaveFileSize;
    if(pLooping)
    {
        pAudioTrack->buffer.LoopCount = XAUDIO2_LOOP_INFINITE;
    }

    if(FAILED(hr = pAudioTrack->mAudioSource->SubmitSourceBuffer(&pAudioTrack->buffer)))
    {
        pAudioTrack->mAudioSource->DestroyVoice();
        if(lWaveData)
            delete [] lWaveData;
        return false;
    }

    return true;
}

Wave file loading function is called in Game.cpp:

AudMa->LoadPCMFile(L"running.wav", mpCharacter->runningSound, true); 

SDKwavefile is in use.

Please help!

Answer 1

That smells awfully like a null pointer. The line in question is:

xAudio2Engine->CreateSourceVoice(&pAudioTrack->mAudioSource, lWaveFileFormat)

So the obvious possibilities for being null are xAudio2Engine and pAudioTrack . Add some diagnostics to check for null. If you find null then dig deeper to understand why it is so.