Xaudio2 pop sound when changing buffer or looping - c++

Question

I have a simple program that plays a sine wave.
At the end of the buffer I get a pop sound.
If I try to loop I get the pop sound between each loop.
If I alternate between buffers I get the pop sound.
struct win32_audio_buffer
{
XAUDIO2_BUFFER XAudioBuffer = {};
int16 *Memory;
};
struct win32_audio_setteings
{
int32 SampleRate = 44100;
int32 ToneHz = 200;
int32 Channels = 2;
int32 LoopTime = 10;
int32 TotalSamples = SampleRate * LoopTime;
};
win32_audio_setteings AudioSetteings;
win32_audio_buffer MainAudioBuffer;
win32_audio_buffer SecondaryAudioBuffer;
IXAudio2SourceVoice* pSourceVoice;
internal void Win32InitXaudio2()
{
WAVEFORMATEX WaveFormat = {};
WaveFormat.wFormatTag = WAVE_FORMAT_PCM;
WaveFormat.nChannels = AudioSetteings.Channels;
WaveFormat.nSamplesPerSec = AudioSetteings.SampleRate;
WaveFormat.wBitsPerSample = 16;
WaveFormat.nBlockAlign = (WaveFormat.nChannels * WaveFormat.wBitsPerSample) / 8;
WaveFormat.nAvgBytesPerSec = WaveFormat.nSamplesPerSec * WaveFormat.nBlockAlign;
WaveFormat.cbSize = 0;
IXAudio2* pXAudio2;
IXAudio2MasteringVoice* pMasterVoice;
XAudio2Create(&pXAudio2);
pXAudio2->CreateMasteringVoice(&pMasterVoice);
pXAudio2->CreateSourceVoice(&pSourceVoice, &WaveFormat);
}
//DOC: AudioBytes - Size of the audio data
//DOC: pAudioData - The buffer start loaction (Needs to be type cast into BYTE pointer)
internal void Win32CreateAudioBuffer(win32_audio_buffer *AudioBuffer)
{
int32 Size = (int16)sizeof(int16) * AudioSetteings.Channels * AudioSetteings.SampleRate * AudioSetteings.LoopTime;
AudioBuffer->Memory = (int16 *)VirtualAlloc(0, Size, MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE);
AudioBuffer->XAudioBuffer.AudioBytes = Size;
AudioBuffer->XAudioBuffer.pAudioData = (BYTE *) AudioBuffer->Memory;
//AudioBuffer->XAudioBuffer.Flags = XAUDIO2_END_OF_STREAM;
AudioBuffer->XAudioBuffer.PlayBegin = 0;
AudioBuffer->XAudioBuffer.PlayLength = AudioSetteings.TotalSamples;
//AudioBuffer->XAudioBuffer.LoopCount = 10;
}
internal void Win32Playback(win32_audio_buffer *AudioBuffer)
{
for (int32 Index = 0, Sample = 0; Sample < AudioSetteings.TotalSamples; Sample++)
{
real32 Sine = sinf(Sample * 2.0f * Pi32 / AudioSetteings.ToneHz);
int16 value = (int16)(4000 * Sine);
AudioBuffer->Memory[Index++] = value;
AudioBuffer->Memory[Index++] = value;
}
pSourceVoice->SubmitSourceBuffer(&AudioBuffer->XAudioBuffer);
}
Win32InitXaudio2();
Win32CreateAudioBuffer(&MainAudioBuffer);
//Win32CreateAudioBuffer(&SecondaryAudioBuffer);
Win32Playback(&MainAudioBuffer);
//Win32Playback(&SecondaryAudioBuffer);
pSourceVoice->Start(0);
I have posted the relevant code here and it just play one sine buffer.
I tried altrantaing buffers and to start and end on a zero-crossing.

Answer 1

I had a similar problem.
Maybe it will help someone.
The problem is in allocating more memory for audio than needed.
So I tried something like this and found the problem (this is not solution I just show how I found problem! Probably, if it will not help in your case, then the problem somewhere else)
// XAUDIO2_BUFFER m_xaudio2Buffer...
m_xaudio2Buffer.pAudioData = source->m_data;
m_xaudio2Buffer.AudioBytes = source->m_dataSize - 100; // -100 and `pop` sound is gone
m_xaudio2Buffer.Flags = XAUDIO2_END_OF_STREAM;