问题描述
过去几天,我一直在用 C++ 制作音频播放器。我遵循了 msdn 上的教程,如何使用 xaudio2 播放音频。我设法编写了正确的代码,但是关于 msds 的教程真的很混乱而且很糟糕。所以我想在这里发布我的代码,这样对每个和我面临同样问题的人来说都会容易得多。
#include <xaudio2.h>
#include <iostream>
using namespace std;
#ifdef _XBox
#define fourccRIFF 'RIFF'
#define fourccDATA 'data'
#define fourccFMT 'fmt '
#define fourccwAVE 'WAVE'
#define fourccXWMA 'XWMA'
#define fourccDPDS 'dpds'
#endif
#ifndef _XBox
#define fourccRIFF 'FFIR'
#define fourccDATA 'atad'
#define fourccFMT ' tmf'
#define fourccwAVE 'EVAW'
#define fourccXWMA 'AMWX'
#define fourccDPDS 'sdpd'
#endif
HRESULT FindChunk(HANDLE hFile,DWORD fourcc,DWORD& dwChunkSize,DWORD& dwChunkDataPosition)
{
HRESULT hr = S_OK;
if (INVALID_SET_FILE_POINTER == SetFilePointer(hFile,NULL,FILE_BEGIN))
return HRESULT_FROM_WIN32(GetLastError());
DWORD dwChunkType;
DWORD dwChunkDataSize;
DWORD dwRIFFDataSize = 0;
DWORD dwFileType;
DWORD bytesRead = 0;
DWORD dwOffset = 0;
while (hr == S_OK)
{
DWORD dwRead;
if (0 == ReadFile(hFile,&dwChunkType,sizeof(DWORD),&dwRead,NULL))
hr = HRESULT_FROM_WIN32(GetLastError());
if (0 == ReadFile(hFile,&dwChunkDataSize,NULL))
hr = HRESULT_FROM_WIN32(GetLastError());
switch (dwChunkType)
{
case fourccRIFF:
dwRIFFDataSize = dwChunkDataSize;
dwChunkDataSize = 4;
if (0 == ReadFile(hFile,&dwFileType,NULL))
hr = HRESULT_FROM_WIN32(GetLastError());
break;
default:
if (INVALID_SET_FILE_POINTER == SetFilePointer(hFile,dwChunkDataSize,FILE_CURRENT))
return HRESULT_FROM_WIN32(GetLastError());
}
dwOffset += sizeof(DWORD) * 2;
if (dwChunkType == fourcc)
{
dwChunkSize = dwChunkDataSize;
dwChunkDataPosition = dwOffset;
return S_OK;
}
dwOffset += dwChunkDataSize;
if (bytesRead >= dwRIFFDataSize) return S_FALSE;
}
return S_OK;
}
HRESULT ReadChunkData(HANDLE hFile,void* buffer,DWORD buffersize,DWORD bufferoffset)
{
HRESULT hr = S_OK;
if (INVALID_SET_FILE_POINTER == SetFilePointer(hFile,bufferoffset,FILE_BEGIN))
return HRESULT_FROM_WIN32(GetLastError());
DWORD dwRead;
if (0 == ReadFile(hFile,buffer,buffersize,NULL))
hr = HRESULT_FROM_WIN32(GetLastError());
return hr;
}
int main()
{
HRESULT hr;
hr = CoInitializeEx(nullptr,COINIT_MULTITHREADED);
if (Failed(hr))
cout << hr;
Ixaudio2* pxaudio2 = nullptr;
if (Failed(hr = xaudio2Create(&pxaudio2,xaudio2_DEFAULT_PROCESSOR)))
cout << hr;
Ixaudio2MasteringVoice* pMasterVoice = nullptr;
if (Failed(hr = pxaudio2->CreateMasteringVoice(&pMasterVoice)))
cout << hr;
WAVEFORMATEXTENSIBLE wfx = { 0 };
xaudio2_BUFFER buffer = { 0 };
#ifdef _XBox
char* strFileName = "s.wav";
#else
const TCHAR* strFileName = TEXT("s.wav");
#endif
HANDLE hFile = CreateFile(
strFileName,GENERIC_READ,FILE_SHARE_READ,OPEN_EXISTING,NULL);
if (INVALID_HANDLE_VALUE == hFile)
cout << HRESULT_FROM_WIN32(GetLastError());
if (INVALID_SET_FILE_POINTER == SetFilePointer(hFile,FILE_BEGIN))
cout << HRESULT_FROM_WIN32(GetLastError());
DWORD dwChunkSize;
DWORD dwChunkPosition;
//check the file type,should be fourccwAVE or 'XWMA'
FindChunk(hFile,fourccRIFF,dwChunkSize,dwChunkPosition);
DWORD filetype;
ReadChunkData(hFile,&filetype,dwChunkPosition);
if (filetype != fourccwAVE)
return S_FALSE;
FindChunk(hFile,fourccFMT,dwChunkPosition);
ReadChunkData(hFile,&wfx,dwChunkPosition);
FindChunk(hFile,fourccDATA,dwChunkPosition);
BYTE* pDataBuffer = new BYTE[dwChunkSize];
ReadChunkData(hFile,pDataBuffer,dwChunkPosition);
buffer.AudioBytes = dwChunkSize; //size of the audio buffer in bytes
buffer.pAudioData = pDataBuffer; //buffer containing audio data
buffer.Flags = xaudio2_END_OF_STREAM; // tell the source voice not to expect any data after this buffer
Ixaudio2SourceVoice* pSourceVoice;
if (Failed(hr = pxaudio2->CreateSourceVoice(&pSourceVoice,(WAVEFORMATEX*)&wfx))) cout << hr;
if (Failed(hr = pSourceVoice->SubmitSourceBuffer(&buffer)))
cout << hr;
if (Failed(hr = pSourceVoice->Start(0)))
cout << hr;
cout << "playing" << endl;
cin.get();
}
这就是使用 xaudio2 播放音频的代码。 PS:好像只能播放 .wav 文件。如果有人知道如何使用 xaudio2 播放 .mp3 文件,我将不胜感激。
解决方法
XAudio2 专为实时源速率转换、混合和应用 PCM 和 ADPCM 数据的音频效果而设计。 XAudio 2.9 还支持 Microsoft Media 格式的“xWMA”变体,以及在 Xbox 上的硬件辅助格式 XMA2。
要播放其他格式,您需要在 CPU 上将其解压缩并使用 PCM 格式数据将其流式传输为 XAudio2 语音。有关此示例,请参阅 XAudio2MFStream。它使用 Windows Media Foundation 从 WMA 文件执行这种流式传输。您可以使用一些 3rd 方库来播放 MP3、OGG 或任何做同样基本事情的东西。
您可能还会发现使用 DX11 和 DX12 版本中包含的 DirectX Tool Kit for Audio 很有用。