C++解析wav文件方法介绍

第C++解析wav文件方法介绍目录一、前言二、接口三、具体步骤四、完整源码

一、前言

一开始本来在网上找代码，不过改了好几个都不是很好用。因为很多wav文件的fmt块后面并不是data块，经常还带有其他块，正确的方法应该是按MSDN的方法，找到data块再读取。

二、接口

最后接口如下：

classAudioReader

public:

structPCM

int_numChannel;//通道数1,2AL_FORMAT_MONO8,AL_FORMAT_STEREO8

int_bitPerSample;//采样数8,16

byte*_data;

size_t_size;

size_t_freq;//采样率

voidDelete(){delete[]_data;}

staticboolReadWAV(string_viewpath_name,PCMpcm);

};

三、具体步骤

打开文件，这里就是普通的文件流，按二进制、只读打开文件即可：

ifstreamifs;

if(!g_file-GetFile(path_name,ifs))

debug_err(format("打开文件失败：{}",path_name));

returnfalse;

}

查找riff块：

uint32_tdwChunkSize;

uint32_tdwChunkPosition;

//查找riff块

FindChunk(ifs,fourccRIFF,dwChunkSize,dwChunkPosition);

uint32_tfiletype;

ReadChunkData(ifs,filetype,sizeof(uint32_t),dwChunkPosition);

if(filetype!=fourccWAVE)

debug_err(format("匹配标记失败（fourccWAVE）：{}",path_name));

returnfalse;

}

其中fourccRIFF和fourccWAVE是我们定义的标记，也就是处理了下大小端，如下：

#ifdefDND_ENDIAN_BIG

#definefourccRIFF'RIFF'

#definefourccDATA'data'

#definefourccFMT'fmt'

#definefourccWAVE'WAVE'

#definefourccXWMA'XWMA'

#definefourccDPDS'dpds'

#endif

#ifdefDND_ENDIAN_LITTLE

#definefourccRIFF'FFIR'

#definefourccDATA'atad'

#definefourccFMT'tmf'

#definefourccWAVE'EVAW'

#definefourccXWMA'AMWX'

#definefourccDPDS'sdpd'

#endif

而FindChunk和ReadChunkData两个函数，分别是查找一个块，和读取一个块。代码实现有点长，可以参考后面我给出的完整源码。

接着，查找并读取fmt块，这个块描述了wav文件的音频属性，结构如下（部分字段会用到）：

//16字节

structWAVEFormat

int16_taudioFormat;

int16_tnumChannels;

int32_tsampleRate;

int32_tbyteRate;

int16_tblockAlign;

int16_tbitsPerSample;

};

//查找fmt块

if(!FindChunk(ifs,fourccFMT,dwChunkSize,dwChunkPosition))

debug_err(format("查找块失败（fourccFMT）：{}",path_name));

returnfalse;

//读wave信息

WAVEFormatwave_format;

if(!ReadChunkData(ifs,wave_format,dwChunkSize,dwChunkPosition))

debug_err(format("读取块失败（wave_format）：{}",path_name));

returnfalse;

};

接下来查找data块，根据返回的大小分配内存：

//查找音频数据

if(!FindChunk(ifs,fourccDATA,dwChunkSize,dwChunkPosition))

debug_err(format("查找块失败（fourccDATA）：{}",path_name));

returnfalse;

pcm._data=newbyte[dwChunkSize];

然后读取data块，将数据读取到我们分配的内存pcm._data。然后记录下一些重要的字段。由于OpenaAL不能直接播放32位（只8、16）的数据，这里简单返回失败。

if(!ReadChunkData(ifs,pcm._data,dwChunkSize,dwChunkPosition))

debug_err(format("读取块失败（pcm数据）：{}",path_name));

pcm.Delete();

returnfalse;

pcm._size=dwChunkSize;

pcm._numChannel=wave_format.numChannels;

pcm._bitPerSample=wave_format.bitsPerSample;

pcm._freq=wave_format.sampleRate;

if(pcm._bitPerSample==32)

debug_err(format("不支持32位：{}",path_name));

pcm.Delete();

returnfalse;

returntrue;

四、完整源码

可以此处获取最新的源码（我将来会添加ogg格式的解析），也可以用下面的：传送门

//.h

classAudioReader

public:

structPCM

int_numChannel;//通道数1,2AL_FORMAT_MONO8,AL_FORMAT_STEREO8

int_bitPerSample;//采样数8,16

byte*_data;

size_t_size;

size_t_freq;//采样率

voidDelete(){delete[]_data;}

staticboolReadWAV(string_viewpath_name,PCMpcm);

//16字节

structWAVEFormat

int16_taudioFormat;

int16_tnumChannels;

int32_tsampleRate;

int32_tbyteRate;

int16_tblockAlign;

int16_tbitsPerSample;

//.cpp

#ifdefDND_ENDIAN_BIG

#definefourccRIFF'RIFF'

#definefourccDATA'data'

#definefourccFMT'fmt'

#definefourccWAVE'WAVE'

#definefourccXWMA'XWMA'

#definefourccDPDS'dpds'

#endif

#ifdefDND_ENDIAN_LITTLE

#definefourccRIFF'FFIR'

#definefourccDATA'atad'

#definefourccFMT'tmf'

#definefourccWAVE'EVAW'

#definefourccXWMA'AMWX'

#definefourccDPDS'sdpd'

#endif

boolFindChunk(ifstreamifs,uint32_tfourcc,uint32_tsize,uint32_tpos)

boolret=true;

ifs.seekg(0);

if(ifs.fail())

returnfalse;

uint32_tdwChunkType;

uint32_tdwChunkDataSize;

uint32_tdwRIFFDataSize=0;

uint32_tdwFileType;

uint32_tbytesRead=0;

uint32_tdwOffset=0;

while(ret)

ifs.read((char*)dwChunkType,sizeof(uint32_t));

ifs.read((char*)dwChunkDataSize,sizeof(uint32_t));

switch(dwChunkType)

casefourccRIFF:

dwRIFFDataSize=dwChunkDataSize;

dwChunkDataSize=4;

ifs.read((char*)dwFileType,sizeof(uint32_t));

break;

default:

ifs.seekg(dwChunkDataSize,std::ios::cur);

if(ifs.fail())

returnfalse;

break;

dwOffset+=sizeof(uint32_t)*2;

if(dwChunkType==fourcc)

size=dwChunkDataSize;

pos=dwOffset;

returntrue;

dwOffset+=dwChunkDataSize;

if(bytesRead=dwRIFFDataSize)

returnfalse;

returntrue;

boolReadChunkData(ifstreamifs,void*buffer,uint32_tsize,uint32_tpos)

ifs.seekg(pos);

if(ifs.fail())

returnfalse;

ifs.read((char*)buffer,size);

returntrue;

boolAudioReader::ReadWAV(string_viewpath_name,PCMpcm)

ifstreamifs;

if(!g_file-GetFile(path_name,ifs))

debug_err(format("打开文件失败：{}",path_name));

returnfalse;

uint32_tdwChunkSize;

uint32_tdwChunkPosition;

//查找riff块

FindChunk(ifs,fourccRIFF,dwChunkSize,dwChunkPosition);

uint32_tfiletype;

ReadChunkData(ifs,filetype,sizeof(uint32_t),dwChunkPosition);

if(filetype!=fourccWAVE)

debug_err(format("匹配标记失败（fourccWAVE）：{}",path_name));

returnfalse;

//查找fmt块

if(!FindChunk(ifs,fourccFMT,dwChunkSize,dwChunkPosition))

debug_err(format("查找块失败（fourccFMT）：{}",path_name));

returnfalse;

//读wave信息

WAVEFormatwave_format;

if(!ReadChunkData(ifs,wave_format,dwChunkSize,dwChunkPosition))

debug_err(format("读取块失败（wave_format）：{}",path_name));

returnfalse;

//查找音频数据

if(!Fin