C#读取音频文件

/// <summary>
/// WAV文件信息
/// </summary>
public struct WavInfo
{
public string groupid;
public string rifftype;
public long filesize;
public string chunkid;
public long chunksize;
public short wformattag; //记录着此声音的格式代号
public ushort wchannels; //记录声音的频道数。
public ulong dwsamplespersec;//记录每秒取样数。
public ulong dwavgbytespersec;//记录每秒的数据量。
public ushort wblockalign;//记录区块的对齐单位。
public ushort wbitspersample;//记录每个取样所需的位元数。
public string datachunkid;
public long datasize;
}

/// <summary>
/// 获取WAV文件信息
/// </summary>
/// <param name="fileName">文件路径</param>
/// <returns></returns>
private WavInfo GetWavInfo(string fileName)
{
WavInfo wavInfo = new WavInfo();
FileInfo fi = new FileInfo(fileName);
using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
if (fs.Length >= 44)
{
byte[] bInfo = new byte[44];
fs.Read(bInfo, 0, 44);
Encoding.Default.GetString(bInfo, 0, 4);
if (Encoding.Default.GetString(bInfo, 0, 4) == "RIFF" && Encoding.Default.GetString(bInfo, 8, 4) == "WAVE" && Encoding.Default.GetString(bInfo, 12, 4) == "fmt ")
{
wavInfo.groupid = Encoding.Default.GetString(bInfo, 0, 4);
System.BitConverter.ToInt32(bInfo, 4);
wavInfo.filesize = System.BitConverter.ToInt32(bInfo, 4);
wavInfo.rifftype = Encoding.Default.GetString(bInfo, 8, 4);
wavInfo.chunkid = Encoding.Default.GetString(bInfo, 12, 4);
wavInfo.chunksize = System.BitConverter.ToInt32(bInfo, 16);
wavInfo.wformattag = System.BitConverter.ToInt16(bInfo, 20);
wavInfo.wchannels = System.BitConverter.ToUInt16(bInfo, 22);
wavInfo.dwsamplespersec = System.BitConverter.ToUInt32(bInfo, 24);
wavInfo.dwavgbytespersec = System.BitConverter.ToUInt32(bInfo, 28);
wavInfo.wblockalign = System.BitConverter.ToUInt16(bInfo, 32);
wavInfo.wbitspersample = System.BitConverter.ToUInt16(bInfo, 34);
wavInfo.datachunkid = Encoding.Default.GetString(bInfo, 36, 4);
wavInfo.datasize = System.BitConverter.ToInt32(bInfo, 40);
}
}
}

return wavInfo;
}

/// <summary>
/// 获取音频文件长度
/// </summary>
/// <param name="fileName">文件路径</param>
/// <returns>返回单位(秒)</returns>
private int GetVoiceDuration(string fileName)
{
int duration = 0;
try
{
WavInfo wavInfo = this.GetWavInfo(fileName);
duration = Convert.ToInt32(wavInfo.datasize / Convert.ToInt64(wavInfo.dwavgbytespersec));
}
catch (Exception ex)
{
LOG.Error(new StringBuilder("获取音频文件长度出错：").Append(fileName).Append(", ").Append(ex.Message));
}

return duration;
}