public static WaveFileHeader ReadWaveData(byte[] waveData)
{
WaveFileHeader waveHeader = new WaveFileHeader();
using (MemoryStream fs = new MemoryStream(waveData))
{
waveReaderCore(waveHeader, fs);
}
return(waveHeader);
}
private static void waveReaderCore(WaveFileHeader waveHeader, Stream fs)
{
BinaryReader br = new BinaryReader(fs);
waveHeader.RiffHeader = Encoding.GetEncoding(20127).GetString(br.ReadBytes(4));
waveHeader.FileSize = BitConverter.ToInt32(br.ReadBytes(4), 0);
waveHeader.WaveHeaderData = Encoding.GetEncoding(20127).GetString(br.ReadBytes(4));
bool readFmtChunk = false;
bool readDataChunk = false;
while (!readFmtChunk || !readDataChunk)
{
// ChunkIDを取得する
string chunk = Encoding.GetEncoding(20127).GetString(br.ReadBytes(4));
if (chunk.ToLower().CompareTo("fmt ") == 0)
{
// fmtチャンクの読み込み
waveHeader.FormatChunk = chunk;
waveHeader.FormatChunkSize = BitConverter.ToInt32(br.ReadBytes(4), 0);
waveHeader.FormatID = BitConverter.ToInt16(br.ReadBytes(2), 0);
waveHeader.Channel = BitConverter.ToInt16(br.ReadBytes(2), 0);
waveHeader.SampleRate = BitConverter.ToInt32(br.ReadBytes(4), 0);
waveHeader.BytePerSec = BitConverter.ToInt32(br.ReadBytes(4), 0);
waveHeader.BlockSize = BitConverter.ToInt16(br.ReadBytes(2), 0);
waveHeader.BitPerSample = BitConverter.ToInt16(br.ReadBytes(2), 0);
readFmtChunk = true;
}
else if (chunk.ToLower().CompareTo("data") == 0)
{
// dataチャンクの読み込み
waveHeader.DataChunk = chunk;
waveHeader.DataChunkSize = BitConverter.ToInt32(br.ReadBytes(4), 0);
waveHeader.Data = br.ReadBytes(waveHeader.DataChunkSize);
// 再生時間を算出する
int bytesPerSec = waveHeader.SampleRate * waveHeader.BlockSize;
waveHeader.PlayTimeMsec = (int)(((double)waveHeader.DataChunkSize / (double)bytesPerSec) * 1000);
readDataChunk = true;
}
else
{
// 不要なチャンクの読み捨て
Int32 size = BitConverter.ToInt32(br.ReadBytes(4), 0);
if (0 < size)
{
br.ReadBytes(size);
}
}
}
}
public static WaveFileHeader ReadWaveFile(string waveFilePath)
{
// ファイルの存在を確認する
if (!File.Exists(waveFilePath))
{
return(null);
}
WaveFileHeader waveHeader = new WaveFileHeader();
using (FileStream fs = new FileStream(waveFilePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
waveReaderCore(waveHeader, fs);
}
return(waveHeader);
}
