using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
namespace kr2000
{
public class WaveReader
{
public Int32[][] Data { get; private set; }
public int CompressionCode { get; private set; }
public int NumberOfChannels { get; private set; }
public int SampleRate { get; private set; }
public int AverageBytesPerSecond { get; private set; }
public int SignificantBitsPerSample { get; private set; }
public int BlockAlign { get; private set; }
public int Frames { get; private set; }
public double TimeLength { get; private set; }
/// <summary>
/// Reads a Wave file from the input stream, but don't closes the stream
/// </summary>
/// <param name="stream">Input WAVE file stream</param>
public WaveReader(Stream stream)
{
BinaryReader br = new BinaryReader(stream);
try
{
if (new string(br.ReadChars(4)).ToUpper() == "RIFF")
{
int length = br.ReadInt32();
if (new string(br.ReadChars(4)).ToUpper() == "WAVE")
{
string chunkName = new string(br.ReadChars(4)); //"fmt "
int chunkLength = br.ReadInt32();
this.CompressionCode = br.ReadInt16(); //1 for PCM/uncompressed
this.NumberOfChannels = br.ReadInt16();
this.SampleRate = br.ReadInt32();
this.AverageBytesPerSecond = br.ReadInt32();
this.BlockAlign = br.ReadInt16();
this.SignificantBitsPerSample = br.ReadInt16();
if (this.SignificantBitsPerSample == 0)
throw new Exception("The input stream uses an unhandled SignificantBitsPerSample parameter");
if (chunkLength > 16)
{
br.ReadChars(chunkLength - 16);
}
chunkName = new string(br.ReadChars(4));
try
{
while (chunkName.ToLower() != "data")
{
br.ReadChars(br.ReadInt32());
chunkName = new string(br.ReadChars(4));
}
}
catch
{
throw new Exception("Input stream misses the data chunk");
}
chunkLength = br.ReadInt32();
try
{
this.Frames = 8 * (chunkLength / this.SignificantBitsPerSample) / this.NumberOfChannels;
}
catch
{
throw new Exception("The input stream has zero channels");
}
this.TimeLength = ((double)this.Frames) / ((double)this.SampleRate);
this.Data = new Int32[this.NumberOfChannels][];
for (int j = 0; j < this.NumberOfChannels; j++)
{
this.Data[j] = new Int32[this.Frames];
}
switch (SignificantBitsPerSample)
{
case 4:
Byte b = new Byte();
bool IsEven = true;
for (int i = 0; i < this.Frames; i++)
{
for (int j = 0; j < this.NumberOfChannels; j++)
{
if (IsEven)
{
b = br.ReadByte();
Data[j][i] = Convert.ToInt32((b >> 4) & 0x0F);
}
else
{
Data[j][i] = Convert.ToInt32(b & 0x0F);
}
IsEven = !IsEven;
}
}
break;
case 8:
for (int i = 0; i < this.Frames; i++)
{
for (int j = 0; j < this.NumberOfChannels; j++)
{
Data[j][i] = Convert.ToInt32(br.ReadByte());
}
}
break;
case 16:
for (int i = 0; i < this.Frames; i++)
{
for (int j = 0; j < this.NumberOfChannels; j++)
{
Data[j][i] = br.ReadInt16();
}
}
break;
case 24:
for (int i = 0; i < this.Frames; i++)
{
for (int j = 0; j < this.NumberOfChannels; j++)
{
Byte[] int24 = br.ReadBytes(3);
Data[j][i] = Convert.ToInt32(int24[0]) + (Convert.ToInt32(int24[1])<<8) + (Convert.ToInt32(int24[3])<<16);
}
}
break;
case 32:
for (int i = 0; i < Frames; i++)
{
for (int j = 0; j < this.NumberOfChannels; j++)
{
Data[j][i] = br.ReadInt32();
}
}
break;
default:
throw new Exception("The input stream uses an unhandled SignificantBitsPerSample parameter");
}
}
else
{
throw new Exception("Input stream doesn't comply with the WAVE specification");
}
}
else
{
throw new Exception("Input stream doesn't comply with the RIFF specification");
}
}
finally
{
br.Close();
}
}
}
}
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