public static CWavStreamReadHeaders ReadWavStreamReadHeaders(BinaryReader r)
{
CWavStreamReadHeaders info = new CWavStreamReadHeaders();
info.bIsValid = false;
string riff = new string(r.ReadChars(4));
if (!riff.Equals("RIFF"))
throw new WavCutException("No 'RIFF' Tag, probably not a valid wav file.");
info.nCompleteLength = r.ReadUInt32(); // (length of file in bytes) - 8
string wave = new string(r.ReadChars(4));
if (!wave.Equals("WAVE"))
throw new WavCutException("No 'WAVE' tag, probably not a valid wav file.");
string format = new string(r.ReadChars(4)); // assume that fmt tag is first
if (!format.Equals("fmt "))
throw new WavCutException("No 'fmt ' tag");
uint size = r.ReadUInt32(); // size of fmt header
if (size != 16)
throw new WavCutException("Size of fmt header != 16");
info.nAudioFormat = r.ReadUInt16(); // audio format. 1 refers to uncompressed PCM
// read the format header
info.nChannels = r.ReadUInt16();
info.nSampleRate = r.ReadUInt32();
info.byteRate = r.ReadUInt32();
info.blockAlign = r.ReadUInt16();
info.nBitsPerSample = r.ReadUInt16();
info.bIsValid = true;
return info;
}
public static CWavStreamReadHeaders ReadWavStreamReadHeaders(BinaryReader r)
{
CWavStreamReadHeaders info = new CWavStreamReadHeaders();
info.bIsValid = false;
string riff = new string(r.ReadChars(4));
if (!riff.Equals("RIFF"))
{
throw new WavCutException("No 'RIFF' Tag, probably not a valid wav file.");
}
info.nCompleteLength = r.ReadUInt32(); // (length of file in bytes) - 8
string wave = new string(r.ReadChars(4));
if (!wave.Equals("WAVE"))
{
throw new WavCutException("No 'WAVE' tag, probably not a valid wav file.");
}
string format = new string(r.ReadChars(4)); // assume that fmt tag is first
if (!format.Equals("fmt "))
{
throw new WavCutException("No 'fmt ' tag");
}
uint size = r.ReadUInt32(); // size of fmt header
if (size != 16)
{
throw new WavCutException("Size of fmt header != 16");
}
info.nAudioFormat = r.ReadUInt16(); // audio format. 1 refers to uncompressed PCM
// read the format header
info.nChannels = r.ReadUInt16();
info.nSampleRate = r.ReadUInt32();
info.byteRate = r.ReadUInt32();
info.blockAlign = r.ReadUInt16();
info.nBitsPerSample = r.ReadUInt16();
info.bIsValid = true;
return(info);
}
public static void StartWavAnalyze(BinaryReader r, long nActualLength)
{
CWavStreamReadHeaders info = CWavStreamReadHeaders.ReadWavStreamReadHeaders(r);
// display header info
Console.WriteLine("Audio format: " + info.nAudioFormat + " (1 is uncompressed PCM)");
Console.WriteLine("Sample rate: " + info.nSampleRate);
Console.WriteLine("BitsPerSample: " + info.nBitsPerSample);
Console.WriteLine("Channels: " + info.nChannels);
if (nActualLength != info.nCompleteLength + 8)
{
Console.WriteLine("Warning: length of file is " + nActualLength + " but expected " + info.nCompleteLength);
}
while (true)
{
// are we at the end of the file? if so, exit loop
byte[] arTest = r.ReadBytes(4);
if (arTest.Length == 0)
{
break;
}
else
{
r.BaseStream.Seek(-arTest.Length, SeekOrigin.Current);
}
// read the next chunk
string sDatatag = new string(r.ReadChars(4));
uint nDataSize = r.ReadUInt32();
Console.WriteLine("TYPE:" + sDatatag + " SIZE:" + nDataSize);
if (sDatatag == "data")
{
long nLengthInSamples = nDataSize / (info.nChannels * (info.nBitsPerSample / 8));
Console.WriteLine("\tlength in samples " + nLengthInSamples +
" length in secs " + (nLengthInSamples / ((double)info.nSampleRate)));
}
if (sDatatag != "data" && sDatatag != "LIST")
{
Console.WriteLine("warning, datatag is not 'data' or 'LIST'.");
}
r.BaseStream.Seek(nDataSize, SeekOrigin.Current);
}
Console.WriteLine("Looks ok.");
}
public static void StreamThroughWaveFile(BinaryReader r, IReadWaveData objCallback)
{
bool bRaw = objCallback.PreferRawSample();
CWavStreamReadHeaders winfo = CWavStreamReadHeaders.ReadWavStreamReadHeaders(r);
if (winfo.nAudioFormat != 1)
{
throw new WavCutException("Only audio format 1 is supported");
}
if (winfo.nSampleRate != 44100)
{
throw new WavCutException("expect samplerate==44100");
}
if (winfo.nBitsPerSample != 16)
{
throw new WavCutException("expect nBitsPerSample==16");
}
if (winfo.nChannels != 2)
{
throw new WavCutException("expect nChannels==2");
}
uint nDataSize = 0;
while (true)
{
// Go through chunks. We are looking for "data" chunk
string sDatatag = new string(r.ReadChars(4));
nDataSize = r.ReadUInt32();
if (nDataSize > int.MaxValue)
{
throw new WavCutException("File too large.");
}
if (sDatatag == "data") // found the data section
{
break;
}
else // something else, continue looping
{
r.BaseStream.Seek(nDataSize, SeekOrigin.Current);
}
}
uint nLengthOfDataChunk = (uint)(nDataSize / (winfo.nChannels * (winfo.nBitsPerSample / 8)));
int nSample = 0;
const int nReadsize = 1024;
bool bComplete = false;
// loop through wave until we reach the expected number of samples.
// we should not read until eof because there might be a later riff chunk.
while (!bComplete)
{
byte[] rawdata = r.ReadBytes((int)nReadsize);
if (rawdata == null || rawdata.Length == 0)
{
break;
}
for (int j = 0; j < rawdata.Length; j += 4)
{
if (bRaw)
{
objCallback.ReceiveRawSample(rawdata[j], rawdata[j + 1], rawdata[j + 2], rawdata[j + 3]);
}
else
{
short sha1 = rawdata[j + 0]; // intel byte order
short sha2 = (short)(((short)rawdata[j + 1]) << 8);
short sha = (short)(sha1 + sha2);
double sa = sha / ((double)short.MaxValue);
short shb1 = rawdata[j + 2]; // intel byte order
short shb2 = (short)(((short)rawdata[j + 3]) << 8);
short shb = (short)(sha1 + sha2);
double sb = shb / ((double)short.MaxValue);
if (sa != sb)
{
throw new WavCutException("different here");
}
objCallback.ReceiveProcessedSample(sa, sb);
}
nSample++;
if (nSample >= nLengthOfDataChunk)
{
bComplete = true;
break;
}
}
}
if (nSample != nLengthOfDataChunk)
{
Console.WriteLine("warning: eof reached earlier than expected. Expected " + nLengthOfDataChunk + " got " + nSample);
}
objCallback.OnFinished();
}
