public RIFFDataChunk ReadDataChunk()
{
RIFFDataChunk data = new RIFFDataChunk();
data.chunkID = FOURCC.data;
data.dwChunkSize = fReader.ReadUInt32();
//ReadUInt32 is the most important function here.
//Once we've read in the ChunkSize,
//we're at the start of the actual data.
data.lFilePosition = fReader.BaseStream.Position;
//If the fact chunk exists, we don't have to calculate
//the number of samples ourselves.
if (null != fFact)
data.dwNumSamples = fFact.dwNumSamples;
else
data.dwNumSamples = data.dwChunkSize /
(fFormat.dwBitsPerSample / 8 * fFormat.wChannels);
//The above could be written as data.dwChunkSize / format.wBlockAlign,
//but I want to emphasize
//what the frames look like.
data.dwMinLength = (data.dwChunkSize / fFormat.dwAvgBytesPerSec) / 60;
data.dSecLength = ((double)data.dwChunkSize /
(double)fFormat.dwAvgBytesPerSec) -
(double)data.dwMinLength * 60;
if (fFormat.dwBitsPerSample == 8)
data.byteArray = fReader.ReadBytes((int)data.dwNumSamples);
return data;
}
public WaveFile(string filename)
{
fFileName = filename;
RIFFStreamReader fReader = new RIFFStreamReader(filename);
fBinaryReader = fReader.BinaryReader;
fHeader = fReader.ReadHeader();
// Read the chunks from the file
uint chunkName = 0;
while (fReader.Position < (long) fHeader.dwFileLength)
{
chunkName = fReader.ReadFourCC();
switch (chunkName)
{
case FOURCC.fmt:
fFormat = fReader.ReadFormatChunk();
if (fReader.Position + fFormat.dwChunkSize == fHeader.dwFileLength)
return;
break;
case FOURCC.fact:
fFact = fReader.ReadFactChunk();
if (fReader.Position + fFact.dwChunkSize == fHeader.dwFileLength)
return;
break;
case FOURCC.data:
fData = fReader.ReadDataChunk();
if (fReader.Position + fData.dwChunkSize == fHeader.dwFileLength)
return;
break;
default:
// Skip over unsupported chunks.
fReader.AdvanceToNext();
break;
}
}
}
