protected virtual bool InitializeForWriting(Stream underlyingStream, WaveFormat2 wfIn, WaveFormat2 wfOut, bool fAppend)
{
if (fAppend)
{
long position = underlyingStream.Position;
underlyingStream.Seek(0, SeekOrigin.Begin);
LoadHeader();
_ckData.BeginWrite();
_ckData.Seek(position - _ckData.DataStart, SeekOrigin.Begin);
}
else
{
_baseStream.Position = 0;
_mmc = new RiffChunk(underlyingStream);
(_mmc as RiffChunk).BeginWrite();
_ckFmt = new FmtChunk(underlyingStream, wfOut);
_mmc.AppendChunk(_ckFmt);
_ckFmt.BeginWrite();
_ckFmt.Write(_ckFmt.WaveFormat.GetBytes());
_fmt = wfOut;
_ckData = new DataChunk(underlyingStream);
_mmc.AppendChunk(_ckData);
_ckData.BeginWrite();
}
return(true);
}
protected void SetFormat(WaveFormat2 fmt)
{
_fmt = fmt;
if (_ckFmt == null)
{
_baseStream.Position = _ckData.Start + 12;
_ckFmt = new FmtChunk(_baseStream, fmt);
}
}
protected virtual void LoadHeader()
{
_mmc = MMChunk.FromStream(_baseStream);
_ckFmt = _mmc.FindChunk(FourCC.Fmt) as FmtChunk;
if (_ckFmt != null)
{
_fmt = _ckFmt.WaveFormat;
}
_ckData = _mmc.FindChunk(FourCC.Data) as DataChunk;
if (_ckData != null)
{
_posData = _ckData.DataStart;
}
_baseStream.Seek(_posData, SeekOrigin.Begin);
}
static public MMChunk FromStream(Stream st)
{
if (!st.CanRead)
{
return(null);
}
if (st.Position > st.Length - 4)
{
return(null);
}
byte[] data = new byte[4];
st.Read(data, 0, 4);
FourCC fourCC = BitConverter.ToInt32(data, 0);
if (fourCC == FourCC.Riff)
{
RiffChunk ck = new RiffChunk(st);
ck.LoadFromStream(st);
return(ck);
}
else if (fourCC == FourCC.Fmt)
{
FmtChunk ck = new FmtChunk(st, null);
ck.LoadFromStream(st);
return(ck);
}
else if (fourCC == FourCC.Data)
{
DataChunk ck = new DataChunk(st);
ck.LoadFromStream(st);
return(ck);
}
else
{
_RiffChunk ck = new _RiffChunk(fourCC, st);
ck.LoadFromStream(st);
return(ck);
}
}
virtual public MMChunk CreateSubChunk(FourCC fourCC, Stream st)
{
if (fourCC == FourCC.Riff)
{
MMChunk ck = new RiffChunk(st);
m_chunkList.Add(ck);
return(ck);
}
else if (fourCC == FourCC.Fmt)
{
MMChunk ck = new FmtChunk(st, null);
m_chunkList.Add(ck);
return(ck);
}
else if (fourCC == FourCC.Data)
{
MMChunk ck = new DataChunk(st);
m_chunkList.Add(ck);
return(ck);
}
return(null);
}
