/// <summary>Converts data buffer to desired format</summary>
/// <param name="inlen">source length</param>
/// <param name="outlen">destination length</param>
/// <param name="inused">length of source buffer used</param>
/// <param name="outused">length of destination buffer used</param>
/// <param name="last">last conversion cycle</param>
/// <returns>MMSYSERR</returns>
private MMSYSERR Convert(uint inlen, uint outlen, ref uint inused, ref uint outused, bool last)
{
uint lngFlags;
ACMSTREAMHEADER udtHdr = new ACMSTREAMHEADER();
lngFlags = ACM_STREAMCONVERTF_BLOCKALIGN;
if (_bInFirst)
{
lngFlags = lngFlags | ACM_STREAMCONVERTF_START;
}
if (last)
{
lngFlags = lngFlags | ACM_STREAMCONVERTF_END;
}
MMSYSERR mmr;
fixed(byte *pbtIn = _btInput, pbtOut = _btOutput)
{
{
udtHdr.cbStruct = (uint)Marshal.SizeOf(udtHdr);
udtHdr.cbSrcLength = inlen;
udtHdr.cbDstLength = outlen;
udtHdr.pbDst = pbtOut;
udtHdr.pbSrc = pbtIn;
mmr = acmStreamPrepareHeader(_hStream, ref udtHdr, 0);
if (mmr == MMSYSERR.NOERROR)
{
_bInFirst = false;
mmr = acmStreamConvert(_hStream, ref udtHdr, lngFlags);
}
if (mmr == MMSYSERR.NOERROR)
{
inused = (uint)udtHdr.cbSrcLengthUsed;
outused = (uint)udtHdr.cbDstLengthUsed;
_iKeepInBuffer = (uint)(udtHdr.cbSrcLength - udtHdr.cbSrcLengthUsed);
if (_iKeepInBuffer > 0)
// codec didn't use all the input bytes,
// move them to the first index of the input buffer
// to decode them with the next call to convert()
fixed(byte *pbtFt = &_btInput[0], pbtIn2 = &_btInput[(inlen - _iKeepInBuffer)])
{
RtlMoveMemory(pbtFt, pbtIn2, _iKeepInBuffer);
}
}
acmStreamUnprepareHeader(_hStream, ref udtHdr, 0);
}
return(mmr);
}
}
public static extern int acmStreamConvert(IntPtr has, ref ACMSTREAMHEADER pash, int pdwConvert);
public static extern int acmStreamUnprepareHeader(IntPtr has, ref ACMSTREAMHEADER pash, int fdwUnprepare);
private static extern MMSYSERR acmStreamConvert(IntPtr has, ref ACMSTREAMHEADER pash, uint fdwConvert);
private static extern MMSYSERR acmStreamUnprepareHeader(IntPtr has, ref ACMSTREAMHEADER pash, uint fdwUnprepare);
public static void AcmStreamUnprepareHeader(IntPtr has,
ref ACMSTREAMHEADER pash,
uint fdwUnprepare)
=> MMErrCheck(acmStreamUnprepareHeader(has, ref pash, fdwUnprepare));
public static void AcmStreamConvert(IntPtr has,
ref ACMSTREAMHEADER pash,
uint fdwConvert)
=> MMErrCheck(acmStreamConvert(has, ref pash, fdwConvert));
private static extern MMRESULT acmStreamPrepareHeader(IntPtr has,
ref ACMSTREAMHEADER pash,
uint fdwPrepare);
public static extern int acmStreamUnprepareHeader(IntPtr has, ref ACMSTREAMHEADER pash, int fdwUnprepare);
public static extern int acmStreamConvert(IntPtr has, ref ACMSTREAMHEADER pash, int pdwConvert);
