/// <summary>
/// Creates a new ACM stream to convert one format to another. Note that
/// not all conversions can be done in one step
/// </summary>
/// <param name="sourceFormat">The source audio format</param>
/// <param name="destFormat">The destination audio format</param>
public AcmStream(WaveFormat sourceFormat, WaveFormat destFormat)
{
try
{
streamHandle = IntPtr.Zero;
this.sourceFormat = sourceFormat;
int sourceBufferSize = Math.Max(65536, sourceFormat.AverageBytesPerSecond);
sourceBufferSize -= (sourceBufferSize % sourceFormat.BlockAlign);
IntPtr sourceFormatPointer = WaveFormat.MarshalToPtr(sourceFormat);
IntPtr destFormatPointer = WaveFormat.MarshalToPtr(destFormat);
try
{
MmException.Try(AcmInterop.acmStreamOpen(out streamHandle, driverHandle,
sourceFormatPointer, destFormatPointer, null, IntPtr.Zero, IntPtr.Zero, AcmStreamOpenFlags.None), "acmStreamOpen");
}
finally
{
Marshal.FreeHGlobal(sourceFormatPointer);
Marshal.FreeHGlobal(destFormatPointer);
}
int destBufferSize = SourceToDest(sourceBufferSize);
streamHeader = new AcmStreamHeader(streamHandle, sourceBufferSize, destBufferSize);
driverHandle = IntPtr.Zero;
}
catch
{
// suppress the finalise and clean up resources
Dispose();
throw;
}
}
/// <summary>
/// Frees resources associated with this ACM Stream
/// </summary>
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
// Free other state (managed objects).
if (streamHeader != null)
{
streamHeader.Dispose();
streamHeader = null;
}
}
// Free your own state (unmanaged objects).
if (streamHandle != IntPtr.Zero)
{
MmResult result = AcmInterop.acmStreamClose(streamHandle, 0);
streamHandle = IntPtr.Zero;
if (result != MmResult.NoError)
{
throw new MmException(result, "acmStreamClose");
}
}
// Set large fields to null.
if (driverHandle != IntPtr.Zero)
{
AcmInterop.acmDriverClose(driverHandle, 0);
driverHandle = IntPtr.Zero;
}
}
private unsafe void Prepare()
{
streamHeader.cbStruct = Marshal.SizeOf(streamHeader);
streamHeader.sourceBufferLength = sourceBuffer.Length;
streamHeader.sourceBufferPointer = (IntPtr)hSourceBuffer.Pointer;
streamHeader.destBufferLength = destBuffer.Length;
streamHeader.destBufferPointer = (IntPtr)hDestBuffer.Pointer;
MmException.Try(AcmInterop.acmStreamPrepareHeader(streamHandle, streamHeader, 0), "acmStreamPrepareHeader");
}
/// <summary>
/// Returns the number of source bytes for a given number of destination bytes
/// </summary>
/// <param name="dest">Number of destination bytes</param>
/// <returns>Number of source bytes</returns>
public int DestToSource(int dest)
{
if (dest == 0) // zero is an invalid parameter to acmStreamSize
{
return(0);
}
int convertedBytes;
MmException.Try(AcmInterop.acmStreamSize(streamHandle, dest, out convertedBytes, AcmStreamSizeFlags.Destination), "acmStreamSize");
return(convertedBytes);
}
/// <summary>
/// Returns the number of output bytes for a given number of input bytes
/// </summary>
/// <param name="source">Number of input bytes</param>
/// <returns>Number of output bytes</returns>
public int SourceToDest(int source)
{
if (source == 0) // zero is an invalid parameter to acmStreamSize
{
return(0);
}
int convertedBytes;
var mmResult = AcmInterop.acmStreamSize(streamHandle, source, out convertedBytes, AcmStreamSizeFlags.Source);
MmException.Try(mmResult, "acmStreamSize");
return(convertedBytes);
}
private unsafe void Unprepare()
{
streamHeader.sourceBufferLength = sourceBuffer.Length;
streamHeader.sourceBufferPointer = (IntPtr)hSourceBuffer.Pointer;
streamHeader.destBufferLength = destBuffer.Length;
streamHeader.destBufferPointer = (IntPtr)hDestBuffer.Pointer;
MmResult result = AcmInterop.acmStreamUnprepareHeader(streamHandle, streamHeader, 0);
if (result != MmResult.NoError)
{
//if (result == MmResult.AcmHeaderUnprepared)
throw new MmException(result, "acmStreamUnprepareHeader");
}
}
public int Convert(int bytesToConvert, out int sourceBytesConverted)
{
Prepare();
try
{
streamHeader.sourceBufferLength = bytesToConvert;
streamHeader.sourceBufferLengthUsed = bytesToConvert;
AcmStreamConvertFlags flags = firstTime ? (AcmStreamConvertFlags.Start | AcmStreamConvertFlags.BlockAlign) : AcmStreamConvertFlags.BlockAlign;
MmException.Try(AcmInterop.acmStreamConvert(streamHandle, streamHeader, flags), "acmStreamConvert");
firstTime = false;
System.Diagnostics.Debug.Assert(streamHeader.destBufferLength == destBuffer.Length, "Codecs should not change dest buffer length");
sourceBytesConverted = streamHeader.sourceBufferLengthUsed;
}
finally
{
Unprepare();
}
return(streamHeader.destBufferLengthUsed);
}
/// <summary>
/// Suggests an appropriate PCM format that the compressed format can be converted
/// to in one step
/// </summary>
/// <param name="compressedFormat">The compressed format</param>
/// <returns>The PCM format</returns>
public static WaveFormat SuggestPcmFormat(WaveFormat compressedFormat)
{
// create a PCM format
WaveFormat suggestedFormat = new WaveFormat(compressedFormat.SampleRate, 16, compressedFormat.Channels);
//MmException.Try(AcmInterop.acmFormatSuggest(IntPtr.Zero, compressedFormat, suggestedFormat, Marshal.SizeOf(suggestedFormat), AcmFormatSuggestFlags.FormatTag), "acmFormatSuggest");
IntPtr suggestedFormatPointer = WaveFormat.MarshalToPtr(suggestedFormat);
IntPtr compressedFormatPointer = WaveFormat.MarshalToPtr(compressedFormat);
try
{
MmResult result = AcmInterop.acmFormatSuggest(IntPtr.Zero, compressedFormatPointer, suggestedFormatPointer, Marshal.SizeOf(suggestedFormat), AcmFormatSuggestFlags.FormatTag);
suggestedFormat = WaveFormat.MarshalFromPtr(suggestedFormatPointer);
MmException.Try(result, "acmFormatSuggest");
}
finally
{
Marshal.FreeHGlobal(suggestedFormatPointer);
Marshal.FreeHGlobal(compressedFormatPointer);
}
return(suggestedFormat);
}
/// <summary>
/// Creates a new ACM stream to convert one format to another, using a
/// specified driver identified and wave filter
/// </summary>
/// <param name="driverId">the driver identifier</param>
/// <param name="sourceFormat">the source format</param>
/// <param name="waveFilter">the wave filter</param>
public AcmStream(IntPtr driverId, WaveFormat sourceFormat, WaveFilter waveFilter)
{
int sourceBufferSize = Math.Max(16384, sourceFormat.AverageBytesPerSecond);
this.sourceFormat = sourceFormat;
sourceBufferSize -= (sourceBufferSize % sourceFormat.BlockAlign);
MmException.Try(AcmInterop.acmDriverOpen(out driverHandle, driverId, 0), "acmDriverOpen");
IntPtr sourceFormatPointer = WaveFormat.MarshalToPtr(sourceFormat);
try
{
MmException.Try(AcmInterop.acmStreamOpen(out streamHandle, driverHandle,
sourceFormatPointer, sourceFormatPointer, waveFilter, IntPtr.Zero, IntPtr.Zero, AcmStreamOpenFlags.None), "acmStreamOpen");
}
finally
{
Marshal.FreeHGlobal(sourceFormatPointer);
}
//MmException.Try(AcmInterop.acmStreamOpen(out streamHandle, driverHandle,
// sourceFormat, sourceFormat, waveFilter, IntPtr.Zero, IntPtr.Zero, AcmStreamOpenFlags.NonRealTime), "acmStreamOpen");
streamHeader = new AcmStreamHeader(streamHandle, sourceBufferSize, SourceToDest(sourceBufferSize));
}