/// <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.acmStreamOpen2(out streamHandle, IntPtr.Zero, sourceFormatPointer, destFormatPointer, null, IntPtr.Zero, IntPtr.Zero, AcmStreamOpenFlags.NonRealTime), "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> /// Creates a new ACM stream to convert one format to another, using a /// specified driver identifier 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.acmStreamOpen2(out streamHandle, driverHandle, sourceFormatPointer, sourceFormatPointer, waveFilter, IntPtr.Zero, IntPtr.Zero, AcmStreamOpenFlags.NonRealTime), "acmStreamOpen"); } finally { Marshal.FreeHGlobal(sourceFormatPointer); } streamHeader = new AcmStreamHeader(streamHandle, sourceBufferSize, SourceToDest(sourceBufferSize)); }