static IntPtr InitializeMagicCookie(NativeAudioFile audioFile, NativeAudioConverter converter)
{
Contract.Requires(audioFile != null);
Contract.Requires(converter != null);
uint dataSize;
uint isWritable;
AudioFileStatus getStatus = audioFile.GetPropertyInfo(AudioFilePropertyId.MagicCookieData, out dataSize,
out isWritable);
if (getStatus != AudioFileStatus.Ok)
{
throw new IOException(string.Format(CultureInfo.CurrentCulture,
Resources.LosslessSampleDecoderGetCookieInfoError, getStatus));
}
if (dataSize == 0)
{
return(IntPtr.Zero);
}
IntPtr cookie = audioFile.GetProperty(AudioFilePropertyId.MagicCookieData, dataSize);
AudioConverterStatus setStatus = converter.SetProperty(AudioConverterPropertyId.DecompressionMagicCookie,
dataSize, cookie);
if (setStatus != AudioConverterStatus.Ok)
{
throw new IOException(string.Format(CultureInfo.CurrentCulture,
Resources.LosslessSampleDecoderSetCookieError, setStatus));
}
return(cookie);
}
internal NativeAudioFile(AudioFileType fileType, Stream stream)
{
Contract.Requires(stream != null);
Contract.Requires(stream.CanRead);
Contract.Requires(stream.CanSeek);
Contract.Ensures(_stream != null);
Contract.Ensures(_stream == stream);
Contract.Ensures(Handle != null);
Contract.Ensures(!Handle.IsClosed);
Contract.Ensures(_readCallback != null);
Contract.Ensures(_getSizeCallback != null);
_readCallback = ReadCallback;
_getSizeCallback = GetSizeCallback;
_stream = stream;
NativeAudioFileHandle outHandle;
AudioFileStatus status = SafeNativeMethods.AudioFileOpenWithCallbacks(IntPtr.Zero, _readCallback, null,
_getSizeCallback, null, fileType, out outHandle);
if (status != AudioFileStatus.Ok)
{
throw new IOException(string.Format(CultureInfo.CurrentCulture,
Resources.NativeAudioFileInitializationError, status));
}
Handle = outHandle;
}
AudioConverterStatus InputCallback(IntPtr handle, ref uint numberPackets, ref AudioBufferList data, IntPtr packetDescriptions, IntPtr userData)
{
Contract.Requires(data.Buffers.Length > 0);
if (_buffer == null)
{
_buffer = new byte[numberPackets * _audioFile.GetProperty <uint>(AudioFilePropertyId.PacketSizeUpperBound)];
_bufferHandle = GCHandle.Alloc(_buffer, GCHandleType.Pinned);
}
if (_descriptionsHandle.IsAllocated)
{
_descriptionsHandle.Free();
}
uint numBytes;
var inputDescriptions = new AudioStreamPacketDescription[numberPackets];
AudioFileStatus status = _audioFile.ReadPackets(out numBytes, inputDescriptions, _packetIndex,
ref numberPackets, _bufferHandle.AddrOfPinnedObject());
if (status != AudioFileStatus.Ok)
{
throw new IOException(string.Format(CultureInfo.CurrentCulture, Resources.NativeAudioConverterReadError,
status));
}
_packetIndex += numberPackets;
data.Buffers[0].DataByteSize = numBytes;
data.Buffers[0].Data = _bufferHandle.AddrOfPinnedObject();
// If this conversion requires packet descriptions, provide them:
if (packetDescriptions != IntPtr.Zero)
{
_descriptionsHandle = GCHandle.Alloc(inputDescriptions, GCHandleType.Pinned);
Marshal.WriteIntPtr(packetDescriptions, _descriptionsHandle.AddrOfPinnedObject());
}
return(AudioConverterStatus.Ok);
}
