public static bool GetDataFromExtAudioFile (ExtAudioFile ext, AudioStreamBasicDescription outputFormat, int maxBufferSize,
byte[] dataBuffer, out int dataBufferSize, out ALFormat format, out double sampleRate)
{
uint errorStatus = 0;
uint bufferSizeInFrames = 0;
dataBufferSize = 0;
format = ALFormat.Mono16;
sampleRate = 0;
/* Compute how many frames will fit into our max buffer size */
bufferSizeInFrames = (uint)(maxBufferSize / outputFormat.BytesPerFrame);
if (dataBuffer != null) {
var audioBufferList = new AudioBuffers(maxBufferSize);
// This a hack so if there is a problem speak to kjpou1 -Kenneth
// the cleanest way is to copy the buffer to the pointer already allocated
// but what we are going to do is replace the pointer with our own and restore it later
//
GCHandle meBePinned = GCHandle.Alloc (dataBuffer, GCHandleType.Pinned);
IntPtr meBePointer = meBePinned.AddrOfPinnedObject ();
audioBufferList.SetData (0, meBePointer);
try {
// Read the data into an AudioBufferList
// errorStatus here returns back the amount of information read
ExtAudioFileError extAudioFileError = ExtAudioFileError.OK;
errorStatus = ext.Read (bufferSizeInFrames, audioBufferList, out extAudioFileError);
if (errorStatus >= 0) {
/* Success */
/* Note: 0 == bufferSizeInFrames is a legitimate value meaning we are EOF. */
/* ExtAudioFile.Read returns the number of frames actually read.
* Need to convert back to bytes.
*/
dataBufferSize = (int)bufferSizeInFrames * outputFormat.BytesPerFrame;
// Now we set our format
format = outputFormat.ChannelsPerFrame > 1 ? ALFormat.Stereo16 : ALFormat.Mono16;
sampleRate = outputFormat.SampleRate;
} else {
#if DEBUG
Console.WriteLine ("ExtAudioFile.Read failed, Error = " + errorStatus);
#endif
return false;
}
} catch (Exception exc) {
#if DEBUG
Console.WriteLine ("ExtAudioFile.Read failed: " + exc.Message);
#endif
return false;
} finally {
// Don't forget to free our dataBuffer memory pointer that was pinned above
meBePinned.Free ();
// and restore what was allocated to beginwith
audioBufferList.SetData (0, IntPtr.Zero);
}
}
return true;
}
static AudioConverterError HandleInputData (ref int numberDataPackets, AudioBuffers data, ref AudioStreamPacketDescription[] dataPacketDescription)
{
int maxPackets = afio.SrcBufferSize / afio.SrcSizePerPacket;
if (numberDataPackets > maxPackets)
numberDataPackets = maxPackets;
// read from the file
int outNumBytes;
var res = afio.SourceFile.ReadPackets (false, out outNumBytes, afio.PacketDescriptions, afio.SrcFilePos, ref numberDataPackets, afio.SrcBuffer);
if (res != 0) {
throw new ApplicationException (res.ToString ());
}
// advance input file packet position
afio.SrcFilePos += numberDataPackets;
// put the data pointer into the buffer list
data.SetData (0, afio.SrcBuffer, outNumBytes);
// don't forget the packet descriptions if required
if (dataPacketDescription != null) {
if (afio.PacketDescriptions != null) {
dataPacketDescription = afio.PacketDescriptions;
} else {
dataPacketDescription = null;
}
}
return AudioConverterError.None;
}