/// <summary>
/// Queues up a file to record to the next time the beat is played
/// </summary>
/// <param name="fileName">File name.</param>
public void QueueFileRecording(string fileName)
{
_file = ExtAudioFile.CreateWithUrl(
new Foundation.NSUrl(fileName, false),
AudioFileType.WAVE,
AudioStreamBasicDescription.CreateLinearPCM(),
AudioFileFlags.EraseFlags,
out ExtAudioFileError e
);
_fileRecordingQueued = true;
}
unsafe static void RenderAudio(CFUrl sourceUrl, CFUrl destinationUrl)
{
AudioStreamBasicDescription dataFormat;
AudioQueueBuffer * buffer = null;
long currentPacket = 0;
int packetsToRead = 0;
AudioStreamPacketDescription[] packetDescs = null;
bool flushed = false;
bool done = false;
int bufferSize;
using (var audioFile = AudioFile.Open(sourceUrl, AudioFilePermission.Read, (AudioFileType)0)) {
dataFormat = audioFile.StreamBasicDescription;
using (var queue = new OutputAudioQueue(dataFormat, CFRunLoop.Current, CFRunLoop.ModeCommon)) {
queue.BufferCompleted += (sender, e) => {
HandleOutput(audioFile, queue, buffer, ref packetsToRead, ref currentPacket, ref done, ref flushed, ref packetDescs);
};
// we need to calculate how many packets we read at a time and how big a buffer we need
// we base this on the size of the packets in the file and an approximate duration for each buffer
bool isVBR = dataFormat.BytesPerPacket == 0 || dataFormat.FramesPerPacket == 0;
// first check to see what the max size of a packet is - if it is bigger
// than our allocation default size, that needs to become larger
// adjust buffer size to represent about a second of audio based on this format
CalculateBytesForTime(dataFormat, audioFile.MaximumPacketSize, 1.0, out bufferSize, out packetsToRead);
if (isVBR)
{
packetDescs = new AudioStreamPacketDescription [packetsToRead];
}
else
{
packetDescs = null; // we don't provide packet descriptions for constant bit rate formats (like linear PCM)
}
if (audioFile.MagicCookie.Length != 0)
{
queue.MagicCookie = audioFile.MagicCookie;
}
// allocate the input read buffer
queue.AllocateBuffer(bufferSize, out buffer);
// prepare the capture format
var captureFormat = AudioStreamBasicDescription.CreateLinearPCM(dataFormat.SampleRate, (uint)dataFormat.ChannelsPerFrame, 32);
captureFormat.BytesPerFrame = captureFormat.BytesPerPacket = dataFormat.ChannelsPerFrame * 4;
queue.SetOfflineRenderFormat(captureFormat, audioFile.ChannelLayout);
// prepare the target format
var dstFormat = AudioStreamBasicDescription.CreateLinearPCM(dataFormat.SampleRate, (uint)dataFormat.ChannelsPerFrame);
using (var captureFile = ExtAudioFile.CreateWithUrl(destinationUrl, AudioFileType.CAF, dstFormat, AudioFileFlags.EraseFlags)) {
captureFile.ClientDataFormat = captureFormat;
int captureBufferSize = bufferSize / 2;
AudioBuffers captureABL = new AudioBuffers(1);
AudioQueueBuffer *captureBuffer;
queue.AllocateBuffer(captureBufferSize, out captureBuffer);
captureABL [0] = new AudioBuffer()
{
Data = captureBuffer->AudioData,
NumberChannels = captureFormat.ChannelsPerFrame
};
queue.Start();
double ts = 0;
queue.RenderOffline(ts, captureBuffer, 0);
HandleOutput(audioFile, queue, buffer, ref packetsToRead, ref currentPacket, ref done, ref flushed, ref packetDescs);
while (true)
{
int reqFrames = captureBufferSize / captureFormat.BytesPerFrame;
queue.RenderOffline(ts, captureBuffer, reqFrames);
captureABL.SetData(0, captureBuffer->AudioData, (int)captureBuffer->AudioDataByteSize);
var writeFrames = captureABL [0].DataByteSize / captureFormat.BytesPerFrame;
// Console.WriteLine ("ts: {0} AudioQueueOfflineRender: req {1} frames / {2} bytes, got {3} frames / {4} bytes",
// ts, reqFrames, captureBufferSize, writeFrames, captureABL.Buffers [0].DataByteSize);
captureFile.WriteAsync((uint)writeFrames, captureABL);
if (flushed)
{
break;
}
ts += writeFrames;
}
CFRunLoop.Current.RunInMode(CFRunLoop.ModeDefault, 1, false);
}
}
}
}
/// <summary>
/// Renders the given number of seconds to the given wav file
/// </summary>
/// <param name="fileName">File name.</param>
/// <param name="seconds">Seconds.</param>
public void RenderToFile(string fileName, double seconds)
{
long samples = (long)(seconds * Metronome.SampleRate);
var inputStream = MixerNode.GetAudioFormat(AudioUnitScopeType.Output);
var outputStream = AudioStreamBasicDescription.CreateLinearPCM(44100, 2);
AudioConverter converter = AudioConverter.Create(inputStream, outputStream);
var file = ExtAudioFile.CreateWithUrl(
new Foundation.NSUrl(fileName, false),
AudioFileType.WAVE,
outputStream,
AudioFileFlags.EraseFlags,
out ExtAudioFileError e
);
long samplesRead = 0;
// initialize the buffers
var buffers = new AudioBuffers(2);
buffers[0] = new AudioBuffer()
{
DataByteSize = BufferSize * 4,
NumberChannels = 1,
Data = Marshal.AllocHGlobal(sizeof(float) * BufferSize)
};
buffers[1] = new AudioBuffer()
{
DataByteSize = BufferSize * 4,
NumberChannels = 1,
Data = Marshal.AllocHGlobal(sizeof(float) * BufferSize)
};
var convBuffers = new AudioBuffers(1);
convBuffers[0] = new AudioBuffer()
{
DataByteSize = BufferSize * 4,
NumberChannels = 2,
Data = Marshal.AllocHGlobal(sizeof(float) * BufferSize)
};
while (samples > 0)
{
int numSamples = (int)(Math.Min(BufferSize, samples));
// get samples from the mixer
Render((uint)numSamples, buffers, samplesRead);
// conver to the file's format
converter.ConvertComplexBuffer(numSamples, buffers, convBuffers);
// write samples to the file
var error = file.Write((uint)numSamples, convBuffers);
if (error != ExtAudioFileError.OK)
{
throw new ApplicationException();
}
samples -= BufferSize;
samplesRead += numSamples;
}
buffers.Dispose();
convBuffers.Dispose();
converter.Dispose();
file.Dispose();
}