/// <summary>
/// Respond to capture event.
/// This should return as fast as possible.
/// </summary>
public void HandleCapturedSamples(object sender, AudioDataEventArgs e)
{
if (e.Samples == null || e.Samples.Length <= 0)
{
return;
}
int sample_sec = 44100;
short[] result = null;
if (_channels == 1)
{
result = ResampleBuffer(e, sample_sec);
}
else
{
result = ResampleStereo(e, sample_sec);
}
TimedSample ts = new TimedSample(result, e.CaptureTime);
try {
if (ProcessorQueue != null)
{
foreach (var item in ProcessorQueue)
{
item.ProcessSample(ts);
}
}
} catch { }
lock (_sampleBuffer) {
_sampleBuffer.Add(ts);
}
}
/// <summary>
/// Join the first two samples together, making a large first sample.
/// Resulting sample retains first sample's timecode.
/// </summary>
private void MergeFirstSample()
{
lock (_sampleBuffer) {
if (_sampleBuffer.Count < 2)
{
return; // no samples to merge.
}
short[] übersample = _sampleBuffer[0].Samples.Concat(_sampleBuffer[1].Samples).ToArray();
TimedSample ts = new TimedSample(übersample, _sampleBuffer[0].Seconds);
_sampleBuffer.RemoveRange(0, 2);
_sampleBuffer.Insert(0, ts);
}
}
/// <summary>
/// Add unused samples back into the sample buffer.
/// </summary>
/// <remarks>Time stamps need to be properly re-integrated!</remarks>
private void PrependUnusedSamples(MediaFrame Frame)
{
// checks:
if (_sampleBuffer == null)
{
return;
}
_sampleBuffer.RemoveAll((a) => a == null); // clean out bad transfers
if (_sampleBuffer.Count < 1)
{
return;
}
if ((ulong)_sampleBuffer[0].Samples.LongLength != Frame.AudioSize)
{
throw new Exception("Frames unloaded out-of-sync. Frames must be loaded then unloaded in order and one-at-a-time!"); // wrong frame!
}
// Build new truncated sample:
ulong new_sample_count = Frame.AudioSize - Frame.AudioSamplesConsumed;
if (new_sample_count < 1)
{
_sampleBuffer.RemoveAt(0);
return;
}
short[] cut = new short[new_sample_count]; // pun intended ;-)
Array.Copy(_sampleBuffer[0].Samples, (long)Frame.AudioSamplesConsumed, cut, 0, (long)new_sample_count);
double new_time_stamp = Frame.AudioSampleTime + (Frame.AudioSamplesConsumed / 44100.0);
TimedSample sample = new TimedSample(cut, new_time_stamp);
lock (_sampleBuffer) {
// Over-write the old sample with the new, shorter version
_sampleBuffer[0] = sample;
// clean out bad transfers:
_sampleBuffer.Sort((a, b) => a.Seconds.CompareTo(b.Seconds));
}
// merge function to join first two samples if the first is small.
if (_sampleBuffer.Count >= 2)
{
if (_sampleBuffer[0].Samples.Length < 4608)
{
MergeFirstSample(); // 4 frames
}
}
}
/// <summary>
/// Load the buffer into a MediaFrame for the encoder.
/// IMPORTANT: You must call UnloadFrame after this method is called.
/// For effciency, unload as soon as possible.
/// </summary>
public void LoadToFrame(ref MediaFrame Frame)
{
try {
TimedSample ts = null;
lock (_sampleBuffer) {
if (_sampleBuffer.Count < 1)
{
Frame.AudioSize = 0UL;
Frame.AudioSamplesConsumed = 0;
return;
}
_sampleBuffer.RemoveAll(a => a == null);
_sampleBuffer.Sort((a, b) => a.Seconds.CompareTo(b.Seconds));
if (_sampleBuffer[0].Samples.Length < FrameSize)
{
MergeFirstSample(); // Make sure frames are large enough!
}
if (_sampleBuffer.Count > 0)
{
ts = _sampleBuffer[0];
}
else
{
Frame.AudioSize = 0;
Frame.AudioBuffer = IntPtr.Zero;
return;
}
}
_samples = ts.Samples;
Frame.AudioSampleTime = ts.Seconds;
Frame.AudioSize = (ulong)_samples.LongLength;
Frame.AudioSamplesConsumed = 0;
// Outgoing sample rate is always 44100, to support iPhone
Frame.AudioSampleRate = 44100; // this is used to correct timing on the encoder.
_pinSamples = GCHandle.Alloc(_samples, GCHandleType.Pinned);
Frame.AudioBuffer = _pinSamples.AddrOfPinnedObject();
} catch (Exception ex) {
UnloadFrame(ref Frame);
Console.WriteLine("Loading audio frame failed: " + ex.Message);
}
}
/// <summary>
/// Called by plug-in host (encoder)
/// </summary>
public void ProcessSample(TimedSample Sample)
{
float[] samps = ResampleForTone(Sample.Samples);
foreach (float s in samps) {
osc[osc_pos] *= decay; // fade old signal, to reduce response time
osc[osc_pos] += s * gain;
osc_pos = (osc_pos + 1) % osc.Length;
if (osc_pos == 0) {
// Prepare
BalanceOscillator();
FilterOscillator();
// Tone detection
DetectTone();
}
}
}
/// <summary>
/// Force a timed frame into the encoder's buffers.
/// May cause unexpected operation. Use with caution!
/// </summary>
public void ForceInsertFrame(TimedSample AudioFrame)
{
if (AudioBuffers != null) AudioBuffers.HandleCapturedSamples(this, new AudioDataEventArgs() { Samples = AudioFrame.Samples, CaptureTime = AudioFrame.Seconds });
else throw new Exception("Can't send audio frame to uninitialised buffer. Please include an audio device in your config.");
}
/// <summary>
/// Respond to capture event.
/// This should return as fast as possible.
/// </summary>
public void HandleCapturedSamples(object sender, AudioDataEventArgs e)
{
if (e.Samples == null || e.Samples.Length <= 0) return;
int sample_sec = 44100;
short[] result = null;
if (_channels == 1) result = ResampleBuffer(e, sample_sec);
else result = ResampleStereo(e, sample_sec);
TimedSample ts = new TimedSample(result, e.CaptureTime);
try {
if (ProcessorQueue != null) {
foreach (var item in ProcessorQueue) {
item.ProcessSample(ts);
}
}
} catch { }
lock (_sampleBuffer) {
_sampleBuffer.Add(ts);
}
}
/// <summary>
/// Add unused samples back into the sample buffer.
/// </summary>
/// <remarks>Time stamps need to be properly re-integrated!</remarks>
private void PrependUnusedSamples(MediaFrame Frame)
{
// checks:
if (_sampleBuffer == null) return;
_sampleBuffer.RemoveAll((a) => a == null); // clean out bad transfers
if (_sampleBuffer.Count < 1) return;
if ((ulong)_sampleBuffer[0].Samples.LongLength != Frame.AudioSize) throw new Exception("Frames unloaded out-of-sync. Frames must be loaded then unloaded in order and one-at-a-time!"); // wrong frame!
// Build new truncated sample:
ulong new_sample_count = Frame.AudioSize - Frame.AudioSamplesConsumed;
if (new_sample_count < 1) {
_sampleBuffer.RemoveAt(0);
return;
}
short[] cut = new short[new_sample_count]; // pun intended ;-)
Array.Copy(_sampleBuffer[0].Samples, (long)Frame.AudioSamplesConsumed, cut, 0, (long)new_sample_count);
double new_time_stamp = Frame.AudioSampleTime + (Frame.AudioSamplesConsumed / 44100.0);
TimedSample sample = new TimedSample(cut, new_time_stamp);
lock (_sampleBuffer) {
// Over-write the old sample with the new, shorter version
_sampleBuffer[0] = sample;
// clean out bad transfers:
_sampleBuffer.Sort((a, b) => a.Seconds.CompareTo(b.Seconds));
}
// merge function to join first two samples if the first is small.
if (_sampleBuffer.Count >= 2) {
if (_sampleBuffer[0].Samples.Length < 4608) MergeFirstSample(); // 4 frames
}
}
/// <summary>
/// Join the first two samples together, making a large first sample.
/// Resulting sample retains first sample's timecode.
/// </summary>
private void MergeFirstSample()
{
lock (_sampleBuffer) {
if (_sampleBuffer.Count < 2) return; // no samples to merge.
short[] übersample = _sampleBuffer[0].Samples.Concat(_sampleBuffer[1].Samples).ToArray();
TimedSample ts = new TimedSample(übersample, _sampleBuffer[0].Seconds);
_sampleBuffer.RemoveRange(0, 2);
_sampleBuffer.Insert(0, ts);
}
}
