/// <summary>
/// Stops recording WAV audio from the underlying <see cref="IAudioStream"/> and finishes writing the WAV file.
/// </summary>
public void StopRecorder()
{
try
{
if (audioStream != null)
{
audioStream.OnBroadcast -= OnStreamBroadcast;
audioStream.OnActiveChanged -= StreamActiveChanged;
}
if (writer != null)
{
if (streamWriter.BaseStream.CanWrite)
{
//now that audio is finished recording, write a WAV/RIFF header at the beginning of the file
writer.Seek(0, SeekOrigin.Begin);
AudioFunctions.WriteWavHeader(writer, audioStream.ChannelCount, audioStream.SampleRate, audioStream.BitsPerSample, byteCount);
}
writer.Dispose(); //this should properly close/dispose the underlying stream as well
writer = null;
fileStream = null;
streamWriter = null;
}
audioStream = null;
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("Error during StopRecorder: {0}", ex);
throw;
}
}
void AudioStream_OnBroadcast(object sender, byte [] bytes)
{
var level = AudioFunctions.CalculateLevel(bytes);
if (level > SilenceThreshold) //did we find a signal?
{
audioDetected = true;
silenceTime = null;
}
else //no audio detected
{
//see if we've detected 'near' silence for more than <audioTimeout>
if (StopRecordingOnSilence && silenceTime.HasValue)
{
if (DateTime.Now.Subtract(silenceTime.Value) > AudioSilenceTimeout)
{
Timeout("AudioRecorderService.AudioStream_OnBroadcast (): AudioSilenceTimeout exceeded, stopping recording");
return;
}
}
else
{
silenceTime = DateTime.Now;
}
}
if (StopRecordingAfterTimeout && DateTime.Now - startTime > TotalAudioTimeout)
{
Timeout("AudioRecorderService.AudioStream_OnBroadcast(): TotalAudioTimeout exceeded, stopping recording");
}
}
/// <summary>
/// Stops recording WAV audio from the underlying <see cref="IAudioStream"/> and finishes writing the WAV file.
/// </summary>
public void StopRecorder()
{
try
{
if (audioStream != null)
{
audioStream.OnBroadcast -= OnStreamBroadcast;
audioStream.OnActiveChanged -= StreamActiveChanged;
}
using (var fileStream = new FileStream(audioFilePath, FileMode.Create, FileAccess.Write))
{
using (var fileWriter = new BinaryWriter(fileStream, Encoding.UTF8))
{
//now that audio is finished recording, write a WAV/RIFF header at the beginning of the file
AudioFunctions.WriteWavHeader(fileWriter, audioStream.ChannelCount, audioStream.SampleRate,
audioStream.BitsPerSample, byteCount);
memoryAudioStream.Seek(0, SeekOrigin.Begin);
memoryAudioStream.CopyTo(fileStream);
}
}
audioStream = null;
}
catch (Exception ex)
{
Debug.WriteLine("Error during StopRecorder: {0}", ex.Message);
throw;
}
}
unsafe void Graph_QuantumStarted(AudioGraph sender, object args)
{
// we'll only broadcast if we're actively monitoring audio packets
if (!Active)
{
return;
}
try
{
// get an audio frame from the output node
AudioFrame frame = outputNode.GetFrame();
if (frame.Duration?.Milliseconds == 0) // discard any empty frames
{
return;
}
using (var buffer = frame.LockBuffer(AudioBufferAccessMode.Read))
using (IMemoryBufferReference reference = buffer.CreateReference())
{
// Get the buffer from the AudioFrame
((IMemoryBufferByteAccess)reference).GetBuffer(out byte *dataInBytes, out uint capacityInBytes);
// convert the bytes into float
float *dataInFloat = (float *)dataInBytes;
if (audioBytes == null)
{
audioBytes = new byte [buffer.Length * broadcastSize / 2]; // buffer length * # of frames we want to accrue / 2 (because we're transforming float audio to Int 16)
}
for (int i = 0; i < capacityInBytes / sizeof(float); i++)
{
// convert the float into a double byte for 16 bit PCM
var shortVal = AudioFunctions.FloatToInt16(dataInFloat [i]);
byte [] chunkBytes = BitConverter.GetBytes(shortVal);
audioBytes [bufferPosition++] = chunkBytes [0];
audioBytes [bufferPosition++] = chunkBytes [1];
}
// we want to wait until we accrue <broadcastSize> # of frames and then broadcast them
// in practice, this will take us from 20ms chunks to 100ms chunks and result in more accurate audio level calculations
// we could maybe use the audiograph latency settings to achieve similar results but this seems to work well
if (bufferPosition == audioBytes.Length || !Active)
{
// broadcast the audio data to any listeners
OnBroadcast?.Invoke(this, audioBytes);
audioBytes = null;
bufferPosition = 0;
}
}
}
catch (Exception ex)
{
OnException?.Invoke(this, new Exception($"AudioStream.QueueInputCompleted() :: Error: {ex.Message}"));
}
}
void AudioStream_OnBroadcast(object sender, byte [] bytes)
{
var level = AudioFunctions.CalculateLevel(bytes);
AudioLevelUpdated?.Invoke(this, level);
if (level < NearZero && !audioDetected) // discard any initial 0s so we don't jump the gun on timing out
{
Debug.WriteLine("level == {0} && !audioDetected", level);
return;
}
if (level > SilenceThreshold) // did we find a signal?
{
audioDetected = true;
silenceTime = null;
Debug.WriteLine("AudioStream_OnBroadcast :: {0} :: level > SilenceThreshold :: bytes: {1}; level: {2}", DateTime.Now, bytes.Length, level);
}
else // no audio detected
{
// see if we've detected 'near' silence for more than <audioTimeout>
if (StopRecordingOnSilence && silenceTime.HasValue)
{
var currentTime = DateTime.Now;
if (currentTime.Subtract(silenceTime.Value).TotalMilliseconds > AudioSilenceTimeout.TotalMilliseconds)
{
Timeout($"AudioStream_OnBroadcast :: {currentTime} :: AudioSilenceTimeout exceeded, stopping recording :: Near-silence detected at: {silenceTime}");
return;
}
}
else
{
silenceTime = DateTime.Now;
Debug.WriteLine("AudioStream_OnBroadcast :: {0} :: Near-silence detected :: bytes: {1}; level: {2}", silenceTime, bytes.Length, level);
}
}
if (StopRecordingAfterTimeout && DateTime.Now - startTime > TotalAudioTimeout)
{
Timeout("AudioStream_OnBroadcast(): TotalAudioTimeout exceeded, stopping recording");
}
}
async void AudioStream_OnBroadcast(object sender, byte [] bytes)
{
var level = AudioFunctions.CalculateLevel(bytes);//, bigEndian: true);//, bigEndian: true, signed: false);
//var level = Decode(bytes).Select(Math.Abs).Average(x => x);
//double level = Math.Sqrt(sum / (bytes.Length / 2));
System.Diagnostics.Debug.WriteLine("AudioStream_OnBroadcast :: calculateLevel == {0}", level);
if (level > SilenceThreshold) //did we find a signal?
{
audioDetected = true;
silenceTime = null;
}
else //no audio detected
{
//see if we've detected 'near' silence for more than <audioTimeout>
if (StopRecordingOnSilence && silenceTime.HasValue)
{
if (DateTime.Now.Subtract(silenceTime.Value) > AudioSilenceTimeout)
{
System.Diagnostics.Debug.WriteLine("AudioRecorderService.AudioStream_OnBroadcast(): AudioSilenceTimeout exceeded, stopping recording");
await StopRecording();
return;
}
}
else
{
silenceTime = DateTime.Now;
}
}
if (StopRecordingAfterTimeout && DateTime.Now - startTime > TotalAudioTimeout)
{
System.Diagnostics.Debug.WriteLine("AudioRecorderService.AudioStream_OnBroadcast(): TotalAudioTimeout exceeded, stopping recording");
await StopRecording();
}
}
