/// <summary>
/// Gets the time duration of a single video frame.
/// </summary>
/// <returns>The time duration of a single video frame, in seconds.</returns>
private float GetVideoFrameDuration()
{
return(0.0001f * UnityCompositorInterface.GetColorDuration() / 1000);
}
// This function is not/not always called on the main thread.
private void OnAudioFilterRead(float[] data, int channels)
{
if (!UnityCompositorInterface.IsRecording())
{
return;
}
//Create new stream
if (audioMemoryStream == null)
{
audioMemoryStream = new MemoryStream();
audioStreamWriter = new BinaryWriter(audioMemoryStream);
double audioSettingsTime = AudioSettings.dspTime; // Audio time in seconds, more accurate than Time.time
double captureFrameTime = UnityCompositorInterface.GetCaptureFrameIndex() * UnityCompositorInterface.GetColorDuration() / 10000000.0; // Capture Frame Time in seconds
DebugLog($"Obtained Audio Sample, AudioSettingsTime:{audioSettingsTime}, CaptureFrameTime:{captureFrameTime}");
audioStartTime = captureFrameTime;
numCachedAudioFrames = 0;
}
//Put data into stream
for (int i = 0; i < data.Length; i++)
{
// Rescale float to short range for encoding.
short audioEntry = (short)(data[i] * short.MaxValue);
audioStreamWriter.Write(audioEntry);
}
numCachedAudioFrames++;
//Send to compositor (buffer a few calls to reduce potential timing errors between packages)
if (numCachedAudioFrames >= MAX_NUM_CACHED_AUDIO_FRAMES)
{
audioStreamWriter.Flush();
byte[] outBytes = audioMemoryStream.ToArray();
audioMemoryStream = null;
// The Unity compositor assumes that the audioStartTime will be in capture frame sample time.
// Above we default to capture frame time compared to AudioSettings.dspTime.
// Any interpolation between these two time sources needs to be done in the editor before handing sample time values to the compositor.
UnityCompositorInterface.SetAudioData(outBytes, outBytes.Length, audioStartTime);
}
}
