private void PlayMetronome()
{
const int amp = 10000;
double twopi = 8*Math.Atan(1.0);
const double fr = 440.0;
double ph = 0.0;
int lastBpm = metronCurrentBpm;
Animation anim = new AlphaAnimation(0.5f, 1.0f);
anim.Duration = (60000/metronCurrentBpm)/2;
anim.StartOffset = 0;
anim.RepeatMode = RepeatMode.Reverse;
anim.RepeatCount = Animation.Infinite;
RunOnUiThread(() => { metronBpmText.StartAnimation(anim); });
metronAudioTrack = new AudioTrack(Android.Media.Stream.Music, 44100, ChannelOut.Mono,
Encoding.Pcm16bit, metronBuffSize, AudioTrackMode.Stream);
metronAudioTrack.Play();
while (reading)
{
Thread.Sleep(60000/metronCurrentBpm);
if (lastBpm != metronCurrentBpm)
{
// The BPM has changed - change the animation speed!
lastBpm = metronCurrentBpm;
anim.Duration = (60000/metronCurrentBpm)/2;
RunOnUiThread(() =>
{
metronBpmText.ClearAnimation();
metronBpmText.StartAnimation(anim);
});
}
for (int i = 0; i < metronAudioBuffer.Length; i++)
{
metronAudioBuffer[i] = (short) (amp*Math.Sin(ph));
ph += twopi*fr/44100;
}
metronAudioTrack.Write(metronAudioBuffer, 0, metronAudioBuffer.Length);
}
metronAudioTrack.Stop();
metronAudioTrack.Release();
RunOnUiThread(() => { metronBpmText.ClearAnimation(); });
}
private void TransferSend()
{
CurrentTransferDataLeft = CurrentTransfer.FileLength;
var at = new AudioTrack(Android.Media.Stream.Music,
44100,
ChannelConfiguration.Mono,
Android.Media.Encoding.Pcm16bit,
0x1000,
AudioTrackMode.Stream);
at.Play();
// Polarity calibration header
for (int i = 0; i < 200; i++)
{
WriteValue(at, BitConverter.GetBytes(-0x7fff), Bitlen);
WriteValue(at, BitConverter.GetBytes(0x7fff), Bitlen * 3);
}
// Lead-in
for (int i = 0; i < 20; i++)
PutByte(at, 0xff);
// Sync sequence
for (byte i = 0x08; i >= 0x04; i--)
PutByte(at, i);
// Data
byte[] buf = new byte[1];
while (CurrentTransferDataLeft > 0 && !AbortCurrentTransfer)
{
CurrentTransfer.GetData(buf);
PutByte(at, buf[0]);
CurrentTransferDataLeft--;
}
at.Stop();
at.Release();
at.Dispose();
CurrentTransfer.Close();
ParentConnection.RaiseFileTransferEnded(CurrentTransfer, true, AbortCurrentTransfer);
}
