/// <summary>
/// Creates a new instance with the specified tempo
/// </summary>
/// <param name="tempo">The tempo</param>
public MidiMessageMetaTempo(double tempo) : this(MidiUtility.TempoToMicroTempo(tempo))
{
}
/// <summary> /// Adjusts the tempo of a MIDI file /// </summary> /// <param name="tempo">The new tempo</param> /// <returns>A new file with an adjusted tempo. All other tempo messages are adjusted relatively to the first one</returns> public MidiFile AdjustTempo(double tempo) => AdjustTempo(MidiUtility.TempoToMicroTempo(tempo));
/// <summary>
/// Plays the sequence to the specified MIDI device using the specified timebase
/// </summary>
/// <param name="timeBase">The timebase to use, in pulses/ticks per quarter note</param>
/// <param name="deviceIndex">The MIDI device to output to</param>
/// <param name="loop">Indicates whether to loop playback or not</param>
public void Preview(short timeBase = 480, int deviceIndex = 0, bool loop = false)
{
var handle = MidiUtility.OpenOutputDevice(deviceIndex);
var ppq = timeBase;
var mt = MidiUtility.TempoToMicroTempo(120d);
try
{
while (loop)
{
var ticksusec = mt / (double)timeBase;
var tickspertick = ticksusec / (TimeSpan.TicksPerMillisecond / 1000) * 100;
var tickStart = MidiUtility.PreciseUtcNowTicks;
var tickCurrent = tickStart;
var end = (long)(Length * tickspertick + tickStart);
var tpm = TimeSpan.TicksPerMillisecond;
using (var e = AbsoluteEvents.GetEnumerator())
{
if (!e.MoveNext())
{
return;
}
var done = false;
while (!done && tickCurrent <= end)
{
tickCurrent = MidiUtility.PreciseUtcNowTicks;
var ce = (long)((tickCurrent - tickStart) / tickspertick);
while (!done && e.Current.Position <= ce)
{
if (0xFF == e.Current.Message.Status)
{
var mbs = e.Current.Message as MidiMessageMeta;
if (0x51 == mbs.Data1)
{
if (BitConverter.IsLittleEndian)
{
mt = (mbs.Data[0] << 16) | (mbs.Data[1] << 8) | mbs.Data[2];
}
else
{
mt = (mbs.Data[2] << 16) | (mbs.Data[1] << 8) | mbs.Data[0];
}
ticksusec = mt / (double)ppq;
tickspertick = ticksusec / (tpm / 1000) * 100;
end = (long)(Length * tickspertick + tickStart);
}
else if (0x2F == mbs.Data1)
{
done = true;
}
}
MidiUtility.Send(handle, e.Current.Message);
if (!e.MoveNext())
{
done = true;
}
}
}
}
}
}
finally
{
MidiUtility.CloseOutputDevice(handle);
}
}
