/// <summary>
/// Packs the data from a tempo meta message into an integer.
/// </summary>
/// <param name="message">
/// The tempo meta message.
/// </param>
/// <returns>
/// Returns the tempo packed into an integer.
/// </returns>
/// <exception cref="ArgumentException">
/// Thrown if the message is not a tempo meta message.
/// </exception>
public static int PackTempo(MetaMessage message)
{
// Enforce preconditions.
if (message.Type != MetaType.Tempo)
{
throw new ArgumentException(
"Message is not a tempo meta message", "message");
}
int tempo = 0;
if (BitConverter.IsLittleEndian)
{
int d = message.data.Length - 1;
for (int i = 0; i < message.data.Length; i++)
{
tempo |= message.data[d] << (Shift * i);
d--;
}
}
else
{
for (int i = 0; i < message.data.Length; i++)
{
tempo |= message.data[i] << (Shift * i);
}
}
return(tempo);
}
/// <summary>
/// Visits meta messages.
/// </summary>
/// <param name="message">
/// The MetaMessage to visit.
/// </param>
void Multimedia.Midi.IMidiMessageVisitor.Visit(MetaMessage message)
{
// If the meta message is a tempo change message type.
if (message.Type == MetaType.Tempo)
{
// Change tempo.
Tempo = MetaMessage.PackTempo(message);
}
// Else if the meta message is an end of track message type.
else if (message.Type == MetaType.EndOfTrack)
{
// Stop playback.
Stop();
}
}
/// <summary>
/// Reads the data for the next track from the Midi file.
/// </summary>
/// <param name="trackNum">
/// The track number.
/// </param>
private void ReadNextTrack(int trackNum)
{
MetaType metaType = MetaType.TrackName;
int status = 0;
int runningStatus = 0;
// Read length of track.
binReader.ReadBytes(LengthByteCount);
// Continue reading Midi events until the end of the track.
while(metaType != MetaType.EndOfTrack)
{
// Next Midi message in track.
IMidiMessage msg = null;
// Ticks for next Midi event.
int ticks = ReadVariableLengthQuantity();
// Read status byte for the next Midi message.
status = binReader.ReadByte();
// If this is a status byte.
if((status & StatusFlag) == StatusFlag)
{
// If the next Midi message is a channel message.
if(ChannelMessage.IsChannelMessage(status))
{
// Read channel message from the Midi file.
msg = ReadChannelMessage(status);
// Update running status.
runningStatus = status;
}
// Else if the next Midi message is a meta message.
else if(MetaMessage.IsMetaMessage(status))
{
// Read the type of meta message.
metaType = (MetaType)binReader.ReadByte();
// Read the length of the meta message data.
int length = ReadVariableLengthQuantity();
// Read the meta message data.
byte[] data = binReader.ReadBytes(length);
// Create meta message.
msg = new MetaMessage(metaType, data);
}
// Else if the next Midi message is a system exclusive
// message.
else if(SysExMessage.IsSysExMessage(status))
{
// The type of system exclusive message.
SysExType type = (SysExType)status;
// Read the length of the system exclusive data.
int length = ReadVariableLengthQuantity();
// Read the system exclusive data.
byte[] data = binReader.ReadBytes(length);
// Create system exclusive message.
msg = new SysExMessage(type, data);
}
}
// Assumes running status.
else
{
// Create channel message.
msg = ReadChannelMessage(runningStatus, status);
}
// Create the next Midi event and store it in the specified
// track.
MidiEvent e = new MidiEvent(msg, ticks);
tracks[trackNum].Add(e);
}
}
/// <summary>
/// Initializes a new instance of the MetaMessage class with
/// another instance of the MetaMessage class.
/// </summary>
/// <param name="message">
/// The MetaMessage instance to use for initialization.
/// </param>
public MetaMessage(MetaMessage message)
{
type = message.type;
data = new byte[message.data.Length];
message.data.CopyTo(data, 0);
}
/// <summary>
/// Reads the data for the next track from the Midi file.
/// </summary>
/// <param name="trackNum">
/// The track number.
/// </param>
private void ReadNextTrack(int trackNum)
{
MetaType metaType = MetaType.TrackName;
int status = 0;
int runningStatus = 0;
// Read length of track.
binReader.ReadBytes(LengthByteCount);
// Continue reading Midi events until the end of the track.
while (metaType != MetaType.EndOfTrack)
{
// Next Midi message in track.
IMidiMessage msg = null;
// Ticks for next Midi event.
int ticks = ReadVariableLengthQuantity();
// Read status byte for the next Midi message.
status = binReader.ReadByte();
// If this is a status byte.
if ((status & StatusFlag) == StatusFlag)
{
// If the next Midi message is a channel message.
if (ChannelMessage.IsChannelMessage(status))
{
// Read channel message from the Midi file.
msg = ReadChannelMessage(status);
// Update running status.
runningStatus = status;
}
// Else if the next Midi message is a meta message.
else if (MetaMessage.IsMetaMessage(status))
{
// Read the type of meta message.
metaType = (MetaType)binReader.ReadByte();
// Read the length of the meta message data.
int length = ReadVariableLengthQuantity();
// Read the meta message data.
byte[] data = binReader.ReadBytes(length);
// Create meta message.
msg = new MetaMessage(metaType, data);
}
// Else if the next Midi message is a system exclusive
// message.
else if (SysExMessage.IsSysExMessage(status))
{
// The type of system exclusive message.
SysExType type = (SysExType)status;
// Read the length of the system exclusive data.
int length = ReadVariableLengthQuantity();
// Read the system exclusive data.
byte[] data = binReader.ReadBytes(length);
// Create system exclusive message.
msg = new SysExMessage(type, data);
}
}
// Assumes running status.
else
{
// Create channel message.
msg = ReadChannelMessage(runningStatus, status);
}
// Create the next Midi event and store it in the specified
// track.
MidiEvent e = new MidiEvent(msg, ticks);
tracks[trackNum].Add(e);
}
}
/// <summary>
/// Packs the data from a tempo meta message into an integer.
/// </summary>
/// <param name="message">
/// The tempo meta message.
/// </param>
/// <returns>
/// Returns the tempo packed into an integer.
/// </returns>
/// <exception cref="ArgumentException">
/// Thrown if the message is not a tempo meta message.
/// </exception>
public static int PackTempo(MetaMessage message)
{
// Enforce preconditions.
if(message.Type != MetaType.Tempo)
throw new ArgumentException(
"Message is not a tempo meta message", "message");
int tempo = 0;
if(BitConverter.IsLittleEndian)
{
int d = message.data.Length - 1;
for(int i = 0; i < message.data.Length; i++)
{
tempo |= message.data[d] << (Shift * i);
d--;
}
}
else
{
for(int i = 0; i < message.data.Length; i++)
{
tempo |= message.data[i] << (Shift * i);
}
}
return tempo;
}
/// <summary>
/// Initializes a new instance of the MetaMessage class with
/// another instance of the MetaMessage class.
/// </summary>
/// <param name="message">
/// The MetaMessage instance to use for initialization.
/// </param>
public MetaMessage(MetaMessage message)
{
type = message.type;
data = new byte[message.data.Length];
message.data.CopyTo(data, 0);
}
/// <summary>
/// Visits meta messages.
/// </summary>
/// <param name="message">
/// The MetaMessage to visit.
/// </param>
void Multimedia.Midi.IMidiMessageVisitor.Visit(MetaMessage message)
{
// If the meta message is a tempo change message type.
if(message.Type == MetaType.Tempo)
{
// Change tempo.
Tempo = MetaMessage.PackTempo(message);
}
// Else if the meta message is an end of track message type.
else if(message.Type == MetaType.EndOfTrack)
{
// Stop playback.
Stop();
}
}
