public MThdChunkHeader(int format, int numTracks, int division)
{
if ((format < 0) || (format > 2))
{
throw new ArgumentOutOfRangeException("format", format, "Format must be 0, 1, or 2.");
}
if (numTracks < 1)
{
throw new ArgumentOutOfRangeException("numTracks", numTracks, "There must be at least 1 track.");
}
if (division < 1)
{
throw new ArgumentOutOfRangeException("division", division, "Division must be at least 1.");
}
this._header = new ChunkHeader(MThdID, 6L);
this._format = format;
this._numTracks = numTracks;
this._division = division;
}
/// <summary>Initialize the MThd chunk header.</summary>
/// <param name="format">
/// The format for the MIDI file (0, 1, or 2).
/// 0 - a single multi-channel track
/// 1 - one or more simultaneous tracks
/// 2 - one or more sequentially independent single-track patterns
/// </param>
/// <param name="numTracks">The number of tracks in the MIDI file.</param>
/// <param name="division">
/// The meaning of the delta-times in the file.
/// If the number is zero or positive, then bits 14 thru 0 represent the number of delta-time
/// ticks which make up a quarter-note. If number is negative, then bits 14 through 0 represent
/// subdivisions of a second, in a way consistent with SMPTE and MIDI time code.
/// </param>
public MThdChunkHeader(int format, int numTracks, int division)
{
// Verify the parameters
if (format < 0 || format > 2)
{
throw new ArgumentOutOfRangeException("format", format, "Format must be 0, 1, or 2.");
}
if (numTracks < 1)
{
throw new ArgumentOutOfRangeException("numTracks", numTracks, "There must be at least 1 track.");
}
if (division < 1)
{
throw new ArgumentOutOfRangeException("division", division, "Division must be at least 1.");
}
_header = new ChunkHeader(
MThdID, // 0x4d546864 = "MThd"
6); // 2 bytes for each of the format, num tracks, and division == 6
_format = format;
_numTracks = numTracks;
_division = division;
}
private static void ValidateHeader(ChunkHeader header)
{
byte[] mThdID = MThdID;
for (int i = 0; i < 4; i++)
{
if (header.ID[i] != mThdID[i])
{
throw new InvalidOperationException("Invalid MThd header.");
}
}
if (header.Length != 6L)
{
throw new InvalidOperationException("The length of the MThd header is incorrect.");
}
}
/// <summary>Validates that a header is correct as an MThd header.</summary>
/// <param name="header">The header to be validated.</param>
private static void ValidateHeader(ChunkHeader header)
{
byte [] validHeader = MTrkID;
for(int i=0; i<4; i++)
{
if (header.ID[i] != validHeader[i]) throw new InvalidOperationException("Invalid MThd header.");
}
if (header.Length <= 0) throw new InvalidOperationException("The length of the MThd header is incorrect.");
}
/// <summary>Initialize the MTrk chunk header.</summary>
/// <param name="data">The track data for which this is a header.</param>
public MTrkChunkHeader(byte [] data)
{
_header = new ChunkHeader(
MTrkID, // 0x4d54726b = "MTrk"
data != null ? data.Length : 0);
_data = data;
}
/// <summary>Initialize the MThd chunk header.</summary>
/// <param name="format">
/// The format for the MIDI file (0, 1, or 2).
/// 0 - a single multi-channel track
/// 1 - one or more simultaneous tracks
/// 2 - one or more sequentially independent single-track patterns
/// </param>
/// <param name="numTracks">The number of tracks in the MIDI file.</param>
/// <param name="division">
/// The meaning of the delta-times in the file.
/// If the number is zero or positive, then bits 14 thru 0 represent the number of delta-time
/// ticks which make up a quarter-note. If number is negative, then bits 14 through 0 represent
/// subdivisions of a second, in a way consistent with SMPTE and MIDI time code.
/// </param>
public MThdChunkHeader(int format, int numTracks, int division)
{
// Verify the parameters
if (format < 0 || format > 2) throw new ArgumentOutOfRangeException("format", format, "Format must be 0, 1, or 2.");
if (numTracks < 1) throw new ArgumentOutOfRangeException("numTracks", numTracks, "There must be at least 1 track.");
if (division < 1) throw new ArgumentOutOfRangeException("division", division, "Division must be at least 1.");
_header = new ChunkHeader(
MThdID, // 0x4d546864 = "MThd"
6); // 2 bytes for each of the format, num tracks, and division == 6
_format = format;
_numTracks = numTracks;
_division = division;
}
public MTrkChunkHeader(byte[] data)
{
this._header = new ChunkHeader(MTrkID, (data != null) ? ((long) data.Length) : ((long) 0));
this._data = data;
}
/// <summary>Read in an MThd chunk from the stream.</summary>
/// <param name="inputStream">The stream from which to read the MThd chunk.</param>
/// <returns>The MThd chunk read.</returns>
public static MThdChunkHeader Read(Stream inputStream)
{
// Validate input
if (inputStream == null)
{
throw new ArgumentNullException("inputStream");
}
if (!inputStream.CanRead)
{
throw new ArgumentException("Stream must be readable.", "inputStream");
}
// Read in a header from the stream and validate it
ChunkHeader header = ChunkHeader.Read(inputStream);
ValidateHeader(header);
// Read in the format
int format = 0;
for (int i = 0; i < 2; i++)
{
int val = inputStream.ReadByte();
if (val < 0)
{
throw new InvalidOperationException("The stream is invalid.");
}
format <<= 8;
format |= val;
}
// Read in the number of tracks
int numTracks = 0;
for (int i = 0; i < 2; i++)
{
int val = inputStream.ReadByte();
if (val < 0)
{
throw new InvalidOperationException("The stream is invalid.");
}
numTracks <<= 8;
numTracks |= val;
}
// Read in the division
int division = 0;
for (int i = 0; i < 2; i++)
{
int val = inputStream.ReadByte();
if (val < 0)
{
throw new InvalidOperationException("The stream is invalid.");
}
division <<= 8;
division |= val;
}
// Create a new MThd header and return it
return(new MThdChunkHeader(format, numTracks, division));
}
