public StreamHeader(File file, long streamLength)
{
if (file == null)
{
throw new ArgumentNullException("file");
}
stream_length = streamLength;
version = 7;
header_data = 0;
frames = 0;
sample_rate = 0;
channels = 2;
framecount = 0;
file.Seek(0);
ByteVector magic = file.ReadBlock(4);
if (magic.StartsWith(FileIdentifierSv7))
{
ReadSv7Properties(magic + file.ReadBlock((int)SizeSV7 - 4));
}
else if (magic.StartsWith(FileIdentifierSv8))
{
ReadSv8Properties(file);
}
else
{
throw new CorruptFileException("Data does not begin with identifier.");
}
}
private void ReadSv8Properties(File file)
{
bool foundSH = false;
while (!foundSH)
{
ByteVector packetType = file.ReadBlock(2);
uint packetSizeLength = 0;
bool eof = false;
ulong packetSize = ReadSize(file, ref packetSizeLength, ref eof);
if (eof)
{
break;
}
ulong payloadSize = packetSize - 2 - packetSizeLength;
ByteVector data = file.ReadBlock((int)payloadSize);
if (packetType == "SH")
{
foundSH = true;
if (payloadSize <= 5)
{
break;
}
int pos = 4;
version = data[pos];
pos += 1;
frames = (uint)ReadSize(data, ref pos);
if (pos > (uint)payloadSize - 3)
{
break;
}
ulong beginSilence = ReadSize(data, ref pos);
if (pos > (uint)payloadSize - 2)
{
break;
}
ushort flags = data.Mid(pos, 1).ToUShort(true);
sample_rate = sftable[(flags >> 13) & 0x07];
channels = ((flags >> 4) & 0x0F) + 1;
framecount = frames - beginSilence;
}
else if (packetType == "SE")
{
break;
}
else
{
file.Seek((int)payloadSize, SeekOrigin.Current);
}
}
}
/// <summary>
/// Constructs and initializes a new instance of <see
/// cref="StreamHeader" /> for a specified header block and
/// stream length.
/// </summary>
/// <param name="data">
/// A <see cref="ByteVector" /> object containing the stream
/// header data.
/// </param>
/// <param name="streamLength">
/// A <see cref="long" /> value containing the length of the
/// MusePAck stream in bytes.
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="data" /> is <see langword="null" />.
/// </exception>
/// <exception cref="CorruptFileException">
/// <paramref name="data" /> does not begin with <see
/// cref="FileIdentifierSv7" /> or with <see
/// cref="FileIdentifierSv8" /> or is less than
/// <see cref="Size" /> bytes long.
/// </exception>
public StreamHeader(File file, long streamLength)
{
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
// Assign default values, to be able to call methods
// in the constructor
stream_length = streamLength;
version = 7;
header_data = 0;
frames = 0;
sample_rate = 0;
channels = 2;
framecount = 0;
file.Seek(0);
ByteVector magic = file.ReadBlock(4);
if (magic.StartsWith(FileIdentifierSv7))
{
// SV7 Format has a fixed Header size
ReadSv7Properties(magic + file.ReadBlock((int)SizeSV7 - 4));
}
else if (magic.StartsWith(FileIdentifierSv8))
{
// for SV8 the properties need to be read from
// packet information inside the file
ReadSv8Properties(file);
}
else
{
throw new CorruptFileException(
"Data does not begin with identifier.");
}
}
