internal static ChannelGroupBlock Read(Mdf mdf, Stream stream, uint position)
{
stream.Position = position;
var block = new ChannelGroupBlock(mdf);
block.Read(stream);
block.stream = stream;
var data = new byte[block.Size - 4];
var read = stream.Read(data, 0, data.Length);
if (read != data.Length)
{
throw new FormatException();
}
block.next = null;
block.Channels = new ChannelCollection(mdf);
block.Comment = null;
block.SampleReductions = null;
block.ptrNextChannelGroup = BitConverter.ToUInt32(data, 0);
block.ptrFirstChannelBlock = BitConverter.ToUInt32(data, 4);
block.ptrTextBlock = BitConverter.ToUInt32(data, 8);
block.RecordID = BitConverter.ToUInt16(data, 12);
block.NumChannels = BitConverter.ToUInt16(data, 14);
block.RecordSize = BitConverter.ToUInt16(data, 16);
block.NumRecords = BitConverter.ToUInt32(data, 18);
if (data.Length >= 26)
{
block.ptrFirstSampleReductionBlock = BitConverter.ToUInt32(data, 22);
}
if (block.ptrTextBlock != 0)
{
stream.Position = block.ptrTextBlock;
block.Comment = TextBlock.Read(mdf, stream);
}
if (block.ptrFirstChannelBlock != 0)
{
block.Channels.Read(ChannelBlock.Read(mdf, stream, block.ptrFirstChannelBlock));
}
//if (m_ptrFirstSampleReductionBlock != 0)
//{
// mdf.Data.Position = m_ptrFirstSampleReductionBlock;
// SampleReductions = new SampleReductionCollection(mdf, new SampleReductionBlock(mdf));
//}
return(block);
}
public object GetValue(ChannelBlock channel)
{
if (ChannelGroup.Channels.Contains(channel) == false)
{
throw new ArgumentException("channel");
}
var byteOffset = channel.BitOffset / 8;
var value = (object)null;
// TODO: BigEndian byte order not supported yet.
switch (channel.SignalType)
{
case SignalType.UInt:
{
var result = 0u;
for (int i = 0; i < channel.NumberOfBits; i++)
{
result |= (uint)((GetBit(Data, channel.BitOffset + i) ? 1 : 0) << i);
}
value = result;
break;
}
case SignalType.Int:
{
var result = 0;
for (int i = 0; i < channel.NumberOfBits; i++)
{
result |= (GetBit(Data, channel.BitOffset + i) ? 1 : 0) << i;
}
var maxValue = Math.Pow(2, channel.NumberOfBits) / 2;
if (result > maxValue)
{
result -= (int)(maxValue * 2);
}
value = result;
break;
}
case SignalType.IEEE754Float:
if (channel.NumberOfBits == 32)
{
value = BitConverter.ToSingle(Data, byteOffset);
}
if (channel.NumberOfBits == 64)
{
value = (float)BitConverter.ToDouble(Data, byteOffset);
}
break;
case SignalType.IEEE754Double:
if (channel.NumberOfBits == 32)
{
value = (double)BitConverter.ToSingle(Data, byteOffset);
}
if (channel.NumberOfBits == 64)
{
value = BitConverter.ToDouble(Data, byteOffset);
}
break;
case SignalType.String:
value = ChannelGroup.Mdf.IDBlock.Encoding.GetString(Data, byteOffset, channel.NumberOfBits / 8);
break;
}
if (channel.ChannelConversion != null && value != null)
{
return(channel.ChannelConversion.AdditionalConversionData.GetPhyValue(Convert.ToDouble(value)));
}
return(value);
}
