public TapeSection(TapDataBlock tapBlock)
{
// PILOT tone :
// - number of pulses : 8063 header (flag<128), 3223 data (flag>=128)
// - pulse length : 2168
// First SYNC pulse :
// - pulse length : 667
// Second SYNC pulse :
// - pulse length : 735
// DATA :
// - length of ZERO bit pulse : 855
// - length of ONE bit pulse : 1710
// The 'current pulse level' after playing the block is the opposite of the last pulse level played, so that a subsequent pulse will produce an edge.
if (tapBlock.Flag < 128)
{
_soundSequences.Add(new ToneSequence("Pilot tone", 8063, 2168));
}
else
{
_soundSequences.Add(new ToneSequence("Pilot tone", 3223, 2168));
}
// First and Second SYNC pulse
_soundSequences.Add(new PulsesSequence("Sync pulses", new ushort[] { 667, 735 }));
// DATA
_soundSequences.Add(new DataSequence("Data", tapBlock.TapeData, 855, 1710, 8));
ComputeDuration();
Label = GetSectionLabel(tapBlock) + " [" + Math.Round(Duration / 1000f) + " sec]";
}
public static TapFile ReadTapFile(Stream inputStream, string fileName)
{
TapFile resultFile = new TapFile(fileName);
using (BinaryReader fileReader = new BinaryReader(inputStream, Encoding.GetEncoding("ISO-8859-1")))
{
while (fileReader.PeekChar() >= 0)
{
TapDataBlock dataBlock = ReadTapDataBlock(fileReader);
resultFile.DataBlocks.Add(dataBlock);
TapeSection section = new TapeSection(dataBlock);
resultFile.Sections.Add(section);
}
}
TapeSection lastSection = resultFile.Sections[resultFile.Sections.Count - 1];
TapeSoundSequence lastSoundSequence = lastSection.SoundSequences[lastSection.SoundSequences.Count - 1];
if (lastSoundSequence.GetType() != typeof(PauseSequence))
{
lastSection.SoundSequences.Add(new PauseSequence("End of tape", 1));
}
foreach (TapeSection section in resultFile.Sections)
{
resultFile.Duration += section.Duration;
}
resultFile.Description = ""; // Tap file do not contain metadata
return(resultFile);
}
private static string GetSectionLabel(TapDataBlock dataBlock)
{
string sectionLabel = null;
switch (dataBlock.Type)
{
case TapDataBlockType.StandardHeader:
TapHeader header = (TapHeader)dataBlock;
switch (header.HeaderType)
{
case TapHeaderType.ProgramHeader:
ProgramHeader programHeader = (ProgramHeader)header;
sectionLabel = "Program header : " + programHeader.GetProperties();
break;
case TapHeaderType.ByteArrayHeader:
ByteArrayHeader byteArrayHeader = (ByteArrayHeader)header;
sectionLabel = "Byte array header : " + byteArrayHeader.GetProperties();
break;
case TapHeaderType.StringArrayHeader:
AlphanumArrayHeader stringArrayHeader = (AlphanumArrayHeader)header;
sectionLabel = "String array header : " + stringArrayHeader.GetProperties();
break;
case TapHeaderType.NumberArrayHeader:
AlphanumArrayHeader numberArrayHeader = (AlphanumArrayHeader)header;
sectionLabel = "Number array header : " + numberArrayHeader.GetProperties();
break;
}
break;
case TapDataBlockType.StandardDataBlock:
sectionLabel = "Standard data block : " + dataBlock.DataLength + " bytes";
break;
case TapDataBlockType.CustomDataBlock:
sectionLabel = "Custom data block : " + dataBlock.DataLength + " bytes";
break;
case TapDataBlockType.FragmentedDataBlock:
sectionLabel = "Fragmented data block : " + dataBlock.DataLength + " bytes";
break;
}
if (dataBlock.HasInvalidChecksum)
{
sectionLabel += " [invalid checksum]";
}
return(sectionLabel);
}
private static bool CheckIfChecksumIsValid(TapDataBlock tapDataBlock)
{
if (tapDataBlock.TapeData != null && tapDataBlock.TapeData.Length > 2)
{
byte computedChecksum = tapDataBlock.Flag;
for (int i = 1; i < (tapDataBlock.TapeData.Length - 1); i++)
{
computedChecksum ^= tapDataBlock.TapeData[i];
}
return(computedChecksum == tapDataBlock.CheckSum);
}
else
{
return(false);
}
}
private static string GetSectionLabel(TapDataBlock dataBlock)
{
string sectionLabel = null;
switch (dataBlock.Type)
{
case TapDataBlockType.StandardHeader:
TapHeader header = (TapHeader)dataBlock;
switch (header.HeaderType)
{
case TapHeaderType.ProgramHeader:
ProgramHeader programHeader = (ProgramHeader)header;
sectionLabel = "Program header : " + programHeader.GetProperties();
break;
case TapHeaderType.ByteArrayHeader:
ByteArrayHeader byteArrayHeader = (ByteArrayHeader)header;
sectionLabel = "Byte array header : " + byteArrayHeader.GetProperties();
break;
case TapHeaderType.StringArrayHeader:
AlphanumArrayHeader stringArrayHeader = (AlphanumArrayHeader)header;
sectionLabel = "String array header : " + stringArrayHeader.GetProperties();
break;
case TapHeaderType.NumberArrayHeader:
AlphanumArrayHeader numberArrayHeader = (AlphanumArrayHeader)header;
sectionLabel = "Number array header : " + numberArrayHeader.GetProperties();
break;
}
break;
case TapDataBlockType.StandardDataBlock:
sectionLabel = "Standard data block : " + dataBlock.DataLength + " bytes";
break;
case TapDataBlockType.CustomDataBlock:
sectionLabel = "Custom data block : " + dataBlock.DataLength + " bytes";
break;
case TapDataBlockType.FragmentedDataBlock:
sectionLabel = "Fragmented data block : " + dataBlock.DataLength + " bytes";
break;
}
if (dataBlock.HasInvalidChecksum)
{
sectionLabel += " [invalid checksum]";
}
return sectionLabel;
}
public TapeSection(TapDataBlock tapBlock)
{
// PILOT tone :
// - number of pulses : 8063 header (flag<128), 3223 data (flag>=128)
// - pulse length : 2168
// First SYNC pulse :
// - pulse length : 667
// Second SYNC pulse :
// - pulse length : 735
// DATA :
// - length of ZERO bit pulse : 855
// - length of ONE bit pulse : 1710
// The 'current pulse level' after playing the block is the opposite of the last pulse level played, so that a subsequent pulse will produce an edge.
if (tapBlock.Flag < 128)
{
_soundSequences.Add(new ToneSequence("Pilot tone", 8063, 2168));
}
else
{
_soundSequences.Add(new ToneSequence("Pilot tone", 3223, 2168));
}
// First and Second SYNC pulse
_soundSequences.Add(new PulsesSequence("Sync pulses", new ushort[] { 667, 735 }));
// DATA
_soundSequences.Add(new DataSequence("Data", tapBlock.TapeData, 855, 1710, 8));
ComputeDuration();
Label = GetSectionLabel(tapBlock) + " [" + Math.Round(Duration / 1000f) + " sec]";
}
internal static TapDataBlock ReadTapDataBlock(BinaryReader fileReader, int dataLengthBytesCount)
{
// Data block length
int dataLength = fileReader.ReadUInt16();
if (dataLengthBytesCount == 3)
{
dataLength += (fileReader.ReadByte() * 256 * 256);
}
// Read tape data block
byte[] tapeData = null;
if (dataLength > 0)
{
tapeData = fileReader.ReadBytes(dataLength);
}
TapDataBlock tapDataBlock = null;
if (dataLength > 0)
{
byte flag = tapeData[0];
// Standard header
if (flag == 0 && dataLength == 19)
{
using (BinaryReader headerReader = new BinaryReader(new MemoryStream(tapeData)))
{
headerReader.ReadByte(); // flag
byte dataType = headerReader.ReadByte();
TapHeaderType headerType = TapHeader.GetTapHeaderTypeFromDataType(dataType);
switch (headerType)
{
case TapHeaderType.ProgramHeader:
tapDataBlock = new ProgramHeader();
break;
case TapHeaderType.NumberArrayHeader:
case TapHeaderType.StringArrayHeader:
tapDataBlock = new AlphanumArrayHeader(dataType);
break;
default:
//case TapHeaderType.ByteArrayHeader:
tapDataBlock = new ByteArrayHeader();
break;
}
TapHeader tapHeader = (TapHeader)tapDataBlock;
tapHeader.FileName = Encoding.GetEncoding("ISO-8859-1").GetString(headerReader.ReadBytes(10));
tapHeader.FollowingDataLength = headerReader.ReadUInt16();
switch (headerType)
{
case TapHeaderType.ProgramHeader:
ReadProgramHeader(headerReader, (ProgramHeader)tapDataBlock);
break;
case TapHeaderType.NumberArrayHeader:
case TapHeaderType.StringArrayHeader:
ReadAlphanumArrayHeader(headerReader, (AlphanumArrayHeader)tapDataBlock);
break;
default:
//case TapHeaderType.ByteArrayHeader:
ReadByteArrayHeader(headerReader, (ByteArrayHeader)tapDataBlock);
break;
}
}
}
// Anonymous data block
else
{
tapDataBlock = new TapDataBlock();
tapDataBlock.Flag = flag;
}
tapDataBlock.DataLength = dataLength;
tapDataBlock.TapeData = tapeData;
if (dataLength >= 2)
{
tapDataBlock.CheckSum = tapeData[dataLength-1];
tapDataBlock.HasInvalidChecksum = !CheckIfChecksumIsValid(tapDataBlock);
}
}
return tapDataBlock;
}
private static bool CheckIfChecksumIsValid(TapDataBlock tapDataBlock)
{
if(tapDataBlock.TapeData != null && tapDataBlock.TapeData.Length > 2)
{
byte computedChecksum = tapDataBlock.Flag;
for (int i = 1; i < (tapDataBlock.TapeData.Length - 1); i++ )
{
computedChecksum ^= tapDataBlock.TapeData[i];
}
return computedChecksum == tapDataBlock.CheckSum;
}
else
{
return false;
}
}
internal static TapDataBlock ReadTapDataBlock(BinaryReader fileReader, int dataLengthBytesCount)
{
// Data block length
int dataLength = fileReader.ReadUInt16();
if (dataLengthBytesCount == 3)
{
dataLength += (fileReader.ReadByte() * 256 * 256);
}
// Read tape data block
byte[] tapeData = null;
if (dataLength > 0)
{
tapeData = fileReader.ReadBytes(dataLength);
}
TapDataBlock tapDataBlock = null;
if (dataLength > 0)
{
byte flag = tapeData[0];
// Standard header
if (flag == 0 && dataLength == 19)
{
using (BinaryReader headerReader = new BinaryReader(new MemoryStream(tapeData)))
{
headerReader.ReadByte(); // flag
byte dataType = headerReader.ReadByte();
TapHeaderType headerType = TapHeader.GetTapHeaderTypeFromDataType(dataType);
switch (headerType)
{
case TapHeaderType.ProgramHeader:
tapDataBlock = new ProgramHeader();
break;
case TapHeaderType.NumberArrayHeader:
case TapHeaderType.StringArrayHeader:
tapDataBlock = new AlphanumArrayHeader(dataType);
break;
default:
//case TapHeaderType.ByteArrayHeader:
tapDataBlock = new ByteArrayHeader();
break;
}
TapHeader tapHeader = (TapHeader)tapDataBlock;
tapHeader.FileName = Encoding.GetEncoding("ISO-8859-1").GetString(headerReader.ReadBytes(10));
tapHeader.FollowingDataLength = headerReader.ReadUInt16();
switch (headerType)
{
case TapHeaderType.ProgramHeader:
ReadProgramHeader(headerReader, (ProgramHeader)tapDataBlock);
break;
case TapHeaderType.NumberArrayHeader:
case TapHeaderType.StringArrayHeader:
ReadAlphanumArrayHeader(headerReader, (AlphanumArrayHeader)tapDataBlock);
break;
default:
//case TapHeaderType.ByteArrayHeader:
ReadByteArrayHeader(headerReader, (ByteArrayHeader)tapDataBlock);
break;
}
}
}
// Anonymous data block
else
{
tapDataBlock = new TapDataBlock();
tapDataBlock.Flag = flag;
}
tapDataBlock.DataLength = dataLength;
tapDataBlock.TapeData = tapeData;
if (dataLength >= 2)
{
tapDataBlock.CheckSum = tapeData[dataLength - 1];
tapDataBlock.HasInvalidChecksum = !CheckIfChecksumIsValid(tapDataBlock);
}
}
return(tapDataBlock);
}
