void Preload()
{
while (true)
{
VocBlock block = new VocBlock();
try
{
block.Code = stream.ReadByte();
block.Length = 0;
}
catch (EndOfStreamException)
{
// Stream is allowed to end without a last block
break;
}
if (block.Code == 0 || block.Code > 9)
{
break;
}
block.Length = stream.ReadByte();
block.Length |= stream.ReadByte() << 8;
block.Length |= stream.ReadByte() << 16;
var skip = 0;
switch (block.Code)
{
// Sound data
case 1:
{
if (block.Length < 2)
{
throw new InvalidDataException("Invalid sound data block length in voc file");
}
var freqDiv = stream.ReadByte();
block.SampleBlock.Rate = GetSampleRateFromVocRate(freqDiv);
var codec = stream.ReadByte();
if (codec != 0)
{
throw new InvalidDataException("Unhandled codec used in voc file");
}
skip = block.Length - 2;
block.SampleBlock.Samples = skip;
block.SampleBlock.Offset = stream.Position;
// See if last block contained additional information
if (blocks.Count > 0)
{
var b = blocks.Last();
if (b.Code == 8)
{
block.SampleBlock.Rate = b.SampleBlock.Rate;
blocks.Remove(b);
}
}
SampleRate = Math.Max(SampleRate, block.SampleBlock.Rate);
break;
}
// Silence
case 3:
{
if (block.Length != 3)
{
throw new InvalidDataException("Invalid silence block length in voc file");
}
block.SampleBlock.Offset = 0;
block.SampleBlock.Samples = stream.ReadUInt16() + 1;
var freqDiv = stream.ReadByte();
block.SampleBlock.Rate = GetSampleRateFromVocRate(freqDiv);
break;
}
// Repeat start
case 6:
{
if (block.Length != 2)
{
throw new InvalidDataException("Invalid repeat start block length in voc file");
}
block.LoopBlock.Count = stream.ReadUInt16() + 1;
break;
}
// Repeat end
case 7:
break;
// Extra info
case 8:
{
if (block.Length != 4)
{
throw new InvalidDataException("Invalid info block length in voc file");
}
int freqDiv = stream.ReadUInt16();
if (freqDiv == 65536)
{
throw new InvalidDataException("Invalid frequency divisor 65536 in voc file");
}
var codec = stream.ReadByte();
if (codec != 0)
{
throw new InvalidDataException("Unhandled codec used in voc file");
}
var channels = stream.ReadByte() + 1;
if (channels != 1)
{
throw new InvalidDataException("Unhandled number of channels in voc file");
}
block.SampleBlock.Offset = 0;
block.SampleBlock.Samples = 0;
block.SampleBlock.Rate = (int)(256000000L / (65536L - freqDiv));
break;
}
// Sound data (New format)
case 9:
default:
throw new InvalidDataException("Unhandled code in voc file");
}
if (skip > 0)
{
stream.Seek(skip, SeekOrigin.Current);
}
blocks.Add(block);
}
// Check validity and calculated total number of samples
foreach (var b in blocks)
{
if (b.Code == 8)
{
throw new InvalidDataException("Unused block 8 in voc file");
}
if (b.Code != 1 && b.Code != 9)
{
continue;
}
if (b.SampleBlock.Rate != SampleRate)
{
throw new InvalidDataException("Voc file contains chunks with different sample rate");
}
totalSamples += b.SampleBlock.Samples;
}
Rewind();
}
void Preload()
{
while (true)
{
VocBlock block = new VocBlock();
try
{
block.Code = stream.ReadByte();
block.Length = 0;
}
catch (EndOfStreamException)
{
// Stream is allowed to end without a last block
break;
}
if (block.Code == 0 || block.Code > 9)
break;
block.Length = stream.ReadByte();
block.Length |= stream.ReadByte() << 8;
block.Length |= stream.ReadByte() << 16;
var skip = 0;
switch (block.Code)
{
// Sound data
case 1:
{
if (block.Length < 2)
throw new InvalidDataException("Invalid sound data block length in voc file");
var freqDiv = stream.ReadByte();
block.SampleBlock.Rate = GetSampleRateFromVocRate(freqDiv);
var codec = stream.ReadByte();
if (codec != 0)
throw new InvalidDataException("Unhandled codec used in voc file");
skip = block.Length - 2;
block.SampleBlock.Samples = skip;
block.SampleBlock.Offset = stream.Position;
// See if last block contained additional information
if (blocks.Count > 0)
{
var b = blocks.Last();
if (b.Code == 8)
{
block.SampleBlock.Rate = b.SampleBlock.Rate;
blocks.Remove(b);
}
}
SampleRate = Math.Max(SampleRate, block.SampleBlock.Rate);
break;
}
// Silence
case 3:
{
if (block.Length != 3)
throw new InvalidDataException("Invalid silence block length in voc file");
block.SampleBlock.Offset = 0;
block.SampleBlock.Samples = stream.ReadUInt16() + 1;
var freqDiv = stream.ReadByte();
block.SampleBlock.Rate = GetSampleRateFromVocRate(freqDiv);
break;
}
// Repeat start
case 6:
{
if (block.Length != 2)
throw new InvalidDataException("Invalid repeat start block length in voc file");
block.LoopBlock.Count = stream.ReadUInt16() + 1;
break;
}
// Repeat end
case 7:
break;
// Extra info
case 8:
{
if (block.Length != 4)
throw new InvalidDataException("Invalid info block length in voc file");
int freqDiv = stream.ReadUInt16();
if (freqDiv == 65536)
throw new InvalidDataException("Invalid frequency divisor 65536 in voc file");
var codec = stream.ReadByte();
if (codec != 0)
throw new InvalidDataException("Unhandled codec used in voc file");
var channels = stream.ReadByte() + 1;
if (channels != 1)
throw new InvalidDataException("Unhandled number of channels in voc file");
block.SampleBlock.Offset = 0;
block.SampleBlock.Samples = 0;
block.SampleBlock.Rate = (int)(256000000L / (65536L - freqDiv));
break;
}
// Sound data (New format)
case 9:
default:
throw new InvalidDataException("Unhandled code in voc file");
}
if (skip > 0)
stream.Seek(skip, SeekOrigin.Current);
blocks.Add(block);
}
// Check validity and calculated total number of samples
foreach (var b in blocks)
{
if (b.Code == 8)
throw new InvalidDataException("Unused block 8 in voc file");
if (b.Code != 1 && b.Code != 9)
continue;
if (b.SampleBlock.Rate != SampleRate)
throw new InvalidDataException("Voc file contains chunks with different sample rate");
totalSamples += b.SampleBlock.Samples;
}
Rewind();
}
