static void UnpackV2(byte[] input, byte[] output)
{
output[output.Length - 1] = input[36];
using (var mem = new MemoryStream(input, 38, input.Length - 38))
using (var bits = new ReverseBitStream(mem))
{
for (int dst = 0; dst < output.Length; dst += 2)
{
if (0 != bits.GetNextBit())
{
output[dst + 1] = (byte)bits.GetBits(8);
output[dst] = (byte)bits.GetBits(8);
}
else
{
int j;
for (j = 0; j < 30; j += 2)
{
if (0 != bits.GetNextBit())
{
break;
}
}
output[dst] = input[4 + j];
output[dst + 1] = input[5 + j];
}
}
}
}
static void UnpackV3(byte[] input, byte[] output)
{
int src = 4;
int dst = 0;
if (output.Length <= 128)
{
Buffer.BlockCopy(input, src, output, dst, output.Length);
return;
}
Buffer.BlockCopy(input, src, output, dst, 128);
src += 128;
dst += 128;
using (var mem = new MemoryStream(input, src, input.Length - src))
using (var bits = new ReverseBitStream(mem))
{
while (dst < output.Length)
{
if (0 != bits.GetNextBit())
{
int offset = bits.GetBits(7) + 1;
int count = bits.GetBits(4) + 2;
Binary.CopyOverlapped(output, dst - offset, dst, count);
dst += count;
}
else
{
output[dst++] = (byte)bits.GetBits(8);
}
}
}
}
static void UnpackV1(byte[] input, byte[] output)
{
int dst = 0;
using (var mem = new MemoryStream(input, 4, input.Length - 4))
using (var bits = new ReverseBitStream(mem))
{
while (dst < output.Length)
{
int count = bits.GetBits(4);
if (0 != bits.GetNextBit())
{
for (int i = 0; i <= count; ++i)
{
output[dst++] = (byte)bits.GetBits(8);
}
}
else
{
byte b = (byte)bits.GetBits(8);
for (int i = 0; i < count; ++i)
{
output[dst++] = b;
}
}
}
}
}