Ryujinx/Ryujinx.Graphics/VDec/BitStreamWriter.cs

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C#
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using System.IO;
namespace Ryujinx.Graphics.VDec
{
class BitStreamWriter
{
private const int BufferSize = 8;
private Stream _baseStream;
private int _buffer;
private int _bufferPos;
public BitStreamWriter(Stream baseStream)
{
_baseStream = baseStream;
}
public void WriteBit(bool value)
{
WriteBits(value ? 1 : 0, 1);
}
public void WriteBits(int value, int valueSize)
{
int valuePos = 0;
int remaining = valueSize;
while (remaining > 0)
{
int copySize = remaining;
int free = GetFreeBufferBits();
if (copySize > free)
{
copySize = free;
}
int mask = (1 << copySize) - 1;
int srcShift = (valueSize - valuePos) - copySize;
int dstShift = (BufferSize - _bufferPos) - copySize;
_buffer |= ((value >> srcShift) & mask) << dstShift;
valuePos += copySize;
_bufferPos += copySize;
remaining -= copySize;
}
}
private int GetFreeBufferBits()
{
if (_bufferPos == BufferSize)
{
Flush();
}
return BufferSize - _bufferPos;
}
public void Flush()
{
if (_bufferPos != 0)
{
_baseStream.WriteByte((byte)_buffer);
_buffer = 0;
_bufferPos = 0;
}
}
}
}