mirror of
https://github.com/bsnes-emu/bsnes.git
synced 2025-04-02 10:42:14 -04:00
46a1eb8cce
This is an experimental release, as such it is posted only to Google Code.
Changelog:
- 21fx API moved to pre-finalized form as S-MSU1; more about this on the forum
- OpenGL driver now uses GL_CLAMP_TO_BORDER instead of GL_CLAMP_TO_EDGE to support screen curvature shader
- rewrote file open dialog; code is greatly simplified, interface is improved
- all cheat code columns are now enquoted, and empty codes at the bottom of the file are omitted (format is compatible with previous releases still)
- debugger: added missing DMA variables to S-CPU properties viewer
- snesfilter: added OpenMP (multi-threading) support to HQ2x filter
- lots of other miscellaneous code cleanup work
73 lines
1.9 KiB
C++
73 lines
1.9 KiB
C++
#ifndef __COMPRESSION_BITCODER_H
|
|
#define __COMPRESSION_BITCODER_H
|
|
|
|
#include "rngcoder.h"
|
|
|
|
namespace NCompression {
|
|
namespace NArithmetic {
|
|
|
|
const int kNumBitModelTotalBits = 11;
|
|
const UINT32 kBitModelTotal = (1 << kNumBitModelTotalBits);
|
|
|
|
const int kNumMoveReducingBits = 2;
|
|
|
|
/////////////////////////////
|
|
// CBitModel
|
|
|
|
template <int aNumMoveBits>
|
|
class CBitModel
|
|
{
|
|
public:
|
|
UINT32 m_Probability;
|
|
void UpdateModel(UINT32 aSymbol)
|
|
{
|
|
/*
|
|
m_Probability -= (m_Probability + ((aSymbol - 1) & ((1 << aNumMoveBits) - 1))) >> aNumMoveBits;
|
|
m_Probability += (1 - aSymbol) << (kNumBitModelTotalBits - aNumMoveBits);
|
|
*/
|
|
if (aSymbol == 0)
|
|
m_Probability += (kBitModelTotal - m_Probability) >> aNumMoveBits;
|
|
else
|
|
m_Probability -= (m_Probability) >> aNumMoveBits;
|
|
}
|
|
public:
|
|
void Init() { m_Probability = kBitModelTotal / 2; }
|
|
};
|
|
|
|
template <int aNumMoveBits>
|
|
class CBitDecoder: public CBitModel<aNumMoveBits>
|
|
{
|
|
public:
|
|
UINT32 Decode(CRangeDecoder *aRangeDecoder)
|
|
{
|
|
UINT32 aNewBound = (aRangeDecoder->m_Range >> kNumBitModelTotalBits) * CBitModel<aNumMoveBits>::m_Probability;
|
|
if (aRangeDecoder->m_Code < aNewBound)
|
|
{
|
|
aRangeDecoder->m_Range = aNewBound;
|
|
CBitModel<aNumMoveBits>::m_Probability += (kBitModelTotal - CBitModel<aNumMoveBits>::m_Probability) >> aNumMoveBits;
|
|
if (aRangeDecoder->m_Range < kTopValue)
|
|
{
|
|
aRangeDecoder->m_Code = (aRangeDecoder->m_Code << 8) | aRangeDecoder->m_Stream.ReadByte();
|
|
aRangeDecoder->m_Range <<= 8;
|
|
}
|
|
return 0;
|
|
}
|
|
else
|
|
{
|
|
aRangeDecoder->m_Range -= aNewBound;
|
|
aRangeDecoder->m_Code -= aNewBound;
|
|
CBitModel<aNumMoveBits>::m_Probability -= (CBitModel<aNumMoveBits>::m_Probability) >> aNumMoveBits;
|
|
if (aRangeDecoder->m_Range < kTopValue)
|
|
{
|
|
aRangeDecoder->m_Code = (aRangeDecoder->m_Code << 8) | aRangeDecoder->m_Stream.ReadByte();
|
|
aRangeDecoder->m_Range <<= 8;
|
|
}
|
|
return 1;
|
|
}
|
|
}
|
|
};
|
|
|
|
}}
|
|
|
|
|
|
#endif
|