| 0,0 → 1,191 |
|---|
| #include "RangeCoderBitTree.h" |
| #include "lzma.h" |
| |
| static unsigned _cacheSize; |
| static byte _cache; |
| static uint64 low; |
| static unsigned range; |
| |
| static unsigned PriceTable[kBitModelTotal >> kNumMoveReducingBits]; |
| |
| void RangeEncoder_Init(void) |
| { |
| int i; |
| unsigned start,end,j; |
| low = 0; |
| range = 0xFFFFFFFF; |
| _cacheSize = 1; |
| _cache = 0; |
| /* init price table */ |
| #define kNumBits (kNumBitModelTotalBits - kNumMoveReducingBits) |
| for (i=kNumBits;i--;) |
| { |
| start = 1 << (kNumBits - i - 1); |
| end = 1 << (kNumBits - i); |
| for (j=start;j<end;j++) |
| PriceTable[j] = (i<<kNumBitPriceShiftBits) + |
| (((end-j)<<kNumBitPriceShiftBits) >> (kNumBits - i - 1)); |
| } |
| #undef kNumBits |
| } |
| |
| void RangeEncoder_ShiftLow(void) |
| { |
| if ((unsigned)low < 0xFF000000U || (int)(low>>32)) |
| { |
| byte temp = _cache; |
| do |
| { |
| *curout++ = (byte)(temp + (byte)(low>>32)); |
| temp = 0xFF; |
| } while (--_cacheSize); |
| _cache = (byte)((unsigned)low>>24); |
| } |
| _cacheSize++; |
| low = (unsigned)low << 8; |
| } |
| |
| void RangeEncoder_FlushData(void) |
| { |
| int i; |
| for (i=0;i<5;i++) |
| RangeEncoder_ShiftLow(); |
| } |
| |
| void RangeEncoder_EncodeDirectBits(unsigned value,int numTotalBits) |
| { |
| int i; |
| for (i=numTotalBits;i--;) |
| { |
| range >>= 1; |
| if (((value >> i) & 1) == 1) |
| low += range; |
| if (range < kTopValue) |
| { |
| range <<= 8; |
| RangeEncoder_ShiftLow(); |
| } |
| } |
| } |
| |
| void CMyBitEncoder_Encode(CMyBitEncoder* e,unsigned symbol) |
| { |
| unsigned newBound; |
| newBound = (range >> kNumBitModelTotalBits) * *e; |
| if (symbol == 0) |
| { |
| range = newBound; |
| *e += (kBitModelTotal - *e) >> kNumMoveBits; |
| } |
| else |
| { |
| low += newBound; |
| range -= newBound; |
| *e -= *e >> kNumMoveBits; |
| } |
| if (range < kTopValue) |
| { |
| range <<= 8; |
| RangeEncoder_ShiftLow(); |
| } |
| } |
| |
| unsigned CMyBitEncoder_GetPrice(CMyBitEncoder* e, unsigned symbol) |
| { |
| return PriceTable[(((*e-symbol)^((-(int)symbol))) & (kBitModelTotal-1)) >> kNumMoveReducingBits]; |
| } |
| unsigned CMyBitEncoder_GetPrice0(CMyBitEncoder* e) |
| { |
| return PriceTable[*e >> kNumMoveReducingBits]; |
| } |
| unsigned CMyBitEncoder_GetPrice1(CMyBitEncoder* e) |
| { |
| return PriceTable[(kBitModelTotal - *e) >> kNumMoveReducingBits]; |
| } |
| |
| void CBitTreeEncoder_Init(NRangeCoder_CBitTreeEncoder*e,int numBitLevels) |
| { |
| unsigned i; |
| e->numBitLevels = numBitLevels; |
| for (i=1;i<((unsigned)1<<numBitLevels);i++) |
| CMyBitEncoder_Init(e->Models[i]); |
| } |
| void CBitTreeEncoder_Encode(NRangeCoder_CBitTreeEncoder*e,unsigned symbol) |
| { |
| unsigned modelIndex = 1; |
| int bitIndex; |
| unsigned bit; |
| for (bitIndex = e->numBitLevels; bitIndex--;) |
| { |
| bit = (symbol >> bitIndex) & 1; |
| CMyBitEncoder_Encode(&e->Models[modelIndex],bit); |
| modelIndex = (modelIndex << 1) | bit; |
| } |
| } |
| void CBitTreeEncoder_ReverseEncode(NRangeCoder_CBitTreeEncoder*e,unsigned symbol) |
| { |
| unsigned modelIndex = 1; |
| int i; |
| unsigned bit; |
| for (i=0;i<e->numBitLevels;i++) |
| { |
| bit = symbol & 1; |
| CMyBitEncoder_Encode(&e->Models[modelIndex],bit); |
| modelIndex = (modelIndex << 1) | bit; |
| symbol >>= 1; |
| } |
| } |
| unsigned CBitTreeEncoder_GetPrice(NRangeCoder_CBitTreeEncoder*e,unsigned symbol) |
| { |
| unsigned price = 0; |
| symbol |= (1 << e->numBitLevels); |
| while (symbol != 1) |
| { |
| price += CMyBitEncoder_GetPrice(&e->Models[symbol>>1],symbol&1); |
| symbol >>= 1; |
| } |
| return price; |
| } |
| unsigned CBitTreeEncoder_ReverseGetPrice(NRangeCoder_CBitTreeEncoder*e,unsigned symbol) |
| { |
| unsigned price=0; |
| unsigned modelIndex=1; |
| int i; |
| unsigned bit; |
| for (i=e->numBitLevels;i;i--) |
| { |
| bit = symbol&1; |
| symbol >>= 1; |
| price += CMyBitEncoder_GetPrice(&e->Models[modelIndex],bit); |
| modelIndex = (modelIndex<<1)|bit; |
| } |
| return price; |
| } |
| unsigned ReverseBitTreeGetPrice(CMyBitEncoder*Models,unsigned NumBitLevels,unsigned symbol) |
| { |
| unsigned price=0; |
| unsigned modelIndex=1; |
| unsigned bit; |
| int i; |
| for (i=NumBitLevels;i;i--) |
| { |
| bit = symbol & 1; |
| symbol >>= 1; |
| price += CMyBitEncoder_GetPrice(Models+modelIndex,bit); |
| modelIndex = (modelIndex<<1)|bit; |
| } |
| return price; |
| } |
| void ReverseBitTreeEncode(CMyBitEncoder*Models,int NumBitLevels,unsigned symbol) |
| { |
| unsigned modelIndex = 1; |
| int i; |
| unsigned bit; |
| for (i=0;i<NumBitLevels;i++) |
| { |
| bit = symbol & 1; |
| CMyBitEncoder_Encode(Models+modelIndex,bit); |
| modelIndex = (modelIndex<<1)|bit; |
| symbol >>= 1; |
| } |
| } |