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This commit is contained in:
Igor Pavlov
2005-05-30 00:00:00 +00:00
committed by Kornel Lesiński
parent 8c1b5c7b7e
commit 3c510ba80b
926 changed files with 40559 additions and 23519 deletions
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49
7zip/Compress/RangeCoder/RangeCoderBit.cpp
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@@ -7,12 +7,27 @@
namespace NCompress {
namespace NRangeCoder {
CPriceTables::CPriceTables()
UInt32 CPriceTables::ProbPrices[kBitModelTotal >> kNumMoveReducingBits];
static CPriceTables g_PriceTables;
CPriceTables::CPriceTables() { Init(); }
void CPriceTables::Init()
{
const int kNumBits = (kNumBitModelTotalBits - kNumMoveReducingBits);
for(int i = kNumBits - 1; i >= 0; i--)
{
UInt32 start = 1 << (kNumBits - i - 1);
UInt32 end = 1 << (kNumBits - i);
for (UInt32 j = start; j < end; j++)
ProbPrices[j] = (i << kNumBitPriceShiftBits) +
(((end - j) << kNumBitPriceShiftBits) >> (kNumBits - i - 1));
}
/*
// simplest: bad solution
for(UINT32 i = 1; i < (kBitModelTotal >> kNumMoveReducingBits) - 1; i++)
StatePrices[i] = kBitPrice;
for(UInt32 i = 1; i < (kBitModelTotal >> kNumMoveReducingBits) - 1; i++)
ProbPrices[i] = kBitPrice;
*/
/*
@@ -21,20 +36,20 @@ CPriceTables::CPriceTables()
// float solution
double ln2 = log(double(2));
double lnAll = log(double(kBitModelTotal >> kNumMoveReducingBits));
for(UINT32 i = 1; i < (kBitModelTotal >> kNumMoveReducingBits) - 1; i++)
StatePrices[i] = UINT32((fabs(lnAll - log(double(i))) / ln2 + kDummyMultMid) * kBitPrice);
for(UInt32 i = 1; i < (kBitModelTotal >> kNumMoveReducingBits) - 1; i++)
ProbPrices[i] = UInt32((fabs(lnAll - log(double(i))) / ln2 + kDummyMultMid) * kBitPrice);
*/
/*
// experimental, slow, solution:
for(UINT32 i = 1; i < (kBitModelTotal >> kNumMoveReducingBits) - 1; i++)
for(UInt32 i = 1; i < (kBitModelTotal >> kNumMoveReducingBits) - 1; i++)
{
const int kCyclesBits = 5;
const UINT32 kCycles = (1 << kCyclesBits);
const UInt32 kCycles = (1 << kCyclesBits);
UINT32 range = UINT32(-1);
UINT32 bitCount = 0;
for (UINT32 j = 0; j < kCycles; j++)
UInt32 range = UInt32(-1);
UInt32 bitCount = 0;
for (UInt32 j = 0; j < kCycles; j++)
{
range >>= (kNumBitModelTotalBits - kNumMoveReducingBits);
range *= i;
@@ -55,23 +70,11 @@ CPriceTables::CPriceTables()
range -= (1 << 31);
}
}
StatePrices[i] = (bitCount
ProbPrices[i] = (bitCount
// + (1 << (kCyclesBits - 1))
) >> kCyclesBits;
}
*/
const int kNumBits = (kNumBitModelTotalBits - kNumMoveReducingBits);
for(int i = kNumBits - 1; i >= 0; i--)
{
UINT32 start = 1 << (kNumBits - i - 1);
UINT32 end = 1 << (kNumBits - i);
for (UINT32 j = start; j < end; j++)
StatePrices[j] = (i << kNumBitPriceShiftBits) +
(((end - j) << kNumBitPriceShiftBits) >> (kNumBits - i - 1));
}
}
CPriceTables g_PriceTables;
}}