From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- .../src/7zip/Compress/RangeCoder/RangeCoderBit.cpp | 80 ++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 other-licenses/7zstub/src/7zip/Compress/RangeCoder/RangeCoderBit.cpp (limited to 'other-licenses/7zstub/src/7zip/Compress/RangeCoder/RangeCoderBit.cpp') diff --git a/other-licenses/7zstub/src/7zip/Compress/RangeCoder/RangeCoderBit.cpp b/other-licenses/7zstub/src/7zip/Compress/RangeCoder/RangeCoderBit.cpp new file mode 100644 index 000000000..8d273c8f9 --- /dev/null +++ b/other-licenses/7zstub/src/7zip/Compress/RangeCoder/RangeCoderBit.cpp @@ -0,0 +1,80 @@ +// Compress/RangeCoder/RangeCoderBit.cpp + +#include "StdAfx.h" + +#include "RangeCoderBit.h" + +namespace NCompress { +namespace NRangeCoder { + +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++) + ProbPrices[i] = kBitPrice; + */ + + /* + const double kDummyMultMid = (1.0 / kBitPrice) / 2; + const double kDummyMultMid = 0; + // float solution + double ln2 = log(double(2)); + double lnAll = log(double(kBitModelTotal >> kNumMoveReducingBits)); + 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++) + { + const int kCyclesBits = 5; + const UInt32 kCycles = (1 << kCyclesBits); + + UInt32 range = UInt32(-1); + UInt32 bitCount = 0; + for (UInt32 j = 0; j < kCycles; j++) + { + range >>= (kNumBitModelTotalBits - kNumMoveReducingBits); + range *= i; + while(range < (1 << 31)) + { + range <<= 1; + bitCount++; + } + } + bitCount <<= kNumBitPriceShiftBits; + range -= (1 << 31); + for (int k = kNumBitPriceShiftBits - 1; k >= 0; k--) + { + range <<= 1; + if (range > (1 << 31)) + { + bitCount += (1 << k); + range -= (1 << 31); + } + } + ProbPrices[i] = (bitCount + // + (1 << (kCyclesBits - 1)) + ) >> kCyclesBits; + } + */ +} + +}} -- cgit v1.2.3