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Unified Diff: xz/src/liblzma/rangecoder/price.h

Issue 2869016: Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/deps/third_party/
Patch Set: Created 10 years, 6 months ago
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Index: xz/src/liblzma/rangecoder/price.h
===================================================================
--- xz/src/liblzma/rangecoder/price.h (revision 0)
+++ xz/src/liblzma/rangecoder/price.h (revision 0)
@@ -0,0 +1,92 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file price.h
+/// \brief Probability price calculation
+//
+// Author: Igor Pavlov
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_PRICE_H
+#define LZMA_PRICE_H
+
+
+#define RC_MOVE_REDUCING_BITS 4
+#define RC_BIT_PRICE_SHIFT_BITS 4
+#define RC_PRICE_TABLE_SIZE (RC_BIT_MODEL_TOTAL >> RC_MOVE_REDUCING_BITS)
+
+#define RC_INFINITY_PRICE (UINT32_C(1) << 30)
+
+
+/// Lookup table for the inline functions defined in this file.
+extern const uint8_t lzma_rc_prices[RC_PRICE_TABLE_SIZE];
+
+
+static inline uint32_t
+rc_bit_price(const probability prob, const uint32_t bit)
+{
+ return lzma_rc_prices[(prob ^ ((UINT32_C(0) - bit)
+ & (RC_BIT_MODEL_TOTAL - 1))) >> RC_MOVE_REDUCING_BITS];
+}
+
+
+static inline uint32_t
+rc_bit_0_price(const probability prob)
+{
+ return lzma_rc_prices[prob >> RC_MOVE_REDUCING_BITS];
+}
+
+
+static inline uint32_t
+rc_bit_1_price(const probability prob)
+{
+ return lzma_rc_prices[(prob ^ (RC_BIT_MODEL_TOTAL - 1))
+ >> RC_MOVE_REDUCING_BITS];
+}
+
+
+static inline uint32_t
+rc_bittree_price(const probability *const probs,
+ const uint32_t bit_levels, uint32_t symbol)
+{
+ uint32_t price = 0;
+ symbol += UINT32_C(1) << bit_levels;
+
+ do {
+ const uint32_t bit = symbol & 1;
+ symbol >>= 1;
+ price += rc_bit_price(probs[symbol], bit);
+ } while (symbol != 1);
+
+ return price;
+}
+
+
+static inline uint32_t
+rc_bittree_reverse_price(const probability *const probs,
+ uint32_t bit_levels, uint32_t symbol)
+{
+ uint32_t price = 0;
+ uint32_t model_index = 1;
+
+ do {
+ const uint32_t bit = symbol & 1;
+ symbol >>= 1;
+ price += rc_bit_price(probs[model_index], bit);
+ model_index = (model_index << 1) + bit;
+ } while (--bit_levels != 0);
+
+ return price;
+}
+
+
+static inline uint32_t
+rc_direct_price(const uint32_t bits)
+{
+ return bits << RC_BIT_PRICE_SHIFT_BITS;
+}
+
+#endif
Property changes on: xz/src/liblzma/rangecoder/price.h
___________________________________________________________________
Added: svn:eol-style
+ LF
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