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Diffstat (limited to '')
-rw-r--r-- | src/liblzma/rangecoder/range_encoder.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/src/liblzma/rangecoder/range_encoder.c b/src/liblzma/rangecoder/range_encoder.c new file mode 100644 index 00000000..f03bd873 --- /dev/null +++ b/src/liblzma/rangecoder/range_encoder.c @@ -0,0 +1,46 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file range_encoder.c +/// \brief Static initializations for the range encoder's prices array +// +// Copyright (C) 1999-2006 Igor Pavlov +// Copyright (C) 2007 Lasse Collin +// +// This library is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 2.1 of the License, or (at your option) any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Lesser General Public License for more details. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "range_encoder.h" + + +#define NUM_BITS (BIT_MODEL_TOTAL_BITS - MOVE_REDUCING_BITS) + + +uint32_t lzma_rc_prob_prices[BIT_MODEL_TOTAL >> MOVE_REDUCING_BITS]; + + +extern void +lzma_rc_init(void) +{ + // Initialize lzma_rc_prob_prices[]. + for (int i = NUM_BITS - 1; i >= 0; --i) { + const uint32_t start = 1 << (NUM_BITS - i - 1); + const uint32_t end = 1 << (NUM_BITS - i); + + for (uint32_t j = start; j < end; ++j) { + lzma_rc_prob_prices[j] = (i << BIT_PRICE_SHIFT_BITS) + + (((end - j) << BIT_PRICE_SHIFT_BITS) + >> (NUM_BITS - i - 1)); + } + } + + return; +} |