aboutsummaryrefslogtreecommitdiff
path: root/src/liblzma/rangecoder/price_table_init.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/liblzma/rangecoder/price_table_init.c')
-rw-r--r--src/liblzma/rangecoder/price_table_init.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/src/liblzma/rangecoder/price_table_init.c b/src/liblzma/rangecoder/price_table_init.c
new file mode 100644
index 00000000..4714dfd6
--- /dev/null
+++ b/src/liblzma/rangecoder/price_table_init.c
@@ -0,0 +1,48 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file price_table_init.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.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifdef HAVE_CONFIG_H
+# include "range_encoder.h"
+#endif
+
+
+#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;
+}