C++程序  |  49行  |  2.18 KB

/* Copyright (c) 2001-2008 Timothy B. Terriberry
   Copyright (c) 2008-2009 Xiph.Org Foundation */
/*
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   - Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

   - Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#if !defined(_mfrngcode_H)
# define _mfrngcode_H (1)
# include "entcode.h"

/*Constants used by the entropy encoder/decoder.*/

/*The number of bits to output at a time.*/
# define EC_SYM_BITS   (8)
/*The total number of bits in each of the state registers.*/
# define EC_CODE_BITS  (32)
/*The maximum symbol value.*/
# define EC_SYM_MAX    ((1U<<EC_SYM_BITS)-1)
/*Bits to shift by to move a symbol into the high-order position.*/
# define EC_CODE_SHIFT (EC_CODE_BITS-EC_SYM_BITS-1)
/*Carry bit of the high-order range symbol.*/
# define EC_CODE_TOP   (((opus_uint32)1U)<<(EC_CODE_BITS-1))
/*Low-order bit of the high-order range symbol.*/
# define EC_CODE_BOT   (EC_CODE_TOP>>EC_SYM_BITS)
/*The number of bits available for the last, partial symbol in the code field.*/
# define EC_CODE_EXTRA ((EC_CODE_BITS-2)%EC_SYM_BITS+1)
#endif