1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/celt/entdec.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,100 @@
1.4 +/* Copyright (c) 2001-2011 Timothy B. Terriberry
1.5 + Copyright (c) 2008-2009 Xiph.Org Foundation */
1.6 +/*
1.7 + Redistribution and use in source and binary forms, with or without
1.8 + modification, are permitted provided that the following conditions
1.9 + are met:
1.10 +
1.11 + - Redistributions of source code must retain the above copyright
1.12 + notice, this list of conditions and the following disclaimer.
1.13 +
1.14 + - Redistributions in binary form must reproduce the above copyright
1.15 + notice, this list of conditions and the following disclaimer in the
1.16 + documentation and/or other materials provided with the distribution.
1.17 +
1.18 + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.19 + ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.20 + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.21 + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
1.22 + OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
1.23 + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
1.24 + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
1.25 + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
1.26 + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
1.27 + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
1.28 + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.29 +*/
1.30 +
1.31 +#if !defined(_entdec_H)
1.32 +# define _entdec_H (1)
1.33 +# include <limits.h>
1.34 +# include "entcode.h"
1.35 +
1.36 +/*Initializes the decoder.
1.37 + _buf: The input buffer to use.
1.38 + Return: 0 on success, or a negative value on error.*/
1.39 +void ec_dec_init(ec_dec *_this,unsigned char *_buf,opus_uint32 _storage);
1.40 +
1.41 +/*Calculates the cumulative frequency for the next symbol.
1.42 + This can then be fed into the probability model to determine what that
1.43 + symbol is, and the additional frequency information required to advance to
1.44 + the next symbol.
1.45 + This function cannot be called more than once without a corresponding call to
1.46 + ec_dec_update(), or decoding will not proceed correctly.
1.47 + _ft: The total frequency of the symbols in the alphabet the next symbol was
1.48 + encoded with.
1.49 + Return: A cumulative frequency representing the encoded symbol.
1.50 + If the cumulative frequency of all the symbols before the one that
1.51 + was encoded was fl, and the cumulative frequency of all the symbols
1.52 + up to and including the one encoded is fh, then the returned value
1.53 + will fall in the range [fl,fh).*/
1.54 +unsigned ec_decode(ec_dec *_this,unsigned _ft);
1.55 +
1.56 +/*Equivalent to ec_decode() with _ft==1<<_bits.*/
1.57 +unsigned ec_decode_bin(ec_dec *_this,unsigned _bits);
1.58 +
1.59 +/*Advance the decoder past the next symbol using the frequency information the
1.60 + symbol was encoded with.
1.61 + Exactly one call to ec_decode() must have been made so that all necessary
1.62 + intermediate calculations are performed.
1.63 + _fl: The cumulative frequency of all symbols that come before the symbol
1.64 + decoded.
1.65 + _fh: The cumulative frequency of all symbols up to and including the symbol
1.66 + decoded.
1.67 + Together with _fl, this defines the range [_fl,_fh) in which the value
1.68 + returned above must fall.
1.69 + _ft: The total frequency of the symbols in the alphabet the symbol decoded
1.70 + was encoded in.
1.71 + This must be the same as passed to the preceding call to ec_decode().*/
1.72 +void ec_dec_update(ec_dec *_this,unsigned _fl,unsigned _fh,unsigned _ft);
1.73 +
1.74 +/* Decode a bit that has a 1/(1<<_logp) probability of being a one */
1.75 +int ec_dec_bit_logp(ec_dec *_this,unsigned _logp);
1.76 +
1.77 +/*Decodes a symbol given an "inverse" CDF table.
1.78 + No call to ec_dec_update() is necessary after this call.
1.79 + _icdf: The "inverse" CDF, such that symbol s falls in the range
1.80 + [s>0?ft-_icdf[s-1]:0,ft-_icdf[s]), where ft=1<<_ftb.
1.81 + The values must be monotonically non-increasing, and the last value
1.82 + must be 0.
1.83 + _ftb: The number of bits of precision in the cumulative distribution.
1.84 + Return: The decoded symbol s.*/
1.85 +int ec_dec_icdf(ec_dec *_this,const unsigned char *_icdf,unsigned _ftb);
1.86 +
1.87 +/*Extracts a raw unsigned integer with a non-power-of-2 range from the stream.
1.88 + The bits must have been encoded with ec_enc_uint().
1.89 + No call to ec_dec_update() is necessary after this call.
1.90 + _ft: The number of integers that can be decoded (one more than the max).
1.91 + This must be at least one, and no more than 2**32-1.
1.92 + Return: The decoded bits.*/
1.93 +opus_uint32 ec_dec_uint(ec_dec *_this,opus_uint32 _ft);
1.94 +
1.95 +/*Extracts a sequence of raw bits from the stream.
1.96 + The bits must have been encoded with ec_enc_bits().
1.97 + No call to ec_dec_update() is necessary after this call.
1.98 + _ftb: The number of bits to extract.
1.99 + This must be between 0 and 25, inclusive.
1.100 + Return: The decoded bits.*/
1.101 +opus_uint32 ec_dec_bits(ec_dec *_this,unsigned _ftb);
1.102 +
1.103 +#endif
