1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/celt/entcode.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,117 @@
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 +#include "opus_types.h"
1.32 +#include "opus_defines.h"
1.33 +
1.34 +#if !defined(_entcode_H)
1.35 +# define _entcode_H (1)
1.36 +# include <limits.h>
1.37 +# include <stddef.h>
1.38 +# include "ecintrin.h"
1.39 +
1.40 +/*OPT: ec_window must be at least 32 bits, but if you have fast arithmetic on a
1.41 + larger type, you can speed up the decoder by using it here.*/
1.42 +typedef opus_uint32 ec_window;
1.43 +typedef struct ec_ctx ec_ctx;
1.44 +typedef struct ec_ctx ec_enc;
1.45 +typedef struct ec_ctx ec_dec;
1.46 +
1.47 +# define EC_WINDOW_SIZE ((int)sizeof(ec_window)*CHAR_BIT)
1.48 +
1.49 +/*The number of bits to use for the range-coded part of unsigned integers.*/
1.50 +# define EC_UINT_BITS (8)
1.51 +
1.52 +/*The resolution of fractional-precision bit usage measurements, i.e.,
1.53 + 3 => 1/8th bits.*/
1.54 +# define BITRES 3
1.55 +
1.56 +/*The entropy encoder/decoder context.
1.57 + We use the same structure for both, so that common functions like ec_tell()
1.58 + can be used on either one.*/
1.59 +struct ec_ctx{
1.60 + /*Buffered input/output.*/
1.61 + unsigned char *buf;
1.62 + /*The size of the buffer.*/
1.63 + opus_uint32 storage;
1.64 + /*The offset at which the last byte containing raw bits was read/written.*/
1.65 + opus_uint32 end_offs;
1.66 + /*Bits that will be read from/written at the end.*/
1.67 + ec_window end_window;
1.68 + /*Number of valid bits in end_window.*/
1.69 + int nend_bits;
1.70 + /*The total number of whole bits read/written.
1.71 + This does not include partial bits currently in the range coder.*/
1.72 + int nbits_total;
1.73 + /*The offset at which the next range coder byte will be read/written.*/
1.74 + opus_uint32 offs;
1.75 + /*The number of values in the current range.*/
1.76 + opus_uint32 rng;
1.77 + /*In the decoder: the difference between the top of the current range and
1.78 + the input value, minus one.
1.79 + In the encoder: the low end of the current range.*/
1.80 + opus_uint32 val;
1.81 + /*In the decoder: the saved normalization factor from ec_decode().
1.82 + In the encoder: the number of oustanding carry propagating symbols.*/
1.83 + opus_uint32 ext;
1.84 + /*A buffered input/output symbol, awaiting carry propagation.*/
1.85 + int rem;
1.86 + /*Nonzero if an error occurred.*/
1.87 + int error;
1.88 +};
1.89 +
1.90 +static OPUS_INLINE opus_uint32 ec_range_bytes(ec_ctx *_this){
1.91 + return _this->offs;
1.92 +}
1.93 +
1.94 +static OPUS_INLINE unsigned char *ec_get_buffer(ec_ctx *_this){
1.95 + return _this->buf;
1.96 +}
1.97 +
1.98 +static OPUS_INLINE int ec_get_error(ec_ctx *_this){
1.99 + return _this->error;
1.100 +}
1.101 +
1.102 +/*Returns the number of bits "used" by the encoded or decoded symbols so far.
1.103 + This same number can be computed in either the encoder or the decoder, and is
1.104 + suitable for making coding decisions.
1.105 + Return: The number of bits.
1.106 + This will always be slightly larger than the exact value (e.g., all
1.107 + rounding error is in the positive direction).*/
1.108 +static OPUS_INLINE int ec_tell(ec_ctx *_this){
1.109 + return _this->nbits_total-EC_ILOG(_this->rng);
1.110 +}
1.111 +
1.112 +/*Returns the number of bits "used" by the encoded or decoded symbols so far.
1.113 + This same number can be computed in either the encoder or the decoder, and is
1.114 + suitable for making coding decisions.
1.115 + Return: The number of bits scaled by 2**BITRES.
1.116 + This will always be slightly larger than the exact value (e.g., all
1.117 + rounding error is in the positive direction).*/
1.118 +opus_uint32 ec_tell_frac(ec_ctx *_this);
1.119 +
1.120 +#endif
