| Index: opus/celt/entcode.c
|
| ===================================================================
|
| --- opus/celt/entcode.c (revision 0)
|
| +++ opus/celt/entcode.c (revision 0)
|
| @@ -0,0 +1,88 @@
|
| +/* Copyright (c) 2001-2011 Timothy B. Terriberry
|
| +*/
|
| +/*
|
| + 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.
|
| +*/
|
| +
|
| +#ifdef HAVE_CONFIG_H
|
| +#include "config.h"
|
| +#endif
|
| +
|
| +#include "entcode.h"
|
| +#include "arch.h"
|
| +
|
| +#if !defined(EC_CLZ)
|
| +int ec_ilog(opus_uint32 _v){
|
| + /*On a Pentium M, this branchless version tested as the fastest on
|
| + 1,000,000,000 random 32-bit integers, edging out a similar version with
|
| + branches, and a 256-entry LUT version.*/
|
| + int ret;
|
| + int m;
|
| + ret=!!_v;
|
| + m=!!(_v&0xFFFF0000)<<4;
|
| + _v>>=m;
|
| + ret|=m;
|
| + m=!!(_v&0xFF00)<<3;
|
| + _v>>=m;
|
| + ret|=m;
|
| + m=!!(_v&0xF0)<<2;
|
| + _v>>=m;
|
| + ret|=m;
|
| + m=!!(_v&0xC)<<1;
|
| + _v>>=m;
|
| + ret|=m;
|
| + ret+=!!(_v&0x2);
|
| + return ret;
|
| +}
|
| +#endif
|
| +
|
| +opus_uint32 ec_tell_frac(ec_ctx *_this){
|
| + opus_uint32 nbits;
|
| + opus_uint32 r;
|
| + int l;
|
| + int i;
|
| + /*To handle the non-integral number of bits still left in the encoder/decoder
|
| + state, we compute the worst-case number of bits of val that must be
|
| + encoded to ensure that the value is inside the range for any possible
|
| + subsequent bits.
|
| + The computation here is independent of val itself (the decoder does not
|
| + even track that value), even though the real number of bits used after
|
| + ec_enc_done() may be 1 smaller if rng is a power of two and the
|
| + corresponding trailing bits of val are all zeros.
|
| + If we did try to track that special case, then coding a value with a
|
| + probability of 1/(1<<n) might sometimes appear to use more than n bits.
|
| + This may help explain the surprising result that a newly initialized
|
| + encoder or decoder claims to have used 1 bit.*/
|
| + nbits=_this->nbits_total<<BITRES;
|
| + l=EC_ILOG(_this->rng);
|
| + r=_this->rng>>(l-16);
|
| + for(i=BITRES;i-->0;){
|
| + int b;
|
| + r=r*r>>15;
|
| + b=(int)(r>>16);
|
| + l=l<<1|b;
|
| + r>>=b;
|
| + }
|
| + return nbits-l;
|
| +}
|
|
|
| Property changes on: opus/celt/entcode.c
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
|
|
|