GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/cabac_functions.h Lines: 32 34 94.1 %
Date: 2021-04-20 15:25:36 Branches: 12 14 85.7 %

Line Branch Exec Source
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/*
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 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
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 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * Context Adaptive Binary Arithmetic Coder inline functions
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 */
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#ifndef AVCODEC_CABAC_FUNCTIONS_H
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#define AVCODEC_CABAC_FUNCTIONS_H
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#include <stddef.h>
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#include <stdint.h>
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#include "cabac.h"
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#include "config.h"
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#ifndef UNCHECKED_BITSTREAM_READER
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#define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER
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#endif
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#if ARCH_AARCH64
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#   include "aarch64/cabac.h"
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#endif
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#if ARCH_ARM
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#   include "arm/cabac.h"
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#endif
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#if ARCH_X86
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#   include "x86/cabac.h"
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#endif
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#if ARCH_MIPS
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#   include "mips/cabac.h"
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#endif
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static const uint8_t * const ff_h264_norm_shift = ff_h264_cabac_tables + H264_NORM_SHIFT_OFFSET;
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static const uint8_t * const ff_h264_lps_range = ff_h264_cabac_tables + H264_LPS_RANGE_OFFSET;
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static const uint8_t * const ff_h264_mlps_state = ff_h264_cabac_tables + H264_MLPS_STATE_OFFSET;
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static const uint8_t * const ff_h264_last_coeff_flag_offset_8x8 = ff_h264_cabac_tables + H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET;
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#if !defined(get_cabac_bypass) || !defined(get_cabac_terminate)
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23136
static void refill(CABACContext *c){
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#if CABAC_BITS == 16
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23136
        c->low+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
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#else
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        c->low+= c->bytestream[0]<<1;
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#endif
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    c->low -= CABAC_MASK;
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#if !UNCHECKED_BITSTREAM_READER
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21066
    if (c->bytestream < c->bytestream_end)
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#endif
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23090
        c->bytestream += CABAC_BITS / 8;
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23136
}
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#endif
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#ifndef get_cabac_terminate
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10685256
static inline void renorm_cabac_decoder_once(CABACContext *c){
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10685256
    int shift= (uint32_t)(c->range - 0x100)>>31;
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10685256
    c->range<<= shift;
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10685256
    c->low  <<= shift;
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10685256
    if(!(c->low & CABAC_MASK))
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23136
        refill(c);
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10685256
}
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#endif
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#ifndef get_cabac_inline
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static void refill2(CABACContext *c){
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    int i;
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    unsigned x;
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#if !HAVE_FAST_CLZ
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    x= c->low ^ (c->low-1);
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    i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS-1)];
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#else
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    i = ff_ctz(c->low) - CABAC_BITS;
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#endif
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    x= -CABAC_MASK;
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#if CABAC_BITS == 16
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        x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
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#else
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        x+= c->bytestream[0]<<1;
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#endif
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    c->low += x<<i;
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#if !UNCHECKED_BITSTREAM_READER
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    if (c->bytestream < c->bytestream_end)
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#endif
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        c->bytestream += CABAC_BITS/8;
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}
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#endif
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#ifndef get_cabac_inline
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static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const state){
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    int s = *state;
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    int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
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    int bit, lps_mask;
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    c->range -= RangeLPS;
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    lps_mask= ((c->range<<(CABAC_BITS+1)) - c->low)>>31;
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    c->low -= (c->range<<(CABAC_BITS+1)) & lps_mask;
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    c->range += (RangeLPS - c->range) & lps_mask;
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    s^=lps_mask;
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    *state= (ff_h264_mlps_state+128)[s];
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    bit= s&1;
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    lps_mask= ff_h264_norm_shift[c->range];
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    c->range<<= lps_mask;
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    c->low  <<= lps_mask;
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    if(!(c->low & CABAC_MASK))
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        refill2(c);
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    return bit;
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}
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#endif
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static int av_noinline av_unused get_cabac_noinline(CABACContext *c, uint8_t * const state){
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83350584
    return get_cabac_inline(c,state);
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}
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static int av_unused get_cabac(CABACContext *c, uint8_t * const state){
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    return get_cabac_inline(c,state);
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}
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#ifndef get_cabac_bypass
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static int av_unused get_cabac_bypass(CABACContext *c){
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    int range;
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    c->low += c->low;
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    if(!(c->low & CABAC_MASK))
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        refill(c);
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    range= c->range<<(CABAC_BITS+1);
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    if(c->low < range){
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        return 0;
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    }else{
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        c->low -= range;
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        return 1;
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    }
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}
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#endif
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#ifndef get_cabac_bypass_sign
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static av_always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
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    int range, mask;
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    c->low += c->low;
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    if(!(c->low & CABAC_MASK))
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        refill(c);
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    range= c->range<<(CABAC_BITS+1);
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    c->low -= range;
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    mask= c->low >> 31;
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    range &= mask;
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    c->low += range;
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    return (val^mask)-mask;
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}
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#endif
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/**
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 * @return the number of bytes read or 0 if no end
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 */
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#ifndef get_cabac_terminate
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10752091
static int av_unused get_cabac_terminate(CABACContext *c){
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10752091
    c->range -= 2;
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    if(c->low < c->range<<(CABAC_BITS+1)){
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10685256
        renorm_cabac_decoder_once(c);
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10685256
        return 0;
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    }else{
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        return c->bytestream - c->bytestream_start;
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    }
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}
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#endif
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/**
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 * Skip @p n bytes and reset the decoder.
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 * @return the address of the first skipped byte or NULL if there's less than @p n bytes left
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 */
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#ifndef skip_bytes
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static av_unused const uint8_t* skip_bytes(CABACContext *c, int n) {
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    const uint8_t *ptr = c->bytestream;
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    if (c->low & 0x1)
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        ptr--;
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#if CABAC_BITS == 16
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20037
    if (c->low & 0x1FF)
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        ptr--;
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#endif
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    if ((int) (c->bytestream_end - ptr) < n)
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        return NULL;
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    if (ff_init_cabac_decoder(c, ptr + n, c->bytestream_end - ptr - n) < 0)
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        return NULL;
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    return ptr;
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}
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#endif
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#endif /* AVCODEC_CABAC_FUNCTIONS_H */