1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-02 03:06:28 +02:00
FFmpeg/libavcodec/cabac.h
Diego Biurrun c46e28746c Put some disabled functions that are only used in the test program in cabac.c
under TEST as preprocessor conditional, same as the test program.

Originally committed as revision 11601 to svn://svn.ffmpeg.org/ffmpeg/trunk
2008-01-23 10:19:39 +00:00

871 lines
29 KiB
C

/*
* H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file cabac.h
* Context Adaptive Binary Arithmetic Coder.
*/
#ifndef FFMPEG_CABAC_H
#define FFMPEG_CABAC_H
#include "bitstream.h"
//#undef NDEBUG
#include <assert.h>
#ifdef ARCH_X86
#include "x86_cpu.h"
#endif
#define CABAC_BITS 16
#define CABAC_MASK ((1<<CABAC_BITS)-1)
#define BRANCHLESS_CABAC_DECODER 1
//#define ARCH_X86_DISABLED 1
typedef struct CABACContext{
int low;
int range;
int outstanding_count;
#ifdef STRICT_LIMITS
int symCount;
#endif
const uint8_t *bytestream_start;
const uint8_t *bytestream;
const uint8_t *bytestream_end;
PutBitContext pb;
}CABACContext;
extern uint8_t ff_h264_mlps_state[4*64];
extern uint8_t ff_h264_lps_range[4*2*64]; ///< rangeTabLPS
extern uint8_t ff_h264_mps_state[2*64]; ///< transIdxMPS
extern uint8_t ff_h264_lps_state[2*64]; ///< transIdxLPS
extern const uint8_t ff_h264_norm_shift[512];
void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
void ff_init_cabac_states(CABACContext *c);
static inline void put_cabac_bit(CABACContext *c, int b){
put_bits(&c->pb, 1, b);
for(;c->outstanding_count; c->outstanding_count--){
put_bits(&c->pb, 1, 1-b);
}
}
static inline void renorm_cabac_encoder(CABACContext *c){
while(c->range < 0x100){
//FIXME optimize
if(c->low<0x100){
put_cabac_bit(c, 0);
}else if(c->low<0x200){
c->outstanding_count++;
c->low -= 0x100;
}else{
put_cabac_bit(c, 1);
c->low -= 0x200;
}
c->range+= c->range;
c->low += c->low;
}
}
#ifdef TEST
static void put_cabac(CABACContext *c, uint8_t * const state, int bit){
int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state];
if(bit == ((*state)&1)){
c->range -= RangeLPS;
*state= ff_h264_mps_state[*state];
}else{
c->low += c->range - RangeLPS;
c->range = RangeLPS;
*state= ff_h264_lps_state[*state];
}
renorm_cabac_encoder(c);
#ifdef STRICT_LIMITS
c->symCount++;
#endif
}
static void put_cabac_static(CABACContext *c, int RangeLPS, int bit){
assert(c->range > RangeLPS);
if(!bit){
c->range -= RangeLPS;
}else{
c->low += c->range - RangeLPS;
c->range = RangeLPS;
}
renorm_cabac_encoder(c);
#ifdef STRICT_LIMITS
c->symCount++;
#endif
}
/**
* @param bit 0 -> write zero bit, !=0 write one bit
*/
static void put_cabac_bypass(CABACContext *c, int bit){
c->low += c->low;
if(bit){
c->low += c->range;
}
//FIXME optimize
if(c->low<0x200){
put_cabac_bit(c, 0);
}else if(c->low<0x400){
c->outstanding_count++;
c->low -= 0x200;
}else{
put_cabac_bit(c, 1);
c->low -= 0x400;
}
#ifdef STRICT_LIMITS
c->symCount++;
#endif
}
/**
*
* @return the number of bytes written
*/
static int put_cabac_terminate(CABACContext *c, int bit){
c->range -= 2;
if(!bit){
renorm_cabac_encoder(c);
}else{
c->low += c->range;
c->range= 2;
renorm_cabac_encoder(c);
assert(c->low <= 0x1FF);
put_cabac_bit(c, c->low>>9);
put_bits(&c->pb, 2, ((c->low>>7)&3)|1);
flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong
}
#ifdef STRICT_LIMITS
c->symCount++;
#endif
return (put_bits_count(&c->pb)+7)>>3;
}
/**
* put (truncated) unary binarization.
*/
static void put_cabac_u(CABACContext *c, uint8_t * state, int v, int max, int max_index, int truncated){
int i;
assert(v <= max);
#if 1
for(i=0; i<v; i++){
put_cabac(c, state, 1);
if(i < max_index) state++;
}
if(truncated==0 || v<max)
put_cabac(c, state, 0);
#else
if(v <= max_index){
for(i=0; i<v; i++){
put_cabac(c, state+i, 1);
}
if(truncated==0 || v<max)
put_cabac(c, state+i, 0);
}else{
for(i=0; i<=max_index; i++){
put_cabac(c, state+i, 1);
}
for(; i<v; i++){
put_cabac(c, state+max_index, 1);
}
if(truncated==0 || v<max)
put_cabac(c, state+max_index, 0);
}
#endif
}
/**
* put unary exp golomb k-th order binarization.
*/
static void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int is_signed, int k, int max_index){
int i;
if(v==0)
put_cabac(c, state, 0);
else{
const int sign= v < 0;
if(is_signed) v= FFABS(v);
if(v<max){
for(i=0; i<v; i++){
put_cabac(c, state, 1);
if(i < max_index) state++;
}
put_cabac(c, state, 0);
}else{
int m= 1<<k;
for(i=0; i<max; i++){
put_cabac(c, state, 1);
if(i < max_index) state++;
}
v -= max;
while(v >= m){ //FIXME optimize
put_cabac_bypass(c, 1);
v-= m;
m+= m;
}
put_cabac_bypass(c, 0);
while(m>>=1){
put_cabac_bypass(c, v&m);
}
}
if(is_signed)
put_cabac_bypass(c, sign);
}
}
#endif /* TEST */
static void refill(CABACContext *c){
#if CABAC_BITS == 16
c->low+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
#else
c->low+= c->bytestream[0]<<1;
#endif
c->low -= CABAC_MASK;
c->bytestream+= CABAC_BITS/8;
}
#if ! ( defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) )
static void refill2(CABACContext *c){
int i, x;
x= c->low ^ (c->low-1);
i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS-1)];
x= -CABAC_MASK;
#if CABAC_BITS == 16
x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
#else
x+= c->bytestream[0]<<1;
#endif
c->low += x<<i;
c->bytestream+= CABAC_BITS/8;
}
#endif
static inline void renorm_cabac_decoder(CABACContext *c){
while(c->range < 0x100){
c->range+= c->range;
c->low+= c->low;
if(!(c->low & CABAC_MASK))
refill(c);
}
}
static inline void renorm_cabac_decoder_once(CABACContext *c){
#ifdef ARCH_X86_DISABLED
int temp;
#if 0
//P3:683 athlon:475
asm(
"lea -0x100(%0), %2 \n\t"
"shr $31, %2 \n\t" //FIXME 31->63 for x86-64
"shl %%cl, %0 \n\t"
"shl %%cl, %1 \n\t"
: "+r"(c->range), "+r"(c->low), "+c"(temp)
);
#elif 0
//P3:680 athlon:474
asm(
"cmp $0x100, %0 \n\t"
"setb %%cl \n\t" //FIXME 31->63 for x86-64
"shl %%cl, %0 \n\t"
"shl %%cl, %1 \n\t"
: "+r"(c->range), "+r"(c->low), "+c"(temp)
);
#elif 1
int temp2;
//P3:665 athlon:517
asm(
"lea -0x100(%0), %%eax \n\t"
"cdq \n\t"
"mov %0, %%eax \n\t"
"and %%edx, %0 \n\t"
"and %1, %%edx \n\t"
"add %%eax, %0 \n\t"
"add %%edx, %1 \n\t"
: "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
);
#elif 0
int temp2;
//P3:673 athlon:509
asm(
"cmp $0x100, %0 \n\t"
"sbb %%edx, %%edx \n\t"
"mov %0, %%eax \n\t"
"and %%edx, %0 \n\t"
"and %1, %%edx \n\t"
"add %%eax, %0 \n\t"
"add %%edx, %1 \n\t"
: "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
);
#else
int temp2;
//P3:677 athlon:511
asm(
"cmp $0x100, %0 \n\t"
"lea (%0, %0), %%eax \n\t"
"lea (%1, %1), %%edx \n\t"
"cmovb %%eax, %0 \n\t"
"cmovb %%edx, %1 \n\t"
: "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
);
#endif
#else
//P3:675 athlon:476
int shift= (uint32_t)(c->range - 0x100)>>31;
c->range<<= shift;
c->low <<= shift;
#endif
if(!(c->low & CABAC_MASK))
refill(c);
}
static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const state){
//FIXME gcc generates duplicate load/stores for c->low and c->range
#define LOW "0"
#define RANGE "4"
#ifdef ARCH_X86_64
#define BYTESTART "16"
#define BYTE "24"
#define BYTEEND "32"
#else
#define BYTESTART "12"
#define BYTE "16"
#define BYTEEND "20"
#endif
#if defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS)
int bit;
#ifndef BRANCHLESS_CABAC_DECODER
asm volatile(
"movzbl (%1), %0 \n\t"
"movl "RANGE "(%2), %%ebx \n\t"
"movl "RANGE "(%2), %%edx \n\t"
"andl $0xC0, %%ebx \n\t"
"movzbl "MANGLE(ff_h264_lps_range)"(%0, %%ebx, 2), %%esi\n\t"
"movl "LOW "(%2), %%ebx \n\t"
//eax:state ebx:low, edx:range, esi:RangeLPS
"subl %%esi, %%edx \n\t"
"movl %%edx, %%ecx \n\t"
"shll $17, %%ecx \n\t"
"cmpl %%ecx, %%ebx \n\t"
" ja 1f \n\t"
#if 1
//athlon:4067 P3:4110
"lea -0x100(%%edx), %%ecx \n\t"
"shr $31, %%ecx \n\t"
"shl %%cl, %%edx \n\t"
"shl %%cl, %%ebx \n\t"
#else
//athlon:4057 P3:4130
"cmp $0x100, %%edx \n\t" //FIXME avoidable
"setb %%cl \n\t"
"shl %%cl, %%edx \n\t"
"shl %%cl, %%ebx \n\t"
#endif
"movzbl "MANGLE(ff_h264_mps_state)"(%0), %%ecx \n\t"
"movb %%cl, (%1) \n\t"
//eax:state ebx:low, edx:range, esi:RangeLPS
"test %%bx, %%bx \n\t"
" jnz 2f \n\t"
"mov "BYTE "(%2), %%"REG_S" \n\t"
"subl $0xFFFF, %%ebx \n\t"
"movzwl (%%"REG_S"), %%ecx \n\t"
"bswap %%ecx \n\t"
"shrl $15, %%ecx \n\t"
"add $2, %%"REG_S" \n\t"
"addl %%ecx, %%ebx \n\t"
"mov %%"REG_S", "BYTE "(%2) \n\t"
"jmp 2f \n\t"
"1: \n\t"
//eax:state ebx:low, edx:range, esi:RangeLPS
"subl %%ecx, %%ebx \n\t"
"movl %%esi, %%edx \n\t"
"movzbl " MANGLE(ff_h264_norm_shift) "(%%esi), %%ecx \n\t"
"shll %%cl, %%ebx \n\t"
"shll %%cl, %%edx \n\t"
"movzbl "MANGLE(ff_h264_lps_state)"(%0), %%ecx \n\t"
"movb %%cl, (%1) \n\t"
"add $1, %0 \n\t"
"test %%bx, %%bx \n\t"
" jnz 2f \n\t"
"mov "BYTE "(%2), %%"REG_c" \n\t"
"movzwl (%%"REG_c"), %%esi \n\t"
"bswap %%esi \n\t"
"shrl $15, %%esi \n\t"
"subl $0xFFFF, %%esi \n\t"
"add $2, %%"REG_c" \n\t"
"mov %%"REG_c", "BYTE "(%2) \n\t"
"leal -1(%%ebx), %%ecx \n\t"
"xorl %%ebx, %%ecx \n\t"
"shrl $15, %%ecx \n\t"
"movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx \n\t"
"neg %%ecx \n\t"
"add $7, %%ecx \n\t"
"shll %%cl , %%esi \n\t"
"addl %%esi, %%ebx \n\t"
"2: \n\t"
"movl %%edx, "RANGE "(%2) \n\t"
"movl %%ebx, "LOW "(%2) \n\t"
:"=&a"(bit) //FIXME this is fragile gcc either runs out of registers or miscompiles it (for example if "+a"(bit) or "+m"(*state) is used
:"r"(state), "r"(c)
: "%"REG_c, "%ebx", "%edx", "%"REG_S, "memory"
);
bit&=1;
#else /* BRANCHLESS_CABAC_DECODER */
#if defined HAVE_FAST_CMOV
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
"mov "tmp" , %%ecx \n\t"\
"shl $17 , "tmp" \n\t"\
"cmp "low" , "tmp" \n\t"\
"cmova %%ecx , "range" \n\t"\
"sbb %%ecx , %%ecx \n\t"\
"and %%ecx , "tmp" \n\t"\
"sub "tmp" , "low" \n\t"\
"xor %%ecx , "ret" \n\t"
#else /* HAVE_FAST_CMOV */
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
"mov "tmp" , %%ecx \n\t"\
"shl $17 , "tmp" \n\t"\
"sub "low" , "tmp" \n\t"\
"sar $31 , "tmp" \n\t" /*lps_mask*/\
"sub %%ecx , "range" \n\t" /*RangeLPS - range*/\
"and "tmp" , "range" \n\t" /*(RangeLPS - range)&lps_mask*/\
"add %%ecx , "range" \n\t" /*new range*/\
"shl $17 , %%ecx \n\t"\
"and "tmp" , %%ecx \n\t"\
"sub %%ecx , "low" \n\t"\
"xor "tmp" , "ret" \n\t"
#endif /* HAVE_FAST_CMOV */
#define BRANCHLESS_GET_CABAC(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
"movzbl "statep" , "ret" \n\t"\
"mov "range" , "tmp" \n\t"\
"and $0xC0 , "range" \n\t"\
"movzbl "MANGLE(ff_h264_lps_range)"("ret", "range", 2), "range" \n\t"\
"sub "range" , "tmp" \n\t"\
BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
"movzbl " MANGLE(ff_h264_norm_shift) "("range"), %%ecx \n\t"\
"shl %%cl , "range" \n\t"\
"movzbl "MANGLE(ff_h264_mlps_state)"+128("ret"), "tmp" \n\t"\
"mov "tmpbyte" , "statep" \n\t"\
"shl %%cl , "low" \n\t"\
"test "lowword" , "lowword" \n\t"\
" jnz 1f \n\t"\
"mov "BYTE"("cabac"), %%"REG_c" \n\t"\
"movzwl (%%"REG_c") , "tmp" \n\t"\
"bswap "tmp" \n\t"\
"shr $15 , "tmp" \n\t"\
"sub $0xFFFF , "tmp" \n\t"\
"add $2 , %%"REG_c" \n\t"\
"mov %%"REG_c" , "BYTE "("cabac") \n\t"\
"lea -1("low") , %%ecx \n\t"\
"xor "low" , %%ecx \n\t"\
"shr $15 , %%ecx \n\t"\
"movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx \n\t"\
"neg %%ecx \n\t"\
"add $7 , %%ecx \n\t"\
"shl %%cl , "tmp" \n\t"\
"add "tmp" , "low" \n\t"\
"1: \n\t"
asm volatile(
"movl "RANGE "(%2), %%esi \n\t"
"movl "LOW "(%2), %%ebx \n\t"
BRANCHLESS_GET_CABAC("%0", "%2", "(%1)", "%%ebx", "%%bx", "%%esi", "%%edx", "%%dl")
"movl %%esi, "RANGE "(%2) \n\t"
"movl %%ebx, "LOW "(%2) \n\t"
:"=&a"(bit)
:"r"(state), "r"(c)
: "%"REG_c, "%ebx", "%edx", "%esi", "memory"
);
bit&=1;
#endif /* BRANCHLESS_CABAC_DECODER */
#else /* defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
int s = *state;
int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
int bit, lps_mask av_unused;
c->range -= RangeLPS;
#ifndef BRANCHLESS_CABAC_DECODER
if(c->low < (c->range<<(CABAC_BITS+1))){
bit= s&1;
*state= ff_h264_mps_state[s];
renorm_cabac_decoder_once(c);
}else{
bit= ff_h264_norm_shift[RangeLPS];
c->low -= (c->range<<(CABAC_BITS+1));
*state= ff_h264_lps_state[s];
c->range = RangeLPS<<bit;
c->low <<= bit;
bit= (s&1)^1;
if(!(c->low & CABAC_MASK)){
refill2(c);
}
}
#else /* BRANCHLESS_CABAC_DECODER */
lps_mask= ((c->range<<(CABAC_BITS+1)) - c->low)>>31;
c->low -= (c->range<<(CABAC_BITS+1)) & lps_mask;
c->range += (RangeLPS - c->range) & lps_mask;
s^=lps_mask;
*state= (ff_h264_mlps_state+128)[s];
bit= s&1;
lps_mask= ff_h264_norm_shift[c->range];
c->range<<= lps_mask;
c->low <<= lps_mask;
if(!(c->low & CABAC_MASK))
refill2(c);
#endif /* BRANCHLESS_CABAC_DECODER */
#endif /* defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
return bit;
}
static int av_noinline get_cabac_noinline(CABACContext *c, uint8_t * const state){
return get_cabac_inline(c,state);
}
static int get_cabac(CABACContext *c, uint8_t * const state){
return get_cabac_inline(c,state);
}
static int get_cabac_bypass(CABACContext *c){
#if 0 //not faster
int bit;
asm volatile(
"movl "RANGE "(%1), %%ebx \n\t"
"movl "LOW "(%1), %%eax \n\t"
"shl $17, %%ebx \n\t"
"add %%eax, %%eax \n\t"
"sub %%ebx, %%eax \n\t"
"cdq \n\t"
"and %%edx, %%ebx \n\t"
"add %%ebx, %%eax \n\t"
"test %%ax, %%ax \n\t"
" jnz 1f \n\t"
"movl "BYTE "(%1), %%"REG_b" \n\t"
"subl $0xFFFF, %%eax \n\t"
"movzwl (%%"REG_b"), %%ecx \n\t"
"bswap %%ecx \n\t"
"shrl $15, %%ecx \n\t"
"addl $2, %%"REG_b" \n\t"
"addl %%ecx, %%eax \n\t"
"movl %%"REG_b", "BYTE "(%1) \n\t"
"1: \n\t"
"movl %%eax, "LOW "(%1) \n\t"
:"=&d"(bit)
:"r"(c)
: "%eax", "%"REG_b, "%ecx", "memory"
);
return bit+1;
#else
int range;
c->low += c->low;
if(!(c->low & CABAC_MASK))
refill(c);
range= c->range<<(CABAC_BITS+1);
if(c->low < range){
return 0;
}else{
c->low -= range;
return 1;
}
#endif
}
static av_always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
#if defined(ARCH_X86) && !(defined(PIC) && defined(__GNUC__))
asm volatile(
"movl "RANGE "(%1), %%ebx \n\t"
"movl "LOW "(%1), %%eax \n\t"
"shl $17, %%ebx \n\t"
"add %%eax, %%eax \n\t"
"sub %%ebx, %%eax \n\t"
"cdq \n\t"
"and %%edx, %%ebx \n\t"
"add %%ebx, %%eax \n\t"
"xor %%edx, %%ecx \n\t"
"sub %%edx, %%ecx \n\t"
"test %%ax, %%ax \n\t"
" jnz 1f \n\t"
"mov "BYTE "(%1), %%"REG_b" \n\t"
"subl $0xFFFF, %%eax \n\t"
"movzwl (%%"REG_b"), %%edx \n\t"
"bswap %%edx \n\t"
"shrl $15, %%edx \n\t"
"add $2, %%"REG_b" \n\t"
"addl %%edx, %%eax \n\t"
"mov %%"REG_b", "BYTE "(%1) \n\t"
"1: \n\t"
"movl %%eax, "LOW "(%1) \n\t"
:"+c"(val)
:"r"(c)
: "%eax", "%"REG_b, "%edx", "memory"
);
return val;
#else
int range, mask;
c->low += c->low;
if(!(c->low & CABAC_MASK))
refill(c);
range= c->range<<(CABAC_BITS+1);
c->low -= range;
mask= c->low >> 31;
range &= mask;
c->low += range;
return (val^mask)-mask;
#endif
}
//FIXME the x86 code from this file should be moved into i386/h264 or cabac something.c/h (note ill kill you if you move my code away from under my fingers before iam finished with it!)
//FIXME use some macros to avoid duplicatin get_cabac (cannot be done yet as that would make optimization work hard)
#if defined(ARCH_X86) && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS)
static int decode_significance_x86(CABACContext *c, int max_coeff, uint8_t *significant_coeff_ctx_base, int *index){
void *end= significant_coeff_ctx_base + max_coeff - 1;
int minusstart= -(int)significant_coeff_ctx_base;
int minusindex= 4-(int)index;
int coeff_count;
asm volatile(
"movl "RANGE "(%3), %%esi \n\t"
"movl "LOW "(%3), %%ebx \n\t"
"2: \n\t"
BRANCHLESS_GET_CABAC("%%edx", "%3", "(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
"test $1, %%edx \n\t"
" jz 3f \n\t"
BRANCHLESS_GET_CABAC("%%edx", "%3", "61(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
"mov %2, %%"REG_a" \n\t"
"movl %4, %%ecx \n\t"
"add %1, %%"REG_c" \n\t"
"movl %%ecx, (%%"REG_a") \n\t"
"test $1, %%edx \n\t"
" jnz 4f \n\t"
"add $4, %%"REG_a" \n\t"
"mov %%"REG_a", %2 \n\t"
"3: \n\t"
"add $1, %1 \n\t"
"cmp %5, %1 \n\t"
" jb 2b \n\t"
"mov %2, %%"REG_a" \n\t"
"movl %4, %%ecx \n\t"
"add %1, %%"REG_c" \n\t"
"movl %%ecx, (%%"REG_a") \n\t"
"4: \n\t"
"add %6, %%eax \n\t"
"shr $2, %%eax \n\t"
"movl %%esi, "RANGE "(%3) \n\t"
"movl %%ebx, "LOW "(%3) \n\t"
:"=&a"(coeff_count), "+r"(significant_coeff_ctx_base), "+m"(index)\
:"r"(c), "m"(minusstart), "m"(end), "m"(minusindex)\
: "%"REG_c, "%ebx", "%edx", "%esi", "memory"\
);
return coeff_count;
}
static int decode_significance_8x8_x86(CABACContext *c, uint8_t *significant_coeff_ctx_base, int *index, const uint8_t *sig_off){
int minusindex= 4-(int)index;
int coeff_count;
long last=0;
asm volatile(
"movl "RANGE "(%3), %%esi \n\t"
"movl "LOW "(%3), %%ebx \n\t"
"mov %1, %%"REG_D" \n\t"
"2: \n\t"
"mov %6, %%"REG_a" \n\t"
"movzbl (%%"REG_a", %%"REG_D"), %%edi \n\t"
"add %5, %%"REG_D" \n\t"
BRANCHLESS_GET_CABAC("%%edx", "%3", "(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
"mov %1, %%edi \n\t"
"test $1, %%edx \n\t"
" jz 3f \n\t"
"movzbl "MANGLE(last_coeff_flag_offset_8x8)"(%%edi), %%edi\n\t"
"add %5, %%"REG_D" \n\t"
BRANCHLESS_GET_CABAC("%%edx", "%3", "15(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
"mov %2, %%"REG_a" \n\t"
"mov %1, %%edi \n\t"
"movl %%edi, (%%"REG_a") \n\t"
"test $1, %%edx \n\t"
" jnz 4f \n\t"
"add $4, %%"REG_a" \n\t"
"mov %%"REG_a", %2 \n\t"
"3: \n\t"
"addl $1, %%edi \n\t"
"mov %%edi, %1 \n\t"
"cmpl $63, %%edi \n\t"
" jb 2b \n\t"
"mov %2, %%"REG_a" \n\t"
"movl %%edi, (%%"REG_a") \n\t"
"4: \n\t"
"addl %4, %%eax \n\t"
"shr $2, %%eax \n\t"
"movl %%esi, "RANGE "(%3) \n\t"
"movl %%ebx, "LOW "(%3) \n\t"
:"=&a"(coeff_count),"+m"(last), "+m"(index)\
:"r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off)\
: "%"REG_c, "%ebx", "%edx", "%esi", "%"REG_D, "memory"\
);
return coeff_count;
}
#endif /* defined(ARCH_X86) && && defined(HAVE_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
/**
*
* @return the number of bytes read or 0 if no end
*/
static int get_cabac_terminate(CABACContext *c){
c->range -= 2;
if(c->low < c->range<<(CABAC_BITS+1)){
renorm_cabac_decoder_once(c);
return 0;
}else{
return c->bytestream - c->bytestream_start;
}
}
#if 0
/**
* Get (truncated) unary binarization.
*/
static int get_cabac_u(CABACContext *c, uint8_t * state, int max, int max_index, int truncated){
int i;
for(i=0; i<max; i++){
if(get_cabac(c, state)==0)
return i;
if(i< max_index) state++;
}
return truncated ? max : -1;
}
/**
* get unary exp golomb k-th order binarization.
*/
static int get_cabac_ueg(CABACContext *c, uint8_t * state, int max, int is_signed, int k, int max_index){
int i, v;
int m= 1<<k;
if(get_cabac(c, state)==0)
return 0;
if(0 < max_index) state++;
for(i=1; i<max; i++){
if(get_cabac(c, state)==0){
if(is_signed && get_cabac_bypass(c)){
return -i;
}else
return i;
}
if(i < max_index) state++;
}
while(get_cabac_bypass(c)){
i+= m;
m+= m;
}
v=0;
while(m>>=1){
v+= v + get_cabac_bypass(c);
}
i += v;
if(is_signed && get_cabac_bypass(c)){
return -i;
}else
return i;
}
#endif /* 0 */
#endif /* FFMPEG_CABAC_H */