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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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* This file is part of FFmpeg.
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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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* 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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* 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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* Context Adaptive Binary Arithmetic Coder.
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#include "bitstream.h"
39
#define CABAC_MASK ((1<<CABAC_BITS)-1)
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#define BRANCHLESS_CABAC_DECODER 1
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//#define ARCH_X86_DISABLED 1
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typedef struct CABACContext{
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int outstanding_count;
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const uint8_t *bytestream_start;
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const uint8_t *bytestream;
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const uint8_t *bytestream_end;
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extern uint8_t ff_h264_mlps_state[4*64];
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extern uint8_t ff_h264_lps_range[4*2*64]; ///< rangeTabLPS
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extern uint8_t ff_h264_mps_state[2*64]; ///< transIdxMPS
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extern uint8_t ff_h264_lps_state[2*64]; ///< transIdxLPS
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extern const uint8_t ff_h264_norm_shift[512];
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void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
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void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
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void ff_init_cabac_states(CABACContext *c);
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static inline void put_cabac_bit(CABACContext *c, int b){
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put_bits(&c->pb, 1, b);
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for(;c->outstanding_count; c->outstanding_count--){
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put_bits(&c->pb, 1, 1-b);
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static inline void renorm_cabac_encoder(CABACContext *c){
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while(c->range < 0x100){
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}else if(c->low<0x200){
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c->outstanding_count++;
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static void put_cabac(CABACContext *c, uint8_t * const state, int bit){
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int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state];
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if(bit == ((*state)&1)){
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*state= ff_h264_mps_state[*state];
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c->low += c->range - RangeLPS;
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*state= ff_h264_lps_state[*state];
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renorm_cabac_encoder(c);
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static void put_cabac_static(CABACContext *c, int RangeLPS, int bit){
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assert(c->range > RangeLPS);
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c->range -= RangeLPS;
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c->low += c->range - RangeLPS;
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renorm_cabac_encoder(c);
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* @param bit 0 -> write zero bit, !=0 write one bit
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static void put_cabac_bypass(CABACContext *c, int bit){
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}else if(c->low<0x400){
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c->outstanding_count++;
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* @return the number of bytes written
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static int put_cabac_terminate(CABACContext *c, int bit){
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renorm_cabac_encoder(c);
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renorm_cabac_encoder(c);
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assert(c->low <= 0x1FF);
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put_cabac_bit(c, c->low>>9);
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put_bits(&c->pb, 2, ((c->low>>7)&3)|1);
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flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong
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return (put_bits_count(&c->pb)+7)>>3;
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* put (truncated) unary binarization.
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static void put_cabac_u(CABACContext *c, uint8_t * state, int v, int max, int max_index, int truncated){
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put_cabac(c, state, 1);
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if(i < max_index) state++;
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if(truncated==0 || v<max)
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put_cabac(c, state, 0);
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put_cabac(c, state+i, 1);
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if(truncated==0 || v<max)
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put_cabac(c, state+i, 0);
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for(i=0; i<=max_index; i++){
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put_cabac(c, state+i, 1);
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put_cabac(c, state+max_index, 1);
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if(truncated==0 || v<max)
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put_cabac(c, state+max_index, 0);
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* put unary exp golomb k-th order binarization.
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static void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int is_signed, int k, int max_index){
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put_cabac(c, state, 0);
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const int sign= v < 0;
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if(is_signed) v= FFABS(v);
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put_cabac(c, state, 1);
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if(i < max_index) state++;
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put_cabac(c, state, 0);
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for(i=0; i<max; i++){
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put_cabac(c, state, 1);
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if(i < max_index) state++;
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while(v >= m){ //FIXME optimize
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put_cabac_bypass(c, 1);
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put_cabac_bypass(c, 0);
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put_cabac_bypass(c, v&m);
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put_cabac_bypass(c, sign);
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static void refill(CABACContext *c){
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c->low+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
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c->low+= c->bytestream[0]<<1;
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c->low -= CABAC_MASK;
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c->bytestream+= CABAC_BITS/8;
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static void refill2(CABACContext *c){
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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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x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
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x+= c->bytestream[0]<<1;
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c->bytestream+= CABAC_BITS/8;
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static inline void renorm_cabac_decoder(CABACContext *c){
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while(c->range < 0x100){
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if(!(c->low & CABAC_MASK))
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static inline void renorm_cabac_decoder_once(CABACContext *c){
301
#ifdef ARCH_X86_DISABLED
306
"lea -0x100(%0), %2 \n\t"
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"shr $31, %2 \n\t" //FIXME 31->63 for x86-64
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: "+r"(c->range), "+r"(c->low), "+c"(temp)
315
"cmp $0x100, %0 \n\t"
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"setb %%cl \n\t" //FIXME 31->63 for x86-64
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: "+r"(c->range), "+r"(c->low), "+c"(temp)
325
"lea -0x100(%0), %%eax \n\t"
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: "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
338
"cmp $0x100, %0 \n\t"
339
"sbb %%edx, %%edx \n\t"
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: "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
351
"cmp $0x100, %0 \n\t"
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"lea (%0, %0), %%eax \n\t"
353
"lea (%1, %1), %%edx \n\t"
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"cmovb %%eax, %0 \n\t"
355
"cmovb %%edx, %1 \n\t"
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: "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
361
int shift= (uint32_t)(c->range - 0x100)>>31;
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if(!(c->low & CABAC_MASK))
369
static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const state){
370
//FIXME gcc generates duplicate load/stores for c->low and c->range
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#define BYTESTART "16"
378
#define BYTESTART "12"
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#if defined(ARCH_X86) && defined(CONFIG_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS)
385
#ifndef BRANCHLESS_CABAC_DECODER
387
"movzbl (%1), %0 \n\t"
388
"movl "RANGE "(%2), %%ebx \n\t"
389
"movl "RANGE "(%2), %%edx \n\t"
390
"andl $0xC0, %%ebx \n\t"
391
"movzbl "MANGLE(ff_h264_lps_range)"(%0, %%ebx, 2), %%esi\n\t"
392
"movl "LOW "(%2), %%ebx \n\t"
393
//eax:state ebx:low, edx:range, esi:RangeLPS
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"subl %%esi, %%edx \n\t"
395
"movl %%edx, %%ecx \n\t"
396
"shll $17, %%ecx \n\t"
397
"cmpl %%ecx, %%ebx \n\t"
401
//athlon:4067 P3:4110
402
"lea -0x100(%%edx), %%ecx \n\t"
403
"shr $31, %%ecx \n\t"
404
"shl %%cl, %%edx \n\t"
405
"shl %%cl, %%ebx \n\t"
407
//athlon:4057 P3:4130
408
"cmp $0x100, %%edx \n\t" //FIXME avoidable
410
"shl %%cl, %%edx \n\t"
411
"shl %%cl, %%ebx \n\t"
413
"movzbl "MANGLE(ff_h264_mps_state)"(%0), %%ecx \n\t"
414
"movb %%cl, (%1) \n\t"
415
//eax:state ebx:low, edx:range, esi:RangeLPS
416
"test %%bx, %%bx \n\t"
418
"mov "BYTE "(%2), %%"REG_S" \n\t"
419
"subl $0xFFFF, %%ebx \n\t"
420
"movzwl (%%"REG_S"), %%ecx \n\t"
422
"shrl $15, %%ecx \n\t"
423
"add $2, %%"REG_S" \n\t"
424
"addl %%ecx, %%ebx \n\t"
425
"mov %%"REG_S", "BYTE "(%2) \n\t"
428
//eax:state ebx:low, edx:range, esi:RangeLPS
429
"subl %%ecx, %%ebx \n\t"
430
"movl %%esi, %%edx \n\t"
431
"movzbl " MANGLE(ff_h264_norm_shift) "(%%esi), %%ecx \n\t"
432
"shll %%cl, %%ebx \n\t"
433
"shll %%cl, %%edx \n\t"
434
"movzbl "MANGLE(ff_h264_lps_state)"(%0), %%ecx \n\t"
435
"movb %%cl, (%1) \n\t"
437
"test %%bx, %%bx \n\t"
440
"mov "BYTE "(%2), %%"REG_c" \n\t"
441
"movzwl (%%"REG_c"), %%esi \n\t"
443
"shrl $15, %%esi \n\t"
444
"subl $0xFFFF, %%esi \n\t"
445
"add $2, %%"REG_c" \n\t"
446
"mov %%"REG_c", "BYTE "(%2) \n\t"
448
"leal -1(%%ebx), %%ecx \n\t"
449
"xorl %%ebx, %%ecx \n\t"
450
"shrl $15, %%ecx \n\t"
451
"movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx \n\t"
455
"shll %%cl , %%esi \n\t"
456
"addl %%esi, %%ebx \n\t"
458
"movl %%edx, "RANGE "(%2) \n\t"
459
"movl %%ebx, "LOW "(%2) \n\t"
460
:"=&a"(bit) //FIXME this is fragile gcc either runs out of registers or misscompiles it (for example if "+a"(bit) or "+m"(*state) is used
462
: "%"REG_c, "%ebx", "%edx", "%"REG_S, "memory"
465
#else /* BRANCHLESS_CABAC_DECODER */
468
#if defined HAVE_FAST_CMOV
469
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
470
"mov "tmp" , %%ecx \n\t"\
471
"shl $17 , "tmp" \n\t"\
472
"cmp "low" , "tmp" \n\t"\
473
"cmova %%ecx , "range" \n\t"\
474
"sbb %%ecx , %%ecx \n\t"\
475
"and %%ecx , "tmp" \n\t"\
476
"sub "tmp" , "low" \n\t"\
477
"xor %%ecx , "ret" \n\t"
478
#else /* HAVE_FAST_CMOV */
479
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
480
"mov "tmp" , %%ecx \n\t"\
481
"shl $17 , "tmp" \n\t"\
482
"sub "low" , "tmp" \n\t"\
483
"sar $31 , "tmp" \n\t" /*lps_mask*/\
484
"sub %%ecx , "range" \n\t" /*RangeLPS - range*/\
485
"and "tmp" , "range" \n\t" /*(RangeLPS - range)&lps_mask*/\
486
"add %%ecx , "range" \n\t" /*new range*/\
487
"shl $17 , %%ecx \n\t"\
488
"and "tmp" , %%ecx \n\t"\
489
"sub %%ecx , "low" \n\t"\
490
"xor "tmp" , "ret" \n\t"
491
#endif /* HAVE_FAST_CMOV */
494
#define BRANCHLESS_GET_CABAC(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
495
"movzbl "statep" , "ret" \n\t"\
496
"mov "range" , "tmp" \n\t"\
497
"and $0xC0 , "range" \n\t"\
498
"movzbl "MANGLE(ff_h264_lps_range)"("ret", "range", 2), "range" \n\t"\
499
"sub "range" , "tmp" \n\t"\
500
BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
501
"movzbl " MANGLE(ff_h264_norm_shift) "("range"), %%ecx \n\t"\
502
"shl %%cl , "range" \n\t"\
503
"movzbl "MANGLE(ff_h264_mlps_state)"+128("ret"), "tmp" \n\t"\
504
"mov "tmpbyte" , "statep" \n\t"\
505
"shl %%cl , "low" \n\t"\
506
"test "lowword" , "lowword" \n\t"\
508
"mov "BYTE"("cabac"), %%"REG_c" \n\t"\
509
"movzwl (%%"REG_c") , "tmp" \n\t"\
511
"shr $15 , "tmp" \n\t"\
512
"sub $0xFFFF , "tmp" \n\t"\
513
"add $2 , %%"REG_c" \n\t"\
514
"mov %%"REG_c" , "BYTE "("cabac") \n\t"\
515
"lea -1("low") , %%ecx \n\t"\
516
"xor "low" , %%ecx \n\t"\
517
"shr $15 , %%ecx \n\t"\
518
"movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx \n\t"\
520
"add $7 , %%ecx \n\t"\
521
"shl %%cl , "tmp" \n\t"\
522
"add "tmp" , "low" \n\t"\
526
"movl "RANGE "(%2), %%esi \n\t"
527
"movl "LOW "(%2), %%ebx \n\t"
528
BRANCHLESS_GET_CABAC("%0", "%2", "(%1)", "%%ebx", "%%bx", "%%esi", "%%edx", "%%dl")
529
"movl %%esi, "RANGE "(%2) \n\t"
530
"movl %%ebx, "LOW "(%2) \n\t"
534
: "%"REG_c, "%ebx", "%edx", "%esi", "memory"
537
#endif /* BRANCHLESS_CABAC_DECODER */
538
#else /* defined(ARCH_X86) && defined(CONFIG_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
540
int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
541
int bit, lps_mask av_unused;
543
c->range -= RangeLPS;
544
#ifndef BRANCHLESS_CABAC_DECODER
545
if(c->low < (c->range<<(CABAC_BITS+1))){
547
*state= ff_h264_mps_state[s];
548
renorm_cabac_decoder_once(c);
550
bit= ff_h264_norm_shift[RangeLPS];
551
c->low -= (c->range<<(CABAC_BITS+1));
552
*state= ff_h264_lps_state[s];
553
c->range = RangeLPS<<bit;
557
if(!(c->low & CABAC_MASK)){
561
#else /* BRANCHLESS_CABAC_DECODER */
562
lps_mask= ((c->range<<(CABAC_BITS+1)) - c->low)>>31;
564
c->low -= (c->range<<(CABAC_BITS+1)) & lps_mask;
565
c->range += (RangeLPS - c->range) & lps_mask;
568
*state= (ff_h264_mlps_state+128)[s];
571
lps_mask= ff_h264_norm_shift[c->range];
572
c->range<<= lps_mask;
574
if(!(c->low & CABAC_MASK))
576
#endif /* BRANCHLESS_CABAC_DECODER */
577
#endif /* defined(ARCH_X86) && defined(CONFIG_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
581
static int av_noinline get_cabac_noinline(CABACContext *c, uint8_t * const state){
582
return get_cabac_inline(c,state);
585
static int get_cabac(CABACContext *c, uint8_t * const state){
586
return get_cabac_inline(c,state);
589
static int get_cabac_bypass(CABACContext *c){
593
"movl "RANGE "(%1), %%ebx \n\t"
594
"movl "LOW "(%1), %%eax \n\t"
595
"shl $17, %%ebx \n\t"
596
"add %%eax, %%eax \n\t"
597
"sub %%ebx, %%eax \n\t"
599
"and %%edx, %%ebx \n\t"
600
"add %%ebx, %%eax \n\t"
601
"test %%ax, %%ax \n\t"
603
"movl "BYTE "(%1), %%"REG_b" \n\t"
604
"subl $0xFFFF, %%eax \n\t"
605
"movzwl (%%"REG_b"), %%ecx \n\t"
607
"shrl $15, %%ecx \n\t"
608
"addl $2, %%"REG_b" \n\t"
609
"addl %%ecx, %%eax \n\t"
610
"movl %%"REG_b", "BYTE "(%1) \n\t"
612
"movl %%eax, "LOW "(%1) \n\t"
616
: "%eax", "%"REG_b, "%ecx", "memory"
623
if(!(c->low & CABAC_MASK))
626
range= c->range<<(CABAC_BITS+1);
637
static av_always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
638
#if defined(ARCH_X86) && !(defined(PIC) && defined(__GNUC__))
640
"movl "RANGE "(%1), %%ebx \n\t"
641
"movl "LOW "(%1), %%eax \n\t"
642
"shl $17, %%ebx \n\t"
643
"add %%eax, %%eax \n\t"
644
"sub %%ebx, %%eax \n\t"
646
"and %%edx, %%ebx \n\t"
647
"add %%ebx, %%eax \n\t"
648
"xor %%edx, %%ecx \n\t"
649
"sub %%edx, %%ecx \n\t"
650
"test %%ax, %%ax \n\t"
652
"mov "BYTE "(%1), %%"REG_b" \n\t"
653
"subl $0xFFFF, %%eax \n\t"
654
"movzwl (%%"REG_b"), %%edx \n\t"
656
"shrl $15, %%edx \n\t"
657
"add $2, %%"REG_b" \n\t"
658
"addl %%edx, %%eax \n\t"
659
"mov %%"REG_b", "BYTE "(%1) \n\t"
661
"movl %%eax, "LOW "(%1) \n\t"
665
: "%eax", "%"REG_b, "%edx", "memory"
672
if(!(c->low & CABAC_MASK))
675
range= c->range<<(CABAC_BITS+1);
680
return (val^mask)-mask;
684
//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!)
685
//FIXME use some macros to avoid duplicatin get_cabac (cannot be done yet as that would make optimization work hard)
686
#if defined(ARCH_X86) && defined(CONFIG_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS)
687
static int decode_significance_x86(CABACContext *c, int max_coeff, uint8_t *significant_coeff_ctx_base, int *index){
688
void *end= significant_coeff_ctx_base + max_coeff - 1;
689
int minusstart= -(int)significant_coeff_ctx_base;
690
int minusindex= 4-(int)index;
693
"movl "RANGE "(%3), %%esi \n\t"
694
"movl "LOW "(%3), %%ebx \n\t"
698
BRANCHLESS_GET_CABAC("%%edx", "%3", "(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
700
"test $1, %%edx \n\t"
703
BRANCHLESS_GET_CABAC("%%edx", "%3", "61(%1)", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
705
"mov %2, %%"REG_a" \n\t"
706
"movl %4, %%ecx \n\t"
707
"add %1, %%"REG_c" \n\t"
708
"movl %%ecx, (%%"REG_a") \n\t"
710
"test $1, %%edx \n\t"
713
"add $4, %%"REG_a" \n\t"
714
"mov %%"REG_a", %2 \n\t"
720
"mov %2, %%"REG_a" \n\t"
721
"movl %4, %%ecx \n\t"
722
"add %1, %%"REG_c" \n\t"
723
"movl %%ecx, (%%"REG_a") \n\t"
728
"movl %%esi, "RANGE "(%3) \n\t"
729
"movl %%ebx, "LOW "(%3) \n\t"
730
:"=&a"(coeff_count), "+r"(significant_coeff_ctx_base), "+m"(index)\
731
:"r"(c), "m"(minusstart), "m"(end), "m"(minusindex)\
732
: "%"REG_c, "%ebx", "%edx", "%esi", "memory"\
737
static int decode_significance_8x8_x86(CABACContext *c, uint8_t *significant_coeff_ctx_base, int *index, uint8_t *sig_off){
738
int minusindex= 4-(int)index;
742
"movl "RANGE "(%3), %%esi \n\t"
743
"movl "LOW "(%3), %%ebx \n\t"
745
"mov %1, %%"REG_D" \n\t"
748
"mov %6, %%"REG_a" \n\t"
749
"movzbl (%%"REG_a", %%"REG_D"), %%edi \n\t"
750
"add %5, %%"REG_D" \n\t"
752
BRANCHLESS_GET_CABAC("%%edx", "%3", "(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
755
"test $1, %%edx \n\t"
758
"movzbl "MANGLE(last_coeff_flag_offset_8x8)"(%%edi), %%edi\n\t"
759
"add %5, %%"REG_D" \n\t"
761
BRANCHLESS_GET_CABAC("%%edx", "%3", "15(%%"REG_D")", "%%ebx", "%%bx", "%%esi", "%%eax", "%%al")
763
"mov %2, %%"REG_a" \n\t"
765
"movl %%edi, (%%"REG_a") \n\t"
767
"test $1, %%edx \n\t"
770
"add $4, %%"REG_a" \n\t"
771
"mov %%"REG_a", %2 \n\t"
774
"addl $1, %%edi \n\t"
776
"cmpl $63, %%edi \n\t"
778
"mov %2, %%"REG_a" \n\t"
779
"movl %%edi, (%%"REG_a") \n\t"
781
"addl %4, %%eax \n\t"
784
"movl %%esi, "RANGE "(%3) \n\t"
785
"movl %%ebx, "LOW "(%3) \n\t"
786
:"=&a"(coeff_count),"+m"(last), "+m"(index)\
787
:"r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off)\
788
: "%"REG_c, "%ebx", "%edx", "%esi", "%"REG_D, "memory"\
792
#endif /* defined(ARCH_X86) && && defined(CONFIG_7REGS) && defined(HAVE_EBX_AVAILABLE) && !defined(BROKEN_RELOCATIONS) */
796
* @return the number of bytes read or 0 if no end
798
static int get_cabac_terminate(CABACContext *c){
800
if(c->low < c->range<<(CABAC_BITS+1)){
801
renorm_cabac_decoder_once(c);
804
return c->bytestream - c->bytestream_start;
809
* get (truncated) unnary binarization.
811
static int get_cabac_u(CABACContext *c, uint8_t * state, int max, int max_index, int truncated){
814
for(i=0; i<max; i++){
815
if(get_cabac(c, state)==0)
818
if(i< max_index) state++;
821
return truncated ? max : -1;
825
* get unary exp golomb k-th order binarization.
827
static int get_cabac_ueg(CABACContext *c, uint8_t * state, int max, int is_signed, int k, int max_index){
831
if(get_cabac(c, state)==0)
834
if(0 < max_index) state++;
836
for(i=1; i<max; i++){
837
if(get_cabac(c, state)==0){
838
if(is_signed && get_cabac_bypass(c)){
844
if(i < max_index) state++;
847
while(get_cabac_bypass(c)){
854
v+= v + get_cabac_bypass(c);
858
if(is_signed && get_cabac_bypass(c)){