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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 Libav.
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 *
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 * Libav 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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 * Libav 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 Libav; 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.
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 */
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#ifndef AVCODEC_CABAC_H
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#define AVCODEC_CABAC_H
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#include "put_bits.h"
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//#undef NDEBUG
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#include <assert.h>
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#include "libavutil/x86_cpu.h"
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#define CABAC_BITS 16
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#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 low;
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    int range;
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    int outstanding_count;
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#ifdef STRICT_LIMITS
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    int symCount;
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#endif
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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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    PutBitContext pb;
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}CABACContext;
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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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65

    
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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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    }
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}
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static inline void renorm_cabac_encoder(CABACContext *c){
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    while(c->range < 0x100){
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        //FIXME optimize
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        if(c->low<0x100){
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            put_cabac_bit(c, 0);
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        }else if(c->low<0x200){
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            c->outstanding_count++;
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            c->low -= 0x100;
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        }else{
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            put_cabac_bit(c, 1);
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            c->low -= 0x200;
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        }
85

    
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        c->range+= c->range;
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        c->low += c->low;
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    }
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}
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#ifdef TEST
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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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        c->range -= RangeLPS;
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        *state= ff_h264_mps_state[*state];
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    }else{
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        c->low += c->range - RangeLPS;
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        c->range = RangeLPS;
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        *state= ff_h264_lps_state[*state];
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    }
103

    
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    renorm_cabac_encoder(c);
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#ifdef STRICT_LIMITS
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    c->symCount++;
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#endif
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}
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static void put_cabac_static(CABACContext *c, int RangeLPS, int bit){
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    assert(c->range > RangeLPS);
113

    
114
    if(!bit){
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        c->range -= RangeLPS;
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    }else{
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        c->low += c->range - RangeLPS;
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        c->range = RangeLPS;
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    }
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    renorm_cabac_encoder(c);
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#ifdef STRICT_LIMITS
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    c->symCount++;
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#endif
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}
127

    
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/**
129
 * @param bit 0 -> write zero bit, !=0 write one bit
130
 */
131
static void put_cabac_bypass(CABACContext *c, int bit){
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    c->low += c->low;
133

    
134
    if(bit){
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        c->low += c->range;
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    }
137
//FIXME optimize
138
    if(c->low<0x200){
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        put_cabac_bit(c, 0);
140
    }else if(c->low<0x400){
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        c->outstanding_count++;
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        c->low -= 0x200;
143
    }else{
144
        put_cabac_bit(c, 1);
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        c->low -= 0x400;
146
    }
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148
#ifdef STRICT_LIMITS
149
    c->symCount++;
150
#endif
151
}
152

    
153
/**
154
 *
155
 * @return the number of bytes written
156
 */
157
static int put_cabac_terminate(CABACContext *c, int bit){
158
    c->range -= 2;
159

    
160
    if(!bit){
161
        renorm_cabac_encoder(c);
162
    }else{
163
        c->low += c->range;
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        c->range= 2;
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166
        renorm_cabac_encoder(c);
167

    
168
        assert(c->low <= 0x1FF);
169
        put_cabac_bit(c, c->low>>9);
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        put_bits(&c->pb, 2, ((c->low>>7)&3)|1);
171

    
172
        flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong
173
    }
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175
#ifdef STRICT_LIMITS
176
    c->symCount++;
177
#endif
178

    
179
    return (put_bits_count(&c->pb)+7)>>3;
180
}
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182
/**
183
 * put (truncated) unary binarization.
184
 */
185
static void put_cabac_u(CABACContext *c, uint8_t * state, int v, int max, int max_index, int truncated){
186
    int i;
187

    
188
    assert(v <= max);
189

    
190
#if 1
191
    for(i=0; i<v; i++){
192
        put_cabac(c, state, 1);
193
        if(i < max_index) state++;
194
    }
195
    if(truncated==0 || v<max)
196
        put_cabac(c, state, 0);
197
#else
198
    if(v <= max_index){
199
        for(i=0; i<v; i++){
200
            put_cabac(c, state+i, 1);
201
        }
202
        if(truncated==0 || v<max)
203
            put_cabac(c, state+i, 0);
204
    }else{
205
        for(i=0; i<=max_index; i++){
206
            put_cabac(c, state+i, 1);
207
        }
208
        for(; i<v; i++){
209
            put_cabac(c, state+max_index, 1);
210
        }
211
        if(truncated==0 || v<max)
212
            put_cabac(c, state+max_index, 0);
213
    }
214
#endif
215
}
216

    
217
/**
218
 * put unary exp golomb k-th order binarization.
219
 */
220
static void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int is_signed, int k, int max_index){
221
    int i;
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223
    if(v==0)
224
        put_cabac(c, state, 0);
225
    else{
226
        const int sign= v < 0;
227

    
228
        if(is_signed) v= FFABS(v);
229

    
230
        if(v<max){
231
            for(i=0; i<v; i++){
232
                put_cabac(c, state, 1);
233
                if(i < max_index) state++;
234
            }
235

    
236
            put_cabac(c, state, 0);
237
        }else{
238
            int m= 1<<k;
239

    
240
            for(i=0; i<max; i++){
241
                put_cabac(c, state, 1);
242
                if(i < max_index) state++;
243
            }
244

    
245
            v -= max;
246
            while(v >= m){ //FIXME optimize
247
                put_cabac_bypass(c, 1);
248
                v-= m;
249
                m+= m;
250
            }
251
            put_cabac_bypass(c, 0);
252
            while(m>>=1){
253
                put_cabac_bypass(c, v&m);
254
            }
255
        }
256

    
257
        if(is_signed)
258
            put_cabac_bypass(c, sign);
259
    }
260
}
261
#endif /* TEST */
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263
static void refill(CABACContext *c){
264
#if CABAC_BITS == 16
265
        c->low+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
266
#else
267
        c->low+= c->bytestream[0]<<1;
268
#endif
269
    c->low -= CABAC_MASK;
270
    c->bytestream+= CABAC_BITS/8;
271
}
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273
#if ! ( ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) )
274
static void refill2(CABACContext *c){
275
    int i, x;
276

    
277
    x= c->low ^ (c->low-1);
278
    i= 7 - ff_h264_norm_shift[x>>(CABAC_BITS-1)];
279

    
280
    x= -CABAC_MASK;
281

    
282
#if CABAC_BITS == 16
283
        x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
284
#else
285
        x+= c->bytestream[0]<<1;
286
#endif
287

    
288
    c->low += x<<i;
289
    c->bytestream+= CABAC_BITS/8;
290
}
291
#endif
292

    
293
static inline void renorm_cabac_decoder(CABACContext *c){
294
    while(c->range < 0x100){
295
        c->range+= c->range;
296
        c->low+= c->low;
297
        if(!(c->low & CABAC_MASK))
298
            refill(c);
299
    }
300
}
301

    
302
static inline void renorm_cabac_decoder_once(CABACContext *c){
303
#ifdef ARCH_X86_DISABLED
304
    int temp;
305
#if 0
306
    //P3:683    athlon:475
307
    __asm__(
308
        "lea -0x100(%0), %2         \n\t"
309
        "shr $31, %2                \n\t"  //FIXME 31->63 for x86-64
310
        "shl %%cl, %0               \n\t"
311
        "shl %%cl, %1               \n\t"
312
        : "+r"(c->range), "+r"(c->low), "+c"(temp)
313
    );
314
#elif 0
315
    //P3:680    athlon:474
316
    __asm__(
317
        "cmp $0x100, %0             \n\t"
318
        "setb %%cl                  \n\t"  //FIXME 31->63 for x86-64
319
        "shl %%cl, %0               \n\t"
320
        "shl %%cl, %1               \n\t"
321
        : "+r"(c->range), "+r"(c->low), "+c"(temp)
322
    );
323
#elif 1
324
    int temp2;
325
    //P3:665    athlon:517
326
    __asm__(
327
        "lea -0x100(%0), %%eax      \n\t"
328
        "cltd                       \n\t"
329
        "mov %0, %%eax              \n\t"
330
        "and %%edx, %0              \n\t"
331
        "and %1, %%edx              \n\t"
332
        "add %%eax, %0              \n\t"
333
        "add %%edx, %1              \n\t"
334
        : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
335
    );
336
#elif 0
337
    int temp2;
338
    //P3:673    athlon:509
339
    __asm__(
340
        "cmp $0x100, %0             \n\t"
341
        "sbb %%edx, %%edx           \n\t"
342
        "mov %0, %%eax              \n\t"
343
        "and %%edx, %0              \n\t"
344
        "and %1, %%edx              \n\t"
345
        "add %%eax, %0              \n\t"
346
        "add %%edx, %1              \n\t"
347
        : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
348
    );
349
#else
350
    int temp2;
351
    //P3:677    athlon:511
352
    __asm__(
353
        "cmp $0x100, %0             \n\t"
354
        "lea (%0, %0), %%eax        \n\t"
355
        "lea (%1, %1), %%edx        \n\t"
356
        "cmovb %%eax, %0            \n\t"
357
        "cmovb %%edx, %1            \n\t"
358
        : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
359
    );
360
#endif
361
#else
362
    //P3:675    athlon:476
363
    int shift= (uint32_t)(c->range - 0x100)>>31;
364
    c->range<<= shift;
365
    c->low  <<= shift;
366
#endif
367
    if(!(c->low & CABAC_MASK))
368
        refill(c);
369
}
370

    
371
static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const state){
372
    //FIXME gcc generates duplicate load/stores for c->low and c->range
373
#define LOW          "0"
374
#define RANGE        "4"
375
#if ARCH_X86_64
376
#define BYTESTART   "16"
377
#define BYTE        "24"
378
#define BYTEEND     "32"
379
#else
380
#define BYTESTART   "12"
381
#define BYTE        "16"
382
#define BYTEEND     "20"
383
#endif
384
#if ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS)
385
    int bit;
386

    
387
#ifndef BRANCHLESS_CABAC_DECODER
388
    __asm__ volatile(
389
        "movzbl (%1), %0                        \n\t"
390
        "movl "RANGE    "(%2), %%ebx            \n\t"
391
        "movl "RANGE    "(%2), %%edx            \n\t"
392
        "andl $0xC0, %%ebx                      \n\t"
393
        "movzbl "MANGLE(ff_h264_lps_range)"(%0, %%ebx, 2), %%esi\n\t"
394
        "movl "LOW      "(%2), %%ebx            \n\t"
395
//eax:state ebx:low, edx:range, esi:RangeLPS
396
        "subl %%esi, %%edx                      \n\t"
397
        "movl %%edx, %%ecx                      \n\t"
398
        "shll $17, %%ecx                        \n\t"
399
        "cmpl %%ecx, %%ebx                      \n\t"
400
        " ja 1f                                 \n\t"
401

    
402
#if 1
403
        //athlon:4067 P3:4110
404
        "lea -0x100(%%edx), %%ecx               \n\t"
405
        "shr $31, %%ecx                         \n\t"
406
        "shl %%cl, %%edx                        \n\t"
407
        "shl %%cl, %%ebx                        \n\t"
408
#else
409
        //athlon:4057 P3:4130
410
        "cmp $0x100, %%edx                      \n\t" //FIXME avoidable
411
        "setb %%cl                              \n\t"
412
        "shl %%cl, %%edx                        \n\t"
413
        "shl %%cl, %%ebx                        \n\t"
414
#endif
415
        "movzbl "MANGLE(ff_h264_mps_state)"(%0), %%ecx   \n\t"
416
        "movb %%cl, (%1)                        \n\t"
417
//eax:state ebx:low, edx:range, esi:RangeLPS
418
        "test %%bx, %%bx                        \n\t"
419
        " jnz 2f                                \n\t"
420
        "mov  "BYTE     "(%2), %%"REG_S"        \n\t"
421
        "subl $0xFFFF, %%ebx                    \n\t"
422
        "movzwl (%%"REG_S"), %%ecx              \n\t"
423
        "bswap %%ecx                            \n\t"
424
        "shrl $15, %%ecx                        \n\t"
425
        "add  $2, %%"REG_S"                     \n\t"
426
        "addl %%ecx, %%ebx                      \n\t"
427
        "mov  %%"REG_S", "BYTE    "(%2)         \n\t"
428
        "jmp 2f                                 \n\t"
429
        "1:                                     \n\t"
430
//eax:state ebx:low, edx:range, esi:RangeLPS
431
        "subl %%ecx, %%ebx                      \n\t"
432
        "movl %%esi, %%edx                      \n\t"
433
        "movzbl " MANGLE(ff_h264_norm_shift) "(%%esi), %%ecx   \n\t"
434
        "shll %%cl, %%ebx                       \n\t"
435
        "shll %%cl, %%edx                       \n\t"
436
        "movzbl "MANGLE(ff_h264_lps_state)"(%0), %%ecx   \n\t"
437
        "movb %%cl, (%1)                        \n\t"
438
        "add  $1, %0                            \n\t"
439
        "test %%bx, %%bx                        \n\t"
440
        " jnz 2f                                \n\t"
441

    
442
        "mov  "BYTE     "(%2), %%"REG_c"        \n\t"
443
        "movzwl (%%"REG_c"), %%esi              \n\t"
444
        "bswap %%esi                            \n\t"
445
        "shrl $15, %%esi                        \n\t"
446
        "subl $0xFFFF, %%esi                    \n\t"
447
        "add  $2, %%"REG_c"                     \n\t"
448
        "mov  %%"REG_c", "BYTE    "(%2)         \n\t"
449

    
450
        "leal -1(%%ebx), %%ecx                  \n\t"
451
        "xorl %%ebx, %%ecx                      \n\t"
452
        "shrl $15, %%ecx                        \n\t"
453
        "movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx   \n\t"
454
        "neg %%ecx                              \n\t"
455
        "add $7, %%ecx                          \n\t"
456

    
457
        "shll %%cl , %%esi                      \n\t"
458
        "addl %%esi, %%ebx                      \n\t"
459
        "2:                                     \n\t"
460
        "movl %%edx, "RANGE    "(%2)            \n\t"
461
        "movl %%ebx, "LOW      "(%2)            \n\t"
462
        :"=&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
463
        :"r"(state), "r"(c)
464
        : "%"REG_c, "%ebx", "%edx", "%"REG_S, "memory"
465
    );
466
    bit&=1;
467
#else /* BRANCHLESS_CABAC_DECODER */
468

    
469

    
470
#if HAVE_FAST_CMOV
471
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
472
        "mov    "tmp"       , %%ecx                                     \n\t"\
473
        "shl    $17         , "tmp"                                     \n\t"\
474
        "cmp    "low"       , "tmp"                                     \n\t"\
475
        "cmova  %%ecx       , "range"                                   \n\t"\
476
        "sbb    %%ecx       , %%ecx                                     \n\t"\
477
        "and    %%ecx       , "tmp"                                     \n\t"\
478
        "sub    "tmp"       , "low"                                     \n\t"\
479
        "xor    %%ecx       , "ret"                                     \n\t"
480
#else /* HAVE_FAST_CMOV */
481
#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
482
        "mov    "tmp"       , %%ecx                                     \n\t"\
483
        "shl    $17         , "tmp"                                     \n\t"\
484
        "sub    "low"       , "tmp"                                     \n\t"\
485
        "sar    $31         , "tmp"                                     \n\t" /*lps_mask*/\
486
        "sub    %%ecx       , "range"                                   \n\t" /*RangeLPS - range*/\
487
        "and    "tmp"       , "range"                                   \n\t" /*(RangeLPS - range)&lps_mask*/\
488
        "add    %%ecx       , "range"                                   \n\t" /*new range*/\
489
        "shl    $17         , %%ecx                                     \n\t"\
490
        "and    "tmp"       , %%ecx                                     \n\t"\
491
        "sub    %%ecx       , "low"                                     \n\t"\
492
        "xor    "tmp"       , "ret"                                     \n\t"
493
#endif /* HAVE_FAST_CMOV */
494

    
495

    
496
#define BRANCHLESS_GET_CABAC(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
497
        "movzbl "statep"    , "ret"                                     \n\t"\
498
        "mov    "range"     , "tmp"                                     \n\t"\
499
        "and    $0xC0       , "range"                                   \n\t"\
500
        "movzbl "MANGLE(ff_h264_lps_range)"("ret", "range", 2), "range" \n\t"\
501
        "sub    "range"     , "tmp"                                     \n\t"\
502
        BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp, tmpbyte)\
503
        "movzbl " MANGLE(ff_h264_norm_shift) "("range"), %%ecx          \n\t"\
504
        "shl    %%cl        , "range"                                   \n\t"\
505
        "movzbl "MANGLE(ff_h264_mlps_state)"+128("ret"), "tmp"          \n\t"\
506
        "mov    "tmpbyte"   , "statep"                                  \n\t"\
507
        "shl    %%cl        , "low"                                     \n\t"\
508
        "test   "lowword"   , "lowword"                                 \n\t"\
509
        " jnz   1f                                                      \n\t"\
510
        "mov "BYTE"("cabac"), %%"REG_c"                                 \n\t"\
511
        "movzwl (%%"REG_c")     , "tmp"                                 \n\t"\
512
        "bswap  "tmp"                                                   \n\t"\
513
        "shr    $15         , "tmp"                                     \n\t"\
514
        "sub    $0xFFFF     , "tmp"                                     \n\t"\
515
        "add    $2          , %%"REG_c"                                 \n\t"\
516
        "mov    %%"REG_c"   , "BYTE    "("cabac")                       \n\t"\
517
        "lea    -1("low")   , %%ecx                                     \n\t"\
518
        "xor    "low"       , %%ecx                                     \n\t"\
519
        "shr    $15         , %%ecx                                     \n\t"\
520
        "movzbl " MANGLE(ff_h264_norm_shift) "(%%ecx), %%ecx            \n\t"\
521
        "neg    %%ecx                                                   \n\t"\
522
        "add    $7          , %%ecx                                     \n\t"\
523
        "shl    %%cl        , "tmp"                                     \n\t"\
524
        "add    "tmp"       , "low"                                     \n\t"\
525
        "1:                                                             \n\t"
526

    
527
    __asm__ volatile(
528
        "movl "RANGE    "(%2), %%esi            \n\t"
529
        "movl "LOW      "(%2), %%ebx            \n\t"
530
        BRANCHLESS_GET_CABAC("%0", "%2", "(%1)", "%%ebx", "%%bx", "%%esi", "%%edx", "%%dl")
531
        "movl %%esi, "RANGE    "(%2)            \n\t"
532
        "movl %%ebx, "LOW      "(%2)            \n\t"
533

    
534
        :"=&a"(bit)
535
        :"r"(state), "r"(c)
536
        : "%"REG_c, "%ebx", "%edx", "%esi", "memory"
537
    );
538
    bit&=1;
539
#endif /* BRANCHLESS_CABAC_DECODER */
540
#else /* ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) */
541
    int s = *state;
542
    int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + s];
543
    int bit, lps_mask av_unused;
544

    
545
    c->range -= RangeLPS;
546
#ifndef BRANCHLESS_CABAC_DECODER
547
    if(c->low < (c->range<<(CABAC_BITS+1))){
548
        bit= s&1;
549
        *state= ff_h264_mps_state[s];
550
        renorm_cabac_decoder_once(c);
551
    }else{
552
        bit= ff_h264_norm_shift[RangeLPS];
553
        c->low -= (c->range<<(CABAC_BITS+1));
554
        *state= ff_h264_lps_state[s];
555
        c->range = RangeLPS<<bit;
556
        c->low <<= bit;
557
        bit= (s&1)^1;
558

    
559
        if(!(c->low & CABAC_MASK)){
560
            refill2(c);
561
        }
562
    }
563
#else /* BRANCHLESS_CABAC_DECODER */
564
    lps_mask= ((c->range<<(CABAC_BITS+1)) - c->low)>>31;
565

    
566
    c->low -= (c->range<<(CABAC_BITS+1)) & lps_mask;
567
    c->range += (RangeLPS - c->range) & lps_mask;
568

    
569
    s^=lps_mask;
570
    *state= (ff_h264_mlps_state+128)[s];
571
    bit= s&1;
572

    
573
    lps_mask= ff_h264_norm_shift[c->range];
574
    c->range<<= lps_mask;
575
    c->low  <<= lps_mask;
576
    if(!(c->low & CABAC_MASK))
577
        refill2(c);
578
#endif /* BRANCHLESS_CABAC_DECODER */
579
#endif /* ARCH_X86 && HAVE_7REGS && HAVE_EBX_AVAILABLE && !defined(BROKEN_RELOCATIONS) */
580
    return bit;
581
}
582

    
583
static int av_noinline av_unused get_cabac_noinline(CABACContext *c, uint8_t * const state){
584
    return get_cabac_inline(c,state);
585
}
586

    
587
static int av_unused get_cabac(CABACContext *c, uint8_t * const state){
588
    return get_cabac_inline(c,state);
589
}
590

    
591
static int av_unused get_cabac_bypass(CABACContext *c){
592
#if 0 //not faster
593
    int bit;
594
    __asm__ volatile(
595
        "movl "RANGE    "(%1), %%ebx            \n\t"
596
        "movl "LOW      "(%1), %%eax            \n\t"
597
        "shl $17, %%ebx                         \n\t"
598
        "add %%eax, %%eax                       \n\t"
599
        "sub %%ebx, %%eax                       \n\t"
600
        "cltd                                   \n\t"
601
        "and %%edx, %%ebx                       \n\t"
602
        "add %%ebx, %%eax                       \n\t"
603
        "test %%ax, %%ax                        \n\t"
604
        " jnz 1f                                \n\t"
605
        "movl "BYTE     "(%1), %%"REG_b"        \n\t"
606
        "subl $0xFFFF, %%eax                    \n\t"
607
        "movzwl (%%"REG_b"), %%ecx              \n\t"
608
        "bswap %%ecx                            \n\t"
609
        "shrl $15, %%ecx                        \n\t"
610
        "addl $2, %%"REG_b"                     \n\t"
611
        "addl %%ecx, %%eax                      \n\t"
612
        "movl %%"REG_b", "BYTE     "(%1)        \n\t"
613
        "1:                                     \n\t"
614
        "movl %%eax, "LOW      "(%1)            \n\t"
615

616
        :"=&d"(bit)
617
        :"r"(c)
618
        : "%eax", "%"REG_b, "%ecx", "memory"
619
    );
620
    return bit+1;
621
#else
622
    int range;
623
    c->low += c->low;
624

    
625
    if(!(c->low & CABAC_MASK))
626
        refill(c);
627

    
628
    range= c->range<<(CABAC_BITS+1);
629
    if(c->low < range){
630
        return 0;
631
    }else{
632
        c->low -= range;
633
        return 1;
634
    }
635
#endif
636
}
637

    
638

    
639
static av_always_inline int get_cabac_bypass_sign(CABACContext *c, int val){
640
#if ARCH_X86 && HAVE_EBX_AVAILABLE
641
    __asm__ volatile(
642
        "movl "RANGE    "(%1), %%ebx            \n\t"
643
        "movl "LOW      "(%1), %%eax            \n\t"
644
        "shl $17, %%ebx                         \n\t"
645
        "add %%eax, %%eax                       \n\t"
646
        "sub %%ebx, %%eax                       \n\t"
647
        "cltd                                   \n\t"
648
        "and %%edx, %%ebx                       \n\t"
649
        "add %%ebx, %%eax                       \n\t"
650
        "xor %%edx, %%ecx                       \n\t"
651
        "sub %%edx, %%ecx                       \n\t"
652
        "test %%ax, %%ax                        \n\t"
653
        " jnz 1f                                \n\t"
654
        "mov  "BYTE     "(%1), %%"REG_b"        \n\t"
655
        "subl $0xFFFF, %%eax                    \n\t"
656
        "movzwl (%%"REG_b"), %%edx              \n\t"
657
        "bswap %%edx                            \n\t"
658
        "shrl $15, %%edx                        \n\t"
659
        "add  $2, %%"REG_b"                     \n\t"
660
        "addl %%edx, %%eax                      \n\t"
661
        "mov  %%"REG_b", "BYTE     "(%1)        \n\t"
662
        "1:                                     \n\t"
663
        "movl %%eax, "LOW      "(%1)            \n\t"
664

    
665
        :"+c"(val)
666
        :"r"(c)
667
        : "%eax", "%"REG_b, "%edx", "memory"
668
    );
669
    return val;
670
#else
671
    int range, mask;
672
    c->low += c->low;
673

    
674
    if(!(c->low & CABAC_MASK))
675
        refill(c);
676

    
677
    range= c->range<<(CABAC_BITS+1);
678
    c->low -= range;
679
    mask= c->low >> 31;
680
    range &= mask;
681
    c->low += range;
682
    return (val^mask)-mask;
683
#endif
684
}
685

    
686
/**
687
 *
688
 * @return the number of bytes read or 0 if no end
689
 */
690
static int av_unused get_cabac_terminate(CABACContext *c){
691
    c->range -= 2;
692
    if(c->low < c->range<<(CABAC_BITS+1)){
693
        renorm_cabac_decoder_once(c);
694
        return 0;
695
    }else{
696
        return c->bytestream - c->bytestream_start;
697
    }
698
}
699

    
700
#if 0
701
/**
702
 * Get (truncated) unary binarization.
703
 */
704
static int get_cabac_u(CABACContext *c, uint8_t * state, int max, int max_index, int truncated){
705
    int i;
706

707
    for(i=0; i<max; i++){
708
        if(get_cabac(c, state)==0)
709
            return i;
710

711
        if(i< max_index) state++;
712
    }
713

714
    return truncated ? max : -1;
715
}
716

717
/**
718
 * get unary exp golomb k-th order binarization.
719
 */
720
static int get_cabac_ueg(CABACContext *c, uint8_t * state, int max, int is_signed, int k, int max_index){
721
    int i, v;
722
    int m= 1<<k;
723

724
    if(get_cabac(c, state)==0)
725
        return 0;
726

727
    if(0 < max_index) state++;
728

729
    for(i=1; i<max; i++){
730
        if(get_cabac(c, state)==0){
731
            if(is_signed && get_cabac_bypass(c)){
732
                return -i;
733
            }else
734
                return i;
735
        }
736

737
        if(i < max_index) state++;
738
    }
739

740
    while(get_cabac_bypass(c)){
741
        i+= m;
742
        m+= m;
743
    }
744

745
    v=0;
746
    while(m>>=1){
747
        v+= v + get_cabac_bypass(c);
748
    }
749
    i += v;
750

751
    if(is_signed && get_cabac_bypass(c)){
752
        return -i;
753
    }else
754
        return i;
755
}
756
#endif /* 0 */
757

    
758
#endif /* AVCODEC_CABAC_H */