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ffmpeg / libavcodec / mpeg12.c @ 07787186

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1
/*
2
 * MPEG1 encoder / MPEG2 decoder
3
 * Copyright (c) 2000,2001 Fabrice Bellard.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
//#define DEBUG
20
#include "avcodec.h"
21
#include "dsputil.h"
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#include "mpegvideo.h"
23

    
24
#include "mpeg12data.h"
25

    
26
/* Start codes. */
27
#define SEQ_END_CODE                0x000001b7
28
#define SEQ_START_CODE                0x000001b3
29
#define GOP_START_CODE                0x000001b8
30
#define PICTURE_START_CODE        0x00000100
31
#define SLICE_MIN_START_CODE        0x00000101
32
#define SLICE_MAX_START_CODE        0x000001af
33
#define EXT_START_CODE                0x000001b5
34
#define USER_START_CODE                0x000001b2
35

    
36
#define DC_VLC_BITS 9
37
#define MV_VLC_BITS 9
38
#define MBINCR_VLC_BITS 9
39
#define MB_PAT_VLC_BITS 9
40
#define MB_PTYPE_VLC_BITS 6
41
#define MB_BTYPE_VLC_BITS 6
42
#define TEX_VLC_BITS 9
43

    
44
static void mpeg1_encode_block(MpegEncContext *s, 
45
                         DCTELEM *block, 
46
                         int component);
47
static void mpeg1_encode_motion(MpegEncContext *s, int val);
48
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
49
static int mpeg1_decode_block(MpegEncContext *s, 
50
                              DCTELEM *block, 
51
                              int n);
52
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
53
                                        DCTELEM *block, 
54
                                        int n);
55
static int mpeg2_decode_block_intra(MpegEncContext *s, 
56
                                    DCTELEM *block, 
57
                                    int n);
58
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
59

    
60
static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
61
static UINT8 fcode_tab[MAX_MV*2+1];
62

    
63
static void init_2d_vlc_rl(RLTable *rl)
64
{
65
    int i;
66
    
67
    init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2, 
68
             &rl->table_vlc[0][1], 4, 2,
69
             &rl->table_vlc[0][0], 4, 2);
70

    
71
    
72
    rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
73
    for(i=0; i<rl->vlc.table_size; i++){
74
        int code= rl->vlc.table[i][0];
75
        int len = rl->vlc.table[i][1];
76
        int level, run;
77
    
78
        if(len==0){ // illegal code
79
            run= 65;
80
            level= MAX_LEVEL;
81
        }else if(len<0){ //more bits needed
82
            run= 0;
83
            level= code;
84
        }else{
85
            if(code==rl->n){ //esc
86
                run= 65;
87
                level= 0;
88
            }else if(code==rl->n+1){ //eob
89
                run= 192;
90
                level= 1;
91
            }else{
92
                run=   rl->table_run  [code] + 1;
93
                level= rl->table_level[code];
94
            }
95
        }
96
        rl->rl_vlc[0][i].len= len;
97
        rl->rl_vlc[0][i].level= level;
98
        rl->rl_vlc[0][i].run= run;
99
    }
100
}
101

    
102

    
103
static void put_header(MpegEncContext *s, int header)
104
{
105
    align_put_bits(&s->pb);
106
    put_bits(&s->pb, 16, header>>16);
107
    put_bits(&s->pb, 16, header&0xFFFF);
108
}
109

    
110
/* put sequence header if needed */
111
static void mpeg1_encode_sequence_header(MpegEncContext *s)
112
{
113
        unsigned int vbv_buffer_size;
114
        unsigned int fps, v;
115
        int n;
116
        UINT64 time_code;
117
        
118
        if (s->picture_in_gop_number == 0) {
119
            /* mpeg1 header repeated every gop */
120
            put_header(s, SEQ_START_CODE);
121
            
122
            /* search closest frame rate */
123
            {
124
                int i, dmin, d;
125
                s->frame_rate_index = 0;
126
                dmin = 0x7fffffff;
127
                for(i=1;i<9;i++) {
128
                    d = abs(s->frame_rate - frame_rate_tab[i]);
129
                    if (d < dmin) {
130
                        dmin = d;
131
                        s->frame_rate_index = i;
132
                    }
133
                }
134
            }
135
 
136
            put_bits(&s->pb, 12, s->width);
137
            put_bits(&s->pb, 12, s->height);
138
            put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
139
            put_bits(&s->pb, 4, s->frame_rate_index);
140
            v = s->bit_rate / 400;
141
            if (v > 0x3ffff)
142
                v = 0x3ffff;
143
            put_bits(&s->pb, 18, v);
144
            put_bits(&s->pb, 1, 1); /* marker */
145
            /* vbv buffer size: slightly greater than an I frame. We add
146
               some margin just in case */
147
            vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
148
            put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384); 
149
            put_bits(&s->pb, 1, 1); /* constrained parameter flag */
150
            put_bits(&s->pb, 1, 0); /* no custom intra matrix */
151
            put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
152

    
153
            put_header(s, GOP_START_CODE);
154
            put_bits(&s->pb, 1, 0); /* do drop frame */
155
            /* time code : we must convert from the real frame rate to a
156
               fake mpeg frame rate in case of low frame rate */
157
            fps = frame_rate_tab[s->frame_rate_index];
158
            time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
159
            s->gop_picture_number = s->fake_picture_number;
160
            put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
161
            put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
162
            put_bits(&s->pb, 1, 1);
163
            put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
164
            put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
165
            put_bits(&s->pb, 1, 1); /* closed gop */
166
            put_bits(&s->pb, 1, 0); /* broken link */
167
        }
168

    
169
        if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
170
            /* insert empty P pictures to slow down to the desired
171
               frame rate. Each fake pictures takes about 20 bytes */
172
            fps = frame_rate_tab[s->frame_rate_index];
173
            n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
174
            while (s->fake_picture_number < n) {
175
                mpeg1_skip_picture(s, s->fake_picture_number - 
176
                                   s->gop_picture_number); 
177
                s->fake_picture_number++;
178
            }
179

    
180
        }
181
}
182

    
183

    
184
/* insert a fake P picture */
185
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
186
{
187
    unsigned int mb_incr;
188

    
189
    /* mpeg1 picture header */
190
    put_header(s, PICTURE_START_CODE);
191
    /* temporal reference */
192
    put_bits(&s->pb, 10, pict_num & 0x3ff); 
193
    
194
    put_bits(&s->pb, 3, P_TYPE);
195
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
196
    
197
    put_bits(&s->pb, 1, 1); /* integer coordinates */
198
    put_bits(&s->pb, 3, 1); /* forward_f_code */
199
    
200
    put_bits(&s->pb, 1, 0); /* extra bit picture */
201
    
202
    /* only one slice */
203
    put_header(s, SLICE_MIN_START_CODE);
204
    put_bits(&s->pb, 5, 1); /* quantizer scale */
205
    put_bits(&s->pb, 1, 0); /* slice extra information */
206
    
207
    mb_incr = 1;
208
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
209
             mbAddrIncrTable[mb_incr - 1][0]);
210
    
211
    /* empty macroblock */
212
    put_bits(&s->pb, 3, 1); /* motion only */
213
    
214
    /* zero motion x & y */
215
    put_bits(&s->pb, 1, 1); 
216
    put_bits(&s->pb, 1, 1); 
217

    
218
    /* output a number of empty slice */
219
    mb_incr = s->mb_width * s->mb_height - 1;
220
    while (mb_incr > 33) {
221
        put_bits(&s->pb, 11, 0x008);
222
        mb_incr -= 33;
223
    }
224
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
225
             mbAddrIncrTable[mb_incr - 1][0]);
226
    
227
    /* empty macroblock */
228
    put_bits(&s->pb, 3, 1); /* motion only */
229
    
230
    /* zero motion x & y */
231
    put_bits(&s->pb, 1, 1); 
232
    put_bits(&s->pb, 1, 1); 
233
}
234

    
235
static void common_init(MpegEncContext *s)
236
{
237
    s->y_dc_scale_table=
238
    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
239
}
240

    
241
void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
242
{
243
    mpeg1_encode_sequence_header(s);
244

    
245
    /* mpeg1 picture header */
246
    put_header(s, PICTURE_START_CODE);
247
    /* temporal reference */
248
    put_bits(&s->pb, 10, (s->fake_picture_number - 
249
                          s->gop_picture_number) & 0x3ff); 
250
    s->fake_picture_number++;
251
    
252
    put_bits(&s->pb, 3, s->pict_type);
253
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
254
    
255
    if (s->pict_type == P_TYPE) {
256
        put_bits(&s->pb, 1, 0); /* half pel coordinates */
257
        put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
258
    }
259
    
260
    put_bits(&s->pb, 1, 0); /* extra bit picture */
261
    
262
    /* only one slice */
263
    put_header(s, SLICE_MIN_START_CODE);
264
    put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
265
    put_bits(&s->pb, 1, 0); /* slice extra information */
266
}
267

    
268
void mpeg1_encode_mb(MpegEncContext *s,
269
                     DCTELEM block[6][64],
270
                     int motion_x, int motion_y)
271
{
272
    int mb_incr, i, cbp, mb_x, mb_y;
273

    
274
    mb_x = s->mb_x;
275
    mb_y = s->mb_y;
276

    
277
    /* compute cbp */
278
    cbp = 0;
279
    for(i=0;i<6;i++) {
280
        if (s->block_last_index[i] >= 0)
281
            cbp |= 1 << (5 - i);
282
    }
283

    
284
    /* skip macroblock, except if first or last macroblock of a slice */
285
    if ((cbp | motion_x | motion_y) == 0 &&
286
        (!((mb_x | mb_y) == 0 ||
287
           (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
288
        s->mb_incr++;
289
    } else {
290
        /* output mb incr */
291
        mb_incr = s->mb_incr;
292

    
293
        while (mb_incr > 33) {
294
            put_bits(&s->pb, 11, 0x008);
295
            mb_incr -= 33;
296
        }
297
        put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
298
                 mbAddrIncrTable[mb_incr - 1][0]);
299
        
300
        if (s->pict_type == I_TYPE) {
301
            put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
302
        } else {
303
            if (s->mb_intra) {
304
                put_bits(&s->pb, 5, 0x03);
305
            } else {
306
                if (cbp != 0) {
307
                    if (motion_x == 0 && motion_y == 0) {
308
                        put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
309
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
310
                    } else {
311
                        put_bits(&s->pb, 1, 1); /* motion + cbp */
312
                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
313
                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
314
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
315
                    }
316
                } else {
317
                    put_bits(&s->pb, 3, 1); /* motion only */
318
                    mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
319
                    mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
320
                }
321
            }
322
        }
323
        for(i=0;i<6;i++) {
324
            if (cbp & (1 << (5 - i))) {
325
                mpeg1_encode_block(s, block[i], i);
326
            }
327
        }
328
        s->mb_incr = 1;
329
    }
330
    s->last_mv[0][0][0] = motion_x;
331
    s->last_mv[0][0][1] = motion_y;
332
}
333

    
334
static void mpeg1_encode_motion(MpegEncContext *s, int val)
335
{
336
    int code, bit_size, l, m, bits, range, sign;
337

    
338
    if (val == 0) {
339
        /* zero vector */
340
        code = 0;
341
        put_bits(&s->pb,
342
                 mbMotionVectorTable[0][1], 
343
                 mbMotionVectorTable[0][0]); 
344
    } else {
345
        bit_size = s->f_code - 1;
346
        range = 1 << bit_size;
347
        /* modulo encoding */
348
        l = 16 * range;
349
        m = 2 * l;
350
        if (val < -l) {
351
            val += m;
352
        } else if (val >= l) {
353
            val -= m;
354
        }
355

    
356
        if (val >= 0) {
357
            val--;
358
            code = (val >> bit_size) + 1;
359
            bits = val & (range - 1);
360
            sign = 0;
361
        } else {
362
            val = -val;
363
            val--;
364
            code = (val >> bit_size) + 1;
365
            bits = val & (range - 1);
366
            sign = 1;
367
        }
368
        put_bits(&s->pb,
369
                 mbMotionVectorTable[code][1], 
370
                 mbMotionVectorTable[code][0]); 
371
        put_bits(&s->pb, 1, sign);
372
        if (bit_size > 0) {
373
            put_bits(&s->pb, bit_size, bits);
374
        }
375
    }
376
}
377

    
378
void ff_mpeg1_encode_init(MpegEncContext *s)
379
{
380
    static int done=0;
381

    
382
    common_init(s);
383

    
384
    if(!done){
385
        int f_code;
386
        int mv;
387
        int i;
388

    
389
        done=1;
390
        init_rl(&rl_mpeg1);
391
        
392
        for(i=0; i<64; i++)
393
        {
394
                mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
395
                mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
396
        }
397

    
398
        /* build unified dc encoding tables */
399
        for(i=-255; i<256; i++)
400
        {
401
                int adiff, index;
402
                int bits, code;
403
                int diff=i;
404

    
405
                adiff = ABS(diff);
406
                if(diff<0) diff--;
407
                index = vlc_dc_table[adiff];
408

    
409
                bits= vlc_dc_lum_bits[index] + index;
410
                code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
411
                mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
412
                
413
                bits= vlc_dc_chroma_bits[index] + index;
414
                code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
415
                mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
416
        }
417

    
418
        for(f_code=1; f_code<=MAX_FCODE; f_code++){
419
            for(mv=-MAX_MV; mv<=MAX_MV; mv++){
420
                int len;
421

    
422
                if(mv==0) len= mbMotionVectorTable[0][1];
423
                else{
424
                    int val, bit_size, range, code;
425

    
426
                    bit_size = s->f_code - 1;
427
                    range = 1 << bit_size;
428

    
429
                    val=mv;
430
                    if (val < 0) 
431
                        val = -val;
432
                    val--;
433
                    code = (val >> bit_size) + 1;
434
                    if(code<17){
435
                        len= mbMotionVectorTable[code][1] + 1 + bit_size;
436
                    }else{
437
                        len= mbMotionVectorTable[16][1] + 2 + bit_size;
438
                    }
439
                }
440

    
441
                mv_penalty[f_code][mv+MAX_MV]= len;
442
            }
443
        }
444
        
445

    
446
        for(f_code=MAX_FCODE; f_code>0; f_code--){
447
            for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
448
                fcode_tab[mv+MAX_MV]= f_code;
449
            }
450
        }
451
    }
452
    s->mv_penalty= mv_penalty;
453
    s->fcode_tab= fcode_tab;
454
    s->min_qcoeff=-255;
455
    s->max_qcoeff= 255;
456
    s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
457
    s->inter_quant_bias= 0;
458
}
459

    
460
static inline void encode_dc(MpegEncContext *s, int diff, int component)
461
{
462
    if (component == 0) {
463
        put_bits(
464
            &s->pb, 
465
            mpeg1_lum_dc_uni[diff+255]&0xFF,
466
            mpeg1_lum_dc_uni[diff+255]>>8);
467
    } else {
468
        put_bits(
469
            &s->pb, 
470
            mpeg1_chr_dc_uni[diff+255]&0xFF,
471
            mpeg1_chr_dc_uni[diff+255]>>8);
472
    }
473
}
474

    
475
static void mpeg1_encode_block(MpegEncContext *s, 
476
                               DCTELEM *block, 
477
                               int n)
478
{
479
    int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
480
    int code, component;
481
//    RLTable *rl = &rl_mpeg1;
482

    
483
    last_index = s->block_last_index[n];
484

    
485
    /* DC coef */
486
    if (s->mb_intra) {
487
        component = (n <= 3 ? 0 : n - 4 + 1);
488
        dc = block[0]; /* overflow is impossible */
489
        diff = dc - s->last_dc[component];
490
        encode_dc(s, diff, component);
491
        s->last_dc[component] = dc;
492
        i = 1;
493
    } else {
494
        /* encode the first coefficient : needs to be done here because
495
           it is handled slightly differently */
496
        level = block[0];
497
        if (abs(level) == 1) {
498
                code = ((UINT32)level >> 31); /* the sign bit */
499
                put_bits(&s->pb, 2, code | 0x02);
500
                i = 1;
501
        } else {
502
            i = 0;
503
            last_non_zero = -1;
504
            goto next_coef;
505
        }
506
    }
507

    
508
    /* now quantify & encode AC coefs */
509
    last_non_zero = i - 1;
510

    
511
    for(;i<=last_index;i++) {
512
        j = zigzag_direct[i];
513
        level = block[j];
514
    next_coef:
515
#if 0
516
        if (level != 0)
517
            dprintf("level[%d]=%d\n", i, level);
518
#endif            
519
        /* encode using VLC */
520
        if (level != 0) {
521
            run = i - last_non_zero - 1;
522
#ifdef ARCH_X86
523
            asm volatile(
524
                "movl %2, %1                \n\t"
525
                "movl %1, %0                \n\t"
526
                "addl %1, %1                \n\t"
527
                "sbbl %1, %1                \n\t"
528
                "xorl %1, %0                \n\t"
529
                "subl %1, %0                \n\t"
530
                "andl $1, %1                \n\t"
531
                : "=&r" (alevel), "=&r" (sign)
532
                : "g" (level)
533
            );
534
#else
535
            sign = 0;
536
            alevel = level;
537
            if (alevel < 0) {
538
                sign = 1;
539
                alevel = -alevel;
540
            }
541
#endif
542
//            code = get_rl_index(rl, 0, run, alevel);
543
            if (alevel > mpeg1_max_level[0][run])
544
                code= 111; /*rl->n*/
545
            else
546
                code= mpeg1_index_run[0][run] + alevel - 1;
547

    
548
            if (code < 111 /* rl->n */) {
549
                    /* store the vlc & sign at once */
550
                put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
551
            } else {
552
                /* escape seems to be pretty rare <5% so i dont optimize it */
553
                put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
554
                /* escape: only clip in this case */
555
                put_bits(&s->pb, 6, run);
556
                if (alevel < 128) {
557
                    put_bits(&s->pb, 8, level & 0xff);
558
                } else {
559
                    if (level < 0) {
560
                        put_bits(&s->pb, 16, 0x8001 + level + 255);
561
                    } else {
562
                        put_bits(&s->pb, 16, level & 0xffff);
563
                    }
564
                }
565
            }
566
            last_non_zero = i;
567
        }
568
    }
569
    /* end of block */
570
    put_bits(&s->pb, 2, 0x2);
571
}
572

    
573
/******************************************/
574
/* decoding */
575

    
576
static VLC dc_lum_vlc;
577
static VLC dc_chroma_vlc;
578
static VLC mv_vlc;
579
static VLC mbincr_vlc;
580
static VLC mb_ptype_vlc;
581
static VLC mb_btype_vlc;
582
static VLC mb_pat_vlc;
583

    
584
void mpeg1_init_vlc(MpegEncContext *s)
585
{
586
    static int done = 0;
587

    
588
    if (!done) {
589
        done = 1;
590

    
591
        init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12, 
592
                 vlc_dc_lum_bits, 1, 1,
593
                 vlc_dc_lum_code, 2, 2);
594
        init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12, 
595
                 vlc_dc_chroma_bits, 1, 1,
596
                 vlc_dc_chroma_code, 2, 2);
597
        init_vlc(&mv_vlc, MV_VLC_BITS, 17, 
598
                 &mbMotionVectorTable[0][1], 2, 1,
599
                 &mbMotionVectorTable[0][0], 2, 1);
600
        init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 35, 
601
                 &mbAddrIncrTable[0][1], 2, 1,
602
                 &mbAddrIncrTable[0][0], 2, 1);
603
        init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63, 
604
                 &mbPatTable[0][1], 2, 1,
605
                 &mbPatTable[0][0], 2, 1);
606
        
607
        init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 32, 
608
                 &table_mb_ptype[0][1], 2, 1,
609
                 &table_mb_ptype[0][0], 2, 1);
610
        init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 32, 
611
                 &table_mb_btype[0][1], 2, 1,
612
                 &table_mb_btype[0][0], 2, 1);
613
        init_rl(&rl_mpeg1);
614
        init_rl(&rl_mpeg2);
615

    
616
        init_2d_vlc_rl(&rl_mpeg1);
617
        init_2d_vlc_rl(&rl_mpeg2);
618
    }
619
}
620

    
621
static inline int get_dmv(MpegEncContext *s)
622
{
623
    if(get_bits1(&s->gb)) 
624
        return 1 - (get_bits1(&s->gb) << 1);
625
    else
626
        return 0;
627
}
628

    
629
static inline int get_qscale(MpegEncContext *s)
630
{
631
    int qscale;
632
    if (s->mpeg2) {
633
        if (s->q_scale_type) {
634
            qscale = non_linear_qscale[get_bits(&s->gb, 5)];
635
        } else {
636
            qscale = get_bits(&s->gb, 5) << 1;
637
        }
638
    } else {
639
        /* for mpeg1, we use the generic unquant code */
640
        qscale = get_bits(&s->gb, 5);
641
    }
642
    return qscale;
643
}
644

    
645
/* motion type (for mpeg2) */
646
#define MT_FIELD 1
647
#define MT_FRAME 2
648
#define MT_16X8  2
649
#define MT_DMV   3
650

    
651
static int mpeg_decode_mb(MpegEncContext *s,
652
                          DCTELEM block[6][64])
653
{
654
    int i, j, k, cbp, val, code, mb_type, motion_type;
655
    
656
    /* skip mb handling */
657
    if (s->mb_incr == 0) {
658
        /* read again increment */
659
        s->mb_incr = 1;
660
        for(;;) {
661
            code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
662
            if (code < 0)
663
                return 1; /* error = end of slice */
664
            if (code >= 33) {
665
                if (code == 33) {
666
                    s->mb_incr += 33;
667
                }
668
                /* otherwise, stuffing, nothing to do */
669
            } else {
670
                s->mb_incr += code;
671
                break;
672
            }
673
        }
674
    }
675
    if(s->mb_x==-1 /* first MB in a slice */ && s->mb_incr>1){
676
        s->mb_x+= (s->mb_incr - 1) % s->mb_width;
677
        s->mb_y+= (s->mb_incr - 1) / s->mb_width;
678
        s->mb_incr= 1;
679
    }
680

    
681
    if (++s->mb_x >= s->mb_width) {
682
        s->mb_x = 0;
683
        if (s->mb_y >= (s->mb_height - 1)){
684
            fprintf(stderr, "slice too long\n");
685
            return -1;
686
        }
687
        s->mb_y++;
688
    }
689
    dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
690

    
691
    if (--s->mb_incr != 0) {
692
        /* skip mb */
693
        s->mb_intra = 0;
694
        for(i=0;i<6;i++)
695
            s->block_last_index[i] = -1;
696
        s->mv_type = MV_TYPE_16X16;
697
        if (s->pict_type == P_TYPE) {
698
            /* if P type, zero motion vector is implied */
699
            s->mv_dir = MV_DIR_FORWARD;
700
            s->mv[0][0][0] = s->mv[0][0][1] = 0;
701
            s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
702
            s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
703
        } else {
704
            /* if B type, reuse previous vectors and directions */
705
            s->mv[0][0][0] = s->last_mv[0][0][0];
706
            s->mv[0][0][1] = s->last_mv[0][0][1];
707
            s->mv[1][0][0] = s->last_mv[1][0][0];
708
            s->mv[1][0][1] = s->last_mv[1][0][1];
709
        }
710
        s->mb_skiped = 1;
711
        return 0;
712
    }
713

    
714
    switch(s->pict_type) {
715
    default:
716
    case I_TYPE:
717
        if (get_bits1(&s->gb) == 0) {
718
            if (get_bits1(&s->gb) == 0)
719
                return -1;
720
            mb_type = MB_QUANT | MB_INTRA;
721
        } else {
722
            mb_type = MB_INTRA;
723
        }
724
        break;
725
    case P_TYPE:
726
        mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
727
        if (mb_type < 0){
728
            fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
729
            return -1;
730
        }
731
        break;
732
    case B_TYPE:
733
        mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
734
        if (mb_type < 0){
735
            fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
736
            return -1;
737
        }
738
        break;
739
    }
740
    dprintf("mb_type=%x\n", mb_type);
741
    motion_type = 0; /* avoid warning */
742
    if (mb_type & (MB_FOR|MB_BACK)) {
743
        /* get additionnal motion vector type */
744
        if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) 
745
            motion_type = MT_FRAME;
746
        else
747
            motion_type = get_bits(&s->gb, 2);
748
    }
749
    /* compute dct type */
750
    if (s->picture_structure == PICT_FRAME && 
751
        !s->frame_pred_frame_dct &&
752
        (mb_type & (MB_PAT | MB_INTRA))) {
753
        s->interlaced_dct = get_bits1(&s->gb);
754
#ifdef DEBUG
755
        if (s->interlaced_dct)
756
            printf("interlaced_dct\n");
757
#endif
758
    } else {
759
        s->interlaced_dct = 0; /* frame based */
760
    }
761

    
762
    if (mb_type & MB_QUANT) {
763
        s->qscale = get_qscale(s);
764
    }
765
    if (mb_type & MB_INTRA) {
766
        if (s->concealment_motion_vectors) {
767
            /* just parse them */
768
            if (s->picture_structure != PICT_FRAME) 
769
                skip_bits1(&s->gb); /* field select */
770
            mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
771
            mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
772
        }
773
        s->mb_intra = 1;
774
        cbp = 0x3f;
775
        memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
776
    } else {
777
        s->mb_intra = 0;
778
        cbp = 0;
779
    }
780
    /* special case of implicit zero motion vector */
781
    if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
782
        s->mv_dir = MV_DIR_FORWARD;
783
        s->mv_type = MV_TYPE_16X16;
784
        s->last_mv[0][0][0] = 0;
785
        s->last_mv[0][0][1] = 0;
786
        s->last_mv[0][1][0] = 0;
787
        s->last_mv[0][1][1] = 0;
788
        s->mv[0][0][0] = 0;
789
        s->mv[0][0][1] = 0;
790
    } else if (mb_type & (MB_FOR | MB_BACK)) {
791
        /* motion vectors */
792
        s->mv_dir = 0;
793
        for(i=0;i<2;i++) {
794
            if (mb_type & (MB_FOR >> i)) {
795
                s->mv_dir |= (MV_DIR_FORWARD >> i);
796
                dprintf("motion_type=%d\n", motion_type);
797
                switch(motion_type) {
798
                case MT_FRAME: /* or MT_16X8 */
799
                    if (s->picture_structure == PICT_FRAME) {
800
                        /* MT_FRAME */
801
                        s->mv_type = MV_TYPE_16X16;
802
                        for(k=0;k<2;k++) {
803
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k], 
804
                                                     s->last_mv[i][0][k]);
805
                            s->last_mv[i][0][k] = val;
806
                            s->last_mv[i][1][k] = val;
807
                            /* full_pel: only for mpeg1 */
808
                            if (s->full_pel[i])
809
                                val = val << 1;
810
                            s->mv[i][0][k] = val;
811
                            dprintf("mv%d: %d\n", k, val);
812
                        }
813
                    } else {
814
                        /* MT_16X8 */
815
                        s->mv_type = MV_TYPE_16X8;
816
                        for(j=0;j<2;j++) {
817
                            s->field_select[i][j] = get_bits1(&s->gb);
818
                            for(k=0;k<2;k++) {
819
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
820
                                                         s->last_mv[i][j][k]);
821
                                s->last_mv[i][j][k] = val;
822
                                s->mv[i][j][k] = val;
823
                            }
824
                        }
825
                    }
826
                    break;
827
                case MT_FIELD:
828
                    if (s->picture_structure == PICT_FRAME) {
829
                        s->mv_type = MV_TYPE_FIELD;
830
                        for(j=0;j<2;j++) {
831
                            s->field_select[i][j] = get_bits1(&s->gb);
832
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
833
                                                     s->last_mv[i][j][0]);
834
                            s->last_mv[i][j][0] = val;
835
                            s->mv[i][j][0] = val;
836
                            dprintf("fmx=%d\n", val);
837
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
838
                                                     s->last_mv[i][j][1] >> 1);
839
                            s->last_mv[i][j][1] = val << 1;
840
                            s->mv[i][j][1] = val;
841
                            dprintf("fmy=%d\n", val);
842
                        }
843
                    } else {
844
                        s->mv_type = MV_TYPE_16X16;
845
                        s->field_select[i][0] = get_bits1(&s->gb);
846
                        for(k=0;k<2;k++) {
847
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
848
                                                     s->last_mv[i][0][k]);
849
                            s->last_mv[i][0][k] = val;
850
                            s->last_mv[i][1][k] = val;
851
                            s->mv[i][0][k] = val;
852
                        }
853
                    }
854
                    break;
855
                case MT_DMV:
856
                    {
857
                        int dmx, dmy, mx, my, m;
858

    
859
                        mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0], 
860
                                                s->last_mv[i][0][0]);
861
                        s->last_mv[i][0][0] = mx;
862
                        s->last_mv[i][1][0] = mx;
863
                        dmx = get_dmv(s);
864
                        my = mpeg_decode_motion(s, s->mpeg_f_code[i][1], 
865
                                                s->last_mv[i][0][1] >> 1);
866
                        dmy = get_dmv(s);
867
                        s->mv_type = MV_TYPE_DMV;
868
                        /* XXX: totally broken */
869
                        if (s->picture_structure == PICT_FRAME) {
870
                            s->last_mv[i][0][1] = my << 1;
871
                            s->last_mv[i][1][1] = my << 1;
872

    
873
                            m = s->top_field_first ? 1 : 3;
874
                            /* top -> top pred */
875
                            s->mv[i][0][0] = mx; 
876
                            s->mv[i][0][1] = my << 1;
877
                            s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
878
                            s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
879
                            m = 4 - m;
880
                            s->mv[i][2][0] = mx;
881
                            s->mv[i][2][1] = my << 1;
882
                            s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
883
                            s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
884
                        } else {
885
                            s->last_mv[i][0][1] = my;
886
                            s->last_mv[i][1][1] = my;
887
                            s->mv[i][0][0] = mx;
888
                            s->mv[i][0][1] = my;
889
                            s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
890
                            s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1 
891
                                /* + 2 * cur_field */;
892
                        }
893
                    }
894
                    break;
895
                }
896
            }
897
        }
898
    }
899

    
900
    if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
901
        skip_bits1(&s->gb); /* marker */
902
    }
903
    
904
    if (mb_type & MB_PAT) {
905
        cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
906
        if (cbp < 0){
907
            fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
908
            return -1;
909
        }
910
        cbp++;
911
    }
912
    dprintf("cbp=%x\n", cbp);
913

    
914
    if (s->mpeg2) {
915
        if (s->mb_intra) {
916
            for(i=0;i<6;i++) {
917
                if (cbp & (1 << (5 - i))) {
918
                    if (mpeg2_decode_block_intra(s, block[i], i) < 0)
919
                        return -1;
920
                } else {
921
                    s->block_last_index[i] = -1;
922
                }
923
            }
924
        } else {
925
            for(i=0;i<6;i++) {
926
                if (cbp & (1 << (5 - i))) {
927
                    if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
928
                        return -1;
929
                } else {
930
                    s->block_last_index[i] = -1;
931
                }
932
            }
933
        }
934
    } else {
935
        for(i=0;i<6;i++) {
936
            if (cbp & (1 << (5 - i))) {
937
                if (mpeg1_decode_block(s, block[i], i) < 0)
938
                    return -1;
939
            } else {
940
                s->block_last_index[i] = -1;
941
            }
942
        }
943
    }
944
    return 0;
945
}
946

    
947
/* as h263, but only 17 codes */
948
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
949
{
950
    int code, sign, val, m, l, shift;
951

    
952
    code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
953
    if (code < 0) {
954
        return 0xffff;
955
    }
956
    if (code == 0) {
957
        return pred;
958
    }
959
    sign = get_bits1(&s->gb);
960
    shift = fcode - 1;
961
    val = (code - 1) << shift;
962
    if (shift > 0)
963
        val |= get_bits(&s->gb, shift);
964
    val++;
965
    if (sign)
966
        val = -val;
967
    val += pred;
968
    
969
    /* modulo decoding */
970
    l = (1 << shift) * 16;
971
    m = 2 * l;
972
    if (val < -l) {
973
        val += m;
974
    } else if (val >= l) {
975
        val -= m;
976
    }
977
    return val;
978
}
979

    
980
static inline int decode_dc(MpegEncContext *s, int component)
981
{
982
    int code, diff;
983

    
984
    if (component == 0) {
985
        code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
986
    } else {
987
        code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
988
    }
989
    if (code < 0){
990
        fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
991
        return 0xffff;
992
    }
993
    if (code == 0) {
994
        diff = 0;
995
    } else {
996
        diff = get_bits(&s->gb, code);
997
        if ((diff & (1 << (code - 1))) == 0) 
998
            diff = (-1 << code) | (diff + 1);
999
    }
1000
    return diff;
1001
}
1002

    
1003
static int mpeg1_decode_block(MpegEncContext *s, 
1004
                               DCTELEM *block, 
1005
                               int n)
1006
{
1007
    int level, dc, diff, i, j, run;
1008
    int code, component;
1009
    RLTable *rl = &rl_mpeg1;
1010

    
1011
    if (s->mb_intra) {
1012
        /* DC coef */
1013
        component = (n <= 3 ? 0 : n - 4 + 1);
1014
        diff = decode_dc(s, component);
1015
        if (diff >= 0xffff)
1016
            return -1;
1017
        dc = s->last_dc[component];
1018
        dc += diff;
1019
        s->last_dc[component] = dc;
1020
        block[0] = dc;
1021
        dprintf("dc=%d diff=%d\n", dc, diff);
1022
        i = 1;
1023
    } else {
1024
        int v;
1025
        OPEN_READER(re, &s->gb);
1026
        i = 0;
1027
        /* special case for the first coef. no need to add a second vlc table */
1028
        UPDATE_CACHE(re, &s->gb);
1029
        v= SHOW_UBITS(re, &s->gb, 2);
1030
        if (v & 2) {
1031
            run = 0;
1032
            level = 1 - ((v & 1) << 1);
1033
            SKIP_BITS(re, &s->gb, 2);
1034
            CLOSE_READER(re, &s->gb);
1035
            goto add_coef;
1036
        }
1037
        CLOSE_READER(re, &s->gb);
1038
    }
1039

    
1040
    /* now quantify & encode AC coefs */
1041
    for(;;) {
1042
        code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1043
        if (code < 0) {
1044
            return -1;
1045
        }
1046
        if (code == 112) {
1047
            break;
1048
        } else if (code == 111) {
1049
            /* escape */
1050
            run = get_bits(&s->gb, 6);
1051
            level = get_bits(&s->gb, 8);
1052
            level= (level + ((-1)<<7)) ^ ((-1)<<7); //sign extension
1053
            if (level == -128) {
1054
                level = get_bits(&s->gb, 8) - 256;
1055
            } else if (level == 0) {
1056
                level = get_bits(&s->gb, 8);
1057
            }
1058
        } else {
1059
            run = rl->table_run[code];
1060
            level = rl->table_level[code];
1061
            if (get_bits1(&s->gb))
1062
                level = -level;
1063
        }
1064
        i += run;
1065
        if (i >= 64)
1066
            return -1;
1067
    add_coef:
1068
        dprintf("%d: run=%d level=%d\n", n, run, level);
1069
        j = zigzag_direct[i];
1070
        block[j] = level;
1071
        i++;
1072
    }
1073
    s->block_last_index[n] = i-1;
1074
    return 0;
1075
}
1076

    
1077
/* Also does unquantization here, since I will never support mpeg2
1078
   encoding */
1079
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
1080
                                        DCTELEM *block, 
1081
                                        int n)
1082
{
1083
    int level, i, j, run;
1084
    int code;
1085
    RLTable *rl = &rl_mpeg1;
1086
    const UINT8 *scan_table;
1087
    const UINT16 *matrix;
1088
    int mismatch;
1089

    
1090
    if (s->alternate_scan)
1091
        scan_table = ff_alternate_vertical_scan;
1092
    else
1093
        scan_table = zigzag_direct;
1094
    mismatch = 1;
1095

    
1096
    {
1097
        int v;
1098
        OPEN_READER(re, &s->gb);
1099
        i = 0;
1100
        if (n < 4)
1101
            matrix = s->inter_matrix;
1102
        else
1103
            matrix = s->chroma_inter_matrix;
1104

    
1105
        /* special case for the first coef. no need to add a second vlc table */
1106
        UPDATE_CACHE(re, &s->gb);
1107
        v= SHOW_UBITS(re, &s->gb, 2);
1108
        if (v & 2) {
1109
            run = 0;
1110
            level = 1 - ((v & 1) << 1);
1111
            SKIP_BITS(re, &s->gb, 2);
1112
            CLOSE_READER(re, &s->gb);
1113
            goto add_coef;
1114
        }
1115
        CLOSE_READER(re, &s->gb);
1116
    }
1117

    
1118
    /* now quantify & encode AC coefs */
1119
    for(;;) {
1120
        code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1121
        if (code < 0){
1122
            fprintf(stderr, "invalid ac code at %d %d\n", s->mb_x, s->mb_y);
1123
            return -1;
1124
        }
1125
        if (code == 112) {
1126
            break;
1127
        } else if (code == 111) {
1128
            /* escape */
1129
            run = get_bits(&s->gb, 6);
1130
            level = get_bits(&s->gb, 12);
1131
            level= (level + ((-1)<<11)) ^ ((-1)<<11); //sign extension
1132
        } else {
1133
            run = rl->table_run[code];
1134
            level = rl->table_level[code];
1135
            if (get_bits1(&s->gb))
1136
                level = -level;
1137
        }
1138
        i += run;
1139
        if (i >= 64){
1140
            fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
1141
            return -1;
1142
        }
1143
    add_coef:
1144
        j = scan_table[i];
1145
        dprintf("%d: run=%d level=%d\n", n, run, level);
1146
        /* XXX: optimize */
1147
        if (level > 0) {
1148
            level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1149
        } else {
1150
            level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1151
            level = -level;
1152
        }
1153
        /* XXX: is it really necessary to saturate since the encoder
1154
           knows whats going on ? */
1155
        mismatch ^= level;
1156
        block[j] = level;
1157
        i++;
1158
    }
1159
    block[63] ^= (mismatch & 1);
1160
    s->block_last_index[n] = i;
1161
    return 0;
1162
}
1163

    
1164
static int mpeg2_decode_block_intra(MpegEncContext *s, 
1165
                                    DCTELEM *block, 
1166
                                    int n)
1167
{
1168
    int level, dc, diff, i, j, run;
1169
    int code, component;
1170
    RLTable *rl;
1171
    const UINT8 *scan_table;
1172
    const UINT16 *matrix;
1173
    int mismatch;
1174

    
1175
    if (s->alternate_scan)
1176
        scan_table = ff_alternate_vertical_scan;
1177
    else
1178
        scan_table = zigzag_direct;
1179

    
1180
    /* DC coef */
1181
    component = (n <= 3 ? 0 : n - 4 + 1);
1182
    diff = decode_dc(s, component);
1183
    if (diff >= 0xffff)
1184
        return -1;
1185
    dc = s->last_dc[component];
1186
    dc += diff;
1187
    s->last_dc[component] = dc;
1188
    block[0] = dc << (3 - s->intra_dc_precision);
1189
    dprintf("dc=%d\n", block[0]);
1190
    mismatch = block[0] ^ 1;
1191
    i = 1;
1192
    if (s->intra_vlc_format)
1193
        rl = &rl_mpeg2;
1194
    else
1195
        rl = &rl_mpeg1;
1196
    if (n < 4) 
1197
        matrix = s->intra_matrix;
1198
    else
1199
        matrix = s->chroma_intra_matrix;
1200

    
1201
    /* now quantify & encode AC coefs */
1202
    for(;;) {
1203
        code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1204
        if (code < 0){
1205
            fprintf(stderr, "invalid ac code at %d %d\n", s->mb_x, s->mb_y);
1206
            return -1;
1207
        }
1208
        if (code == 112) {
1209
            break;
1210
        } else if (code == 111) {
1211
            /* escape */
1212
            run = get_bits(&s->gb, 6);
1213
            level = get_bits(&s->gb, 12);
1214
            level= (level + ((-1)<<11)) ^ ((-1)<<11); //sign extension
1215
        } else {
1216
            run = rl->table_run[code];
1217
            level = rl->table_level[code];
1218
            if (get_bits1(&s->gb))
1219
                level = -level;
1220
        }
1221
        i += run;
1222
        if (i >= 64){
1223
            fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
1224
            return -1;
1225
        }
1226
        j = scan_table[i];
1227
        dprintf("%d: run=%d level=%d\n", n, run, level);
1228
        level = (level * s->qscale * matrix[j]) / 16;
1229
        /* XXX: is it really necessary to saturate since the encoder
1230
           knows whats going on ? */
1231
        mismatch ^= level;
1232
        block[j] = level;
1233
        i++;
1234
    }
1235
    block[63] ^= (mismatch & 1);
1236
    s->block_last_index[n] = i;
1237
    return 0;
1238
}
1239

    
1240
/* compressed picture size */
1241
#define PICTURE_BUFFER_SIZE 100000
1242

    
1243
typedef struct Mpeg1Context {
1244
    MpegEncContext mpeg_enc_ctx;
1245
    UINT32 header_state;
1246
    int start_code; /* current start code */
1247
    UINT8 buffer[PICTURE_BUFFER_SIZE]; 
1248
    UINT8 *buf_ptr;
1249
    int buffer_size;
1250
    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1251
    int repeat_field; /* true if we must repeat the field */
1252
} Mpeg1Context;
1253

    
1254
static int mpeg_decode_init(AVCodecContext *avctx)
1255
{
1256
    Mpeg1Context *s = avctx->priv_data;
1257
    
1258
    s->mpeg_enc_ctx.flags= avctx->flags;
1259
    common_init(&s->mpeg_enc_ctx);
1260

    
1261
    s->header_state = 0xff;
1262
    s->mpeg_enc_ctx_allocated = 0;
1263
    s->buffer_size = PICTURE_BUFFER_SIZE;
1264
    s->start_code = -1;
1265
    s->buf_ptr = s->buffer;
1266
    s->mpeg_enc_ctx.picture_number = 0;
1267
    s->repeat_field = 0;
1268
    s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1269
    avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1270
    return 0;
1271
}
1272

    
1273
/* return the 8 bit start code value and update the search
1274
   state. Return -1 if no start code found */
1275
static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end, 
1276
                           UINT32 *header_state)
1277
{
1278
    UINT8 *buf_ptr;
1279
    unsigned int state, v;
1280
    int val;
1281

    
1282
    state = *header_state;
1283
    buf_ptr = *pbuf_ptr;
1284
    while (buf_ptr < buf_end) {
1285
        v = *buf_ptr++;
1286
        if (state == 0x000001) {
1287
            state = ((state << 8) | v) & 0xffffff;
1288
            val = state;
1289
            goto found;
1290
        }
1291
        state = ((state << 8) | v) & 0xffffff;
1292
    }
1293
    val = -1;
1294
 found:
1295
    *pbuf_ptr = buf_ptr;
1296
    *header_state = state;
1297
    return val;
1298
}
1299

    
1300
static int mpeg1_decode_picture(AVCodecContext *avctx, 
1301
                                UINT8 *buf, int buf_size)
1302
{
1303
    Mpeg1Context *s1 = avctx->priv_data;
1304
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1305
    int ref, f_code;
1306

    
1307
    init_get_bits(&s->gb, buf, buf_size);
1308

    
1309
    ref = get_bits(&s->gb, 10); /* temporal ref */
1310
    s->pict_type = get_bits(&s->gb, 3);
1311
    dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1312
    skip_bits(&s->gb, 16);
1313
    if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1314
        s->full_pel[0] = get_bits1(&s->gb);
1315
        f_code = get_bits(&s->gb, 3);
1316
        if (f_code == 0)
1317
            return -1;
1318
        s->mpeg_f_code[0][0] = f_code;
1319
        s->mpeg_f_code[0][1] = f_code;
1320
    }
1321
    if (s->pict_type == B_TYPE) {
1322
        s->full_pel[1] = get_bits1(&s->gb);
1323
        f_code = get_bits(&s->gb, 3);
1324
        if (f_code == 0)
1325
            return -1;
1326
        s->mpeg_f_code[1][0] = f_code;
1327
        s->mpeg_f_code[1][1] = f_code;
1328
    }
1329
    s->y_dc_scale = 8;
1330
    s->c_dc_scale = 8;
1331
    s->first_slice = 1;
1332
    return 0;
1333
}
1334

    
1335
static void mpeg_decode_sequence_extension(MpegEncContext *s)
1336
{
1337
    int horiz_size_ext, vert_size_ext;
1338
    int bit_rate_ext, vbv_buf_ext, low_delay;
1339
    int frame_rate_ext_n, frame_rate_ext_d;
1340

    
1341
    skip_bits(&s->gb, 8); /* profil and level */
1342
    s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1343
    skip_bits(&s->gb, 2); /* chroma_format */
1344
    horiz_size_ext = get_bits(&s->gb, 2);
1345
    vert_size_ext = get_bits(&s->gb, 2);
1346
    s->width |= (horiz_size_ext << 12);
1347
    s->height |= (vert_size_ext << 12);
1348
    bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1349
    s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1350
    skip_bits1(&s->gb); /* marker */
1351
    vbv_buf_ext = get_bits(&s->gb, 8);
1352
    low_delay = get_bits1(&s->gb);
1353
    frame_rate_ext_n = get_bits(&s->gb, 2);
1354
    frame_rate_ext_d = get_bits(&s->gb, 5);
1355
    if (frame_rate_ext_d >= 1)
1356
        s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1357
    dprintf("sequence extension\n");
1358
    s->mpeg2 = 1;
1359
    s->avctx->sub_id = 2; /* indicates mpeg2 found */
1360
}
1361

    
1362
static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1363
{
1364
    int i, v, j;
1365

    
1366
    dprintf("matrix extension\n");
1367

    
1368
    if (get_bits1(&s->gb)) {
1369
        for(i=0;i<64;i++) {
1370
            v = get_bits(&s->gb, 8);
1371
            j = zigzag_direct[i];
1372
            s->intra_matrix[j] = v;
1373
            s->chroma_intra_matrix[j] = v;
1374
        }
1375
    }
1376
    if (get_bits1(&s->gb)) {
1377
        for(i=0;i<64;i++) {
1378
            v = get_bits(&s->gb, 8);
1379
            j = zigzag_direct[i];
1380
            s->inter_matrix[j] = v;
1381
            s->chroma_inter_matrix[j] = v;
1382
        }
1383
    }
1384
    if (get_bits1(&s->gb)) {
1385
        for(i=0;i<64;i++) {
1386
            v = get_bits(&s->gb, 8);
1387
            j = zigzag_direct[i];
1388
            s->chroma_intra_matrix[j] = v;
1389
        }
1390
    }
1391
    if (get_bits1(&s->gb)) {
1392
        for(i=0;i<64;i++) {
1393
            v = get_bits(&s->gb, 8);
1394
            j = zigzag_direct[i];
1395
            s->chroma_inter_matrix[j] = v;
1396
        }
1397
    }
1398
}
1399

    
1400
static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1401
{
1402
    s->full_pel[0] = s->full_pel[1] = 0;
1403
    s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1404
    s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1405
    s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1406
    s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1407
    s->intra_dc_precision = get_bits(&s->gb, 2);
1408
    s->picture_structure = get_bits(&s->gb, 2);
1409
    s->top_field_first = get_bits1(&s->gb);
1410
    s->frame_pred_frame_dct = get_bits1(&s->gb);
1411
    s->concealment_motion_vectors = get_bits1(&s->gb);
1412
    s->q_scale_type = get_bits1(&s->gb);
1413
    s->intra_vlc_format = get_bits1(&s->gb);
1414
    s->alternate_scan = get_bits1(&s->gb);
1415
    s->repeat_first_field = get_bits1(&s->gb);
1416
    s->chroma_420_type = get_bits1(&s->gb);
1417
    s->progressive_frame = get_bits1(&s->gb);
1418
    /* composite display not parsed */
1419
    dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1420
    dprintf("picture_structure=%d\n", s->picture_structure);
1421
    dprintf("top field first=%d\n", s->top_field_first);
1422
    dprintf("repeat first field=%d\n", s->repeat_first_field);
1423
    dprintf("conceal=%d\n", s->concealment_motion_vectors);
1424
    dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1425
    dprintf("alternate_scan=%d\n", s->alternate_scan);
1426
    dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1427
    dprintf("progressive_frame=%d\n", s->progressive_frame);
1428
}
1429

    
1430
static void mpeg_decode_extension(AVCodecContext *avctx, 
1431
                                  UINT8 *buf, int buf_size)
1432
{
1433
    Mpeg1Context *s1 = avctx->priv_data;
1434
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1435
    int ext_type;
1436

    
1437
    init_get_bits(&s->gb, buf, buf_size);
1438
    
1439
    ext_type = get_bits(&s->gb, 4);
1440
    switch(ext_type) {
1441
    case 0x1:
1442
        /* sequence ext */
1443
        mpeg_decode_sequence_extension(s);
1444
        break;
1445
    case 0x3:
1446
        /* quant matrix extension */
1447
        mpeg_decode_quant_matrix_extension(s);
1448
        break;
1449
    case 0x8:
1450
        /* picture extension */
1451
        mpeg_decode_picture_coding_extension(s);
1452
        break;
1453
    }
1454
}
1455

    
1456
/* return 1 if end of frame */
1457
static int mpeg_decode_slice(AVCodecContext *avctx, 
1458
                              AVPicture *pict,
1459
                              int start_code,
1460
                              UINT8 *buf, int buf_size)
1461
{
1462
    Mpeg1Context *s1 = avctx->priv_data;
1463
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1464
    int ret;
1465

    
1466
    start_code = (start_code - 1) & 0xff;
1467
    if (start_code >= s->mb_height){
1468
        fprintf(stderr, "slice below image\n");
1469
        return -1;
1470
    }
1471
    s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1472
    s->last_dc[1] = s->last_dc[0];
1473
    s->last_dc[2] = s->last_dc[0];
1474
    memset(s->last_mv, 0, sizeof(s->last_mv));
1475
    s->mb_x = -1;
1476
    s->mb_y = start_code;
1477
    s->mb_incr = 0;
1478
    /* start frame decoding */
1479
    if (s->first_slice) {
1480
        s->first_slice = 0;
1481
        MPV_frame_start(s, avctx);
1482
    }
1483

    
1484
    init_get_bits(&s->gb, buf, buf_size);
1485

    
1486
    s->qscale = get_qscale(s);
1487
    /* extra slice info */
1488
    while (get_bits1(&s->gb) != 0) {
1489
        skip_bits(&s->gb, 8);
1490
    }
1491

    
1492
    for(;;) {
1493
        clear_blocks(s->block[0]);
1494
        emms_c();
1495
        ret = mpeg_decode_mb(s, s->block);
1496
        dprintf("ret=%d\n", ret);
1497
        if (ret < 0)
1498
            return -1;
1499
        if (ret == 1)
1500
            break;
1501
        MPV_decode_mb(s, s->block);
1502
    }
1503
    emms_c();
1504

    
1505
    /* end of slice reached */
1506
    if (s->mb_x == (s->mb_width - 1) &&
1507
        s->mb_y == (s->mb_height - 1)) {
1508
        /* end of image */
1509
        UINT8 **picture;
1510

    
1511
        MPV_frame_end(s);
1512

    
1513
        /* XXX: incorrect reported qscale for mpeg2 */
1514
        if (s->pict_type == B_TYPE) {
1515
            picture = s->current_picture;
1516
            avctx->quality = s->qscale;
1517
        } else {
1518
            /* latency of 1 frame for I and P frames */
1519
            /* XXX: use another variable than picture_number */
1520
            if (s->picture_number == 0) {
1521
                picture = NULL;
1522
            } else {
1523
                picture = s->last_picture;
1524
                avctx->quality = s->last_qscale;
1525
            }
1526
            s->last_qscale = s->qscale;
1527
            s->picture_number++;
1528
        }
1529
        if (picture) {
1530
            pict->data[0] = picture[0];
1531
            pict->data[1] = picture[1];
1532
            pict->data[2] = picture[2];
1533
            pict->linesize[0] = s->linesize;
1534
            pict->linesize[1] = s->uvlinesize;
1535
            pict->linesize[2] = s->uvlinesize;
1536
            return 1;
1537
        } else {
1538
            return 0;
1539
        }
1540
    } else {
1541
        return 0;
1542
    }
1543
}
1544

    
1545
static int mpeg1_decode_sequence(AVCodecContext *avctx, 
1546
                                 UINT8 *buf, int buf_size)
1547
{
1548
    Mpeg1Context *s1 = avctx->priv_data;
1549
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1550
    int width, height, i, v, j;
1551

    
1552
    init_get_bits(&s->gb, buf, buf_size);
1553

    
1554
    width = get_bits(&s->gb, 12);
1555
    height = get_bits(&s->gb, 12);
1556
    skip_bits(&s->gb, 4);
1557
    s->frame_rate_index = get_bits(&s->gb, 4);
1558
    if (s->frame_rate_index == 0)
1559
        return -1;
1560
    s->bit_rate = get_bits(&s->gb, 18) * 400;
1561
    if (get_bits1(&s->gb) == 0) /* marker */
1562
        return -1;
1563
    if (width <= 0 || height <= 0 ||
1564
        (width % 2) != 0 || (height % 2) != 0)
1565
        return -1;
1566
    if (width != s->width ||
1567
        height != s->height) {
1568
        /* start new mpeg1 context decoding */
1569
        s->out_format = FMT_MPEG1;
1570
        if (s1->mpeg_enc_ctx_allocated) {
1571
            MPV_common_end(s);
1572
        }
1573
        s->width = width;
1574
        s->height = height;
1575
        avctx->has_b_frames= s->has_b_frames = 1;
1576
        s->avctx = avctx;
1577
        avctx->width = width;
1578
        avctx->height = height;
1579
        if (s->frame_rate_index >= 9) {
1580
            /* at least give a valid frame rate (some old mpeg1 have this) */
1581
            avctx->frame_rate = 25 * FRAME_RATE_BASE;
1582
        } else {
1583
            avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1584
        }
1585
        s->frame_rate = avctx->frame_rate;
1586
        avctx->bit_rate = s->bit_rate;
1587
        
1588
        if (MPV_common_init(s) < 0)
1589
            return -1;
1590
        mpeg1_init_vlc(s);
1591
        s1->mpeg_enc_ctx_allocated = 1;
1592
    }
1593

    
1594
    skip_bits(&s->gb, 10); /* vbv_buffer_size */
1595
    skip_bits(&s->gb, 1);
1596

    
1597
    /* get matrix */
1598
    if (get_bits1(&s->gb)) {
1599
        for(i=0;i<64;i++) {
1600
            v = get_bits(&s->gb, 8);
1601
            j = zigzag_direct[i];
1602
            s->intra_matrix[j] = v;
1603
            s->chroma_intra_matrix[j] = v;
1604
        }
1605
#ifdef DEBUG
1606
        dprintf("intra matrix present\n");
1607
        for(i=0;i<64;i++)
1608
            dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1609
        printf("\n");
1610
#endif
1611
    } else {
1612
        for(i=0;i<64;i++) {
1613
            v = ff_mpeg1_default_intra_matrix[i];
1614
            s->intra_matrix[i] = v;
1615
            s->chroma_intra_matrix[i] = v;
1616
        }
1617
    }
1618
    if (get_bits1(&s->gb)) {
1619
        for(i=0;i<64;i++) {
1620
            v = get_bits(&s->gb, 8);
1621
            j = zigzag_direct[i];
1622
            s->inter_matrix[j] = v;
1623
            s->chroma_inter_matrix[j] = v;
1624
        }
1625
#ifdef DEBUG
1626
        dprintf("non intra matrix present\n");
1627
        for(i=0;i<64;i++)
1628
            dprintf(" %d", s->inter_matrix[zigzag_direct[i]]);
1629
        printf("\n");
1630
#endif
1631
    } else {
1632
        for(i=0;i<64;i++) {
1633
            v = ff_mpeg1_default_non_intra_matrix[i];
1634
            s->inter_matrix[i] = v;
1635
            s->chroma_inter_matrix[i] = v;
1636
        }
1637
    }
1638

    
1639
    /* we set mpeg2 parameters so that it emulates mpeg1 */
1640
    s->progressive_sequence = 1;
1641
    s->progressive_frame = 1;
1642
    s->picture_structure = PICT_FRAME;
1643
    s->frame_pred_frame_dct = 1;
1644
    s->mpeg2 = 0;
1645
    avctx->sub_id = 1; /* indicates mpeg1 */
1646
    return 0;
1647
}
1648

    
1649
/* handle buffering and image synchronisation */
1650
static int mpeg_decode_frame(AVCodecContext *avctx, 
1651
                             void *data, int *data_size,
1652
                             UINT8 *buf, int buf_size)
1653
{
1654
    Mpeg1Context *s = avctx->priv_data;
1655
    UINT8 *buf_end, *buf_ptr, *buf_start;
1656
    int len, start_code_found, ret, code, start_code, input_size;
1657
    AVPicture *picture = data;
1658
    MpegEncContext *s2 = &s->mpeg_enc_ctx;
1659
            
1660
    dprintf("fill_buffer\n");
1661

    
1662
    *data_size = 0;
1663

    
1664
    /* special case for last picture */
1665
    if (buf_size == 0) {
1666
        if (s2->picture_number > 0) {
1667
            picture->data[0] = s2->next_picture[0];
1668
            picture->data[1] = s2->next_picture[1];
1669
            picture->data[2] = s2->next_picture[2];
1670
            picture->linesize[0] = s2->linesize;
1671
            picture->linesize[1] = s2->uvlinesize;
1672
            picture->linesize[2] = s2->uvlinesize;
1673
            *data_size = sizeof(AVPicture);
1674
        }
1675
        return 0;
1676
    }
1677

    
1678
    buf_ptr = buf;
1679
    buf_end = buf + buf_size;
1680

    
1681
#if 0    
1682
    if (s->repeat_field % 2 == 1) { 
1683
        s->repeat_field++;
1684
        //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1685
        //        s2->picture_number, s->repeat_field);
1686
        if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
1687
            *data_size = sizeof(AVPicture);
1688
            goto the_end;
1689
        }
1690
    }
1691
#endif
1692
    while (buf_ptr < buf_end) {
1693
        buf_start = buf_ptr;
1694
        /* find start next code */
1695
        code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1696
        if (code >= 0) {
1697
            start_code_found = 1;
1698
        } else {
1699
            start_code_found = 0;
1700
        }
1701
        /* copy to buffer */
1702
        len = buf_ptr - buf_start;
1703
        if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1704
            /* data too big : flush */
1705
            s->buf_ptr = s->buffer;
1706
            if (start_code_found)
1707
                s->start_code = code;
1708
        } else {
1709
            memcpy(s->buf_ptr, buf_start, len);
1710
            s->buf_ptr += len;
1711
            
1712
            if (start_code_found) {
1713
                /* prepare data for next start code */
1714
                input_size = s->buf_ptr - s->buffer;
1715
                start_code = s->start_code;
1716
                s->buf_ptr = s->buffer;
1717
                s->start_code = code;
1718
                switch(start_code) {
1719
                case SEQ_START_CODE:
1720
                    mpeg1_decode_sequence(avctx, s->buffer, 
1721
                                          input_size);
1722
                    break;
1723
                            
1724
                case PICTURE_START_CODE:
1725
                    /* we have a complete image : we try to decompress it */
1726
                    mpeg1_decode_picture(avctx, 
1727
                                         s->buffer, input_size);
1728
                    break;
1729
                case EXT_START_CODE:
1730
                    mpeg_decode_extension(avctx,
1731
                                          s->buffer, input_size);
1732
                    break;
1733
                default:
1734
                    if (start_code >= SLICE_MIN_START_CODE &&
1735
                        start_code <= SLICE_MAX_START_CODE) {
1736
                        ret = mpeg_decode_slice(avctx, picture,
1737
                                                start_code, s->buffer, input_size);
1738
                        if (ret == 1) {
1739
                            /* got a picture: exit */
1740
                            /* first check if we must repeat the frame */
1741
                            avctx->repeat_pict = 0;
1742
#if 0
1743
                            if (s2->progressive_frame && s2->repeat_first_field) {
1744
                                //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1745
                                //s2->repeat_first_field = 0;
1746
                                //s2->progressive_frame = 0;
1747
                                if (++s->repeat_field > 2)
1748
                                    s->repeat_field = 0;
1749
                                avctx->repeat_pict = 1;
1750
                            }
1751
#endif                      
1752
                            if (s2->repeat_first_field) {
1753
                                if (s2->progressive_sequence) {
1754
                                    if (s2->top_field_first)
1755
                                        avctx->repeat_pict = 4;
1756
                                    else
1757
                                        avctx->repeat_pict = 2;
1758
                                } else if (s2->progressive_frame) {
1759
                                    avctx->repeat_pict = 1;
1760
                                }
1761
                            }         
1762
                            *data_size = sizeof(AVPicture);
1763
                            goto the_end;
1764
                        }else if(ret==-1){
1765
                            printf("Error while decoding slice\n");
1766
                        }
1767
                    }
1768
                    break;
1769
                }
1770
            }
1771
        }
1772
    }
1773
 the_end:
1774
    return buf_ptr - buf;
1775
}
1776

    
1777
static int mpeg_decode_end(AVCodecContext *avctx)
1778
{
1779
    Mpeg1Context *s = avctx->priv_data;
1780

    
1781
    if (s->mpeg_enc_ctx_allocated)
1782
        MPV_common_end(&s->mpeg_enc_ctx);
1783
    return 0;
1784
}
1785

    
1786
AVCodec mpeg_decoder = {
1787
    "mpegvideo",
1788
    CODEC_TYPE_VIDEO,
1789
    CODEC_ID_MPEG1VIDEO,
1790
    sizeof(Mpeg1Context),
1791
    mpeg_decode_init,
1792
    NULL,
1793
    mpeg_decode_end,
1794
    mpeg_decode_frame,
1795
    CODEC_CAP_DR1,
1796
};