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1
/*
2
 * MPEG1 encoder / MPEG2 decoder
3
 * Copyright (c) 2000,2001 Gerard Lantau.
4
 *
5
 * This program is free software; you can redistribute it and/or modify
6
 * it under the terms of the GNU General Public License as published by
7
 * the Free Software Foundation; either version 2 of the License, or
8
 * (at your option) any later version.
9
 *
10
 * This program 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
13
 * GNU General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU General Public License
16
 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18
 */
19
//#define DEBUG
20
#include "avcodec.h"
21
#include "dsputil.h"
22
#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 ABS(a) ((a)<0 ? -(a) : (a))
37

    
38
static void mpeg1_encode_block(MpegEncContext *s, 
39
                         DCTELEM *block, 
40
                         int component);
41
static void mpeg1_encode_motion(MpegEncContext *s, int val);
42
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
43
static int mpeg1_decode_block(MpegEncContext *s, 
44
                              DCTELEM *block, 
45
                              int n);
46
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
47
                                        DCTELEM *block, 
48
                                        int n);
49
static int mpeg2_decode_block_intra(MpegEncContext *s, 
50
                                    DCTELEM *block, 
51
                                    int n);
52
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
53

    
54
static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
55
static UINT8 fcode_tab[MAX_MV*2+1];
56

    
57
static void put_header(MpegEncContext *s, int header)
58
{
59
    align_put_bits(&s->pb);
60
    put_bits(&s->pb, 16, header>>16);
61
    put_bits(&s->pb, 16, header&0xFFFF);
62
}
63

    
64
/* put sequence header if needed */
65
static void mpeg1_encode_sequence_header(MpegEncContext *s)
66
{
67
        unsigned int vbv_buffer_size;
68
        unsigned int fps, v;
69
        int n;
70
        UINT64 time_code;
71
        
72
        if (s->picture_in_gop_number == 0) {
73
            /* mpeg1 header repeated every gop */
74
            put_header(s, SEQ_START_CODE);
75
            
76
            /* search closest frame rate */
77
            {
78
                int i, dmin, d;
79
                s->frame_rate_index = 0;
80
                dmin = 0x7fffffff;
81
                for(i=1;i<9;i++) {
82
                    d = abs(s->frame_rate - frame_rate_tab[i]);
83
                    if (d < dmin) {
84
                        dmin = d;
85
                        s->frame_rate_index = i;
86
                    }
87
                }
88
            }
89
 
90
            put_bits(&s->pb, 12, s->width);
91
            put_bits(&s->pb, 12, s->height);
92
            put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
93
            put_bits(&s->pb, 4, s->frame_rate_index);
94
            v = s->bit_rate / 400;
95
            if (v > 0x3ffff)
96
                v = 0x3ffff;
97
            put_bits(&s->pb, 18, v);
98
            put_bits(&s->pb, 1, 1); /* marker */
99
            /* vbv buffer size: slightly greater than an I frame. We add
100
               some margin just in case */
101
            vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
102
            put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384); 
103
            put_bits(&s->pb, 1, 1); /* constrained parameter flag */
104
            put_bits(&s->pb, 1, 0); /* no custom intra matrix */
105
            put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
106

    
107
            put_header(s, GOP_START_CODE);
108
            put_bits(&s->pb, 1, 0); /* do drop frame */
109
            /* time code : we must convert from the real frame rate to a
110
               fake mpeg frame rate in case of low frame rate */
111
            fps = frame_rate_tab[s->frame_rate_index];
112
            time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
113
            s->gop_picture_number = s->fake_picture_number;
114
            put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
115
            put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
116
            put_bits(&s->pb, 1, 1);
117
            put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
118
            put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
119
            put_bits(&s->pb, 1, 1); /* closed gop */
120
            put_bits(&s->pb, 1, 0); /* broken link */
121
        }
122

    
123
        if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
124
            /* insert empty P pictures to slow down to the desired
125
               frame rate. Each fake pictures takes about 20 bytes */
126
            fps = frame_rate_tab[s->frame_rate_index];
127
            n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
128
            while (s->fake_picture_number < n) {
129
                mpeg1_skip_picture(s, s->fake_picture_number - 
130
                                   s->gop_picture_number); 
131
                s->fake_picture_number++;
132
            }
133

    
134
        }
135
}
136

    
137

    
138
/* insert a fake P picture */
139
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
140
{
141
    unsigned int mb_incr;
142

    
143
    /* mpeg1 picture header */
144
    put_header(s, PICTURE_START_CODE);
145
    /* temporal reference */
146
    put_bits(&s->pb, 10, pict_num & 0x3ff); 
147
    
148
    put_bits(&s->pb, 3, P_TYPE);
149
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
150
    
151
    put_bits(&s->pb, 1, 1); /* integer coordinates */
152
    put_bits(&s->pb, 3, 1); /* forward_f_code */
153
    
154
    put_bits(&s->pb, 1, 0); /* extra bit picture */
155
    
156
    /* only one slice */
157
    put_header(s, SLICE_MIN_START_CODE);
158
    put_bits(&s->pb, 5, 1); /* quantizer scale */
159
    put_bits(&s->pb, 1, 0); /* slice extra information */
160
    
161
    mb_incr = 1;
162
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
163
             mbAddrIncrTable[mb_incr - 1][0]);
164
    
165
    /* empty macroblock */
166
    put_bits(&s->pb, 3, 1); /* motion only */
167
    
168
    /* zero motion x & y */
169
    put_bits(&s->pb, 1, 1); 
170
    put_bits(&s->pb, 1, 1); 
171

    
172
    /* output a number of empty slice */
173
    mb_incr = s->mb_width * s->mb_height - 1;
174
    while (mb_incr > 33) {
175
        put_bits(&s->pb, 11, 0x008);
176
        mb_incr -= 33;
177
    }
178
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
179
             mbAddrIncrTable[mb_incr - 1][0]);
180
    
181
    /* empty macroblock */
182
    put_bits(&s->pb, 3, 1); /* motion only */
183
    
184
    /* zero motion x & y */
185
    put_bits(&s->pb, 1, 1); 
186
    put_bits(&s->pb, 1, 1); 
187
}
188

    
189
void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
190
{
191
    static int done=0;
192

    
193
    if (!done) {
194
        int i;
195
        done = 1;
196
        init_rl(&rl_mpeg1);
197
        
198
        for(i=0; i<64; i++)
199
        {
200
                mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
201
                mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
202
        }
203

    
204
        /* build unified dc encoding tables */
205
        for(i=-255; i<256; i++)
206
        {
207
                int adiff, index;
208
                int bits, code;
209
                int diff=i;
210

    
211
                adiff = ABS(diff);
212
                if(diff<0) diff--;
213
                index = vlc_dc_table[adiff];
214

    
215
                bits= vlc_dc_lum_bits[index] + index;
216
                code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
217
                mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
218
                
219
                bits= vlc_dc_chroma_bits[index] + index;
220
                code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
221
                mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
222
        }
223
    }
224
    mpeg1_encode_sequence_header(s);
225

    
226
    /* mpeg1 picture header */
227
    put_header(s, PICTURE_START_CODE);
228
    /* temporal reference */
229
    put_bits(&s->pb, 10, (s->fake_picture_number - 
230
                          s->gop_picture_number) & 0x3ff); 
231
    s->fake_picture_number++;
232
    
233
    put_bits(&s->pb, 3, s->pict_type);
234
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
235
    
236
    if (s->pict_type == P_TYPE) {
237
        put_bits(&s->pb, 1, 0); /* half pel coordinates */
238
        put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
239
    }
240
    
241
    put_bits(&s->pb, 1, 0); /* extra bit picture */
242
    
243
    /* only one slice */
244
    put_header(s, SLICE_MIN_START_CODE);
245
    put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
246
    put_bits(&s->pb, 1, 0); /* slice extra information */
247
}
248

    
249
void mpeg1_encode_mb(MpegEncContext *s,
250
                     DCTELEM block[6][64],
251
                     int motion_x, int motion_y)
252
{
253
    int mb_incr, i, cbp, mb_x, mb_y;
254

    
255
    mb_x = s->mb_x;
256
    mb_y = s->mb_y;
257

    
258
    /* compute cbp */
259
    cbp = 0;
260
    for(i=0;i<6;i++) {
261
        if (s->block_last_index[i] >= 0)
262
            cbp |= 1 << (5 - i);
263
    }
264

    
265
    /* skip macroblock, except if first or last macroblock of a slice */
266
    if ((cbp | motion_x | motion_y) == 0 &&
267
        (!((mb_x | mb_y) == 0 ||
268
           (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
269
        s->mb_incr++;
270
    } else {
271
        /* output mb incr */
272
        mb_incr = s->mb_incr;
273

    
274
        while (mb_incr > 33) {
275
            put_bits(&s->pb, 11, 0x008);
276
            mb_incr -= 33;
277
        }
278
        put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
279
                 mbAddrIncrTable[mb_incr - 1][0]);
280
        
281
        if (s->pict_type == I_TYPE) {
282
            put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
283
        } else {
284
            if (s->mb_intra) {
285
                put_bits(&s->pb, 5, 0x03);
286
            } else {
287
                if (cbp != 0) {
288
                    if (motion_x == 0 && motion_y == 0) {
289
                        put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
290
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
291
                    } else {
292
                        put_bits(&s->pb, 1, 1); /* motion + cbp */
293
                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
294
                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
295
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
296
                    }
297
                } else {
298
                    put_bits(&s->pb, 3, 1); /* motion only */
299
                    mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
300
                    mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
301
                }
302
            }
303
        }
304
        for(i=0;i<6;i++) {
305
            if (cbp & (1 << (5 - i))) {
306
                mpeg1_encode_block(s, block[i], i);
307
            }
308
        }
309
        s->mb_incr = 1;
310
    }
311
    s->last_mv[0][0][0] = motion_x;
312
    s->last_mv[0][0][1] = motion_y;
313
}
314

    
315
static void mpeg1_encode_motion(MpegEncContext *s, int val)
316
{
317
    int code, bit_size, l, m, bits, range, sign;
318

    
319
    if (val == 0) {
320
        /* zero vector */
321
        code = 0;
322
        put_bits(&s->pb,
323
                 mbMotionVectorTable[0][1], 
324
                 mbMotionVectorTable[0][0]); 
325
    } else {
326
        bit_size = s->f_code - 1;
327
        range = 1 << bit_size;
328
        /* modulo encoding */
329
        l = 16 * range;
330
        m = 2 * l;
331
        if (val < -l) {
332
            val += m;
333
        } else if (val >= l) {
334
            val -= m;
335
        }
336

    
337
        if (val >= 0) {
338
            val--;
339
            code = (val >> bit_size) + 1;
340
            bits = val & (range - 1);
341
            sign = 0;
342
        } else {
343
            val = -val;
344
            val--;
345
            code = (val >> bit_size) + 1;
346
            bits = val & (range - 1);
347
            sign = 1;
348
        }
349
        put_bits(&s->pb,
350
                 mbMotionVectorTable[code][1], 
351
                 mbMotionVectorTable[code][0]); 
352
        put_bits(&s->pb, 1, sign);
353
        if (bit_size > 0) {
354
            put_bits(&s->pb, bit_size, bits);
355
        }
356
    }
357
}
358

    
359
void mpeg1_encode_init(MpegEncContext *s)
360
{
361
    static int done=0;
362
    if(!done){
363
        int f_code;
364
        int mv;
365

    
366
        done=1;
367
        for(f_code=1; f_code<=MAX_FCODE; f_code++){
368
            for(mv=-MAX_MV; mv<=MAX_MV; mv++){
369
                int len;
370

    
371
                if(mv==0) len= mbMotionVectorTable[0][1];
372
                else{
373
                    int val, bit_size, range, code;
374

    
375
                    bit_size = s->f_code - 1;
376
                    range = 1 << bit_size;
377

    
378
                    val=mv;
379
                    if (val < 0) 
380
                        val = -val;
381
                    val--;
382
                    code = (val >> bit_size) + 1;
383
                    if(code<17){
384
                        len= mbMotionVectorTable[code][1] + 1 + bit_size;
385
                    }else{
386
                        len= mbMotionVectorTable[16][1] + 2 + bit_size;
387
                    }
388
                }
389

    
390
                mv_penalty[f_code][mv+MAX_MV]= len;
391
            }
392
        }
393
        
394

    
395
        for(f_code=MAX_FCODE; f_code>0; f_code--){
396
            for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
397
                fcode_tab[mv+MAX_MV]= f_code;
398
            }
399
        }
400
    }
401
    s->mv_penalty= mv_penalty;
402
    s->fcode_tab= fcode_tab;
403
    s->min_qcoeff=-255;
404
    s->max_qcoeff= 255;
405
    s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
406
    s->inter_quant_bias= 0;
407
}
408
 
409
static inline void encode_dc(MpegEncContext *s, int diff, int component)
410
{
411
    if (component == 0) {
412
        put_bits(
413
            &s->pb, 
414
            mpeg1_lum_dc_uni[diff+255]&0xFF,
415
            mpeg1_lum_dc_uni[diff+255]>>8);
416
    } else {
417
        put_bits(
418
            &s->pb, 
419
            mpeg1_chr_dc_uni[diff+255]&0xFF,
420
            mpeg1_chr_dc_uni[diff+255]>>8);
421
    }
422
}
423

    
424
static void mpeg1_encode_block(MpegEncContext *s, 
425
                               DCTELEM *block, 
426
                               int n)
427
{
428
    int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
429
    int code, component;
430
//    RLTable *rl = &rl_mpeg1;
431

    
432
    last_index = s->block_last_index[n];
433

    
434
    /* DC coef */
435
    if (s->mb_intra) {
436
        component = (n <= 3 ? 0 : n - 4 + 1);
437
        dc = block[0]; /* overflow is impossible */
438
        diff = dc - s->last_dc[component];
439
        encode_dc(s, diff, component);
440
        s->last_dc[component] = dc;
441
        i = 1;
442
    } else {
443
        /* encode the first coefficient : needs to be done here because
444
           it is handled slightly differently */
445
        level = block[0];
446
        if (abs(level) == 1) {
447
                code = ((UINT32)level >> 31); /* the sign bit */
448
                put_bits(&s->pb, 2, code | 0x02);
449
                i = 1;
450
        } else {
451
            i = 0;
452
            last_non_zero = -1;
453
            goto next_coef;
454
        }
455
    }
456

    
457
    /* now quantify & encode AC coefs */
458
    last_non_zero = i - 1;
459

    
460
    for(;i<=last_index;i++) {
461
        j = zigzag_direct[i];
462
        level = block[j];
463
    next_coef:
464
#if 0
465
        if (level != 0)
466
            dprintf("level[%d]=%d\n", i, level);
467
#endif            
468
        /* encode using VLC */
469
        if (level != 0) {
470
            run = i - last_non_zero - 1;
471
#ifdef ARCH_X86
472
            asm volatile(
473
                "movl %2, %1                \n\t"
474
                "movl %1, %0                \n\t"
475
                "addl %1, %1                \n\t"
476
                "sbbl %1, %1                \n\t"
477
                "xorl %1, %0                \n\t"
478
                "subl %1, %0                \n\t"
479
                "andl $1, %1                \n\t"
480
                : "=&r" (alevel), "=&r" (sign)
481
                : "g" (level)
482
            );
483
#else
484
            sign = 0;
485
            alevel = level;
486
            if (alevel < 0) {
487
                sign = 1;
488
                alevel = -alevel;
489
            }
490
#endif
491
//            code = get_rl_index(rl, 0, run, alevel);
492
            if (alevel > mpeg1_max_level[0][run])
493
                code= 111; /*rl->n*/
494
            else
495
                code= mpeg1_index_run[0][run] + alevel - 1;
496

    
497
            if (code < 111 /* rl->n */) {
498
                    /* store the vlc & sign at once */
499
                put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
500
            } else {
501
                /* escape seems to be pretty rare <5% so i dont optimize it */
502
                put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
503
                /* escape: only clip in this case */
504
                put_bits(&s->pb, 6, run);
505
                if (alevel < 128) {
506
                    put_bits(&s->pb, 8, level & 0xff);
507
                } else {
508
                    if (level < 0) {
509
                        put_bits(&s->pb, 16, 0x8001 + level + 255);
510
                    } else {
511
                        put_bits(&s->pb, 16, level & 0xffff);
512
                    }
513
                }
514
            }
515
            last_non_zero = i;
516
        }
517
    }
518
    /* end of block */
519
    put_bits(&s->pb, 2, 0x2);
520
}
521

    
522
/******************************************/
523
/* decoding */
524

    
525
static VLC dc_lum_vlc;
526
static VLC dc_chroma_vlc;
527
static VLC mv_vlc;
528
static VLC mbincr_vlc;
529
static VLC mb_ptype_vlc;
530
static VLC mb_btype_vlc;
531
static VLC mb_pat_vlc;
532

    
533
void mpeg1_init_vlc(MpegEncContext *s)
534
{
535
    static int done = 0;
536

    
537
    if (!done) {
538

    
539
        init_vlc(&dc_lum_vlc, 9, 12, 
540
                 vlc_dc_lum_bits, 1, 1,
541
                 vlc_dc_lum_code, 2, 2);
542
        init_vlc(&dc_chroma_vlc, 9, 12, 
543
                 vlc_dc_chroma_bits, 1, 1,
544
                 vlc_dc_chroma_code, 2, 2);
545
        init_vlc(&mv_vlc, 9, 17, 
546
                 &mbMotionVectorTable[0][1], 2, 1,
547
                 &mbMotionVectorTable[0][0], 2, 1);
548
        init_vlc(&mbincr_vlc, 9, 35, 
549
                 &mbAddrIncrTable[0][1], 2, 1,
550
                 &mbAddrIncrTable[0][0], 2, 1);
551
        init_vlc(&mb_pat_vlc, 9, 63, 
552
                 &mbPatTable[0][1], 2, 1,
553
                 &mbPatTable[0][0], 2, 1);
554
        
555
        init_vlc(&mb_ptype_vlc, 6, 32, 
556
                 &table_mb_ptype[0][1], 2, 1,
557
                 &table_mb_ptype[0][0], 2, 1);
558
        init_vlc(&mb_btype_vlc, 6, 32, 
559
                 &table_mb_btype[0][1], 2, 1,
560
                 &table_mb_btype[0][0], 2, 1);
561
        init_rl(&rl_mpeg1);
562
        init_rl(&rl_mpeg2);
563
        /* cannot use generic init because we must add the EOB code */
564
        init_vlc(&rl_mpeg1.vlc, 9, rl_mpeg1.n + 2, 
565
                 &rl_mpeg1.table_vlc[0][1], 4, 2,
566
                 &rl_mpeg1.table_vlc[0][0], 4, 2);
567
        init_vlc(&rl_mpeg2.vlc, 9, rl_mpeg2.n + 2, 
568
                 &rl_mpeg2.table_vlc[0][1], 4, 2,
569
                 &rl_mpeg2.table_vlc[0][0], 4, 2);
570
    }
571
}
572

    
573
static inline int get_dmv(MpegEncContext *s)
574
{
575
    if(get_bits1(&s->gb)) 
576
        return 1 - (get_bits1(&s->gb) << 1);
577
    else
578
        return 0;
579
}
580

    
581
static inline int get_qscale(MpegEncContext *s)
582
{
583
    int qscale;
584
    if (s->mpeg2) {
585
        if (s->q_scale_type) {
586
            qscale = non_linear_qscale[get_bits(&s->gb, 5)];
587
        } else {
588
            qscale = get_bits(&s->gb, 5) << 1;
589
        }
590
    } else {
591
        /* for mpeg1, we use the generic unquant code */
592
        qscale = get_bits(&s->gb, 5);
593
    }
594
    return qscale;
595
}
596

    
597
/* motion type (for mpeg2) */
598
#define MT_FIELD 1
599
#define MT_FRAME 2
600
#define MT_16X8  2
601
#define MT_DMV   3
602

    
603
static int mpeg_decode_mb(MpegEncContext *s,
604
                          DCTELEM block[6][64])
605
{
606
    int i, j, k, cbp, val, code, mb_type, motion_type;
607
    
608
    /* skip mb handling */
609
    if (s->mb_incr == 0) {
610
        /* read again increment */
611
        s->mb_incr = 1;
612
        for(;;) {
613
            code = get_vlc(&s->gb, &mbincr_vlc);
614
            if (code < 0)
615
                return 1; /* error = end of slice */
616
            if (code >= 33) {
617
                if (code == 33) {
618
                    s->mb_incr += 33;
619
                }
620
                /* otherwise, stuffing, nothing to do */
621
            } else {
622
                s->mb_incr += code;
623
                break;
624
            }
625
        }
626
    }
627
    if (++s->mb_x >= s->mb_width) {
628
        s->mb_x = 0;
629
        if (s->mb_y >= (s->mb_height - 1))
630
            return -1;
631
        s->mb_y++;
632
    }
633
    dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
634

    
635
    if (--s->mb_incr != 0) {
636
        /* skip mb */
637
        s->mb_intra = 0;
638
        for(i=0;i<6;i++)
639
            s->block_last_index[i] = -1;
640
        s->mv_type = MV_TYPE_16X16;
641
        if (s->pict_type == P_TYPE) {
642
            /* if P type, zero motion vector is implied */
643
            s->mv_dir = MV_DIR_FORWARD;
644
            s->mv[0][0][0] = s->mv[0][0][1] = 0;
645
            s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
646
            s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
647
        } else {
648
            /* if B type, reuse previous vectors and directions */
649
            s->mv[0][0][0] = s->last_mv[0][0][0];
650
            s->mv[0][0][1] = s->last_mv[0][0][1];
651
            s->mv[1][0][0] = s->last_mv[1][0][0];
652
            s->mv[1][0][1] = s->last_mv[1][0][1];
653
        }
654
        s->mb_skiped = 1;
655
        return 0;
656
    }
657

    
658
    switch(s->pict_type) {
659
    default:
660
    case I_TYPE:
661
        if (get_bits1(&s->gb) == 0) {
662
            if (get_bits1(&s->gb) == 0)
663
                return -1;
664
            mb_type = MB_QUANT | MB_INTRA;
665
        } else {
666
            mb_type = MB_INTRA;
667
        }
668
        break;
669
    case P_TYPE:
670
        mb_type = get_vlc(&s->gb, &mb_ptype_vlc);
671
        if (mb_type < 0)
672
            return -1;
673
        break;
674
    case B_TYPE:
675
        mb_type = get_vlc(&s->gb, &mb_btype_vlc);
676
        if (mb_type < 0)
677
            return -1;
678
        break;
679
    }
680
    dprintf("mb_type=%x\n", mb_type);
681
    motion_type = 0; /* avoid warning */
682
    if (mb_type & (MB_FOR|MB_BACK)) {
683
        /* get additionnal motion vector type */
684
        if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) 
685
            motion_type = MT_FRAME;
686
        else
687
            motion_type = get_bits(&s->gb, 2);
688
    }
689
    /* compute dct type */
690
    if (s->picture_structure == PICT_FRAME && 
691
        !s->frame_pred_frame_dct &&
692
        (mb_type & (MB_PAT | MB_INTRA))) {
693
        s->interlaced_dct = get_bits1(&s->gb);
694
#ifdef DEBUG
695
        if (s->interlaced_dct)
696
            printf("interlaced_dct\n");
697
#endif
698
    } else {
699
        s->interlaced_dct = 0; /* frame based */
700
    }
701

    
702
    if (mb_type & MB_QUANT) {
703
        s->qscale = get_qscale(s);
704
    }
705
    if (mb_type & MB_INTRA) {
706
        if (s->concealment_motion_vectors) {
707
            /* just parse them */
708
            if (s->picture_structure != PICT_FRAME) 
709
                skip_bits1(&s->gb); /* field select */
710
            mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
711
            mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
712
        }
713
        s->mb_intra = 1;
714
        cbp = 0x3f;
715
        memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
716
    } else {
717
        s->mb_intra = 0;
718
        cbp = 0;
719
    }
720
    /* special case of implicit zero motion vector */
721
    if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
722
        s->mv_dir = MV_DIR_FORWARD;
723
        s->mv_type = MV_TYPE_16X16;
724
        s->last_mv[0][0][0] = 0;
725
        s->last_mv[0][0][1] = 0;
726
        s->last_mv[0][1][0] = 0;
727
        s->last_mv[0][1][1] = 0;
728
        s->mv[0][0][0] = 0;
729
        s->mv[0][0][1] = 0;
730
    } else if (mb_type & (MB_FOR | MB_BACK)) {
731
        /* motion vectors */
732
        s->mv_dir = 0;
733
        for(i=0;i<2;i++) {
734
            if (mb_type & (MB_FOR >> i)) {
735
                s->mv_dir |= (MV_DIR_FORWARD >> i);
736
                dprintf("motion_type=%d\n", motion_type);
737
                switch(motion_type) {
738
                case MT_FRAME: /* or MT_16X8 */
739
                    if (s->picture_structure == PICT_FRAME) {
740
                        /* MT_FRAME */
741
                        s->mv_type = MV_TYPE_16X16;
742
                        for(k=0;k<2;k++) {
743
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k], 
744
                                                     s->last_mv[i][0][k]);
745
                            s->last_mv[i][0][k] = val;
746
                            s->last_mv[i][1][k] = val;
747
                            /* full_pel: only for mpeg1 */
748
                            if (s->full_pel[i])
749
                                val = val << 1;
750
                            s->mv[i][0][k] = val;
751
                            dprintf("mv%d: %d\n", k, val);
752
                        }
753
                    } else {
754
                        /* MT_16X8 */
755
                        s->mv_type = MV_TYPE_16X8;
756
                        for(j=0;j<2;j++) {
757
                            s->field_select[i][j] = get_bits1(&s->gb);
758
                            for(k=0;k<2;k++) {
759
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
760
                                                         s->last_mv[i][j][k]);
761
                                s->last_mv[i][j][k] = val;
762
                                s->mv[i][j][k] = val;
763
                            }
764
                        }
765
                    }
766
                    break;
767
                case MT_FIELD:
768
                    if (s->picture_structure == PICT_FRAME) {
769
                        s->mv_type = MV_TYPE_FIELD;
770
                        for(j=0;j<2;j++) {
771
                            s->field_select[i][j] = get_bits1(&s->gb);
772
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
773
                                                     s->last_mv[i][j][0]);
774
                            s->last_mv[i][j][0] = val;
775
                            s->mv[i][j][0] = val;
776
                            dprintf("fmx=%d\n", val);
777
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
778
                                                     s->last_mv[i][j][1] >> 1);
779
                            s->last_mv[i][j][1] = val << 1;
780
                            s->mv[i][j][1] = val;
781
                            dprintf("fmy=%d\n", val);
782
                        }
783
                    } else {
784
                        s->mv_type = MV_TYPE_16X16;
785
                        s->field_select[i][0] = get_bits1(&s->gb);
786
                        for(k=0;k<2;k++) {
787
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
788
                                                     s->last_mv[i][0][k]);
789
                            s->last_mv[i][0][k] = val;
790
                            s->last_mv[i][1][k] = val;
791
                            s->mv[i][0][k] = val;
792
                        }
793
                    }
794
                    break;
795
                case MT_DMV:
796
                    {
797
                        int dmx, dmy, mx, my, m;
798

    
799
                        mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0], 
800
                                                s->last_mv[i][0][0]);
801
                        s->last_mv[i][0][0] = mx;
802
                        s->last_mv[i][1][0] = mx;
803
                        dmx = get_dmv(s);
804
                        my = mpeg_decode_motion(s, s->mpeg_f_code[i][1], 
805
                                                s->last_mv[i][0][1] >> 1);
806
                        dmy = get_dmv(s);
807
                        s->mv_type = MV_TYPE_DMV;
808
                        /* XXX: totally broken */
809
                        if (s->picture_structure == PICT_FRAME) {
810
                            s->last_mv[i][0][1] = my << 1;
811
                            s->last_mv[i][1][1] = my << 1;
812

    
813
                            m = s->top_field_first ? 1 : 3;
814
                            /* top -> top pred */
815
                            s->mv[i][0][0] = mx; 
816
                            s->mv[i][0][1] = my << 1;
817
                            s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
818
                            s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
819
                            m = 4 - m;
820
                            s->mv[i][2][0] = mx;
821
                            s->mv[i][2][1] = my << 1;
822
                            s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
823
                            s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
824
                        } else {
825
                            s->last_mv[i][0][1] = my;
826
                            s->last_mv[i][1][1] = my;
827
                            s->mv[i][0][0] = mx;
828
                            s->mv[i][0][1] = my;
829
                            s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
830
                            s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1 
831
                                /* + 2 * cur_field */;
832
                        }
833
                    }
834
                    break;
835
                }
836
            }
837
        }
838
    }
839

    
840
    if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
841
        skip_bits1(&s->gb); /* marker */
842
    }
843
    
844
    if (mb_type & MB_PAT) {
845
        cbp = get_vlc(&s->gb, &mb_pat_vlc);
846
        if (cbp < 0)
847
            return -1;
848
        cbp++;
849
    }
850
    dprintf("cbp=%x\n", cbp);
851

    
852
    if (s->mpeg2) {
853
        if (s->mb_intra) {
854
            for(i=0;i<6;i++) {
855
                if (cbp & (1 << (5 - i))) {
856
                    if (mpeg2_decode_block_intra(s, block[i], i) < 0)
857
                        return -1;
858
                }
859
            }
860
        } else {
861
            for(i=0;i<6;i++) {
862
                if (cbp & (1 << (5 - i))) {
863
                    if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
864
                        return -1;
865
                }
866
            }
867
        }
868
    } else {
869
        for(i=0;i<6;i++) {
870
            if (cbp & (1 << (5 - i))) {
871
                if (mpeg1_decode_block(s, block[i], i) < 0)
872
                    return -1;
873
            }
874
        }
875
    }
876
    return 0;
877
}
878

    
879
/* as h263, but only 17 codes */
880
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
881
{
882
    int code, sign, val, m, l, shift;
883

    
884
    code = get_vlc(&s->gb, &mv_vlc);
885
    if (code < 0) {
886
        return 0xffff;
887
    }
888
    if (code == 0) {
889
        return pred;
890
    }
891
    sign = get_bits1(&s->gb);
892
    shift = fcode - 1;
893
    val = (code - 1) << shift;
894
    if (shift > 0)
895
        val |= get_bits(&s->gb, shift);
896
    val++;
897
    if (sign)
898
        val = -val;
899
    val += pred;
900
    
901
    /* modulo decoding */
902
    l = (1 << shift) * 16;
903
    m = 2 * l;
904
    if (val < -l) {
905
        val += m;
906
    } else if (val >= l) {
907
        val -= m;
908
    }
909
    return val;
910
}
911

    
912
static inline int decode_dc(MpegEncContext *s, int component)
913
{
914
    int code, diff;
915

    
916
    if (component == 0) {
917
        code = get_vlc(&s->gb, &dc_lum_vlc);
918
    } else {
919
        code = get_vlc(&s->gb, &dc_chroma_vlc);
920
    }
921
    if (code < 0)
922
        return 0xffff;
923
    if (code == 0) {
924
        diff = 0;
925
    } else {
926
        diff = get_bits(&s->gb, code);
927
        if ((diff & (1 << (code - 1))) == 0) 
928
            diff = (-1 << code) | (diff + 1);
929
    }
930
    return diff;
931
}
932

    
933
static int mpeg1_decode_block(MpegEncContext *s, 
934
                               DCTELEM *block, 
935
                               int n)
936
{
937
    int level, dc, diff, i, j, run;
938
    int code, component;
939
    RLTable *rl = &rl_mpeg1;
940

    
941
    if (s->mb_intra) {
942
        /* DC coef */
943
        component = (n <= 3 ? 0 : n - 4 + 1);
944
        diff = decode_dc(s, component);
945
        if (diff >= 0xffff)
946
            return -1;
947
        dc = s->last_dc[component];
948
        dc += diff;
949
        s->last_dc[component] = dc;
950
        block[0] = dc;
951
        dprintf("dc=%d diff=%d\n", dc, diff);
952
        i = 1;
953
    } else {
954
        int bit_cnt, v;
955
        UINT32 bit_buf;
956
        UINT8 *buf_ptr;
957
        i = 0;
958
        /* special case for the first coef. no need to add a second vlc table */
959
        SAVE_BITS(&s->gb);
960
        SHOW_BITS(&s->gb, v, 2);
961
        if (v & 2) {
962
            run = 0;
963
            level = 1 - ((v & 1) << 1);
964
            FLUSH_BITS(2);
965
            RESTORE_BITS(&s->gb);
966
            goto add_coef;
967
        }
968
        RESTORE_BITS(&s->gb);
969
    }
970

    
971
    /* now quantify & encode AC coefs */
972
    for(;;) {
973
        code = get_vlc(&s->gb, &rl->vlc);
974
        if (code < 0) {
975
            return -1;
976
        }
977
        if (code == 112) {
978
            break;
979
        } else if (code == 111) {
980
            /* escape */
981
            run = get_bits(&s->gb, 6);
982
            level = get_bits(&s->gb, 8);
983
            level = (level << 24) >> 24;
984
            if (level == -128) {
985
                level = get_bits(&s->gb, 8) - 256;
986
            } else if (level == 0) {
987
                level = get_bits(&s->gb, 8);
988
            }
989
        } else {
990
            run = rl->table_run[code];
991
            level = rl->table_level[code];
992
            if (get_bits1(&s->gb))
993
                level = -level;
994
        }
995
        i += run;
996
        if (i >= 64)
997
            return -1;
998
    add_coef:
999
        dprintf("%d: run=%d level=%d\n", n, run, level);
1000
        j = zigzag_direct[i];
1001
        block[j] = level;
1002
        i++;
1003
    }
1004
    s->block_last_index[n] = i-1;
1005
    return 0;
1006
}
1007

    
1008
/* Also does unquantization here, since I will never support mpeg2
1009
   encoding */
1010
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
1011
                                        DCTELEM *block, 
1012
                                        int n)
1013
{
1014
    int level, i, j, run;
1015
    int code;
1016
    RLTable *rl = &rl_mpeg1;
1017
    const UINT8 *scan_table;
1018
    const UINT16 *matrix;
1019
    int mismatch;
1020

    
1021
    if (s->alternate_scan)
1022
        scan_table = ff_alternate_vertical_scan;
1023
    else
1024
        scan_table = zigzag_direct;
1025
    mismatch = 1;
1026

    
1027
    {
1028
        int bit_cnt, v;
1029
        UINT32 bit_buf;
1030
        UINT8 *buf_ptr;
1031
        i = 0;
1032
        if (n < 4) 
1033
            matrix = s->inter_matrix;
1034
        else
1035
            matrix = s->chroma_inter_matrix;
1036
            
1037
        /* special case for the first coef. no need to add a second vlc table */
1038
        SAVE_BITS(&s->gb);
1039
        SHOW_BITS(&s->gb, v, 2);
1040
        if (v & 2) {
1041
            run = 0;
1042
            level = 1 - ((v & 1) << 1);
1043
            FLUSH_BITS(2);
1044
            RESTORE_BITS(&s->gb);
1045
            goto add_coef;
1046
        }
1047
        RESTORE_BITS(&s->gb);
1048
    }
1049

    
1050
    /* now quantify & encode AC coefs */
1051
    for(;;) {
1052
        code = get_vlc(&s->gb, &rl->vlc);
1053
        if (code < 0)
1054
            return -1;
1055
        if (code == 112) {
1056
            break;
1057
        } else if (code == 111) {
1058
            /* escape */
1059
            run = get_bits(&s->gb, 6);
1060
            level = get_bits(&s->gb, 12);
1061
            level = (level << 20) >> 20;
1062
        } else {
1063
            run = rl->table_run[code];
1064
            level = rl->table_level[code];
1065
            if (get_bits1(&s->gb))
1066
                level = -level;
1067
        }
1068
        i += run;
1069
        if (i >= 64)
1070
            return -1;
1071
    add_coef:
1072
        j = scan_table[i];
1073
        dprintf("%d: run=%d level=%d\n", n, run, level);
1074
        /* XXX: optimize */
1075
        if (level > 0) {
1076
            level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1077
        } else {
1078
            level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1079
            level = -level;
1080
        }
1081
        /* XXX: is it really necessary to saturate since the encoder
1082
           knows whats going on ? */
1083
        mismatch ^= level;
1084
        block[j] = level;
1085
        i++;
1086
    }
1087
    block[63] ^= (mismatch & 1);
1088
    s->block_last_index[n] = i;
1089
    return 0;
1090
}
1091

    
1092
static int mpeg2_decode_block_intra(MpegEncContext *s, 
1093
                                    DCTELEM *block, 
1094
                                    int n)
1095
{
1096
    int level, dc, diff, i, j, run;
1097
    int code, component;
1098
    RLTable *rl;
1099
    const UINT8 *scan_table;
1100
    const UINT16 *matrix;
1101
    int mismatch;
1102

    
1103
    if (s->alternate_scan)
1104
        scan_table = ff_alternate_vertical_scan;
1105
    else
1106
        scan_table = zigzag_direct;
1107

    
1108
    /* DC coef */
1109
    component = (n <= 3 ? 0 : n - 4 + 1);
1110
    diff = decode_dc(s, component);
1111
    if (diff >= 0xffff)
1112
        return -1;
1113
    dc = s->last_dc[component];
1114
    dc += diff;
1115
    s->last_dc[component] = dc;
1116
    block[0] = dc << (3 - s->intra_dc_precision);
1117
    dprintf("dc=%d\n", block[0]);
1118
    mismatch = block[0] ^ 1;
1119
    i = 1;
1120
    if (s->intra_vlc_format)
1121
        rl = &rl_mpeg2;
1122
    else
1123
        rl = &rl_mpeg1;
1124
    if (n < 4) 
1125
        matrix = s->intra_matrix;
1126
    else
1127
        matrix = s->chroma_intra_matrix;
1128

    
1129
    /* now quantify & encode AC coefs */
1130
    for(;;) {
1131
        code = get_vlc(&s->gb, &rl->vlc);
1132
        if (code < 0)
1133
            return -1;
1134
        if (code == 112) {
1135
            break;
1136
        } else if (code == 111) {
1137
            /* escape */
1138
            run = get_bits(&s->gb, 6);
1139
            level = get_bits(&s->gb, 12);
1140
            level = (level << 20) >> 20;
1141
        } else {
1142
            run = rl->table_run[code];
1143
            level = rl->table_level[code];
1144
            if (get_bits1(&s->gb))
1145
                level = -level;
1146
        }
1147
        i += run;
1148
        if (i >= 64)
1149
            return -1;
1150
        j = scan_table[i];
1151
        dprintf("%d: run=%d level=%d\n", n, run, level);
1152
        level = (level * s->qscale * matrix[j]) / 16;
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
/* compressed picture size */
1165
#define PICTURE_BUFFER_SIZE 100000
1166

    
1167
typedef struct Mpeg1Context {
1168
    MpegEncContext mpeg_enc_ctx;
1169
    UINT32 header_state;
1170
    int start_code; /* current start code */
1171
    UINT8 buffer[PICTURE_BUFFER_SIZE]; 
1172
    UINT8 *buf_ptr;
1173
    int buffer_size;
1174
    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1175
    int repeat_field; /* true if we must repeat the field */
1176
} Mpeg1Context;
1177

    
1178
static int mpeg_decode_init(AVCodecContext *avctx)
1179
{
1180
    Mpeg1Context *s = avctx->priv_data;
1181

    
1182
    s->header_state = 0xff;
1183
    s->mpeg_enc_ctx_allocated = 0;
1184
    s->buffer_size = PICTURE_BUFFER_SIZE;
1185
    s->start_code = -1;
1186
    s->buf_ptr = s->buffer;
1187
    s->mpeg_enc_ctx.picture_number = 0;
1188
    s->repeat_field = 0;
1189
    s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1190
    avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1191
    return 0;
1192
}
1193

    
1194
/* return the 8 bit start code value and update the search
1195
   state. Return -1 if no start code found */
1196
static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end, 
1197
                           UINT32 *header_state)
1198
{
1199
    UINT8 *buf_ptr;
1200
    unsigned int state, v;
1201
    int val;
1202

    
1203
    state = *header_state;
1204
    buf_ptr = *pbuf_ptr;
1205
    while (buf_ptr < buf_end) {
1206
        v = *buf_ptr++;
1207
        if (state == 0x000001) {
1208
            state = ((state << 8) | v) & 0xffffff;
1209
            val = state;
1210
            goto found;
1211
        }
1212
        state = ((state << 8) | v) & 0xffffff;
1213
    }
1214
    val = -1;
1215
 found:
1216
    *pbuf_ptr = buf_ptr;
1217
    *header_state = state;
1218
    return val;
1219
}
1220

    
1221
static int mpeg1_decode_picture(AVCodecContext *avctx, 
1222
                                UINT8 *buf, int buf_size)
1223
{
1224
    Mpeg1Context *s1 = avctx->priv_data;
1225
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1226
    int ref, f_code;
1227

    
1228
    init_get_bits(&s->gb, buf, buf_size);
1229

    
1230
    ref = get_bits(&s->gb, 10); /* temporal ref */
1231
    s->pict_type = get_bits(&s->gb, 3);
1232
    dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1233
    skip_bits(&s->gb, 16);
1234
    if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1235
        s->full_pel[0] = get_bits1(&s->gb);
1236
        f_code = get_bits(&s->gb, 3);
1237
        if (f_code == 0)
1238
            return -1;
1239
        s->mpeg_f_code[0][0] = f_code;
1240
        s->mpeg_f_code[0][1] = f_code;
1241
    }
1242
    if (s->pict_type == B_TYPE) {
1243
        s->full_pel[1] = get_bits1(&s->gb);
1244
        f_code = get_bits(&s->gb, 3);
1245
        if (f_code == 0)
1246
            return -1;
1247
        s->mpeg_f_code[1][0] = f_code;
1248
        s->mpeg_f_code[1][1] = f_code;
1249
    }
1250
    s->y_dc_scale = 8;
1251
    s->c_dc_scale = 8;
1252
    s->first_slice = 1;
1253
    return 0;
1254
}
1255

    
1256
static void mpeg_decode_sequence_extension(MpegEncContext *s)
1257
{
1258
    int horiz_size_ext, vert_size_ext;
1259
    int bit_rate_ext, vbv_buf_ext, low_delay;
1260
    int frame_rate_ext_n, frame_rate_ext_d;
1261

    
1262
    skip_bits(&s->gb, 8); /* profil and level */
1263
    s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1264
    skip_bits(&s->gb, 2); /* chroma_format */
1265
    horiz_size_ext = get_bits(&s->gb, 2);
1266
    vert_size_ext = get_bits(&s->gb, 2);
1267
    s->width |= (horiz_size_ext << 12);
1268
    s->height |= (vert_size_ext << 12);
1269
    bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1270
    s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1271
    skip_bits1(&s->gb); /* marker */
1272
    vbv_buf_ext = get_bits(&s->gb, 8);
1273
    low_delay = get_bits1(&s->gb);
1274
    frame_rate_ext_n = get_bits(&s->gb, 2);
1275
    frame_rate_ext_d = get_bits(&s->gb, 5);
1276
    if (frame_rate_ext_d >= 1)
1277
        s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1278
    dprintf("sequence extension\n");
1279
    s->mpeg2 = 1;
1280
}
1281

    
1282
static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1283
{
1284
    int i, v, j;
1285

    
1286
    dprintf("matrix extension\n");
1287

    
1288
    if (get_bits1(&s->gb)) {
1289
        for(i=0;i<64;i++) {
1290
            v = get_bits(&s->gb, 8);
1291
            j = zigzag_direct[i];
1292
            s->intra_matrix[j] = v;
1293
            s->chroma_intra_matrix[j] = v;
1294
        }
1295
    }
1296
    if (get_bits1(&s->gb)) {
1297
        for(i=0;i<64;i++) {
1298
            v = get_bits(&s->gb, 8);
1299
            j = zigzag_direct[i];
1300
            s->inter_matrix[j] = v;
1301
            s->chroma_inter_matrix[j] = v;
1302
        }
1303
    }
1304
    if (get_bits1(&s->gb)) {
1305
        for(i=0;i<64;i++) {
1306
            v = get_bits(&s->gb, 8);
1307
            j = zigzag_direct[i];
1308
            s->chroma_intra_matrix[j] = v;
1309
        }
1310
    }
1311
    if (get_bits1(&s->gb)) {
1312
        for(i=0;i<64;i++) {
1313
            v = get_bits(&s->gb, 8);
1314
            j = zigzag_direct[i];
1315
            s->chroma_inter_matrix[j] = v;
1316
        }
1317
    }
1318
}
1319

    
1320
static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1321
{
1322
    s->full_pel[0] = s->full_pel[1] = 0;
1323
    s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1324
    s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1325
    s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1326
    s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1327
    s->intra_dc_precision = get_bits(&s->gb, 2);
1328
    s->picture_structure = get_bits(&s->gb, 2);
1329
    s->top_field_first = get_bits1(&s->gb);
1330
    s->frame_pred_frame_dct = get_bits1(&s->gb);
1331
    s->concealment_motion_vectors = get_bits1(&s->gb);
1332
    s->q_scale_type = get_bits1(&s->gb);
1333
    s->intra_vlc_format = get_bits1(&s->gb);
1334
    s->alternate_scan = get_bits1(&s->gb);
1335
    s->repeat_first_field = get_bits1(&s->gb);
1336
    s->chroma_420_type = get_bits1(&s->gb);
1337
    s->progressive_frame = get_bits1(&s->gb);
1338
    /* composite display not parsed */
1339
    dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1340
    dprintf("picture_structure=%d\n", s->picture_structure);
1341
    dprintf("conceal=%d\n", s->concealment_motion_vectors);
1342
    dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1343
    dprintf("alternate_scan=%d\n", s->alternate_scan);
1344
    dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1345
    dprintf("progressive_frame=%d\n", s->progressive_frame);
1346
}
1347

    
1348
static void mpeg_decode_extension(AVCodecContext *avctx, 
1349
                                  UINT8 *buf, int buf_size)
1350
{
1351
    Mpeg1Context *s1 = avctx->priv_data;
1352
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1353
    int ext_type;
1354

    
1355
    init_get_bits(&s->gb, buf, buf_size);
1356
    
1357
    ext_type = get_bits(&s->gb, 4);
1358
    switch(ext_type) {
1359
    case 0x1:
1360
        /* sequence ext */
1361
        mpeg_decode_sequence_extension(s);
1362
        break;
1363
    case 0x3:
1364
        /* quant matrix extension */
1365
        mpeg_decode_quant_matrix_extension(s);
1366
        break;
1367
    case 0x8:
1368
        /* picture extension */
1369
        mpeg_decode_picture_coding_extension(s);
1370
        break;
1371
    }
1372
}
1373

    
1374
/* return 1 if end of frame */
1375
static int mpeg_decode_slice(AVCodecContext *avctx, 
1376
                              AVPicture *pict,
1377
                              int start_code,
1378
                              UINT8 *buf, int buf_size)
1379
{
1380
    Mpeg1Context *s1 = avctx->priv_data;
1381
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1382
    int ret;
1383

    
1384
    start_code = (start_code - 1) & 0xff;
1385
    if (start_code >= s->mb_height)
1386
        return -1;
1387
    s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1388
    s->last_dc[1] = s->last_dc[0];
1389
    s->last_dc[2] = s->last_dc[0];
1390
    memset(s->last_mv, 0, sizeof(s->last_mv));
1391
    s->mb_x = -1;
1392
    s->mb_y = start_code;
1393
    s->mb_incr = 0;
1394
    /* start frame decoding */
1395
    if (s->first_slice) {
1396
        s->first_slice = 0;
1397
        MPV_frame_start(s);
1398
    }
1399

    
1400
    init_get_bits(&s->gb, buf, buf_size);
1401

    
1402
    s->qscale = get_qscale(s);
1403
    /* extra slice info */
1404
    while (get_bits1(&s->gb) != 0) {
1405
        skip_bits(&s->gb, 8);
1406
    }
1407

    
1408
    for(;;) {
1409
        clear_blocks(s->block[0]);
1410
        emms_c();
1411
        ret = mpeg_decode_mb(s, s->block);
1412
        dprintf("ret=%d\n", ret);
1413
        if (ret < 0)
1414
            return -1;
1415
        if (ret == 1)
1416
            break;
1417
        MPV_decode_mb(s, s->block);
1418
    }
1419
    emms_c();
1420

    
1421
    /* end of slice reached */
1422
    if (s->mb_x == (s->mb_width - 1) &&
1423
        s->mb_y == (s->mb_height - 1)) {
1424
        /* end of image */
1425
        UINT8 **picture;
1426

    
1427
        MPV_frame_end(s);
1428

    
1429
        /* XXX: incorrect reported qscale for mpeg2 */
1430
        if (s->pict_type == B_TYPE) {
1431
            picture = s->current_picture;
1432
            avctx->quality = s->qscale;
1433
        } else {
1434
            /* latency of 1 frame for I and P frames */
1435
            /* XXX: use another variable than picture_number */
1436
            if (s->picture_number == 0) {
1437
                picture = NULL;
1438
            } else {
1439
                picture = s->last_picture;
1440
                avctx->quality = s->last_qscale;
1441
            }
1442
            s->last_qscale = s->qscale;
1443
            s->picture_number++;
1444
        }
1445
        if (picture) {
1446
            pict->data[0] = picture[0];
1447
            pict->data[1] = picture[1];
1448
            pict->data[2] = picture[2];
1449
            pict->linesize[0] = s->linesize;
1450
            pict->linesize[1] = s->linesize / 2;
1451
            pict->linesize[2] = s->linesize / 2;
1452
            return 1;
1453
        } else {
1454
            return 0;
1455
        }
1456
    } else {
1457
        return 0;
1458
    }
1459
}
1460

    
1461
static int mpeg1_decode_sequence(AVCodecContext *avctx, 
1462
                                 UINT8 *buf, int buf_size)
1463
{
1464
    Mpeg1Context *s1 = avctx->priv_data;
1465
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1466
    int width, height, i, v, j;
1467
    
1468
    init_get_bits(&s->gb, buf, buf_size);
1469

    
1470
    width = get_bits(&s->gb, 12);
1471
    height = get_bits(&s->gb, 12);
1472
    skip_bits(&s->gb, 4);
1473
    s->frame_rate_index = get_bits(&s->gb, 4);
1474
    if (s->frame_rate_index == 0)
1475
        return -1;
1476
    s->bit_rate = get_bits(&s->gb, 18) * 400;
1477
    if (get_bits1(&s->gb) == 0) /* marker */
1478
        return -1;
1479
    if (width <= 0 || height <= 0 ||
1480
        (width % 2) != 0 || (height % 2) != 0)
1481
        return -1;
1482
    if (width != s->width ||
1483
        height != s->height) {
1484
        /* start new mpeg1 context decoding */
1485
        s->out_format = FMT_MPEG1;
1486
        if (s1->mpeg_enc_ctx_allocated) {
1487
            MPV_common_end(s);
1488
        }
1489
        s->width = width;
1490
        s->height = height;
1491
        s->has_b_frames = 1;
1492
        s->avctx = avctx;
1493
        avctx->width = width;
1494
        avctx->height = height;
1495
        avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1496
        s->frame_rate = avctx->frame_rate;
1497
        avctx->bit_rate = s->bit_rate;
1498
        
1499
        if (MPV_common_init(s) < 0)
1500
            return -1;
1501
        mpeg1_init_vlc(s);
1502
        s1->mpeg_enc_ctx_allocated = 1;
1503
    }
1504

    
1505
    skip_bits(&s->gb, 10); /* vbv_buffer_size */
1506
    skip_bits(&s->gb, 1);
1507

    
1508
    /* get matrix */
1509
    if (get_bits1(&s->gb)) {
1510
        for(i=0;i<64;i++) {
1511
            v = get_bits(&s->gb, 8);
1512
            j = zigzag_direct[i];
1513
            s->intra_matrix[j] = v;
1514
            s->chroma_intra_matrix[j] = v;
1515
        }
1516
#ifdef DEBUG
1517
        dprintf("intra matrix present\n");
1518
        for(i=0;i<64;i++)
1519
            dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1520
        printf("\n");
1521
#endif
1522
    } else {
1523
        for(i=0;i<64;i++) {
1524
            v = default_intra_matrix[i];
1525
            s->intra_matrix[i] = v;
1526
            s->chroma_intra_matrix[i] = v;
1527
        }
1528
    }
1529
    if (get_bits1(&s->gb)) {
1530
        for(i=0;i<64;i++) {
1531
            v = get_bits(&s->gb, 8);
1532
            j = zigzag_direct[i];
1533
            s->inter_matrix[j] = v;
1534
            s->chroma_inter_matrix[j] = v;
1535
        }
1536
#ifdef DEBUG
1537
        dprintf("non intra matrix present\n");
1538
        for(i=0;i<64;i++)
1539
            dprintf(" %d", s->inter_matrix[zigzag_direct[i]]);
1540
        printf("\n");
1541
#endif
1542
    } else {
1543
        for(i=0;i<64;i++) {
1544
            v = default_non_intra_matrix[i];
1545
            s->inter_matrix[i] = v;
1546
            s->chroma_inter_matrix[i] = v;
1547
        }
1548
    }
1549

    
1550
    /* we set mpeg2 parameters so that it emulates mpeg1 */
1551
    s->progressive_sequence = 1;
1552
    s->progressive_frame = 1;
1553
    s->picture_structure = PICT_FRAME;
1554
    s->frame_pred_frame_dct = 1;
1555
    s->mpeg2 = 0;
1556
    return 0;
1557
}
1558

    
1559
/* handle buffering and image synchronisation */
1560
static int mpeg_decode_frame(AVCodecContext *avctx, 
1561
                             void *data, int *data_size,
1562
                             UINT8 *buf, int buf_size)
1563
{
1564
    Mpeg1Context *s = avctx->priv_data;
1565
    UINT8 *buf_end, *buf_ptr, *buf_start;
1566
    int len, start_code_found, ret, code, start_code, input_size;
1567
    AVPicture *picture = data;
1568
    MpegEncContext *s2 = &s->mpeg_enc_ctx;
1569
            
1570
    dprintf("fill_buffer\n");
1571

    
1572
    *data_size = 0;
1573

    
1574
    /* special case for last picture */
1575
    if (buf_size == 0) {
1576
        if (s2->picture_number > 0) {
1577
            picture->data[0] = s2->next_picture[0];
1578
            picture->data[1] = s2->next_picture[1];
1579
            picture->data[2] = s2->next_picture[2];
1580
            picture->linesize[0] = s2->linesize;
1581
            picture->linesize[1] = s2->linesize / 2;
1582
            picture->linesize[2] = s2->linesize / 2;
1583
            *data_size = sizeof(AVPicture);
1584
        }
1585
        return 0;
1586
    }
1587

    
1588
    buf_ptr = buf;
1589
    buf_end = buf + buf_size;
1590
    
1591
    if (s->repeat_field % 2 == 1) {
1592
        s->repeat_field++;
1593
        //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1594
        //                                                         s2->picture_number, s->repeat_field);
1595
        *data_size = sizeof(AVPicture);
1596
        goto the_end;
1597
    }
1598

    
1599
    while (buf_ptr < buf_end) {
1600
        buf_start = buf_ptr;
1601
        /* find start next code */
1602
        code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1603
        if (code >= 0) {
1604
            start_code_found = 1;
1605
        } else {
1606
            start_code_found = 0;
1607
        }
1608
        /* copy to buffer */
1609
        len = buf_ptr - buf_start;
1610
        if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1611
            /* data too big : flush */
1612
            s->buf_ptr = s->buffer;
1613
            if (start_code_found)
1614
                s->start_code = code;
1615
        } else {
1616
            memcpy(s->buf_ptr, buf_start, len);
1617
            s->buf_ptr += len;
1618
            
1619
            if (start_code_found) {
1620
                /* prepare data for next start code */
1621
                input_size = s->buf_ptr - s->buffer;
1622
                start_code = s->start_code;
1623
                s->buf_ptr = s->buffer;
1624
                s->start_code = code;
1625
                switch(start_code) {
1626
                case SEQ_START_CODE:
1627
                    mpeg1_decode_sequence(avctx, s->buffer, 
1628
                                          input_size);
1629
                    break;
1630
                            
1631
                case PICTURE_START_CODE:
1632
                    /* we have a complete image : we try to decompress it */
1633
                    mpeg1_decode_picture(avctx, 
1634
                                         s->buffer, input_size);
1635
                    break;
1636
                case EXT_START_CODE:
1637
                    mpeg_decode_extension(avctx,
1638
                                          s->buffer, input_size);
1639
                    break;
1640
                default:
1641
                    if (start_code >= SLICE_MIN_START_CODE &&
1642
                        start_code <= SLICE_MAX_START_CODE) {
1643
                        ret = mpeg_decode_slice(avctx, picture,
1644
                                                start_code, s->buffer, input_size);
1645
                        if (ret == 1) {
1646
                            /* got a picture: exit */
1647
                            /* first check if we must repeat the frame */
1648
                            if (s2->progressive_frame && s2->repeat_first_field) {
1649
                                //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1650
                                s2->repeat_first_field = 0;
1651
                                s2->progressive_frame = 0;
1652
                                if (++s->repeat_field > 2)
1653
                                    s->repeat_field = 0;
1654
                            }
1655
                            *data_size = sizeof(AVPicture);
1656
                            goto the_end;
1657
                        }
1658
                    }
1659
                    break;
1660
                }
1661
            }
1662
        }
1663
    }
1664
 the_end:
1665
    return buf_ptr - buf;
1666
}
1667

    
1668
static int mpeg_decode_end(AVCodecContext *avctx)
1669
{
1670
    Mpeg1Context *s = avctx->priv_data;
1671

    
1672
    if (s->mpeg_enc_ctx_allocated)
1673
        MPV_common_end(&s->mpeg_enc_ctx);
1674
    return 0;
1675
}
1676

    
1677
AVCodec mpeg_decoder = {
1678
    "mpegvideo",
1679
    CODEC_TYPE_VIDEO,
1680
    CODEC_ID_MPEG1VIDEO,
1681
    sizeof(Mpeg1Context),
1682
    mpeg_decode_init,
1683
    NULL,
1684
    mpeg_decode_end,
1685
    mpeg_decode_frame,
1686
};