Statistics
| Branch: | Revision:

ffmpeg / libavcodec / mpeg12.c @ 11ce8834

History | View | Annotate | Download (51.6 KB)

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
17
 * 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][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
    
403
    s->fcode_tab= fcode_tab;
404
}
405
 
406
static inline void encode_dc(MpegEncContext *s, int diff, int component)
407
{
408
    if (component == 0) {
409
        put_bits(
410
            &s->pb, 
411
            mpeg1_lum_dc_uni[diff+255]&0xFF,
412
            mpeg1_lum_dc_uni[diff+255]>>8);
413
    } else {
414
        put_bits(
415
            &s->pb, 
416
            mpeg1_chr_dc_uni[diff+255]&0xFF,
417
            mpeg1_chr_dc_uni[diff+255]>>8);
418
    }
419
}
420

    
421
static void mpeg1_encode_block(MpegEncContext *s, 
422
                               DCTELEM *block, 
423
                               int n)
424
{
425
    int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
426
    int code, component;
427
//    RLTable *rl = &rl_mpeg1;
428

    
429
    last_index = s->block_last_index[n];
430

    
431
    /* DC coef */
432
    if (s->mb_intra) {
433
        component = (n <= 3 ? 0 : n - 4 + 1);
434
        dc = block[0]; /* overflow is impossible */
435
        diff = dc - s->last_dc[component];
436
        encode_dc(s, diff, component);
437
        s->last_dc[component] = dc;
438
        i = 1;
439
    } else {
440
        /* encode the first coefficient : needs to be done here because
441
           it is handled slightly differently */
442
        level = block[0];
443
        if (abs(level) == 1) {
444
                code = ((UINT32)level >> 31); /* the sign bit */
445
                put_bits(&s->pb, 2, code | 0x02);
446
                i = 1;
447
        } else {
448
            i = 0;
449
            last_non_zero = -1;
450
            goto next_coef;
451
        }
452
    }
453

    
454
    /* now quantify & encode AC coefs */
455
    last_non_zero = i - 1;
456

    
457
    for(;i<=last_index;i++) {
458
        j = zigzag_direct[i];
459
        level = block[j];
460
    next_coef:
461
#if 0
462
        if (level != 0)
463
            dprintf("level[%d]=%d\n", i, level);
464
#endif            
465
        /* encode using VLC */
466
        if (level != 0) {
467
            run = i - last_non_zero - 1;
468
#ifdef ARCH_X86
469
            asm volatile(
470
                "movl %2, %1                \n\t"
471
                "movl %1, %0                \n\t"
472
                "addl %1, %1                \n\t"
473
                "sbbl %1, %1                \n\t"
474
                "xorl %1, %0                \n\t"
475
                "subl %1, %0                \n\t"
476
                "andl $1, %1                \n\t"
477
                : "=&r" (alevel), "=&r" (sign)
478
                : "g" (level)
479
            );
480
#else
481
            sign = 0;
482
            alevel = level;
483
            if (alevel < 0) {
484
                sign = 1;
485
                alevel = -alevel;
486
            }
487
#endif
488
//            code = get_rl_index(rl, 0, run, alevel);
489
            if (alevel > mpeg1_max_level[0][run])
490
                code= 111; /*rl->n*/
491
            else
492
                code= mpeg1_index_run[0][run] + alevel - 1;
493

    
494
            if (code < 111 /* rl->n */) {
495
                    /* store the vlc & sign at once */
496
                put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
497
            } else {
498
                /* escape seems to be pretty rare <5% so i dont optimize it */
499
                put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
500
                /* escape: only clip in this case */
501
                put_bits(&s->pb, 6, run);
502
                if (alevel < 128) {
503
                    put_bits(&s->pb, 8, level & 0xff);
504
                } else {
505
                    if (level < 0) {
506
                        put_bits(&s->pb, 16, 0x8001 + level + 255);
507
                    } else {
508
                        put_bits(&s->pb, 16, level & 0xffff);
509
                    }
510
                }
511
            }
512
            last_non_zero = i;
513
        }
514
    }
515
    /* end of block */
516
    put_bits(&s->pb, 2, 0x2);
517
}
518

    
519
/******************************************/
520
/* decoding */
521

    
522
static VLC dc_lum_vlc;
523
static VLC dc_chroma_vlc;
524
static VLC mv_vlc;
525
static VLC mbincr_vlc;
526
static VLC mb_ptype_vlc;
527
static VLC mb_btype_vlc;
528
static VLC mb_pat_vlc;
529

    
530
void mpeg1_init_vlc(MpegEncContext *s)
531
{
532
    static int done = 0;
533

    
534
    if (!done) {
535

    
536
        init_vlc(&dc_lum_vlc, 9, 12, 
537
                 vlc_dc_lum_bits, 1, 1,
538
                 vlc_dc_lum_code, 2, 2);
539
        init_vlc(&dc_chroma_vlc, 9, 12, 
540
                 vlc_dc_chroma_bits, 1, 1,
541
                 vlc_dc_chroma_code, 2, 2);
542
        init_vlc(&mv_vlc, 9, 17, 
543
                 &mbMotionVectorTable[0][1], 2, 1,
544
                 &mbMotionVectorTable[0][0], 2, 1);
545
        init_vlc(&mbincr_vlc, 9, 35, 
546
                 &mbAddrIncrTable[0][1], 2, 1,
547
                 &mbAddrIncrTable[0][0], 2, 1);
548
        init_vlc(&mb_pat_vlc, 9, 63, 
549
                 &mbPatTable[0][1], 2, 1,
550
                 &mbPatTable[0][0], 2, 1);
551
        
552
        init_vlc(&mb_ptype_vlc, 6, 32, 
553
                 &table_mb_ptype[0][1], 2, 1,
554
                 &table_mb_ptype[0][0], 2, 1);
555
        init_vlc(&mb_btype_vlc, 6, 32, 
556
                 &table_mb_btype[0][1], 2, 1,
557
                 &table_mb_btype[0][0], 2, 1);
558
        init_rl(&rl_mpeg1);
559
        init_rl(&rl_mpeg2);
560
        /* cannot use generic init because we must add the EOB code */
561
        init_vlc(&rl_mpeg1.vlc, 9, rl_mpeg1.n + 2, 
562
                 &rl_mpeg1.table_vlc[0][1], 4, 2,
563
                 &rl_mpeg1.table_vlc[0][0], 4, 2);
564
        init_vlc(&rl_mpeg2.vlc, 9, rl_mpeg2.n + 2, 
565
                 &rl_mpeg2.table_vlc[0][1], 4, 2,
566
                 &rl_mpeg2.table_vlc[0][0], 4, 2);
567
    }
568
}
569

    
570
static inline int get_dmv(MpegEncContext *s)
571
{
572
    if(get_bits1(&s->gb)) 
573
        return 1 - (get_bits1(&s->gb) << 1);
574
    else
575
        return 0;
576
}
577

    
578
static inline int get_qscale(MpegEncContext *s)
579
{
580
    int qscale;
581
    if (s->mpeg2) {
582
        if (s->q_scale_type) {
583
            qscale = non_linear_qscale[get_bits(&s->gb, 5)];
584
        } else {
585
            qscale = get_bits(&s->gb, 5) << 1;
586
        }
587
    } else {
588
        /* for mpeg1, we use the generic unquant code */
589
        qscale = get_bits(&s->gb, 5);
590
    }
591
    return qscale;
592
}
593

    
594
/* motion type (for mpeg2) */
595
#define MT_FIELD 1
596
#define MT_FRAME 2
597
#define MT_16X8  2
598
#define MT_DMV   3
599

    
600
static int mpeg_decode_mb(MpegEncContext *s,
601
                          DCTELEM block[6][64])
602
{
603
    int i, j, k, cbp, val, code, mb_type, motion_type;
604
    
605
    /* skip mb handling */
606
    if (s->mb_incr == 0) {
607
        /* read again increment */
608
        s->mb_incr = 1;
609
        for(;;) {
610
            code = get_vlc(&s->gb, &mbincr_vlc);
611
            if (code < 0)
612
                return 1; /* error = end of slice */
613
            if (code >= 33) {
614
                if (code == 33) {
615
                    s->mb_incr += 33;
616
                }
617
                /* otherwise, stuffing, nothing to do */
618
            } else {
619
                s->mb_incr += code;
620
                break;
621
            }
622
        }
623
    }
624
    if (++s->mb_x >= s->mb_width) {
625
        s->mb_x = 0;
626
        if (s->mb_y >= (s->mb_height - 1))
627
            return -1;
628
        s->mb_y++;
629
    }
630
    dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
631

    
632
    if (--s->mb_incr != 0) {
633
        /* skip mb */
634
        s->mb_intra = 0;
635
        for(i=0;i<6;i++)
636
            s->block_last_index[i] = -1;
637
        s->mv_type = MV_TYPE_16X16;
638
        if (s->pict_type == P_TYPE) {
639
            /* if P type, zero motion vector is implied */
640
            s->mv_dir = MV_DIR_FORWARD;
641
            s->mv[0][0][0] = s->mv[0][0][1] = 0;
642
            s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
643
            s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
644
        } else {
645
            /* if B type, reuse previous vectors and directions */
646
            s->mv[0][0][0] = s->last_mv[0][0][0];
647
            s->mv[0][0][1] = s->last_mv[0][0][1];
648
            s->mv[1][0][0] = s->last_mv[1][0][0];
649
            s->mv[1][0][1] = s->last_mv[1][0][1];
650
        }
651
        s->mb_skiped = 1;
652
        return 0;
653
    }
654

    
655
    switch(s->pict_type) {
656
    default:
657
    case I_TYPE:
658
        if (get_bits1(&s->gb) == 0) {
659
            if (get_bits1(&s->gb) == 0)
660
                return -1;
661
            mb_type = MB_QUANT | MB_INTRA;
662
        } else {
663
            mb_type = MB_INTRA;
664
        }
665
        break;
666
    case P_TYPE:
667
        mb_type = get_vlc(&s->gb, &mb_ptype_vlc);
668
        if (mb_type < 0)
669
            return -1;
670
        break;
671
    case B_TYPE:
672
        mb_type = get_vlc(&s->gb, &mb_btype_vlc);
673
        if (mb_type < 0)
674
            return -1;
675
        break;
676
    }
677
    dprintf("mb_type=%x\n", mb_type);
678
    motion_type = 0; /* avoid warning */
679
    if (mb_type & (MB_FOR|MB_BACK)) {
680
        /* get additionnal motion vector type */
681
        if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) 
682
            motion_type = MT_FRAME;
683
        else
684
            motion_type = get_bits(&s->gb, 2);
685
    }
686
    /* compute dct type */
687
    if (s->picture_structure == PICT_FRAME && 
688
        !s->frame_pred_frame_dct &&
689
        (mb_type & (MB_PAT | MB_INTRA))) {
690
        s->interlaced_dct = get_bits1(&s->gb);
691
#ifdef DEBUG
692
        if (s->interlaced_dct)
693
            printf("interlaced_dct\n");
694
#endif
695
    } else {
696
        s->interlaced_dct = 0; /* frame based */
697
    }
698

    
699
    if (mb_type & MB_QUANT) {
700
        s->qscale = get_qscale(s);
701
    }
702
    if (mb_type & MB_INTRA) {
703
        if (s->concealment_motion_vectors) {
704
            /* just parse them */
705
            if (s->picture_structure != PICT_FRAME) 
706
                skip_bits1(&s->gb); /* field select */
707
            mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
708
            mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
709
        }
710
        s->mb_intra = 1;
711
        cbp = 0x3f;
712
        memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
713
    } else {
714
        s->mb_intra = 0;
715
        cbp = 0;
716
    }
717
    /* special case of implicit zero motion vector */
718
    if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
719
        s->mv_dir = MV_DIR_FORWARD;
720
        s->mv_type = MV_TYPE_16X16;
721
        s->last_mv[0][0][0] = 0;
722
        s->last_mv[0][0][1] = 0;
723
        s->last_mv[0][1][0] = 0;
724
        s->last_mv[0][1][1] = 0;
725
        s->mv[0][0][0] = 0;
726
        s->mv[0][0][1] = 0;
727
    } else if (mb_type & (MB_FOR | MB_BACK)) {
728
        /* motion vectors */
729
        s->mv_dir = 0;
730
        for(i=0;i<2;i++) {
731
            if (mb_type & (MB_FOR >> i)) {
732
                s->mv_dir |= (MV_DIR_FORWARD >> i);
733
                dprintf("motion_type=%d\n", motion_type);
734
                switch(motion_type) {
735
                case MT_FRAME: /* or MT_16X8 */
736
                    if (s->picture_structure == PICT_FRAME) {
737
                        /* MT_FRAME */
738
                        s->mv_type = MV_TYPE_16X16;
739
                        for(k=0;k<2;k++) {
740
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k], 
741
                                                     s->last_mv[i][0][k]);
742
                            s->last_mv[i][0][k] = val;
743
                            s->last_mv[i][1][k] = val;
744
                            /* full_pel: only for mpeg1 */
745
                            if (s->full_pel[i])
746
                                val = val << 1;
747
                            s->mv[i][0][k] = val;
748
                            dprintf("mv%d: %d\n", k, val);
749
                        }
750
                    } else {
751
                        /* MT_16X8 */
752
                        s->mv_type = MV_TYPE_16X8;
753
                        for(j=0;j<2;j++) {
754
                            s->field_select[i][j] = get_bits1(&s->gb);
755
                            for(k=0;k<2;k++) {
756
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
757
                                                         s->last_mv[i][j][k]);
758
                                s->last_mv[i][j][k] = val;
759
                                s->mv[i][j][k] = val;
760
                            }
761
                        }
762
                    }
763
                    break;
764
                case MT_FIELD:
765
                    if (s->picture_structure == PICT_FRAME) {
766
                        s->mv_type = MV_TYPE_FIELD;
767
                        for(j=0;j<2;j++) {
768
                            s->field_select[i][j] = get_bits1(&s->gb);
769
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
770
                                                     s->last_mv[i][j][0]);
771
                            s->last_mv[i][j][0] = val;
772
                            s->mv[i][j][0] = val;
773
                            dprintf("fmx=%d\n", val);
774
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
775
                                                     s->last_mv[i][j][1] >> 1);
776
                            s->last_mv[i][j][1] = val << 1;
777
                            s->mv[i][j][1] = val;
778
                            dprintf("fmy=%d\n", val);
779
                        }
780
                    } else {
781
                        s->mv_type = MV_TYPE_16X16;
782
                        s->field_select[i][0] = get_bits1(&s->gb);
783
                        for(k=0;k<2;k++) {
784
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
785
                                                     s->last_mv[i][0][k]);
786
                            s->last_mv[i][0][k] = val;
787
                            s->last_mv[i][1][k] = val;
788
                            s->mv[i][0][k] = val;
789
                        }
790
                    }
791
                    break;
792
                case MT_DMV:
793
                    {
794
                        int dmx, dmy, mx, my, m;
795

    
796
                        mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0], 
797
                                                s->last_mv[i][0][0]);
798
                        s->last_mv[i][0][0] = mx;
799
                        s->last_mv[i][1][0] = mx;
800
                        dmx = get_dmv(s);
801
                        my = mpeg_decode_motion(s, s->mpeg_f_code[i][1], 
802
                                                s->last_mv[i][0][1] >> 1);
803
                        dmy = get_dmv(s);
804
                        s->mv_type = MV_TYPE_DMV;
805
                        /* XXX: totally broken */
806
                        if (s->picture_structure == PICT_FRAME) {
807
                            s->last_mv[i][0][1] = my << 1;
808
                            s->last_mv[i][1][1] = my << 1;
809

    
810
                            m = s->top_field_first ? 1 : 3;
811
                            /* top -> top pred */
812
                            s->mv[i][0][0] = mx; 
813
                            s->mv[i][0][1] = my << 1;
814
                            s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
815
                            s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
816
                            m = 4 - m;
817
                            s->mv[i][2][0] = mx;
818
                            s->mv[i][2][1] = my << 1;
819
                            s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
820
                            s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
821
                        } else {
822
                            s->last_mv[i][0][1] = my;
823
                            s->last_mv[i][1][1] = my;
824
                            s->mv[i][0][0] = mx;
825
                            s->mv[i][0][1] = my;
826
                            s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
827
                            s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1 
828
                                /* + 2 * cur_field */;
829
                        }
830
                    }
831
                    break;
832
                }
833
            }
834
        }
835
    }
836

    
837
    if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
838
        skip_bits1(&s->gb); /* marker */
839
    }
840
    
841
    if (mb_type & MB_PAT) {
842
        cbp = get_vlc(&s->gb, &mb_pat_vlc);
843
        if (cbp < 0)
844
            return -1;
845
        cbp++;
846
    }
847
    dprintf("cbp=%x\n", cbp);
848

    
849
    if (s->mpeg2) {
850
        if (s->mb_intra) {
851
            for(i=0;i<6;i++) {
852
                if (cbp & (1 << (5 - i))) {
853
                    if (mpeg2_decode_block_intra(s, block[i], i) < 0)
854
                        return -1;
855
                }
856
            }
857
        } else {
858
            for(i=0;i<6;i++) {
859
                if (cbp & (1 << (5 - i))) {
860
                    if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
861
                        return -1;
862
                }
863
            }
864
        }
865
    } else {
866
        for(i=0;i<6;i++) {
867
            if (cbp & (1 << (5 - i))) {
868
                if (mpeg1_decode_block(s, block[i], i) < 0)
869
                    return -1;
870
            }
871
        }
872
    }
873
    return 0;
874
}
875

    
876
/* as h263, but only 17 codes */
877
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
878
{
879
    int code, sign, val, m, l, shift;
880

    
881
    code = get_vlc(&s->gb, &mv_vlc);
882
    if (code < 0) {
883
        return 0xffff;
884
    }
885
    if (code == 0) {
886
        return pred;
887
    }
888
    sign = get_bits1(&s->gb);
889
    shift = fcode - 1;
890
    val = (code - 1) << shift;
891
    if (shift > 0)
892
        val |= get_bits(&s->gb, shift);
893
    val++;
894
    if (sign)
895
        val = -val;
896
    val += pred;
897
    
898
    /* modulo decoding */
899
    l = (1 << shift) * 16;
900
    m = 2 * l;
901
    if (val < -l) {
902
        val += m;
903
    } else if (val >= l) {
904
        val -= m;
905
    }
906
    return val;
907
}
908

    
909
static inline int decode_dc(MpegEncContext *s, int component)
910
{
911
    int code, diff;
912

    
913
    if (component == 0) {
914
        code = get_vlc(&s->gb, &dc_lum_vlc);
915
    } else {
916
        code = get_vlc(&s->gb, &dc_chroma_vlc);
917
    }
918
    if (code < 0)
919
        return 0xffff;
920
    if (code == 0) {
921
        diff = 0;
922
    } else {
923
        diff = get_bits(&s->gb, code);
924
        if ((diff & (1 << (code - 1))) == 0) 
925
            diff = (-1 << code) | (diff + 1);
926
    }
927
    return diff;
928
}
929

    
930
static int mpeg1_decode_block(MpegEncContext *s, 
931
                               DCTELEM *block, 
932
                               int n)
933
{
934
    int level, dc, diff, i, j, run;
935
    int code, component;
936
    RLTable *rl = &rl_mpeg1;
937

    
938
    if (s->mb_intra) {
939
        /* DC coef */
940
        component = (n <= 3 ? 0 : n - 4 + 1);
941
        diff = decode_dc(s, component);
942
        if (diff >= 0xffff)
943
            return -1;
944
        dc = s->last_dc[component];
945
        dc += diff;
946
        s->last_dc[component] = dc;
947
        block[0] = dc;
948
        dprintf("dc=%d diff=%d\n", dc, diff);
949
        i = 1;
950
    } else {
951
        int bit_cnt, v;
952
        UINT32 bit_buf;
953
        UINT8 *buf_ptr;
954
        i = 0;
955
        /* special case for the first coef. no need to add a second vlc table */
956
        SAVE_BITS(&s->gb);
957
        SHOW_BITS(&s->gb, v, 2);
958
        if (v & 2) {
959
            run = 0;
960
            level = 1 - ((v & 1) << 1);
961
            FLUSH_BITS(2);
962
            RESTORE_BITS(&s->gb);
963
            goto add_coef;
964
        }
965
        RESTORE_BITS(&s->gb);
966
    }
967

    
968
    /* now quantify & encode AC coefs */
969
    for(;;) {
970
        code = get_vlc(&s->gb, &rl->vlc);
971
        if (code < 0) {
972
            return -1;
973
        }
974
        if (code == 112) {
975
            break;
976
        } else if (code == 111) {
977
            /* escape */
978
            run = get_bits(&s->gb, 6);
979
            level = get_bits(&s->gb, 8);
980
            level = (level << 24) >> 24;
981
            if (level == -128) {
982
                level = get_bits(&s->gb, 8) - 256;
983
            } else if (level == 0) {
984
                level = get_bits(&s->gb, 8);
985
            }
986
        } else {
987
            run = rl->table_run[code];
988
            level = rl->table_level[code];
989
            if (get_bits1(&s->gb))
990
                level = -level;
991
        }
992
        i += run;
993
        if (i >= 64)
994
            return -1;
995
    add_coef:
996
        dprintf("%d: run=%d level=%d\n", n, run, level);
997
        j = zigzag_direct[i];
998
        block[j] = level;
999
        i++;
1000
    }
1001
    s->block_last_index[n] = i-1;
1002
    return 0;
1003
}
1004

    
1005
/* Also does unquantization here, since I will never support mpeg2
1006
   encoding */
1007
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
1008
                                        DCTELEM *block, 
1009
                                        int n)
1010
{
1011
    int level, i, j, run;
1012
    int code;
1013
    RLTable *rl = &rl_mpeg1;
1014
    const UINT8 *scan_table;
1015
    const UINT16 *matrix;
1016
    int mismatch;
1017

    
1018
    if (s->alternate_scan)
1019
        scan_table = ff_alternate_vertical_scan;
1020
    else
1021
        scan_table = zigzag_direct;
1022
    mismatch = 1;
1023

    
1024
    {
1025
        int bit_cnt, v;
1026
        UINT32 bit_buf;
1027
        UINT8 *buf_ptr;
1028
        i = 0;
1029
        if (n < 4) 
1030
            matrix = s->non_intra_matrix;
1031
        else
1032
            matrix = s->chroma_non_intra_matrix;
1033
            
1034
        /* special case for the first coef. no need to add a second vlc table */
1035
        SAVE_BITS(&s->gb);
1036
        SHOW_BITS(&s->gb, v, 2);
1037
        if (v & 2) {
1038
            run = 0;
1039
            level = 1 - ((v & 1) << 1);
1040
            FLUSH_BITS(2);
1041
            RESTORE_BITS(&s->gb);
1042
            goto add_coef;
1043
        }
1044
        RESTORE_BITS(&s->gb);
1045
    }
1046

    
1047
    /* now quantify & encode AC coefs */
1048
    for(;;) {
1049
        code = get_vlc(&s->gb, &rl->vlc);
1050
        if (code < 0)
1051
            return -1;
1052
        if (code == 112) {
1053
            break;
1054
        } else if (code == 111) {
1055
            /* escape */
1056
            run = get_bits(&s->gb, 6);
1057
            level = get_bits(&s->gb, 12);
1058
            level = (level << 20) >> 20;
1059
        } else {
1060
            run = rl->table_run[code];
1061
            level = rl->table_level[code];
1062
            if (get_bits1(&s->gb))
1063
                level = -level;
1064
        }
1065
        i += run;
1066
        if (i >= 64)
1067
            return -1;
1068
    add_coef:
1069
        j = scan_table[i];
1070
        dprintf("%d: run=%d level=%d\n", n, run, level);
1071
        /* XXX: optimize */
1072
        if (level > 0) {
1073
            level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1074
        } else {
1075
            level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1076
            level = -level;
1077
        }
1078
        /* XXX: is it really necessary to saturate since the encoder
1079
           knows whats going on ? */
1080
        mismatch ^= level;
1081
        block[j] = level;
1082
        i++;
1083
    }
1084
    block[63] ^= (mismatch & 1);
1085
    s->block_last_index[n] = i;
1086
    return 0;
1087
}
1088

    
1089
static int mpeg2_decode_block_intra(MpegEncContext *s, 
1090
                                    DCTELEM *block, 
1091
                                    int n)
1092
{
1093
    int level, dc, diff, i, j, run;
1094
    int code, component;
1095
    RLTable *rl;
1096
    const UINT8 *scan_table;
1097
    const UINT16 *matrix;
1098
    int mismatch;
1099

    
1100
    if (s->alternate_scan)
1101
        scan_table = ff_alternate_vertical_scan;
1102
    else
1103
        scan_table = zigzag_direct;
1104

    
1105
    /* DC coef */
1106
    component = (n <= 3 ? 0 : n - 4 + 1);
1107
    diff = decode_dc(s, component);
1108
    if (diff >= 0xffff)
1109
        return -1;
1110
    dc = s->last_dc[component];
1111
    dc += diff;
1112
    s->last_dc[component] = dc;
1113
    block[0] = dc << (3 - s->intra_dc_precision);
1114
    dprintf("dc=%d\n", block[0]);
1115
    mismatch = block[0] ^ 1;
1116
    i = 1;
1117
    if (s->intra_vlc_format)
1118
        rl = &rl_mpeg2;
1119
    else
1120
        rl = &rl_mpeg1;
1121
    if (n < 4) 
1122
        matrix = s->intra_matrix;
1123
    else
1124
        matrix = s->chroma_intra_matrix;
1125

    
1126
    /* now quantify & encode AC coefs */
1127
    for(;;) {
1128
        code = get_vlc(&s->gb, &rl->vlc);
1129
        if (code < 0)
1130
            return -1;
1131
        if (code == 112) {
1132
            break;
1133
        } else if (code == 111) {
1134
            /* escape */
1135
            run = get_bits(&s->gb, 6);
1136
            level = get_bits(&s->gb, 12);
1137
            level = (level << 20) >> 20;
1138
        } else {
1139
            run = rl->table_run[code];
1140
            level = rl->table_level[code];
1141
            if (get_bits1(&s->gb))
1142
                level = -level;
1143
        }
1144
        i += run;
1145
        if (i >= 64)
1146
            return -1;
1147
        j = scan_table[i];
1148
        dprintf("%d: run=%d level=%d\n", n, run, level);
1149
        level = (level * s->qscale * matrix[j]) / 16;
1150
        /* XXX: is it really necessary to saturate since the encoder
1151
           knows whats going on ? */
1152
        mismatch ^= level;
1153
        block[j] = level;
1154
        i++;
1155
    }
1156
    block[63] ^= (mismatch & 1);
1157
    s->block_last_index[n] = i;
1158
    return 0;
1159
}
1160

    
1161
/* compressed picture size */
1162
#define PICTURE_BUFFER_SIZE 100000
1163

    
1164
typedef struct Mpeg1Context {
1165
    MpegEncContext mpeg_enc_ctx;
1166
    UINT32 header_state;
1167
    int start_code; /* current start code */
1168
    UINT8 buffer[PICTURE_BUFFER_SIZE]; 
1169
    UINT8 *buf_ptr;
1170
    int buffer_size;
1171
    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1172
    int repeat_field; /* true if we must repeat the field */
1173
} Mpeg1Context;
1174

    
1175
static int mpeg_decode_init(AVCodecContext *avctx)
1176
{
1177
    Mpeg1Context *s = avctx->priv_data;
1178

    
1179
    s->header_state = 0xff;
1180
    s->mpeg_enc_ctx_allocated = 0;
1181
    s->buffer_size = PICTURE_BUFFER_SIZE;
1182
    s->start_code = -1;
1183
    s->buf_ptr = s->buffer;
1184
    s->mpeg_enc_ctx.picture_number = 0;
1185
    s->repeat_field = 0;
1186
    return 0;
1187
}
1188

    
1189
/* return the 8 bit start code value and update the search
1190
   state. Return -1 if no start code found */
1191
static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end, 
1192
                           UINT32 *header_state)
1193
{
1194
    UINT8 *buf_ptr;
1195
    unsigned int state, v;
1196
    int val;
1197

    
1198
    state = *header_state;
1199
    buf_ptr = *pbuf_ptr;
1200
    while (buf_ptr < buf_end) {
1201
        v = *buf_ptr++;
1202
        if (state == 0x000001) {
1203
            state = ((state << 8) | v) & 0xffffff;
1204
            val = state;
1205
            goto found;
1206
        }
1207
        state = ((state << 8) | v) & 0xffffff;
1208
    }
1209
    val = -1;
1210
 found:
1211
    *pbuf_ptr = buf_ptr;
1212
    *header_state = state;
1213
    return val;
1214
}
1215

    
1216
static int mpeg1_decode_picture(AVCodecContext *avctx, 
1217
                                UINT8 *buf, int buf_size)
1218
{
1219
    Mpeg1Context *s1 = avctx->priv_data;
1220
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1221
    int ref, f_code;
1222

    
1223
    init_get_bits(&s->gb, buf, buf_size);
1224

    
1225
    ref = get_bits(&s->gb, 10); /* temporal ref */
1226
    s->pict_type = get_bits(&s->gb, 3);
1227
    dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1228
    skip_bits(&s->gb, 16);
1229
    if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1230
        s->full_pel[0] = get_bits1(&s->gb);
1231
        f_code = get_bits(&s->gb, 3);
1232
        if (f_code == 0)
1233
            return -1;
1234
        s->mpeg_f_code[0][0] = f_code;
1235
        s->mpeg_f_code[0][1] = f_code;
1236
    }
1237
    if (s->pict_type == B_TYPE) {
1238
        s->full_pel[1] = get_bits1(&s->gb);
1239
        f_code = get_bits(&s->gb, 3);
1240
        if (f_code == 0)
1241
            return -1;
1242
        s->mpeg_f_code[1][0] = f_code;
1243
        s->mpeg_f_code[1][1] = f_code;
1244
    }
1245
    s->y_dc_scale = 8;
1246
    s->c_dc_scale = 8;
1247
    s->first_slice = 1;
1248
    return 0;
1249
}
1250

    
1251
static void mpeg_decode_sequence_extension(MpegEncContext *s)
1252
{
1253
    int horiz_size_ext, vert_size_ext;
1254
    int bit_rate_ext, vbv_buf_ext, low_delay;
1255
    int frame_rate_ext_n, frame_rate_ext_d;
1256

    
1257
    skip_bits(&s->gb, 8); /* profil and level */
1258
    s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1259
    skip_bits(&s->gb, 2); /* chroma_format */
1260
    horiz_size_ext = get_bits(&s->gb, 2);
1261
    vert_size_ext = get_bits(&s->gb, 2);
1262
    s->width |= (horiz_size_ext << 12);
1263
    s->height |= (vert_size_ext << 12);
1264
    bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1265
    s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1266
    skip_bits1(&s->gb); /* marker */
1267
    vbv_buf_ext = get_bits(&s->gb, 8);
1268
    low_delay = get_bits1(&s->gb);
1269
    frame_rate_ext_n = get_bits(&s->gb, 2);
1270
    frame_rate_ext_d = get_bits(&s->gb, 5);
1271
    if (frame_rate_ext_d >= 1)
1272
        s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1273
    dprintf("sequence extension\n");
1274
    s->mpeg2 = 1;
1275
}
1276

    
1277
static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1278
{
1279
    int i, v, j;
1280

    
1281
    dprintf("matrix extension\n");
1282

    
1283
    if (get_bits1(&s->gb)) {
1284
        for(i=0;i<64;i++) {
1285
            v = get_bits(&s->gb, 8);
1286
            j = zigzag_direct[i];
1287
            s->intra_matrix[j] = v;
1288
            s->chroma_intra_matrix[j] = v;
1289
        }
1290
    }
1291
    if (get_bits1(&s->gb)) {
1292
        for(i=0;i<64;i++) {
1293
            v = get_bits(&s->gb, 8);
1294
            j = zigzag_direct[i];
1295
            s->non_intra_matrix[j] = v;
1296
            s->chroma_non_intra_matrix[j] = v;
1297
        }
1298
    }
1299
    if (get_bits1(&s->gb)) {
1300
        for(i=0;i<64;i++) {
1301
            v = get_bits(&s->gb, 8);
1302
            j = zigzag_direct[i];
1303
            s->chroma_intra_matrix[j] = v;
1304
        }
1305
    }
1306
    if (get_bits1(&s->gb)) {
1307
        for(i=0;i<64;i++) {
1308
            v = get_bits(&s->gb, 8);
1309
            j = zigzag_direct[i];
1310
            s->chroma_non_intra_matrix[j] = v;
1311
        }
1312
    }
1313
}
1314

    
1315
static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1316
{
1317
    s->full_pel[0] = s->full_pel[1] = 0;
1318
    s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1319
    s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1320
    s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1321
    s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1322
    s->intra_dc_precision = get_bits(&s->gb, 2);
1323
    s->picture_structure = get_bits(&s->gb, 2);
1324
    s->top_field_first = get_bits1(&s->gb);
1325
    s->frame_pred_frame_dct = get_bits1(&s->gb);
1326
    s->concealment_motion_vectors = get_bits1(&s->gb);
1327
    s->q_scale_type = get_bits1(&s->gb);
1328
    s->intra_vlc_format = get_bits1(&s->gb);
1329
    s->alternate_scan = get_bits1(&s->gb);
1330
    s->repeat_first_field = get_bits1(&s->gb);
1331
    s->chroma_420_type = get_bits1(&s->gb);
1332
    s->progressive_frame = get_bits1(&s->gb);
1333
    /* composite display not parsed */
1334
    dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1335
    dprintf("picture_structure=%d\n", s->picture_structure);
1336
    dprintf("conceal=%d\n", s->concealment_motion_vectors);
1337
    dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1338
    dprintf("alternate_scan=%d\n", s->alternate_scan);
1339
    dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1340
    dprintf("progressive_frame=%d\n", s->progressive_frame);
1341
}
1342

    
1343
static void mpeg_decode_extension(AVCodecContext *avctx, 
1344
                                  UINT8 *buf, int buf_size)
1345
{
1346
    Mpeg1Context *s1 = avctx->priv_data;
1347
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1348
    int ext_type;
1349

    
1350
    init_get_bits(&s->gb, buf, buf_size);
1351
    
1352
    ext_type = get_bits(&s->gb, 4);
1353
    switch(ext_type) {
1354
    case 0x1:
1355
        /* sequence ext */
1356
        mpeg_decode_sequence_extension(s);
1357
        break;
1358
    case 0x3:
1359
        /* quant matrix extension */
1360
        mpeg_decode_quant_matrix_extension(s);
1361
        break;
1362
    case 0x8:
1363
        /* picture extension */
1364
        mpeg_decode_picture_coding_extension(s);
1365
        break;
1366
    }
1367
}
1368

    
1369
/* return 1 if end of frame */
1370
static int mpeg_decode_slice(AVCodecContext *avctx, 
1371
                              AVPicture *pict,
1372
                              int start_code,
1373
                              UINT8 *buf, int buf_size)
1374
{
1375
    Mpeg1Context *s1 = avctx->priv_data;
1376
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1377
    int ret;
1378

    
1379
    start_code = (start_code - 1) & 0xff;
1380
    if (start_code >= s->mb_height)
1381
        return -1;
1382
    s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1383
    s->last_dc[1] = s->last_dc[0];
1384
    s->last_dc[2] = s->last_dc[0];
1385
    memset(s->last_mv, 0, sizeof(s->last_mv));
1386
    s->mb_x = -1;
1387
    s->mb_y = start_code;
1388
    s->mb_incr = 0;
1389

    
1390
    /* start frame decoding */
1391
    if (s->first_slice) {
1392
        s->first_slice = 0;
1393
        MPV_frame_start(s);
1394
    }
1395

    
1396
    init_get_bits(&s->gb, buf, buf_size);
1397

    
1398
    s->qscale = get_qscale(s);
1399
    /* extra slice info */
1400
    while (get_bits1(&s->gb) != 0) {
1401
        skip_bits(&s->gb, 8);
1402
    }
1403

    
1404
    for(;;) {
1405
        memset(s->block, 0, sizeof(s->block));
1406
        ret = mpeg_decode_mb(s, s->block);
1407
        dprintf("ret=%d\n", ret);
1408
        if (ret < 0)
1409
            return -1;
1410
        if (ret == 1)
1411
            break;
1412
        MPV_decode_mb(s, s->block);
1413
    }
1414
    
1415
    /* end of slice reached */
1416
    if (s->mb_x == (s->mb_width - 1) &&
1417
        s->mb_y == (s->mb_height - 1)) {
1418
        /* end of image */
1419
        UINT8 **picture;
1420

    
1421
        MPV_frame_end(s);
1422

    
1423
        /* XXX: incorrect reported qscale for mpeg2 */
1424
        if (s->pict_type == B_TYPE) {
1425
            picture = s->current_picture;
1426
            avctx->quality = s->qscale;
1427
        } else {
1428
            /* latency of 1 frame for I and P frames */
1429
            /* XXX: use another variable than picture_number */
1430
            if (s->picture_number == 0) {
1431
                picture = NULL;
1432
            } else {
1433
                picture = s->last_picture;
1434
                avctx->quality = s->last_qscale;
1435
            }
1436
            s->last_qscale = s->qscale;
1437
            s->picture_number++;
1438
        }
1439
        if (picture) {
1440
            pict->data[0] = picture[0];
1441
            pict->data[1] = picture[1];
1442
            pict->data[2] = picture[2];
1443
            pict->linesize[0] = s->linesize;
1444
            pict->linesize[1] = s->linesize / 2;
1445
            pict->linesize[2] = s->linesize / 2;
1446
            return 1;
1447
        } else {
1448
            return 0;
1449
        }
1450
    } else {
1451
        return 0;
1452
    }
1453
}
1454

    
1455
static int mpeg1_decode_sequence(AVCodecContext *avctx, 
1456
                                 UINT8 *buf, int buf_size)
1457
{
1458
    Mpeg1Context *s1 = avctx->priv_data;
1459
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1460
    int width, height, i, v, j;
1461
    
1462
    init_get_bits(&s->gb, buf, buf_size);
1463

    
1464
    width = get_bits(&s->gb, 12);
1465
    height = get_bits(&s->gb, 12);
1466
    skip_bits(&s->gb, 4);
1467
    s->frame_rate_index = get_bits(&s->gb, 4);
1468
    if (s->frame_rate_index == 0)
1469
        return -1;
1470
    s->bit_rate = get_bits(&s->gb, 18) * 400;
1471
    if (get_bits1(&s->gb) == 0) /* marker */
1472
        return -1;
1473
    if (width <= 0 || height <= 0 ||
1474
        (width % 2) != 0 || (height % 2) != 0)
1475
        return -1;
1476
    if (width != s->width ||
1477
        height != s->height) {
1478
        /* start new mpeg1 context decoding */
1479
        s->out_format = FMT_MPEG1;
1480
        if (s1->mpeg_enc_ctx_allocated) {
1481
            MPV_common_end(s);
1482
        }
1483
        s->width = width;
1484
        s->height = height;
1485
        s->has_b_frames = 1;
1486
        s->avctx = avctx;
1487
        avctx->width = width;
1488
        avctx->height = height;
1489
        avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1490
        s->frame_rate = avctx->frame_rate;
1491
        avctx->bit_rate = s->bit_rate;
1492
        
1493
        if (MPV_common_init(s) < 0)
1494
            return -1;
1495
        mpeg1_init_vlc(s);
1496
        s1->mpeg_enc_ctx_allocated = 1;
1497
    }
1498

    
1499
    skip_bits(&s->gb, 10); /* vbv_buffer_size */
1500
    skip_bits(&s->gb, 1);
1501

    
1502
    /* get matrix */
1503
    if (get_bits1(&s->gb)) {
1504
        for(i=0;i<64;i++) {
1505
            v = get_bits(&s->gb, 8);
1506
            j = zigzag_direct[i];
1507
            s->intra_matrix[j] = v;
1508
            s->chroma_intra_matrix[j] = v;
1509
        }
1510
#ifdef DEBUG
1511
        dprintf("intra matrix present\n");
1512
        for(i=0;i<64;i++)
1513
            dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1514
        printf("\n");
1515
#endif
1516
    } else {
1517
        for(i=0;i<64;i++) {
1518
            v = default_intra_matrix[i];
1519
            s->intra_matrix[i] = v;
1520
            s->chroma_intra_matrix[i] = v;
1521
        }
1522
    }
1523
    if (get_bits1(&s->gb)) {
1524
        for(i=0;i<64;i++) {
1525
            v = get_bits(&s->gb, 8);
1526
            j = zigzag_direct[i];
1527
            s->non_intra_matrix[j] = v;
1528
            s->chroma_non_intra_matrix[j] = v;
1529
        }
1530
#ifdef DEBUG
1531
        dprintf("non intra matrix present\n");
1532
        for(i=0;i<64;i++)
1533
            dprintf(" %d", s->non_intra_matrix[zigzag_direct[i]]);
1534
        printf("\n");
1535
#endif
1536
    } else {
1537
        for(i=0;i<64;i++) {
1538
            v = default_non_intra_matrix[i];
1539
            s->non_intra_matrix[i] = v;
1540
            s->chroma_non_intra_matrix[i] = v;
1541
        }
1542
    }
1543

    
1544
    /* we set mpeg2 parameters so that it emulates mpeg1 */
1545
    s->progressive_sequence = 1;
1546
    s->progressive_frame = 1;
1547
    s->picture_structure = PICT_FRAME;
1548
    s->frame_pred_frame_dct = 1;
1549
    s->mpeg2 = 0;
1550
    return 0;
1551
}
1552

    
1553
/* handle buffering and image synchronisation */
1554
static int mpeg_decode_frame(AVCodecContext *avctx, 
1555
                             void *data, int *data_size,
1556
                             UINT8 *buf, int buf_size)
1557
{
1558
    Mpeg1Context *s = avctx->priv_data;
1559
    UINT8 *buf_end, *buf_ptr, *buf_start;
1560
    int len, start_code_found, ret, code, start_code, input_size;
1561
    AVPicture *picture = data;
1562
    MpegEncContext *s2 = &s->mpeg_enc_ctx;
1563
            
1564
    dprintf("fill_buffer\n");
1565

    
1566
    *data_size = 0;
1567
    
1568
    /* special case for last picture */
1569
    if (buf_size == 0) {
1570
        if (s2->picture_number > 0) {
1571
            picture->data[0] = s2->next_picture[0];
1572
            picture->data[1] = s2->next_picture[1];
1573
            picture->data[2] = s2->next_picture[2];
1574
            picture->linesize[0] = s2->linesize;
1575
            picture->linesize[1] = s2->linesize / 2;
1576
            picture->linesize[2] = s2->linesize / 2;
1577
            *data_size = sizeof(AVPicture);
1578
        }
1579
        return 0;
1580
    }
1581

    
1582
    buf_ptr = buf;
1583
    buf_end = buf + buf_size;
1584
    
1585
    if (s->repeat_field % 2 == 1) {
1586
        s->repeat_field++;
1587
        //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1588
        //                                                         s2->picture_number, s->repeat_field);
1589
        *data_size = sizeof(AVPicture);
1590
        goto the_end;
1591
    }
1592
        
1593
    while (buf_ptr < buf_end) {
1594
        buf_start = buf_ptr;
1595
        /* find start next code */
1596
        code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1597
        if (code >= 0) {
1598
            start_code_found = 1;
1599
        } else {
1600
            start_code_found = 0;
1601
        }
1602
        /* copy to buffer */
1603
        len = buf_ptr - buf_start;
1604
        if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1605
            /* data too big : flush */
1606
            s->buf_ptr = s->buffer;
1607
            if (start_code_found)
1608
                s->start_code = code;
1609
        } else {
1610
            memcpy(s->buf_ptr, buf_start, len);
1611
            s->buf_ptr += len;
1612
            
1613
            if (start_code_found) {
1614
                /* prepare data for next start code */
1615
                input_size = s->buf_ptr - s->buffer;
1616
                start_code = s->start_code;
1617
                s->buf_ptr = s->buffer;
1618
                s->start_code = code;
1619
                switch(start_code) {
1620
                case SEQ_START_CODE:
1621
                    mpeg1_decode_sequence(avctx, s->buffer, 
1622
                                          input_size);
1623
                    break;
1624
                            
1625
                case PICTURE_START_CODE:
1626
                    /* we have a complete image : we try to decompress it */
1627
                    mpeg1_decode_picture(avctx, 
1628
                                         s->buffer, input_size);
1629
                    break;
1630
                case EXT_START_CODE:
1631
                    mpeg_decode_extension(avctx,
1632
                                          s->buffer, input_size);
1633
                    break;
1634
                default:
1635
                    if (start_code >= SLICE_MIN_START_CODE &&
1636
                        start_code <= SLICE_MAX_START_CODE) {
1637
                        ret = mpeg_decode_slice(avctx, picture,
1638
                                                start_code, s->buffer, input_size);
1639
                        if (ret == 1) {
1640
                            /* got a picture: exit */
1641
                            /* first check if we must repeat the frame */
1642
                            if (s2->progressive_frame && s2->repeat_first_field) {
1643
                                //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1644
                                s2->repeat_first_field = 0;
1645
                                s2->progressive_frame = 0;
1646
                                if (++s->repeat_field > 2)
1647
                                    s->repeat_field = 0;
1648
                            }
1649
                            *data_size = sizeof(AVPicture);
1650
                            goto the_end;
1651
                        }
1652
                    }
1653
                    break;
1654
                }
1655
            }
1656
        }
1657
    }
1658
 the_end:
1659
    return buf_ptr - buf;
1660
}
1661

    
1662
static int mpeg_decode_end(AVCodecContext *avctx)
1663
{
1664
    Mpeg1Context *s = avctx->priv_data;
1665

    
1666
    if (s->mpeg_enc_ctx_allocated)
1667
        MPV_common_end(&s->mpeg_enc_ctx);
1668
    return 0;
1669
}
1670

    
1671
AVCodec mpeg_decoder = {
1672
    "mpegvideo",
1673
    CODEC_TYPE_VIDEO,
1674
    CODEC_ID_MPEG1VIDEO,
1675
    sizeof(Mpeg1Context),
1676
    mpeg_decode_init,
1677
    NULL,
1678
    mpeg_decode_end,
1679
    mpeg_decode_frame,
1680
};