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

    
24
#include "mpeg12data.h"
25

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

    
36
static void mpeg1_encode_block(MpegEncContext *s, 
37
                         DCTELEM *block, 
38
                         int component);
39
static void mpeg1_encode_motion(MpegEncContext *s, int val);
40
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
41
static int mpeg1_decode_block(MpegEncContext *s, 
42
                              DCTELEM *block, 
43
                              int n);
44
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
45
                                        DCTELEM *block, 
46
                                        int n);
47
static int mpeg2_decode_block_intra(MpegEncContext *s, 
48
                                    DCTELEM *block, 
49
                                    int n);
50
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
51

    
52
static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
53
static UINT8 fcode_tab[MAX_MV*2+1];
54

    
55
static void put_header(MpegEncContext *s, int header)
56
{
57
    align_put_bits(&s->pb);
58
    put_bits(&s->pb, 16, header>>16);
59
    put_bits(&s->pb, 16, header&0xFFFF);
60
}
61

    
62
/* put sequence header if needed */
63
static void mpeg1_encode_sequence_header(MpegEncContext *s)
64
{
65
        unsigned int vbv_buffer_size;
66
        unsigned int fps, v;
67
        int n;
68
        UINT64 time_code;
69
        
70
        if (s->picture_in_gop_number == 0) {
71
            /* mpeg1 header repeated every gop */
72
            put_header(s, SEQ_START_CODE);
73
            
74
            /* search closest frame rate */
75
            {
76
                int i, dmin, d;
77
                s->frame_rate_index = 0;
78
                dmin = 0x7fffffff;
79
                for(i=1;i<9;i++) {
80
                    d = abs(s->frame_rate - frame_rate_tab[i]);
81
                    if (d < dmin) {
82
                        dmin = d;
83
                        s->frame_rate_index = i;
84
                    }
85
                }
86
            }
87
 
88
            put_bits(&s->pb, 12, s->width);
89
            put_bits(&s->pb, 12, s->height);
90
            put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
91
            put_bits(&s->pb, 4, s->frame_rate_index);
92
            v = s->bit_rate / 400;
93
            if (v > 0x3ffff)
94
                v = 0x3ffff;
95
            put_bits(&s->pb, 18, v);
96
            put_bits(&s->pb, 1, 1); /* marker */
97
            /* vbv buffer size: slightly greater than an I frame. We add
98
               some margin just in case */
99
            vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
100
            put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384); 
101
            put_bits(&s->pb, 1, 1); /* constrained parameter flag */
102
            put_bits(&s->pb, 1, 0); /* no custom intra matrix */
103
            put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
104

    
105
            put_header(s, GOP_START_CODE);
106
            put_bits(&s->pb, 1, 0); /* do drop frame */
107
            /* time code : we must convert from the real frame rate to a
108
               fake mpeg frame rate in case of low frame rate */
109
            fps = frame_rate_tab[s->frame_rate_index];
110
            time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
111
            s->gop_picture_number = s->fake_picture_number;
112
            put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
113
            put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
114
            put_bits(&s->pb, 1, 1);
115
            put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
116
            put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
117
            put_bits(&s->pb, 1, 1); /* closed gop */
118
            put_bits(&s->pb, 1, 0); /* broken link */
119
        }
120

    
121
        if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
122
            /* insert empty P pictures to slow down to the desired
123
               frame rate. Each fake pictures takes about 20 bytes */
124
            fps = frame_rate_tab[s->frame_rate_index];
125
            n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
126
            while (s->fake_picture_number < n) {
127
                mpeg1_skip_picture(s, s->fake_picture_number - 
128
                                   s->gop_picture_number); 
129
                s->fake_picture_number++;
130
            }
131

    
132
        }
133
}
134

    
135

    
136
/* insert a fake P picture */
137
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
138
{
139
    unsigned int mb_incr;
140

    
141
    /* mpeg1 picture header */
142
    put_header(s, PICTURE_START_CODE);
143
    /* temporal reference */
144
    put_bits(&s->pb, 10, pict_num & 0x3ff); 
145
    
146
    put_bits(&s->pb, 3, P_TYPE);
147
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
148
    
149
    put_bits(&s->pb, 1, 1); /* integer coordinates */
150
    put_bits(&s->pb, 3, 1); /* forward_f_code */
151
    
152
    put_bits(&s->pb, 1, 0); /* extra bit picture */
153
    
154
    /* only one slice */
155
    put_header(s, SLICE_MIN_START_CODE);
156
    put_bits(&s->pb, 5, 1); /* quantizer scale */
157
    put_bits(&s->pb, 1, 0); /* slice extra information */
158
    
159
    mb_incr = 1;
160
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
161
             mbAddrIncrTable[mb_incr - 1][0]);
162
    
163
    /* empty macroblock */
164
    put_bits(&s->pb, 3, 1); /* motion only */
165
    
166
    /* zero motion x & y */
167
    put_bits(&s->pb, 1, 1); 
168
    put_bits(&s->pb, 1, 1); 
169

    
170
    /* output a number of empty slice */
171
    mb_incr = s->mb_width * s->mb_height - 1;
172
    while (mb_incr > 33) {
173
        put_bits(&s->pb, 11, 0x008);
174
        mb_incr -= 33;
175
    }
176
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
177
             mbAddrIncrTable[mb_incr - 1][0]);
178
    
179
    /* empty macroblock */
180
    put_bits(&s->pb, 3, 1); /* motion only */
181
    
182
    /* zero motion x & y */
183
    put_bits(&s->pb, 1, 1); 
184
    put_bits(&s->pb, 1, 1); 
185
}
186

    
187
static void common_init(MpegEncContext *s)
188
{
189
    s->y_dc_scale_table=
190
    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
191
}
192

    
193
void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
194
{
195
    mpeg1_encode_sequence_header(s);
196

    
197
    /* mpeg1 picture header */
198
    put_header(s, PICTURE_START_CODE);
199
    /* temporal reference */
200
    put_bits(&s->pb, 10, (s->fake_picture_number - 
201
                          s->gop_picture_number) & 0x3ff); 
202
    s->fake_picture_number++;
203
    
204
    put_bits(&s->pb, 3, s->pict_type);
205
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
206
    
207
    if (s->pict_type == P_TYPE) {
208
        put_bits(&s->pb, 1, 0); /* half pel coordinates */
209
        put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
210
    }
211
    
212
    put_bits(&s->pb, 1, 0); /* extra bit picture */
213
    
214
    /* only one slice */
215
    put_header(s, SLICE_MIN_START_CODE);
216
    put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
217
    put_bits(&s->pb, 1, 0); /* slice extra information */
218
}
219

    
220
void mpeg1_encode_mb(MpegEncContext *s,
221
                     DCTELEM block[6][64],
222
                     int motion_x, int motion_y)
223
{
224
    int mb_incr, i, cbp, mb_x, mb_y;
225

    
226
    mb_x = s->mb_x;
227
    mb_y = s->mb_y;
228

    
229
    /* compute cbp */
230
    cbp = 0;
231
    for(i=0;i<6;i++) {
232
        if (s->block_last_index[i] >= 0)
233
            cbp |= 1 << (5 - i);
234
    }
235

    
236
    /* skip macroblock, except if first or last macroblock of a slice */
237
    if ((cbp | motion_x | motion_y) == 0 &&
238
        (!((mb_x | mb_y) == 0 ||
239
           (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
240
        s->mb_incr++;
241
    } else {
242
        /* output mb incr */
243
        mb_incr = s->mb_incr;
244

    
245
        while (mb_incr > 33) {
246
            put_bits(&s->pb, 11, 0x008);
247
            mb_incr -= 33;
248
        }
249
        put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
250
                 mbAddrIncrTable[mb_incr - 1][0]);
251
        
252
        if (s->pict_type == I_TYPE) {
253
            put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
254
        } else {
255
            if (s->mb_intra) {
256
                put_bits(&s->pb, 5, 0x03);
257
            } else {
258
                if (cbp != 0) {
259
                    if (motion_x == 0 && motion_y == 0) {
260
                        put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
261
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
262
                    } else {
263
                        put_bits(&s->pb, 1, 1); /* motion + cbp */
264
                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
265
                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
266
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
267
                    }
268
                } else {
269
                    put_bits(&s->pb, 3, 1); /* motion only */
270
                    mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
271
                    mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
272
                }
273
            }
274
        }
275
        for(i=0;i<6;i++) {
276
            if (cbp & (1 << (5 - i))) {
277
                mpeg1_encode_block(s, block[i], i);
278
            }
279
        }
280
        s->mb_incr = 1;
281
    }
282
    s->last_mv[0][0][0] = motion_x;
283
    s->last_mv[0][0][1] = motion_y;
284
}
285

    
286
static void mpeg1_encode_motion(MpegEncContext *s, int val)
287
{
288
    int code, bit_size, l, m, bits, range, sign;
289

    
290
    if (val == 0) {
291
        /* zero vector */
292
        code = 0;
293
        put_bits(&s->pb,
294
                 mbMotionVectorTable[0][1], 
295
                 mbMotionVectorTable[0][0]); 
296
    } else {
297
        bit_size = s->f_code - 1;
298
        range = 1 << bit_size;
299
        /* modulo encoding */
300
        l = 16 * range;
301
        m = 2 * l;
302
        if (val < -l) {
303
            val += m;
304
        } else if (val >= l) {
305
            val -= m;
306
        }
307

    
308
        if (val >= 0) {
309
            val--;
310
            code = (val >> bit_size) + 1;
311
            bits = val & (range - 1);
312
            sign = 0;
313
        } else {
314
            val = -val;
315
            val--;
316
            code = (val >> bit_size) + 1;
317
            bits = val & (range - 1);
318
            sign = 1;
319
        }
320
        put_bits(&s->pb,
321
                 mbMotionVectorTable[code][1], 
322
                 mbMotionVectorTable[code][0]); 
323
        put_bits(&s->pb, 1, sign);
324
        if (bit_size > 0) {
325
            put_bits(&s->pb, bit_size, bits);
326
        }
327
    }
328
}
329

    
330
void ff_mpeg1_encode_init(MpegEncContext *s)
331
{
332
    static int done=0;
333

    
334
    common_init(s);
335

    
336
    if(!done){
337
        int f_code;
338
        int mv;
339
        int i;
340

    
341
        done=1;
342
        init_rl(&rl_mpeg1);
343
        
344
        for(i=0; i<64; i++)
345
        {
346
                mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
347
                mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
348
        }
349

    
350
        /* build unified dc encoding tables */
351
        for(i=-255; i<256; i++)
352
        {
353
                int adiff, index;
354
                int bits, code;
355
                int diff=i;
356

    
357
                adiff = ABS(diff);
358
                if(diff<0) diff--;
359
                index = vlc_dc_table[adiff];
360

    
361
                bits= vlc_dc_lum_bits[index] + index;
362
                code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
363
                mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
364
                
365
                bits= vlc_dc_chroma_bits[index] + index;
366
                code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
367
                mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
368
        }
369

    
370
        for(f_code=1; f_code<=MAX_FCODE; f_code++){
371
            for(mv=-MAX_MV; mv<=MAX_MV; mv++){
372
                int len;
373

    
374
                if(mv==0) len= mbMotionVectorTable[0][1];
375
                else{
376
                    int val, bit_size, range, code;
377

    
378
                    bit_size = s->f_code - 1;
379
                    range = 1 << bit_size;
380

    
381
                    val=mv;
382
                    if (val < 0) 
383
                        val = -val;
384
                    val--;
385
                    code = (val >> bit_size) + 1;
386
                    if(code<17){
387
                        len= mbMotionVectorTable[code][1] + 1 + bit_size;
388
                    }else{
389
                        len= mbMotionVectorTable[16][1] + 2 + bit_size;
390
                    }
391
                }
392

    
393
                mv_penalty[f_code][mv+MAX_MV]= len;
394
            }
395
        }
396
        
397

    
398
        for(f_code=MAX_FCODE; f_code>0; f_code--){
399
            for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
400
                fcode_tab[mv+MAX_MV]= f_code;
401
            }
402
        }
403
    }
404
    s->mv_penalty= mv_penalty;
405
    s->fcode_tab= fcode_tab;
406
    s->min_qcoeff=-255;
407
    s->max_qcoeff= 255;
408
    s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
409
    s->inter_quant_bias= 0;
410
}
411

    
412
static inline void encode_dc(MpegEncContext *s, int diff, int component)
413
{
414
    if (component == 0) {
415
        put_bits(
416
            &s->pb, 
417
            mpeg1_lum_dc_uni[diff+255]&0xFF,
418
            mpeg1_lum_dc_uni[diff+255]>>8);
419
    } else {
420
        put_bits(
421
            &s->pb, 
422
            mpeg1_chr_dc_uni[diff+255]&0xFF,
423
            mpeg1_chr_dc_uni[diff+255]>>8);
424
    }
425
}
426

    
427
static void mpeg1_encode_block(MpegEncContext *s, 
428
                               DCTELEM *block, 
429
                               int n)
430
{
431
    int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
432
    int code, component;
433
//    RLTable *rl = &rl_mpeg1;
434

    
435
    last_index = s->block_last_index[n];
436

    
437
    /* DC coef */
438
    if (s->mb_intra) {
439
        component = (n <= 3 ? 0 : n - 4 + 1);
440
        dc = block[0]; /* overflow is impossible */
441
        diff = dc - s->last_dc[component];
442
        encode_dc(s, diff, component);
443
        s->last_dc[component] = dc;
444
        i = 1;
445
    } else {
446
        /* encode the first coefficient : needs to be done here because
447
           it is handled slightly differently */
448
        level = block[0];
449
        if (abs(level) == 1) {
450
                code = ((UINT32)level >> 31); /* the sign bit */
451
                put_bits(&s->pb, 2, code | 0x02);
452
                i = 1;
453
        } else {
454
            i = 0;
455
            last_non_zero = -1;
456
            goto next_coef;
457
        }
458
    }
459

    
460
    /* now quantify & encode AC coefs */
461
    last_non_zero = i - 1;
462

    
463
    for(;i<=last_index;i++) {
464
        j = zigzag_direct[i];
465
        level = block[j];
466
    next_coef:
467
#if 0
468
        if (level != 0)
469
            dprintf("level[%d]=%d\n", i, level);
470
#endif            
471
        /* encode using VLC */
472
        if (level != 0) {
473
            run = i - last_non_zero - 1;
474
#ifdef ARCH_X86
475
            asm volatile(
476
                "movl %2, %1                \n\t"
477
                "movl %1, %0                \n\t"
478
                "addl %1, %1                \n\t"
479
                "sbbl %1, %1                \n\t"
480
                "xorl %1, %0                \n\t"
481
                "subl %1, %0                \n\t"
482
                "andl $1, %1                \n\t"
483
                : "=&r" (alevel), "=&r" (sign)
484
                : "g" (level)
485
            );
486
#else
487
            sign = 0;
488
            alevel = level;
489
            if (alevel < 0) {
490
                sign = 1;
491
                alevel = -alevel;
492
            }
493
#endif
494
//            code = get_rl_index(rl, 0, run, alevel);
495
            if (alevel > mpeg1_max_level[0][run])
496
                code= 111; /*rl->n*/
497
            else
498
                code= mpeg1_index_run[0][run] + alevel - 1;
499

    
500
            if (code < 111 /* rl->n */) {
501
                    /* store the vlc & sign at once */
502
                put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
503
            } else {
504
                /* escape seems to be pretty rare <5% so i dont optimize it */
505
                put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
506
                /* escape: only clip in this case */
507
                put_bits(&s->pb, 6, run);
508
                if (alevel < 128) {
509
                    put_bits(&s->pb, 8, level & 0xff);
510
                } else {
511
                    if (level < 0) {
512
                        put_bits(&s->pb, 16, 0x8001 + level + 255);
513
                    } else {
514
                        put_bits(&s->pb, 16, level & 0xffff);
515
                    }
516
                }
517
            }
518
            last_non_zero = i;
519
        }
520
    }
521
    /* end of block */
522
    put_bits(&s->pb, 2, 0x2);
523
}
524

    
525
/******************************************/
526
/* decoding */
527

    
528
static VLC dc_lum_vlc;
529
static VLC dc_chroma_vlc;
530
static VLC mv_vlc;
531
static VLC mbincr_vlc;
532
static VLC mb_ptype_vlc;
533
static VLC mb_btype_vlc;
534
static VLC mb_pat_vlc;
535

    
536
void mpeg1_init_vlc(MpegEncContext *s)
537
{
538
    static int done = 0;
539

    
540
    if (!done) {
541
        done = 1;
542

    
543
        init_vlc(&dc_lum_vlc, 9, 12, 
544
                 vlc_dc_lum_bits, 1, 1,
545
                 vlc_dc_lum_code, 2, 2);
546
        init_vlc(&dc_chroma_vlc, 9, 12, 
547
                 vlc_dc_chroma_bits, 1, 1,
548
                 vlc_dc_chroma_code, 2, 2);
549
        init_vlc(&mv_vlc, 9, 17, 
550
                 &mbMotionVectorTable[0][1], 2, 1,
551
                 &mbMotionVectorTable[0][0], 2, 1);
552
        init_vlc(&mbincr_vlc, 9, 35, 
553
                 &mbAddrIncrTable[0][1], 2, 1,
554
                 &mbAddrIncrTable[0][0], 2, 1);
555
        init_vlc(&mb_pat_vlc, 9, 63, 
556
                 &mbPatTable[0][1], 2, 1,
557
                 &mbPatTable[0][0], 2, 1);
558
        
559
        init_vlc(&mb_ptype_vlc, 6, 32, 
560
                 &table_mb_ptype[0][1], 2, 1,
561
                 &table_mb_ptype[0][0], 2, 1);
562
        init_vlc(&mb_btype_vlc, 6, 32, 
563
                 &table_mb_btype[0][1], 2, 1,
564
                 &table_mb_btype[0][0], 2, 1);
565
        init_rl(&rl_mpeg1);
566
        init_rl(&rl_mpeg2);
567
        /* cannot use generic init because we must add the EOB code */
568
        init_vlc(&rl_mpeg1.vlc, 9, rl_mpeg1.n + 2, 
569
                 &rl_mpeg1.table_vlc[0][1], 4, 2,
570
                 &rl_mpeg1.table_vlc[0][0], 4, 2);
571
        init_vlc(&rl_mpeg2.vlc, 9, rl_mpeg2.n + 2, 
572
                 &rl_mpeg2.table_vlc[0][1], 4, 2,
573
                 &rl_mpeg2.table_vlc[0][0], 4, 2);
574
    }
575
}
576

    
577
static inline int get_dmv(MpegEncContext *s)
578
{
579
    if(get_bits1(&s->gb)) 
580
        return 1 - (get_bits1(&s->gb) << 1);
581
    else
582
        return 0;
583
}
584

    
585
static inline int get_qscale(MpegEncContext *s)
586
{
587
    int qscale;
588
    if (s->mpeg2) {
589
        if (s->q_scale_type) {
590
            qscale = non_linear_qscale[get_bits(&s->gb, 5)];
591
        } else {
592
            qscale = get_bits(&s->gb, 5) << 1;
593
        }
594
    } else {
595
        /* for mpeg1, we use the generic unquant code */
596
        qscale = get_bits(&s->gb, 5);
597
    }
598
    return qscale;
599
}
600

    
601
/* motion type (for mpeg2) */
602
#define MT_FIELD 1
603
#define MT_FRAME 2
604
#define MT_16X8  2
605
#define MT_DMV   3
606

    
607
static int mpeg_decode_mb(MpegEncContext *s,
608
                          DCTELEM block[6][64])
609
{
610
    int i, j, k, cbp, val, code, mb_type, motion_type;
611
    
612
    /* skip mb handling */
613
    if (s->mb_incr == 0) {
614
        /* read again increment */
615
        s->mb_incr = 1;
616
        for(;;) {
617
            code = get_vlc(&s->gb, &mbincr_vlc);
618
            if (code < 0)
619
                return 1; /* error = end of slice */
620
            if (code >= 33) {
621
                if (code == 33) {
622
                    s->mb_incr += 33;
623
                }
624
                /* otherwise, stuffing, nothing to do */
625
            } else {
626
                s->mb_incr += code;
627
                break;
628
            }
629
        }
630
    }
631
    if (++s->mb_x >= s->mb_width) {
632
        s->mb_x = 0;
633
        if (s->mb_y >= (s->mb_height - 1))
634
            return -1;
635
        s->mb_y++;
636
    }
637
    dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
638

    
639
    if (--s->mb_incr != 0) {
640
        /* skip mb */
641
        s->mb_intra = 0;
642
        for(i=0;i<6;i++)
643
            s->block_last_index[i] = -1;
644
        s->mv_type = MV_TYPE_16X16;
645
        if (s->pict_type == P_TYPE) {
646
            /* if P type, zero motion vector is implied */
647
            s->mv_dir = MV_DIR_FORWARD;
648
            s->mv[0][0][0] = s->mv[0][0][1] = 0;
649
            s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
650
            s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
651
        } else {
652
            /* if B type, reuse previous vectors and directions */
653
            s->mv[0][0][0] = s->last_mv[0][0][0];
654
            s->mv[0][0][1] = s->last_mv[0][0][1];
655
            s->mv[1][0][0] = s->last_mv[1][0][0];
656
            s->mv[1][0][1] = s->last_mv[1][0][1];
657
        }
658
        s->mb_skiped = 1;
659
        return 0;
660
    }
661

    
662
    switch(s->pict_type) {
663
    default:
664
    case I_TYPE:
665
        if (get_bits1(&s->gb) == 0) {
666
            if (get_bits1(&s->gb) == 0)
667
                return -1;
668
            mb_type = MB_QUANT | MB_INTRA;
669
        } else {
670
            mb_type = MB_INTRA;
671
        }
672
        break;
673
    case P_TYPE:
674
        mb_type = get_vlc(&s->gb, &mb_ptype_vlc);
675
        if (mb_type < 0)
676
            return -1;
677
        break;
678
    case B_TYPE:
679
        mb_type = get_vlc(&s->gb, &mb_btype_vlc);
680
        if (mb_type < 0)
681
            return -1;
682
        break;
683
    }
684
    dprintf("mb_type=%x\n", mb_type);
685
    motion_type = 0; /* avoid warning */
686
    if (mb_type & (MB_FOR|MB_BACK)) {
687
        /* get additionnal motion vector type */
688
        if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) 
689
            motion_type = MT_FRAME;
690
        else
691
            motion_type = get_bits(&s->gb, 2);
692
    }
693
    /* compute dct type */
694
    if (s->picture_structure == PICT_FRAME && 
695
        !s->frame_pred_frame_dct &&
696
        (mb_type & (MB_PAT | MB_INTRA))) {
697
        s->interlaced_dct = get_bits1(&s->gb);
698
#ifdef DEBUG
699
        if (s->interlaced_dct)
700
            printf("interlaced_dct\n");
701
#endif
702
    } else {
703
        s->interlaced_dct = 0; /* frame based */
704
    }
705

    
706
    if (mb_type & MB_QUANT) {
707
        s->qscale = get_qscale(s);
708
    }
709
    if (mb_type & MB_INTRA) {
710
        if (s->concealment_motion_vectors) {
711
            /* just parse them */
712
            if (s->picture_structure != PICT_FRAME) 
713
                skip_bits1(&s->gb); /* field select */
714
            mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
715
            mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
716
        }
717
        s->mb_intra = 1;
718
        cbp = 0x3f;
719
        memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
720
    } else {
721
        s->mb_intra = 0;
722
        cbp = 0;
723
    }
724
    /* special case of implicit zero motion vector */
725
    if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
726
        s->mv_dir = MV_DIR_FORWARD;
727
        s->mv_type = MV_TYPE_16X16;
728
        s->last_mv[0][0][0] = 0;
729
        s->last_mv[0][0][1] = 0;
730
        s->last_mv[0][1][0] = 0;
731
        s->last_mv[0][1][1] = 0;
732
        s->mv[0][0][0] = 0;
733
        s->mv[0][0][1] = 0;
734
    } else if (mb_type & (MB_FOR | MB_BACK)) {
735
        /* motion vectors */
736
        s->mv_dir = 0;
737
        for(i=0;i<2;i++) {
738
            if (mb_type & (MB_FOR >> i)) {
739
                s->mv_dir |= (MV_DIR_FORWARD >> i);
740
                dprintf("motion_type=%d\n", motion_type);
741
                switch(motion_type) {
742
                case MT_FRAME: /* or MT_16X8 */
743
                    if (s->picture_structure == PICT_FRAME) {
744
                        /* MT_FRAME */
745
                        s->mv_type = MV_TYPE_16X16;
746
                        for(k=0;k<2;k++) {
747
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k], 
748
                                                     s->last_mv[i][0][k]);
749
                            s->last_mv[i][0][k] = val;
750
                            s->last_mv[i][1][k] = val;
751
                            /* full_pel: only for mpeg1 */
752
                            if (s->full_pel[i])
753
                                val = val << 1;
754
                            s->mv[i][0][k] = val;
755
                            dprintf("mv%d: %d\n", k, val);
756
                        }
757
                    } else {
758
                        /* MT_16X8 */
759
                        s->mv_type = MV_TYPE_16X8;
760
                        for(j=0;j<2;j++) {
761
                            s->field_select[i][j] = get_bits1(&s->gb);
762
                            for(k=0;k<2;k++) {
763
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
764
                                                         s->last_mv[i][j][k]);
765
                                s->last_mv[i][j][k] = val;
766
                                s->mv[i][j][k] = val;
767
                            }
768
                        }
769
                    }
770
                    break;
771
                case MT_FIELD:
772
                    if (s->picture_structure == PICT_FRAME) {
773
                        s->mv_type = MV_TYPE_FIELD;
774
                        for(j=0;j<2;j++) {
775
                            s->field_select[i][j] = get_bits1(&s->gb);
776
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
777
                                                     s->last_mv[i][j][0]);
778
                            s->last_mv[i][j][0] = val;
779
                            s->mv[i][j][0] = val;
780
                            dprintf("fmx=%d\n", val);
781
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
782
                                                     s->last_mv[i][j][1] >> 1);
783
                            s->last_mv[i][j][1] = val << 1;
784
                            s->mv[i][j][1] = val;
785
                            dprintf("fmy=%d\n", val);
786
                        }
787
                    } else {
788
                        s->mv_type = MV_TYPE_16X16;
789
                        s->field_select[i][0] = get_bits1(&s->gb);
790
                        for(k=0;k<2;k++) {
791
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
792
                                                     s->last_mv[i][0][k]);
793
                            s->last_mv[i][0][k] = val;
794
                            s->last_mv[i][1][k] = val;
795
                            s->mv[i][0][k] = val;
796
                        }
797
                    }
798
                    break;
799
                case MT_DMV:
800
                    {
801
                        int dmx, dmy, mx, my, m;
802

    
803
                        mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0], 
804
                                                s->last_mv[i][0][0]);
805
                        s->last_mv[i][0][0] = mx;
806
                        s->last_mv[i][1][0] = mx;
807
                        dmx = get_dmv(s);
808
                        my = mpeg_decode_motion(s, s->mpeg_f_code[i][1], 
809
                                                s->last_mv[i][0][1] >> 1);
810
                        dmy = get_dmv(s);
811
                        s->mv_type = MV_TYPE_DMV;
812
                        /* XXX: totally broken */
813
                        if (s->picture_structure == PICT_FRAME) {
814
                            s->last_mv[i][0][1] = my << 1;
815
                            s->last_mv[i][1][1] = my << 1;
816

    
817
                            m = s->top_field_first ? 1 : 3;
818
                            /* top -> top pred */
819
                            s->mv[i][0][0] = mx; 
820
                            s->mv[i][0][1] = my << 1;
821
                            s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
822
                            s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
823
                            m = 4 - m;
824
                            s->mv[i][2][0] = mx;
825
                            s->mv[i][2][1] = my << 1;
826
                            s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
827
                            s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
828
                        } else {
829
                            s->last_mv[i][0][1] = my;
830
                            s->last_mv[i][1][1] = my;
831
                            s->mv[i][0][0] = mx;
832
                            s->mv[i][0][1] = my;
833
                            s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
834
                            s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1 
835
                                /* + 2 * cur_field */;
836
                        }
837
                    }
838
                    break;
839
                }
840
            }
841
        }
842
    }
843

    
844
    if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
845
        skip_bits1(&s->gb); /* marker */
846
    }
847
    
848
    if (mb_type & MB_PAT) {
849
        cbp = get_vlc(&s->gb, &mb_pat_vlc);
850
        if (cbp < 0)
851
            return -1;
852
        cbp++;
853
    }
854
    dprintf("cbp=%x\n", cbp);
855

    
856
    if (s->mpeg2) {
857
        if (s->mb_intra) {
858
            for(i=0;i<6;i++) {
859
                if (cbp & (1 << (5 - i))) {
860
                    if (mpeg2_decode_block_intra(s, block[i], i) < 0)
861
                        return -1;
862
                } else {
863
                    s->block_last_index[i] = -1;
864
                }
865
            }
866
        } else {
867
            for(i=0;i<6;i++) {
868
                if (cbp & (1 << (5 - i))) {
869
                    if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
870
                        return -1;
871
                } else {
872
                    s->block_last_index[i] = -1;
873
                }
874
            }
875
        }
876
    } else {
877
        for(i=0;i<6;i++) {
878
            if (cbp & (1 << (5 - i))) {
879
                if (mpeg1_decode_block(s, block[i], i) < 0)
880
                    return -1;
881
            } else {
882
                s->block_last_index[i] = -1;
883
            }
884
        }
885
    }
886
    return 0;
887
}
888

    
889
/* as h263, but only 17 codes */
890
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
891
{
892
    int code, sign, val, m, l, shift;
893

    
894
    code = get_vlc(&s->gb, &mv_vlc);
895
    if (code < 0) {
896
        return 0xffff;
897
    }
898
    if (code == 0) {
899
        return pred;
900
    }
901
    sign = get_bits1(&s->gb);
902
    shift = fcode - 1;
903
    val = (code - 1) << shift;
904
    if (shift > 0)
905
        val |= get_bits(&s->gb, shift);
906
    val++;
907
    if (sign)
908
        val = -val;
909
    val += pred;
910
    
911
    /* modulo decoding */
912
    l = (1 << shift) * 16;
913
    m = 2 * l;
914
    if (val < -l) {
915
        val += m;
916
    } else if (val >= l) {
917
        val -= m;
918
    }
919
    return val;
920
}
921

    
922
static inline int decode_dc(MpegEncContext *s, int component)
923
{
924
    int code, diff;
925

    
926
    if (component == 0) {
927
        code = get_vlc(&s->gb, &dc_lum_vlc);
928
    } else {
929
        code = get_vlc(&s->gb, &dc_chroma_vlc);
930
    }
931
    if (code < 0)
932
        return 0xffff;
933
    if (code == 0) {
934
        diff = 0;
935
    } else {
936
        diff = get_bits(&s->gb, code);
937
        if ((diff & (1 << (code - 1))) == 0) 
938
            diff = (-1 << code) | (diff + 1);
939
    }
940
    return diff;
941
}
942

    
943
static int mpeg1_decode_block(MpegEncContext *s, 
944
                               DCTELEM *block, 
945
                               int n)
946
{
947
    int level, dc, diff, i, j, run;
948
    int code, component;
949
    RLTable *rl = &rl_mpeg1;
950

    
951
    if (s->mb_intra) {
952
        /* DC coef */
953
        component = (n <= 3 ? 0 : n - 4 + 1);
954
        diff = decode_dc(s, component);
955
        if (diff >= 0xffff)
956
            return -1;
957
        dc = s->last_dc[component];
958
        dc += diff;
959
        s->last_dc[component] = dc;
960
        block[0] = dc;
961
        dprintf("dc=%d diff=%d\n", dc, diff);
962
        i = 1;
963
    } else {
964
        int bit_cnt, v;
965
        UINT32 bit_buf;
966
        UINT8 *buf_ptr;
967
        i = 0;
968
        /* special case for the first coef. no need to add a second vlc table */
969
        SAVE_BITS(&s->gb);
970
        SHOW_BITS(&s->gb, v, 2);
971
        if (v & 2) {
972
            run = 0;
973
            level = 1 - ((v & 1) << 1);
974
            FLUSH_BITS(2);
975
            RESTORE_BITS(&s->gb);
976
            goto add_coef;
977
        }
978
        RESTORE_BITS(&s->gb);
979
    }
980

    
981
    /* now quantify & encode AC coefs */
982
    for(;;) {
983
        code = get_vlc(&s->gb, &rl->vlc);
984
        if (code < 0) {
985
            return -1;
986
        }
987
        if (code == 112) {
988
            break;
989
        } else if (code == 111) {
990
            /* escape */
991
            run = get_bits(&s->gb, 6);
992
            level = get_bits(&s->gb, 8);
993
            level = (level << 24) >> 24;
994
            if (level == -128) {
995
                level = get_bits(&s->gb, 8) - 256;
996
            } else if (level == 0) {
997
                level = get_bits(&s->gb, 8);
998
            }
999
        } else {
1000
            run = rl->table_run[code];
1001
            level = rl->table_level[code];
1002
            if (get_bits1(&s->gb))
1003
                level = -level;
1004
        }
1005
        i += run;
1006
        if (i >= 64)
1007
            return -1;
1008
    add_coef:
1009
        dprintf("%d: run=%d level=%d\n", n, run, level);
1010
        j = zigzag_direct[i];
1011
        block[j] = level;
1012
        i++;
1013
    }
1014
    s->block_last_index[n] = i-1;
1015
    return 0;
1016
}
1017

    
1018
/* Also does unquantization here, since I will never support mpeg2
1019
   encoding */
1020
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
1021
                                        DCTELEM *block, 
1022
                                        int n)
1023
{
1024
    int level, i, j, run;
1025
    int code;
1026
    RLTable *rl = &rl_mpeg1;
1027
    const UINT8 *scan_table;
1028
    const UINT16 *matrix;
1029
    int mismatch;
1030

    
1031
    if (s->alternate_scan)
1032
        scan_table = ff_alternate_vertical_scan;
1033
    else
1034
        scan_table = zigzag_direct;
1035
    mismatch = 1;
1036

    
1037
    {
1038
        int bit_cnt, v;
1039
        UINT32 bit_buf;
1040
        UINT8 *buf_ptr;
1041
        i = 0;
1042
        if (n < 4) 
1043
            matrix = s->inter_matrix;
1044
        else
1045
            matrix = s->chroma_inter_matrix;
1046
            
1047
        /* special case for the first coef. no need to add a second vlc table */
1048
        SAVE_BITS(&s->gb);
1049
        SHOW_BITS(&s->gb, v, 2);
1050
        if (v & 2) {
1051
            run = 0;
1052
            level = 1 - ((v & 1) << 1);
1053
            FLUSH_BITS(2);
1054
            RESTORE_BITS(&s->gb);
1055
            goto add_coef;
1056
        }
1057
        RESTORE_BITS(&s->gb);
1058
    }
1059

    
1060
    /* now quantify & encode AC coefs */
1061
    for(;;) {
1062
        code = get_vlc(&s->gb, &rl->vlc);
1063
        if (code < 0)
1064
            return -1;
1065
        if (code == 112) {
1066
            break;
1067
        } else if (code == 111) {
1068
            /* escape */
1069
            run = get_bits(&s->gb, 6);
1070
            level = get_bits(&s->gb, 12);
1071
            level = (level << 20) >> 20;
1072
        } else {
1073
            run = rl->table_run[code];
1074
            level = rl->table_level[code];
1075
            if (get_bits1(&s->gb))
1076
                level = -level;
1077
        }
1078
        i += run;
1079
        if (i >= 64)
1080
            return -1;
1081
    add_coef:
1082
        j = scan_table[i];
1083
        dprintf("%d: run=%d level=%d\n", n, run, level);
1084
        /* XXX: optimize */
1085
        if (level > 0) {
1086
            level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1087
        } else {
1088
            level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1089
            level = -level;
1090
        }
1091
        /* XXX: is it really necessary to saturate since the encoder
1092
           knows whats going on ? */
1093
        mismatch ^= level;
1094
        block[j] = level;
1095
        i++;
1096
    }
1097
    block[63] ^= (mismatch & 1);
1098
    s->block_last_index[n] = i;
1099
    return 0;
1100
}
1101

    
1102
static int mpeg2_decode_block_intra(MpegEncContext *s, 
1103
                                    DCTELEM *block, 
1104
                                    int n)
1105
{
1106
    int level, dc, diff, i, j, run;
1107
    int code, component;
1108
    RLTable *rl;
1109
    const UINT8 *scan_table;
1110
    const UINT16 *matrix;
1111
    int mismatch;
1112

    
1113
    if (s->alternate_scan)
1114
        scan_table = ff_alternate_vertical_scan;
1115
    else
1116
        scan_table = zigzag_direct;
1117

    
1118
    /* DC coef */
1119
    component = (n <= 3 ? 0 : n - 4 + 1);
1120
    diff = decode_dc(s, component);
1121
    if (diff >= 0xffff)
1122
        return -1;
1123
    dc = s->last_dc[component];
1124
    dc += diff;
1125
    s->last_dc[component] = dc;
1126
    block[0] = dc << (3 - s->intra_dc_precision);
1127
    dprintf("dc=%d\n", block[0]);
1128
    mismatch = block[0] ^ 1;
1129
    i = 1;
1130
    if (s->intra_vlc_format)
1131
        rl = &rl_mpeg2;
1132
    else
1133
        rl = &rl_mpeg1;
1134
    if (n < 4) 
1135
        matrix = s->intra_matrix;
1136
    else
1137
        matrix = s->chroma_intra_matrix;
1138

    
1139
    /* now quantify & encode AC coefs */
1140
    for(;;) {
1141
        code = get_vlc(&s->gb, &rl->vlc);
1142
        if (code < 0)
1143
            return -1;
1144
        if (code == 112) {
1145
            break;
1146
        } else if (code == 111) {
1147
            /* escape */
1148
            run = get_bits(&s->gb, 6);
1149
            level = get_bits(&s->gb, 12);
1150
            level = (level << 20) >> 20;
1151
        } else {
1152
            run = rl->table_run[code];
1153
            level = rl->table_level[code];
1154
            if (get_bits1(&s->gb))
1155
                level = -level;
1156
        }
1157
        i += run;
1158
        if (i >= 64)
1159
            return -1;
1160
        j = scan_table[i];
1161
        dprintf("%d: run=%d level=%d\n", n, run, level);
1162
        level = (level * s->qscale * matrix[j]) / 16;
1163
        /* XXX: is it really necessary to saturate since the encoder
1164
           knows whats going on ? */
1165
        mismatch ^= level;
1166
        block[j] = level;
1167
        i++;
1168
    }
1169
    block[63] ^= (mismatch & 1);
1170
    s->block_last_index[n] = i;
1171
    return 0;
1172
}
1173

    
1174
/* compressed picture size */
1175
#define PICTURE_BUFFER_SIZE 100000
1176

    
1177
typedef struct Mpeg1Context {
1178
    MpegEncContext mpeg_enc_ctx;
1179
    UINT32 header_state;
1180
    int start_code; /* current start code */
1181
    UINT8 buffer[PICTURE_BUFFER_SIZE]; 
1182
    UINT8 *buf_ptr;
1183
    int buffer_size;
1184
    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1185
    int repeat_field; /* true if we must repeat the field */
1186
} Mpeg1Context;
1187

    
1188
static int mpeg_decode_init(AVCodecContext *avctx)
1189
{
1190
    Mpeg1Context *s = avctx->priv_data;
1191
    
1192
    common_init(&s->mpeg_enc_ctx);
1193

    
1194
    s->header_state = 0xff;
1195
    s->mpeg_enc_ctx_allocated = 0;
1196
    s->buffer_size = PICTURE_BUFFER_SIZE;
1197
    s->start_code = -1;
1198
    s->buf_ptr = s->buffer;
1199
    s->mpeg_enc_ctx.picture_number = 0;
1200
    s->repeat_field = 0;
1201
    s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1202
    avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1203
    s->mpeg_enc_ctx.flags= avctx->flags;
1204
    return 0;
1205
}
1206

    
1207
/* return the 8 bit start code value and update the search
1208
   state. Return -1 if no start code found */
1209
static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end, 
1210
                           UINT32 *header_state)
1211
{
1212
    UINT8 *buf_ptr;
1213
    unsigned int state, v;
1214
    int val;
1215

    
1216
    state = *header_state;
1217
    buf_ptr = *pbuf_ptr;
1218
    while (buf_ptr < buf_end) {
1219
        v = *buf_ptr++;
1220
        if (state == 0x000001) {
1221
            state = ((state << 8) | v) & 0xffffff;
1222
            val = state;
1223
            goto found;
1224
        }
1225
        state = ((state << 8) | v) & 0xffffff;
1226
    }
1227
    val = -1;
1228
 found:
1229
    *pbuf_ptr = buf_ptr;
1230
    *header_state = state;
1231
    return val;
1232
}
1233

    
1234
static int mpeg1_decode_picture(AVCodecContext *avctx, 
1235
                                UINT8 *buf, int buf_size)
1236
{
1237
    Mpeg1Context *s1 = avctx->priv_data;
1238
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1239
    int ref, f_code;
1240

    
1241
    init_get_bits(&s->gb, buf, buf_size);
1242

    
1243
    ref = get_bits(&s->gb, 10); /* temporal ref */
1244
    s->pict_type = get_bits(&s->gb, 3);
1245
    dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1246
    skip_bits(&s->gb, 16);
1247
    if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1248
        s->full_pel[0] = get_bits1(&s->gb);
1249
        f_code = get_bits(&s->gb, 3);
1250
        if (f_code == 0)
1251
            return -1;
1252
        s->mpeg_f_code[0][0] = f_code;
1253
        s->mpeg_f_code[0][1] = f_code;
1254
    }
1255
    if (s->pict_type == B_TYPE) {
1256
        s->full_pel[1] = get_bits1(&s->gb);
1257
        f_code = get_bits(&s->gb, 3);
1258
        if (f_code == 0)
1259
            return -1;
1260
        s->mpeg_f_code[1][0] = f_code;
1261
        s->mpeg_f_code[1][1] = f_code;
1262
    }
1263
    s->y_dc_scale = 8;
1264
    s->c_dc_scale = 8;
1265
    s->first_slice = 1;
1266
    return 0;
1267
}
1268

    
1269
static void mpeg_decode_sequence_extension(MpegEncContext *s)
1270
{
1271
    int horiz_size_ext, vert_size_ext;
1272
    int bit_rate_ext, vbv_buf_ext, low_delay;
1273
    int frame_rate_ext_n, frame_rate_ext_d;
1274

    
1275
    skip_bits(&s->gb, 8); /* profil and level */
1276
    s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1277
    skip_bits(&s->gb, 2); /* chroma_format */
1278
    horiz_size_ext = get_bits(&s->gb, 2);
1279
    vert_size_ext = get_bits(&s->gb, 2);
1280
    s->width |= (horiz_size_ext << 12);
1281
    s->height |= (vert_size_ext << 12);
1282
    bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1283
    s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1284
    skip_bits1(&s->gb); /* marker */
1285
    vbv_buf_ext = get_bits(&s->gb, 8);
1286
    low_delay = get_bits1(&s->gb);
1287
    frame_rate_ext_n = get_bits(&s->gb, 2);
1288
    frame_rate_ext_d = get_bits(&s->gb, 5);
1289
    if (frame_rate_ext_d >= 1)
1290
        s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1291
    dprintf("sequence extension\n");
1292
    s->mpeg2 = 1;
1293
    s->avctx->sub_id = 2; /* indicates mpeg2 found */
1294
}
1295

    
1296
static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1297
{
1298
    int i, v, j;
1299

    
1300
    dprintf("matrix extension\n");
1301

    
1302
    if (get_bits1(&s->gb)) {
1303
        for(i=0;i<64;i++) {
1304
            v = get_bits(&s->gb, 8);
1305
            j = zigzag_direct[i];
1306
            s->intra_matrix[j] = v;
1307
            s->chroma_intra_matrix[j] = v;
1308
        }
1309
    }
1310
    if (get_bits1(&s->gb)) {
1311
        for(i=0;i<64;i++) {
1312
            v = get_bits(&s->gb, 8);
1313
            j = zigzag_direct[i];
1314
            s->inter_matrix[j] = v;
1315
            s->chroma_inter_matrix[j] = v;
1316
        }
1317
    }
1318
    if (get_bits1(&s->gb)) {
1319
        for(i=0;i<64;i++) {
1320
            v = get_bits(&s->gb, 8);
1321
            j = zigzag_direct[i];
1322
            s->chroma_intra_matrix[j] = v;
1323
        }
1324
    }
1325
    if (get_bits1(&s->gb)) {
1326
        for(i=0;i<64;i++) {
1327
            v = get_bits(&s->gb, 8);
1328
            j = zigzag_direct[i];
1329
            s->chroma_inter_matrix[j] = v;
1330
        }
1331
    }
1332
}
1333

    
1334
static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1335
{
1336
    s->full_pel[0] = s->full_pel[1] = 0;
1337
    s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1338
    s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1339
    s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1340
    s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1341
    s->intra_dc_precision = get_bits(&s->gb, 2);
1342
    s->picture_structure = get_bits(&s->gb, 2);
1343
    s->top_field_first = get_bits1(&s->gb);
1344
    s->frame_pred_frame_dct = get_bits1(&s->gb);
1345
    s->concealment_motion_vectors = get_bits1(&s->gb);
1346
    s->q_scale_type = get_bits1(&s->gb);
1347
    s->intra_vlc_format = get_bits1(&s->gb);
1348
    s->alternate_scan = get_bits1(&s->gb);
1349
    s->repeat_first_field = get_bits1(&s->gb);
1350
    s->chroma_420_type = get_bits1(&s->gb);
1351
    s->progressive_frame = get_bits1(&s->gb);
1352
    /* composite display not parsed */
1353
    dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1354
    dprintf("picture_structure=%d\n", s->picture_structure);
1355
    dprintf("top field first=%d\n", s->top_field_first);
1356
    dprintf("repeat first field=%d\n", s->repeat_first_field);
1357
    dprintf("conceal=%d\n", s->concealment_motion_vectors);
1358
    dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1359
    dprintf("alternate_scan=%d\n", s->alternate_scan);
1360
    dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1361
    dprintf("progressive_frame=%d\n", s->progressive_frame);
1362
}
1363

    
1364
static void mpeg_decode_extension(AVCodecContext *avctx, 
1365
                                  UINT8 *buf, int buf_size)
1366
{
1367
    Mpeg1Context *s1 = avctx->priv_data;
1368
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1369
    int ext_type;
1370

    
1371
    init_get_bits(&s->gb, buf, buf_size);
1372
    
1373
    ext_type = get_bits(&s->gb, 4);
1374
    switch(ext_type) {
1375
    case 0x1:
1376
        /* sequence ext */
1377
        mpeg_decode_sequence_extension(s);
1378
        break;
1379
    case 0x3:
1380
        /* quant matrix extension */
1381
        mpeg_decode_quant_matrix_extension(s);
1382
        break;
1383
    case 0x8:
1384
        /* picture extension */
1385
        mpeg_decode_picture_coding_extension(s);
1386
        break;
1387
    }
1388
}
1389

    
1390
/* return 1 if end of frame */
1391
static int mpeg_decode_slice(AVCodecContext *avctx, 
1392
                              AVPicture *pict,
1393
                              int start_code,
1394
                              UINT8 *buf, int buf_size)
1395
{
1396
    Mpeg1Context *s1 = avctx->priv_data;
1397
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1398
    int ret;
1399

    
1400
    start_code = (start_code - 1) & 0xff;
1401
    if (start_code >= s->mb_height)
1402
        return -1;
1403
    s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1404
    s->last_dc[1] = s->last_dc[0];
1405
    s->last_dc[2] = s->last_dc[0];
1406
    memset(s->last_mv, 0, sizeof(s->last_mv));
1407
    s->mb_x = -1;
1408
    s->mb_y = start_code;
1409
    s->mb_incr = 0;
1410
    /* start frame decoding */
1411
    if (s->first_slice) {
1412
        s->first_slice = 0;
1413
        MPV_frame_start(s);
1414
    }
1415

    
1416
    init_get_bits(&s->gb, buf, buf_size);
1417

    
1418
    s->qscale = get_qscale(s);
1419
    /* extra slice info */
1420
    while (get_bits1(&s->gb) != 0) {
1421
        skip_bits(&s->gb, 8);
1422
    }
1423

    
1424
    for(;;) {
1425
        clear_blocks(s->block[0]);
1426
        emms_c();
1427
        ret = mpeg_decode_mb(s, s->block);
1428
        dprintf("ret=%d\n", ret);
1429
        if (ret < 0)
1430
            return -1;
1431
        if (ret == 1)
1432
            break;
1433
        MPV_decode_mb(s, s->block);
1434
    }
1435
    emms_c();
1436

    
1437
    /* end of slice reached */
1438
    if (s->mb_x == (s->mb_width - 1) &&
1439
        s->mb_y == (s->mb_height - 1)) {
1440
        /* end of image */
1441
        UINT8 **picture;
1442

    
1443
        MPV_frame_end(s);
1444

    
1445
        /* XXX: incorrect reported qscale for mpeg2 */
1446
        if (s->pict_type == B_TYPE) {
1447
            picture = s->current_picture;
1448
            avctx->quality = s->qscale;
1449
        } else {
1450
            /* latency of 1 frame for I and P frames */
1451
            /* XXX: use another variable than picture_number */
1452
            if (s->picture_number == 0) {
1453
                picture = NULL;
1454
            } else {
1455
                picture = s->last_picture;
1456
                avctx->quality = s->last_qscale;
1457
            }
1458
            s->last_qscale = s->qscale;
1459
            s->picture_number++;
1460
        }
1461
        if (picture) {
1462
            pict->data[0] = picture[0];
1463
            pict->data[1] = picture[1];
1464
            pict->data[2] = picture[2];
1465
            pict->linesize[0] = s->linesize;
1466
            pict->linesize[1] = s->linesize / 2;
1467
            pict->linesize[2] = s->linesize / 2;
1468
            return 1;
1469
        } else {
1470
            return 0;
1471
        }
1472
    } else {
1473
        return 0;
1474
    }
1475
}
1476

    
1477
static int mpeg1_decode_sequence(AVCodecContext *avctx, 
1478
                                 UINT8 *buf, int buf_size)
1479
{
1480
    Mpeg1Context *s1 = avctx->priv_data;
1481
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1482
    int width, height, i, v, j;
1483

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

    
1486
    width = get_bits(&s->gb, 12);
1487
    height = get_bits(&s->gb, 12);
1488
    skip_bits(&s->gb, 4);
1489
    s->frame_rate_index = get_bits(&s->gb, 4);
1490
    if (s->frame_rate_index == 0)
1491
        return -1;
1492
    s->bit_rate = get_bits(&s->gb, 18) * 400;
1493
    if (get_bits1(&s->gb) == 0) /* marker */
1494
        return -1;
1495
    if (width <= 0 || height <= 0 ||
1496
        (width % 2) != 0 || (height % 2) != 0)
1497
        return -1;
1498
    if (width != s->width ||
1499
        height != s->height) {
1500
        /* start new mpeg1 context decoding */
1501
        s->out_format = FMT_MPEG1;
1502
        if (s1->mpeg_enc_ctx_allocated) {
1503
            MPV_common_end(s);
1504
        }
1505
        s->width = width;
1506
        s->height = height;
1507
        s->has_b_frames = 1;
1508
        s->avctx = avctx;
1509
        avctx->width = width;
1510
        avctx->height = height;
1511
        if (s->frame_rate_index >= 9) {
1512
            /* at least give a valid frame rate (some old mpeg1 have this) */
1513
            avctx->frame_rate = 25 * FRAME_RATE_BASE;
1514
        } else {
1515
            avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1516
        }
1517
        s->frame_rate = avctx->frame_rate;
1518
        avctx->bit_rate = s->bit_rate;
1519
        
1520
        if (MPV_common_init(s) < 0)
1521
            return -1;
1522
        mpeg1_init_vlc(s);
1523
        s1->mpeg_enc_ctx_allocated = 1;
1524
    }
1525

    
1526
    skip_bits(&s->gb, 10); /* vbv_buffer_size */
1527
    skip_bits(&s->gb, 1);
1528

    
1529
    /* get matrix */
1530
    if (get_bits1(&s->gb)) {
1531
        for(i=0;i<64;i++) {
1532
            v = get_bits(&s->gb, 8);
1533
            j = zigzag_direct[i];
1534
            s->intra_matrix[j] = v;
1535
            s->chroma_intra_matrix[j] = v;
1536
        }
1537
#ifdef DEBUG
1538
        dprintf("intra matrix present\n");
1539
        for(i=0;i<64;i++)
1540
            dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1541
        printf("\n");
1542
#endif
1543
    } else {
1544
        for(i=0;i<64;i++) {
1545
            v = default_intra_matrix[i];
1546
            s->intra_matrix[i] = v;
1547
            s->chroma_intra_matrix[i] = v;
1548
        }
1549
    }
1550
    if (get_bits1(&s->gb)) {
1551
        for(i=0;i<64;i++) {
1552
            v = get_bits(&s->gb, 8);
1553
            j = zigzag_direct[i];
1554
            s->inter_matrix[j] = v;
1555
            s->chroma_inter_matrix[j] = v;
1556
        }
1557
#ifdef DEBUG
1558
        dprintf("non intra matrix present\n");
1559
        for(i=0;i<64;i++)
1560
            dprintf(" %d", s->inter_matrix[zigzag_direct[i]]);
1561
        printf("\n");
1562
#endif
1563
    } else {
1564
        for(i=0;i<64;i++) {
1565
            v = default_non_intra_matrix[i];
1566
            s->inter_matrix[i] = v;
1567
            s->chroma_inter_matrix[i] = v;
1568
        }
1569
    }
1570

    
1571
    /* we set mpeg2 parameters so that it emulates mpeg1 */
1572
    s->progressive_sequence = 1;
1573
    s->progressive_frame = 1;
1574
    s->picture_structure = PICT_FRAME;
1575
    s->frame_pred_frame_dct = 1;
1576
    s->mpeg2 = 0;
1577
    avctx->sub_id = 1; /* indicates mpeg1 */
1578
    return 0;
1579
}
1580

    
1581
/* handle buffering and image synchronisation */
1582
static int mpeg_decode_frame(AVCodecContext *avctx, 
1583
                             void *data, int *data_size,
1584
                             UINT8 *buf, int buf_size)
1585
{
1586
    Mpeg1Context *s = avctx->priv_data;
1587
    UINT8 *buf_end, *buf_ptr, *buf_start;
1588
    int len, start_code_found, ret, code, start_code, input_size;
1589
    AVPicture *picture = data;
1590
    MpegEncContext *s2 = &s->mpeg_enc_ctx;
1591
            
1592
    dprintf("fill_buffer\n");
1593

    
1594
    *data_size = 0;
1595

    
1596
    /* special case for last picture */
1597
    if (buf_size == 0) {
1598
        if (s2->picture_number > 0) {
1599
            picture->data[0] = s2->next_picture[0];
1600
            picture->data[1] = s2->next_picture[1];
1601
            picture->data[2] = s2->next_picture[2];
1602
            picture->linesize[0] = s2->linesize;
1603
            picture->linesize[1] = s2->linesize / 2;
1604
            picture->linesize[2] = s2->linesize / 2;
1605
            *data_size = sizeof(AVPicture);
1606
        }
1607
        return 0;
1608
    }
1609

    
1610
    buf_ptr = buf;
1611
    buf_end = buf + buf_size;
1612

    
1613
#if 0    
1614
    if (s->repeat_field % 2 == 1) { 
1615
        s->repeat_field++;
1616
        //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1617
        //        s2->picture_number, s->repeat_field);
1618
        if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
1619
            *data_size = sizeof(AVPicture);
1620
            goto the_end;
1621
        }
1622
    }
1623
#endif
1624
    while (buf_ptr < buf_end) {
1625
        buf_start = buf_ptr;
1626
        /* find start next code */
1627
        code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1628
        if (code >= 0) {
1629
            start_code_found = 1;
1630
        } else {
1631
            start_code_found = 0;
1632
        }
1633
        /* copy to buffer */
1634
        len = buf_ptr - buf_start;
1635
        if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1636
            /* data too big : flush */
1637
            s->buf_ptr = s->buffer;
1638
            if (start_code_found)
1639
                s->start_code = code;
1640
        } else {
1641
            memcpy(s->buf_ptr, buf_start, len);
1642
            s->buf_ptr += len;
1643
            
1644
            if (start_code_found) {
1645
                /* prepare data for next start code */
1646
                input_size = s->buf_ptr - s->buffer;
1647
                start_code = s->start_code;
1648
                s->buf_ptr = s->buffer;
1649
                s->start_code = code;
1650
                switch(start_code) {
1651
                case SEQ_START_CODE:
1652
                    mpeg1_decode_sequence(avctx, s->buffer, 
1653
                                          input_size);
1654
                    break;
1655
                            
1656
                case PICTURE_START_CODE:
1657
                    /* we have a complete image : we try to decompress it */
1658
                    mpeg1_decode_picture(avctx, 
1659
                                         s->buffer, input_size);
1660
                    break;
1661
                case EXT_START_CODE:
1662
                    mpeg_decode_extension(avctx,
1663
                                          s->buffer, input_size);
1664
                    break;
1665
                default:
1666
                    if (start_code >= SLICE_MIN_START_CODE &&
1667
                        start_code <= SLICE_MAX_START_CODE) {
1668
                        ret = mpeg_decode_slice(avctx, picture,
1669
                                                start_code, s->buffer, input_size);
1670
                        if (ret == 1) {
1671
                            /* got a picture: exit */
1672
                            /* first check if we must repeat the frame */
1673
                            avctx->repeat_pict = 0;
1674
#if 0
1675
                            if (s2->progressive_frame && s2->repeat_first_field) {
1676
                                //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1677
                                //s2->repeat_first_field = 0;
1678
                                //s2->progressive_frame = 0;
1679
                                if (++s->repeat_field > 2)
1680
                                    s->repeat_field = 0;
1681
                                avctx->repeat_pict = 1;
1682
                            }
1683
#endif                      
1684
                            if (s2->repeat_first_field) {
1685
                                if (s2->progressive_sequence) {
1686
                                    if (s2->top_field_first)
1687
                                        avctx->repeat_pict = 4;
1688
                                    else
1689
                                        avctx->repeat_pict = 2;
1690
                                } else if (s2->progressive_frame) {
1691
                                    avctx->repeat_pict = 1;
1692
                                }
1693
                            }         
1694
                            *data_size = sizeof(AVPicture);
1695
                            goto the_end;
1696
                        }
1697
                    }
1698
                    break;
1699
                }
1700
            }
1701
        }
1702
    }
1703
 the_end:
1704
    return buf_ptr - buf;
1705
}
1706

    
1707
static int mpeg_decode_end(AVCodecContext *avctx)
1708
{
1709
    Mpeg1Context *s = avctx->priv_data;
1710

    
1711
    if (s->mpeg_enc_ctx_allocated)
1712
        MPV_common_end(&s->mpeg_enc_ctx);
1713
    return 0;
1714
}
1715

    
1716
AVCodec mpeg_decoder = {
1717
    "mpegvideo",
1718
    CODEC_TYPE_VIDEO,
1719
    CODEC_ID_MPEG1VIDEO,
1720
    sizeof(Mpeg1Context),
1721
    mpeg_decode_init,
1722
    NULL,
1723
    mpeg_decode_end,
1724
    mpeg_decode_frame,
1725
};