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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
 *
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 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
//#define DEBUG
20
#include "avcodec.h"
21
#include "dsputil.h"
22
#include "mpegvideo.h"
23

    
24
#include "mpeg12data.h"
25

    
26
#if 1
27
#define PRINT_QP(a, b) {}
28
#else
29
#define PRINT_QP(a, b) printf(a, b)
30
#endif
31

    
32
/* Start codes. */
33
#define SEQ_END_CODE                0x000001b7
34
#define SEQ_START_CODE                0x000001b3
35
#define GOP_START_CODE                0x000001b8
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#define PICTURE_START_CODE        0x00000100
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#define SLICE_MIN_START_CODE        0x00000101
38
#define SLICE_MAX_START_CODE        0x000001af
39
#define EXT_START_CODE                0x000001b5
40
#define USER_START_CODE                0x000001b2
41

    
42
#define DC_VLC_BITS 9
43
#define MV_VLC_BITS 9
44
#define MBINCR_VLC_BITS 9
45
#define MB_PAT_VLC_BITS 9
46
#define MB_PTYPE_VLC_BITS 6
47
#define MB_BTYPE_VLC_BITS 6
48
#define TEX_VLC_BITS 9
49

    
50
static void mpeg1_encode_block(MpegEncContext *s, 
51
                         DCTELEM *block, 
52
                         int component);
53
static void mpeg1_encode_motion(MpegEncContext *s, int val);
54
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
55
static int mpeg1_decode_block(MpegEncContext *s, 
56
                              DCTELEM *block, 
57
                              int n);
58
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
59
                                        DCTELEM *block, 
60
                                        int n);
61
static int mpeg2_decode_block_intra(MpegEncContext *s, 
62
                                    DCTELEM *block, 
63
                                    int n);
64
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
65

    
66
static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
67
static UINT8 fcode_tab[MAX_MV*2+1];
68

    
69
static void init_2d_vlc_rl(RLTable *rl)
70
{
71
    int i;
72
    
73
    init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2, 
74
             &rl->table_vlc[0][1], 4, 2,
75
             &rl->table_vlc[0][0], 4, 2);
76

    
77
    
78
    rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
79
    for(i=0; i<rl->vlc.table_size; i++){
80
        int code= rl->vlc.table[i][0];
81
        int len = rl->vlc.table[i][1];
82
        int level, run;
83
    
84
        if(len==0){ // illegal code
85
            run= 65;
86
            level= MAX_LEVEL;
87
        }else if(len<0){ //more bits needed
88
            run= 0;
89
            level= code;
90
        }else{
91
            if(code==rl->n){ //esc
92
                run= 65;
93
                level= 0;
94
            }else if(code==rl->n+1){ //eob
95
                run= 192;
96
                level= 1;
97
            }else{
98
                run=   rl->table_run  [code] + 1;
99
                level= rl->table_level[code];
100
            }
101
        }
102
        rl->rl_vlc[0][i].len= len;
103
        rl->rl_vlc[0][i].level= level;
104
        rl->rl_vlc[0][i].run= run;
105
    }
106
}
107

    
108

    
109
static void put_header(MpegEncContext *s, int header)
110
{
111
    align_put_bits(&s->pb);
112
    put_bits(&s->pb, 16, header>>16);
113
    put_bits(&s->pb, 16, header&0xFFFF);
114
}
115

    
116
/* put sequence header if needed */
117
static void mpeg1_encode_sequence_header(MpegEncContext *s)
118
{
119
        unsigned int vbv_buffer_size;
120
        unsigned int fps, v;
121
        int n;
122
        UINT64 time_code;
123
        
124
        if (s->picture_in_gop_number == 0) {
125
            /* mpeg1 header repeated every gop */
126
            put_header(s, SEQ_START_CODE);
127
            
128
            /* search closest frame rate */
129
            {
130
                int i, dmin, d;
131
                s->frame_rate_index = 0;
132
                dmin = 0x7fffffff;
133
                for(i=1;i<9;i++) {
134
                    d = abs(s->frame_rate - frame_rate_tab[i]);
135
                    if (d < dmin) {
136
                        dmin = d;
137
                        s->frame_rate_index = i;
138
                    }
139
                }
140
            }
141
 
142
            put_bits(&s->pb, 12, s->width);
143
            put_bits(&s->pb, 12, s->height);
144
            put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
145
            put_bits(&s->pb, 4, s->frame_rate_index);
146
            v = s->bit_rate / 400;
147
            if (v > 0x3ffff)
148
                v = 0x3ffff;
149
            put_bits(&s->pb, 18, v);
150
            put_bits(&s->pb, 1, 1); /* marker */
151

    
152
            if(s->avctx->rc_buffer_size)
153
                vbv_buffer_size = s->avctx->rc_buffer_size;
154
            else
155
                /* VBV calculation: Scaled so that a VCD has the proper VBV size of 40 kilobytes */
156
                vbv_buffer_size = (( 20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;         
157
            put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384); 
158
            put_bits(&s->pb, 1, 1); /* constrained parameter flag */
159
            put_bits(&s->pb, 1, 0); /* no custom intra matrix */
160
            put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
161

    
162
            put_header(s, GOP_START_CODE);
163
            put_bits(&s->pb, 1, 0); /* do drop frame */
164
            /* time code : we must convert from the real frame rate to a
165
               fake mpeg frame rate in case of low frame rate */
166
            fps = frame_rate_tab[s->frame_rate_index];
167
            time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
168
            s->gop_picture_number = s->fake_picture_number;
169
            put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
170
            put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
171
            put_bits(&s->pb, 1, 1);
172
            put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
173
            put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
174
            put_bits(&s->pb, 1, 1); /* closed gop */
175
            put_bits(&s->pb, 1, 0); /* broken link */
176
        }
177

    
178
        if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
179
            /* insert empty P pictures to slow down to the desired
180
               frame rate. Each fake pictures takes about 20 bytes */
181
            fps = frame_rate_tab[s->frame_rate_index];
182
            n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
183
            while (s->fake_picture_number < n) {
184
                mpeg1_skip_picture(s, s->fake_picture_number - 
185
                                   s->gop_picture_number); 
186
                s->fake_picture_number++;
187
            }
188

    
189
        }
190
}
191

    
192

    
193
/* insert a fake P picture */
194
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
195
{
196
    unsigned int mb_incr;
197

    
198
    /* mpeg1 picture header */
199
    put_header(s, PICTURE_START_CODE);
200
    /* temporal reference */
201
    put_bits(&s->pb, 10, pict_num & 0x3ff); 
202
    
203
    put_bits(&s->pb, 3, P_TYPE);
204
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
205
    
206
    put_bits(&s->pb, 1, 1); /* integer coordinates */
207
    put_bits(&s->pb, 3, 1); /* forward_f_code */
208
    
209
    put_bits(&s->pb, 1, 0); /* extra bit picture */
210
    
211
    /* only one slice */
212
    put_header(s, SLICE_MIN_START_CODE);
213
    put_bits(&s->pb, 5, 1); /* quantizer scale */
214
    put_bits(&s->pb, 1, 0); /* slice extra information */
215
    
216
    mb_incr = 1;
217
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
218
             mbAddrIncrTable[mb_incr - 1][0]);
219
    
220
    /* empty macroblock */
221
    put_bits(&s->pb, 3, 1); /* motion only */
222
    
223
    /* zero motion x & y */
224
    put_bits(&s->pb, 1, 1); 
225
    put_bits(&s->pb, 1, 1); 
226

    
227
    /* output a number of empty slice */
228
    mb_incr = s->mb_width * s->mb_height - 1;
229
    while (mb_incr > 33) {
230
        put_bits(&s->pb, 11, 0x008);
231
        mb_incr -= 33;
232
    }
233
    put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
234
             mbAddrIncrTable[mb_incr - 1][0]);
235
    
236
    /* empty macroblock */
237
    put_bits(&s->pb, 3, 1); /* motion only */
238
    
239
    /* zero motion x & y */
240
    put_bits(&s->pb, 1, 1); 
241
    put_bits(&s->pb, 1, 1); 
242
}
243

    
244
static void common_init(MpegEncContext *s)
245
{
246
    s->y_dc_scale_table=
247
    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
248
}
249

    
250
void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
251
{
252
    mpeg1_encode_sequence_header(s);
253

    
254
    /* mpeg1 picture header */
255
    put_header(s, PICTURE_START_CODE);
256
    /* temporal reference */
257
    put_bits(&s->pb, 10, (s->fake_picture_number - 
258
                          s->gop_picture_number) & 0x3ff); 
259
    s->fake_picture_number++;
260
    
261
    put_bits(&s->pb, 3, s->pict_type);
262
    put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
263
    
264
    if (s->pict_type == P_TYPE) {
265
        put_bits(&s->pb, 1, 0); /* half pel coordinates */
266
        put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
267
    }
268
    
269
    put_bits(&s->pb, 1, 0); /* extra bit picture */
270
    
271
    /* only one slice */
272
    put_header(s, SLICE_MIN_START_CODE);
273
    put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
274
    put_bits(&s->pb, 1, 0); /* slice extra information */
275
}
276

    
277
void mpeg1_encode_mb(MpegEncContext *s,
278
                     DCTELEM block[6][64],
279
                     int motion_x, int motion_y)
280
{
281
    int mb_incr, i, cbp, mb_x, mb_y;
282

    
283
    mb_x = s->mb_x;
284
    mb_y = s->mb_y;
285

    
286
    /* compute cbp */
287
    cbp = 0;
288
    for(i=0;i<6;i++) {
289
        if (s->block_last_index[i] >= 0)
290
            cbp |= 1 << (5 - i);
291
    }
292

    
293
    /* skip macroblock, except if first or last macroblock of a slice */
294
    if ((cbp | motion_x | motion_y) == 0 &&
295
        (!((mb_x | mb_y) == 0 ||
296
           (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
297
        s->mb_incr++;
298
        s->qscale -= s->dquant;
299
    } else {
300
        /* output mb incr */
301
        mb_incr = s->mb_incr;
302

    
303
        while (mb_incr > 33) {
304
            put_bits(&s->pb, 11, 0x008);
305
            mb_incr -= 33;
306
        }
307
        put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
308
                 mbAddrIncrTable[mb_incr - 1][0]);
309
        
310
        if (s->pict_type == I_TYPE) {
311
            if(s->dquant && cbp){
312
                put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
313
                put_bits(&s->pb, 5, s->qscale);
314
            }else{
315
                put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
316
                s->qscale -= s->dquant;
317
            }
318
        } else {
319
            if (s->mb_intra) {
320
                if(s->dquant && cbp){
321
                    put_bits(&s->pb, 6, 0x01);
322
                    put_bits(&s->pb, 5, s->qscale);
323
                }else{
324
                    put_bits(&s->pb, 5, 0x03);
325
                    s->qscale -= s->dquant;
326
                }
327
            } else {
328
                if (cbp != 0) {
329
                    if (motion_x == 0 && motion_y == 0) {
330
                        if(s->dquant){
331
                            put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
332
                            put_bits(&s->pb, 5, s->qscale);
333
                        }else{
334
                            put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
335
                        }
336
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
337
                    } else {
338
                        if(s->dquant){
339
                            put_bits(&s->pb, 5, 2); /* motion + cbp */
340
                            put_bits(&s->pb, 5, s->qscale);
341
                        }else{
342
                            put_bits(&s->pb, 1, 1); /* motion + cbp */
343
                        }
344
                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
345
                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
346
                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
347
                    }
348
                } else {
349
                    put_bits(&s->pb, 3, 1); /* motion only */
350
                    mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
351
                    mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
352
                    s->qscale -= s->dquant;
353
                }
354
            }
355
        }
356
        for(i=0;i<6;i++) {
357
            if (cbp & (1 << (5 - i))) {
358
                mpeg1_encode_block(s, block[i], i);
359
            }
360
        }
361
        s->mb_incr = 1;
362
    }
363
    s->last_mv[0][0][0] = motion_x;
364
    s->last_mv[0][0][1] = motion_y;
365
}
366

    
367
static void mpeg1_encode_motion(MpegEncContext *s, int val)
368
{
369
    int code, bit_size, l, m, bits, range, sign;
370

    
371
    if (val == 0) {
372
        /* zero vector */
373
        code = 0;
374
        put_bits(&s->pb,
375
                 mbMotionVectorTable[0][1], 
376
                 mbMotionVectorTable[0][0]); 
377
    } else {
378
        bit_size = s->f_code - 1;
379
        range = 1 << bit_size;
380
        /* modulo encoding */
381
        l = 16 * range;
382
        m = 2 * l;
383
        if (val < -l) {
384
            val += m;
385
        } else if (val >= l) {
386
            val -= m;
387
        }
388

    
389
        if (val >= 0) {
390
            val--;
391
            code = (val >> bit_size) + 1;
392
            bits = val & (range - 1);
393
            sign = 0;
394
        } else {
395
            val = -val;
396
            val--;
397
            code = (val >> bit_size) + 1;
398
            bits = val & (range - 1);
399
            sign = 1;
400
        }
401
        put_bits(&s->pb,
402
                 mbMotionVectorTable[code][1], 
403
                 mbMotionVectorTable[code][0]); 
404
        put_bits(&s->pb, 1, sign);
405
        if (bit_size > 0) {
406
            put_bits(&s->pb, bit_size, bits);
407
        }
408
    }
409
}
410

    
411
void ff_mpeg1_encode_init(MpegEncContext *s)
412
{
413
    static int done=0;
414

    
415
    common_init(s);
416

    
417
    if(!done){
418
        int f_code;
419
        int mv;
420
        int i;
421

    
422
        done=1;
423
        init_rl(&rl_mpeg1);
424
        
425
        for(i=0; i<64; i++)
426
        {
427
                mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
428
                mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
429
        }
430

    
431
        /* build unified dc encoding tables */
432
        for(i=-255; i<256; i++)
433
        {
434
                int adiff, index;
435
                int bits, code;
436
                int diff=i;
437

    
438
                adiff = ABS(diff);
439
                if(diff<0) diff--;
440
                index = vlc_dc_table[adiff];
441

    
442
                bits= vlc_dc_lum_bits[index] + index;
443
                code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
444
                mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
445
                
446
                bits= vlc_dc_chroma_bits[index] + index;
447
                code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
448
                mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
449
        }
450

    
451
        for(f_code=1; f_code<=MAX_FCODE; f_code++){
452
            for(mv=-MAX_MV; mv<=MAX_MV; mv++){
453
                int len;
454

    
455
                if(mv==0) len= mbMotionVectorTable[0][1];
456
                else{
457
                    int val, bit_size, range, code;
458

    
459
                    bit_size = s->f_code - 1;
460
                    range = 1 << bit_size;
461

    
462
                    val=mv;
463
                    if (val < 0) 
464
                        val = -val;
465
                    val--;
466
                    code = (val >> bit_size) + 1;
467
                    if(code<17){
468
                        len= mbMotionVectorTable[code][1] + 1 + bit_size;
469
                    }else{
470
                        len= mbMotionVectorTable[16][1] + 2 + bit_size;
471
                    }
472
                }
473

    
474
                mv_penalty[f_code][mv+MAX_MV]= len;
475
            }
476
        }
477
        
478

    
479
        for(f_code=MAX_FCODE; f_code>0; f_code--){
480
            for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
481
                fcode_tab[mv+MAX_MV]= f_code;
482
            }
483
        }
484
    }
485
    s->mv_penalty= mv_penalty;
486
    s->fcode_tab= fcode_tab;
487
    s->min_qcoeff=-255;
488
    s->max_qcoeff= 255;
489
    s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
490
    s->inter_quant_bias= 0;
491
}
492

    
493
static inline void encode_dc(MpegEncContext *s, int diff, int component)
494
{
495
    if (component == 0) {
496
        put_bits(
497
            &s->pb, 
498
            mpeg1_lum_dc_uni[diff+255]&0xFF,
499
            mpeg1_lum_dc_uni[diff+255]>>8);
500
    } else {
501
        put_bits(
502
            &s->pb, 
503
            mpeg1_chr_dc_uni[diff+255]&0xFF,
504
            mpeg1_chr_dc_uni[diff+255]>>8);
505
    }
506
}
507

    
508
static void mpeg1_encode_block(MpegEncContext *s, 
509
                               DCTELEM *block, 
510
                               int n)
511
{
512
    int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
513
    int code, component;
514
//    RLTable *rl = &rl_mpeg1;
515

    
516
    last_index = s->block_last_index[n];
517

    
518
    /* DC coef */
519
    if (s->mb_intra) {
520
        component = (n <= 3 ? 0 : n - 4 + 1);
521
        dc = block[0]; /* overflow is impossible */
522
        diff = dc - s->last_dc[component];
523
        encode_dc(s, diff, component);
524
        s->last_dc[component] = dc;
525
        i = 1;
526
    } else {
527
        /* encode the first coefficient : needs to be done here because
528
           it is handled slightly differently */
529
        level = block[0];
530
        if (abs(level) == 1) {
531
                code = ((UINT32)level >> 31); /* the sign bit */
532
                put_bits(&s->pb, 2, code | 0x02);
533
                i = 1;
534
        } else {
535
            i = 0;
536
            last_non_zero = -1;
537
            goto next_coef;
538
        }
539
    }
540

    
541
    /* now quantify & encode AC coefs */
542
    last_non_zero = i - 1;
543

    
544
    for(;i<=last_index;i++) {
545
        j = s->intra_scantable.permutated[i];
546
        level = block[j];
547
    next_coef:
548
#if 0
549
        if (level != 0)
550
            dprintf("level[%d]=%d\n", i, level);
551
#endif            
552
        /* encode using VLC */
553
        if (level != 0) {
554
            run = i - last_non_zero - 1;
555
            
556
            alevel= level;
557
            MASK_ABS(sign, alevel)
558
            sign&=1;
559

    
560
//            code = get_rl_index(rl, 0, run, alevel);
561
            if (alevel > mpeg1_max_level[0][run])
562
                code= 111; /*rl->n*/
563
            else
564
                code= mpeg1_index_run[0][run] + alevel - 1;
565

    
566
            if (code < 111 /* rl->n */) {
567
                    /* store the vlc & sign at once */
568
                put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
569
            } else {
570
                /* escape seems to be pretty rare <5% so i dont optimize it */
571
                put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
572
                /* escape: only clip in this case */
573
                put_bits(&s->pb, 6, run);
574
                if (alevel < 128) {
575
                    put_bits(&s->pb, 8, level & 0xff);
576
                } else {
577
                    if (level < 0) {
578
                        put_bits(&s->pb, 16, 0x8001 + level + 255);
579
                    } else {
580
                        put_bits(&s->pb, 16, level & 0xffff);
581
                    }
582
                }
583
            }
584
            last_non_zero = i;
585
        }
586
    }
587
    /* end of block */
588
    put_bits(&s->pb, 2, 0x2);
589
}
590

    
591
/******************************************/
592
/* decoding */
593

    
594
static VLC dc_lum_vlc;
595
static VLC dc_chroma_vlc;
596
static VLC mv_vlc;
597
static VLC mbincr_vlc;
598
static VLC mb_ptype_vlc;
599
static VLC mb_btype_vlc;
600
static VLC mb_pat_vlc;
601

    
602
static void init_vlcs(MpegEncContext *s)
603
{
604
    static int done = 0;
605

    
606
    if (!done) {
607
        done = 1;
608

    
609
        init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12, 
610
                 vlc_dc_lum_bits, 1, 1,
611
                 vlc_dc_lum_code, 2, 2);
612
        init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12, 
613
                 vlc_dc_chroma_bits, 1, 1,
614
                 vlc_dc_chroma_code, 2, 2);
615
        init_vlc(&mv_vlc, MV_VLC_BITS, 17, 
616
                 &mbMotionVectorTable[0][1], 2, 1,
617
                 &mbMotionVectorTable[0][0], 2, 1);
618
        init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 35, 
619
                 &mbAddrIncrTable[0][1], 2, 1,
620
                 &mbAddrIncrTable[0][0], 2, 1);
621
        init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63, 
622
                 &mbPatTable[0][1], 2, 1,
623
                 &mbPatTable[0][0], 2, 1);
624
        
625
        init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 32, 
626
                 &table_mb_ptype[0][1], 2, 1,
627
                 &table_mb_ptype[0][0], 2, 1);
628
        init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 32, 
629
                 &table_mb_btype[0][1], 2, 1,
630
                 &table_mb_btype[0][0], 2, 1);
631
        init_rl(&rl_mpeg1);
632
        init_rl(&rl_mpeg2);
633

    
634
        init_2d_vlc_rl(&rl_mpeg1);
635
        init_2d_vlc_rl(&rl_mpeg2);
636
    }
637
}
638

    
639
static inline int get_dmv(MpegEncContext *s)
640
{
641
    if(get_bits1(&s->gb)) 
642
        return 1 - (get_bits1(&s->gb) << 1);
643
    else
644
        return 0;
645
}
646

    
647
static inline int get_qscale(MpegEncContext *s)
648
{
649
    int qscale;
650
    if (s->mpeg2) {
651
        if (s->q_scale_type) {
652
            qscale = non_linear_qscale[get_bits(&s->gb, 5)];
653
        } else {
654
            qscale = get_bits(&s->gb, 5) << 1;
655
        }
656
    } else {
657
        /* for mpeg1, we use the generic unquant code */
658
        qscale = get_bits(&s->gb, 5);
659
    }
660
    return qscale;
661
}
662

    
663
/* motion type (for mpeg2) */
664
#define MT_FIELD 1
665
#define MT_FRAME 2
666
#define MT_16X8  2
667
#define MT_DMV   3
668

    
669
static int mpeg_decode_mb(MpegEncContext *s,
670
                          DCTELEM block[6][64])
671
{
672
    int i, j, k, cbp, val, code, mb_type, motion_type;
673
    
674
    /* skip mb handling */
675
    if (s->mb_incr == 0) {
676
        /* read again increment */
677
        s->mb_incr = 1;
678
        for(;;) {
679
            code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
680
            if (code < 0)
681
                return 1; /* error = end of slice */
682
            if (code >= 33) {
683
                if (code == 33) {
684
                    s->mb_incr += 33;
685
                }
686
                /* otherwise, stuffing, nothing to do */
687
            } else {
688
                s->mb_incr += code;
689
                break;
690
            }
691
        }
692
    }
693
    if(s->mb_x==-1 /* first MB in a slice */ && s->mb_incr>1){
694
        s->mb_x+= (s->mb_incr - 1) % s->mb_width;
695
        s->mb_y+= (s->mb_incr - 1) / s->mb_width;
696
        s->mb_incr= 1;
697
    }
698

    
699
    if (++s->mb_x >= s->mb_width) {
700
        s->mb_x = 0;
701
        if (s->mb_y >= (s->mb_height - 1)){
702
            fprintf(stderr, "slice too long\n");
703
            return -1;
704
        }
705
        s->mb_y++;
706
    }
707
    dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
708

    
709
    if (--s->mb_incr != 0) {
710
        /* skip mb */
711
        s->mb_intra = 0;
712
        for(i=0;i<6;i++)
713
            s->block_last_index[i] = -1;
714
        s->mv_type = MV_TYPE_16X16;
715
        if (s->pict_type == P_TYPE) {
716
            /* if P type, zero motion vector is implied */
717
            s->mv_dir = MV_DIR_FORWARD;
718
            s->mv[0][0][0] = s->mv[0][0][1] = 0;
719
            s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
720
            s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
721
        } else {
722
            /* if B type, reuse previous vectors and directions */
723
            s->mv[0][0][0] = s->last_mv[0][0][0];
724
            s->mv[0][0][1] = s->last_mv[0][0][1];
725
            s->mv[1][0][0] = s->last_mv[1][0][0];
726
            s->mv[1][0][1] = s->last_mv[1][0][1];
727
        }
728
        s->mb_skiped = 1;
729
        return 0;
730
    }
731

    
732
    switch(s->pict_type) {
733
    default:
734
    case I_TYPE:
735
        if (get_bits1(&s->gb) == 0) {
736
            if (get_bits1(&s->gb) == 0)
737
                return -1;
738
            mb_type = MB_QUANT | MB_INTRA;
739
        } else {
740
            mb_type = MB_INTRA;
741
        }
742
        break;
743
    case P_TYPE:
744
        mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
745
        if (mb_type < 0){
746
            fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
747
            return -1;
748
        }
749
        break;
750
    case B_TYPE:
751
        mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
752
        if (mb_type < 0){
753
            fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
754
            return -1;
755
        }
756
        break;
757
    }
758
    dprintf("mb_type=%x\n", mb_type);
759
    motion_type = 0; /* avoid warning */
760
    if (mb_type & (MB_FOR|MB_BACK)) {
761
        /* get additionnal motion vector type */
762
        if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) 
763
            motion_type = MT_FRAME;
764
        else
765
            motion_type = get_bits(&s->gb, 2);
766
    }
767
    /* compute dct type */
768
    if (s->picture_structure == PICT_FRAME && 
769
        !s->frame_pred_frame_dct &&
770
        (mb_type & (MB_PAT | MB_INTRA))) {
771
        s->interlaced_dct = get_bits1(&s->gb);
772
#ifdef DEBUG
773
        if (s->interlaced_dct)
774
            printf("interlaced_dct\n");
775
#endif
776
    } else {
777
        s->interlaced_dct = 0; /* frame based */
778
    }
779

    
780
    if (mb_type & MB_QUANT) {
781
        s->qscale = get_qscale(s);
782
    }
783
    if (mb_type & MB_INTRA) {
784
        if (s->concealment_motion_vectors) {
785
            /* just parse them */
786
            if (s->picture_structure != PICT_FRAME) 
787
                skip_bits1(&s->gb); /* field select */
788
            mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
789
            mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
790
        }
791
        s->mb_intra = 1;
792
        cbp = 0x3f;
793
        memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
794
    } else {
795
        s->mb_intra = 0;
796
        cbp = 0;
797
    }
798
    /* special case of implicit zero motion vector */
799
    if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
800
        s->mv_dir = MV_DIR_FORWARD;
801
        s->mv_type = MV_TYPE_16X16;
802
        s->last_mv[0][0][0] = 0;
803
        s->last_mv[0][0][1] = 0;
804
        s->last_mv[0][1][0] = 0;
805
        s->last_mv[0][1][1] = 0;
806
        s->mv[0][0][0] = 0;
807
        s->mv[0][0][1] = 0;
808
    } else if (mb_type & (MB_FOR | MB_BACK)) {
809
        /* motion vectors */
810
        s->mv_dir = 0;
811
        for(i=0;i<2;i++) {
812
            if (mb_type & (MB_FOR >> i)) {
813
                s->mv_dir |= (MV_DIR_FORWARD >> i);
814
                dprintf("motion_type=%d\n", motion_type);
815
                switch(motion_type) {
816
                case MT_FRAME: /* or MT_16X8 */
817
                    if (s->picture_structure == PICT_FRAME) {
818
                        /* MT_FRAME */
819
                        s->mv_type = MV_TYPE_16X16;
820
                        for(k=0;k<2;k++) {
821
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k], 
822
                                                     s->last_mv[i][0][k]);
823
                            s->last_mv[i][0][k] = val;
824
                            s->last_mv[i][1][k] = val;
825
                            /* full_pel: only for mpeg1 */
826
                            if (s->full_pel[i])
827
                                val = val << 1;
828
                            s->mv[i][0][k] = val;
829
                            dprintf("mv%d: %d\n", k, val);
830
                        }
831
                    } else {
832
                        /* MT_16X8 */
833
                        s->mv_type = MV_TYPE_16X8;
834
                        for(j=0;j<2;j++) {
835
                            s->field_select[i][j] = get_bits1(&s->gb);
836
                            for(k=0;k<2;k++) {
837
                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
838
                                                         s->last_mv[i][j][k]);
839
                                s->last_mv[i][j][k] = val;
840
                                s->mv[i][j][k] = val;
841
                            }
842
                        }
843
                    }
844
                    break;
845
                case MT_FIELD:
846
                    if (s->picture_structure == PICT_FRAME) {
847
                        s->mv_type = MV_TYPE_FIELD;
848
                        for(j=0;j<2;j++) {
849
                            s->field_select[i][j] = get_bits1(&s->gb);
850
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
851
                                                     s->last_mv[i][j][0]);
852
                            s->last_mv[i][j][0] = val;
853
                            s->mv[i][j][0] = val;
854
                            dprintf("fmx=%d\n", val);
855
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
856
                                                     s->last_mv[i][j][1] >> 1);
857
                            s->last_mv[i][j][1] = val << 1;
858
                            s->mv[i][j][1] = val;
859
                            dprintf("fmy=%d\n", val);
860
                        }
861
                    } else {
862
                        s->mv_type = MV_TYPE_16X16;
863
                        s->field_select[i][0] = get_bits1(&s->gb);
864
                        for(k=0;k<2;k++) {
865
                            val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
866
                                                     s->last_mv[i][0][k]);
867
                            s->last_mv[i][0][k] = val;
868
                            s->last_mv[i][1][k] = val;
869
                            s->mv[i][0][k] = val;
870
                        }
871
                    }
872
                    break;
873
                case MT_DMV:
874
                    {
875
                        int dmx, dmy, mx, my, m;
876

    
877
                        mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0], 
878
                                                s->last_mv[i][0][0]);
879
                        s->last_mv[i][0][0] = mx;
880
                        s->last_mv[i][1][0] = mx;
881
                        dmx = get_dmv(s);
882
                        my = mpeg_decode_motion(s, s->mpeg_f_code[i][1], 
883
                                                s->last_mv[i][0][1] >> 1);
884
                        dmy = get_dmv(s);
885
                        s->mv_type = MV_TYPE_DMV;
886
                        /* XXX: totally broken */
887
                        if (s->picture_structure == PICT_FRAME) {
888
                            s->last_mv[i][0][1] = my << 1;
889
                            s->last_mv[i][1][1] = my << 1;
890

    
891
                            m = s->top_field_first ? 1 : 3;
892
                            /* top -> top pred */
893
                            s->mv[i][0][0] = mx; 
894
                            s->mv[i][0][1] = my << 1;
895
                            s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
896
                            s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
897
                            m = 4 - m;
898
                            s->mv[i][2][0] = mx;
899
                            s->mv[i][2][1] = my << 1;
900
                            s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
901
                            s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
902
                        } else {
903
                            s->last_mv[i][0][1] = my;
904
                            s->last_mv[i][1][1] = my;
905
                            s->mv[i][0][0] = mx;
906
                            s->mv[i][0][1] = my;
907
                            s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
908
                            s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1 
909
                                /* + 2 * cur_field */;
910
                        }
911
                    }
912
                    break;
913
                }
914
            }
915
        }
916
    }
917

    
918
    if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
919
        skip_bits1(&s->gb); /* marker */
920
    }
921
    
922
    if (mb_type & MB_PAT) {
923
        cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
924
        if (cbp < 0){
925
            fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
926
            return -1;
927
        }
928
        cbp++;
929
    }
930
    dprintf("cbp=%x\n", cbp);
931

    
932
    if (s->mpeg2) {
933
        if (s->mb_intra) {
934
            for(i=0;i<6;i++) {
935
                if (cbp & (1 << (5 - i))) {
936
                    if (mpeg2_decode_block_intra(s, block[i], i) < 0)
937
                        return -1;
938
                } else {
939
                    s->block_last_index[i] = -1;
940
                }
941
            }
942
        } else {
943
            for(i=0;i<6;i++) {
944
                if (cbp & (1 << (5 - i))) {
945
                    if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
946
                        return -1;
947
                } else {
948
                    s->block_last_index[i] = -1;
949
                }
950
            }
951
        }
952
    } else {
953
        for(i=0;i<6;i++) {
954
            if (cbp & (1 << (5 - i))) {
955
                if (mpeg1_decode_block(s, block[i], i) < 0)
956
                    return -1;
957
            } else {
958
                s->block_last_index[i] = -1;
959
            }
960
        }
961
    }
962
    return 0;
963
}
964

    
965
/* as h263, but only 17 codes */
966
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
967
{
968
    int code, sign, val, m, l, shift;
969

    
970
    code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
971
    if (code < 0) {
972
        return 0xffff;
973
    }
974
    if (code == 0) {
975
        return pred;
976
    }
977
    sign = get_bits1(&s->gb);
978
    shift = fcode - 1;
979
    val = (code - 1) << shift;
980
    if (shift > 0)
981
        val |= get_bits(&s->gb, shift);
982
    val++;
983
    if (sign)
984
        val = -val;
985
    val += pred;
986
    
987
    /* modulo decoding */
988
    l = (1 << shift) * 16;
989
    m = 2 * l;
990
    if (val < -l) {
991
        val += m;
992
    } else if (val >= l) {
993
        val -= m;
994
    }
995
    return val;
996
}
997

    
998
static inline int decode_dc(MpegEncContext *s, int component)
999
{
1000
    int code, diff;
1001

    
1002
    if (component == 0) {
1003
        code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
1004
    } else {
1005
        code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
1006
    }
1007
    if (code < 0){
1008
        fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
1009
        return 0xffff;
1010
    }
1011
    if (code == 0) {
1012
        diff = 0;
1013
    } else {
1014
        diff = get_bits(&s->gb, code);
1015
        if ((diff & (1 << (code - 1))) == 0) 
1016
            diff = (-1 << code) | (diff + 1);
1017
    }
1018
    return diff;
1019
}
1020

    
1021
static int mpeg1_decode_block(MpegEncContext *s, 
1022
                               DCTELEM *block, 
1023
                               int n)
1024
{
1025
    int level, dc, diff, i, j, run;
1026
    int code, component;
1027
    RLTable *rl = &rl_mpeg1;
1028
    UINT8 * const scantable= s->intra_scantable.permutated;
1029

    
1030
    if (s->mb_intra) {
1031
        /* DC coef */
1032
        component = (n <= 3 ? 0 : n - 4 + 1);
1033
        diff = decode_dc(s, component);
1034
        if (diff >= 0xffff)
1035
            return -1;
1036
        dc = s->last_dc[component];
1037
        dc += diff;
1038
        s->last_dc[component] = dc;
1039
        block[0] = dc;
1040
        dprintf("dc=%d diff=%d\n", dc, diff);
1041
        i = 1;
1042
    } else {
1043
        int v;
1044
        OPEN_READER(re, &s->gb);
1045
        i = 0;
1046
        /* special case for the first coef. no need to add a second vlc table */
1047
        UPDATE_CACHE(re, &s->gb);
1048
        v= SHOW_UBITS(re, &s->gb, 2);
1049
        if (v & 2) {
1050
            run = 0;
1051
            level = 1 - ((v & 1) << 1);
1052
            SKIP_BITS(re, &s->gb, 2);
1053
            CLOSE_READER(re, &s->gb);
1054
            goto add_coef;
1055
        }
1056
        CLOSE_READER(re, &s->gb);
1057
    }
1058

    
1059
    /* now quantify & encode AC coefs */
1060
    for(;;) {
1061
        code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1062
        if (code < 0) {
1063
            return -1;
1064
        }
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, 8);
1071
            level= (level + ((-1)<<7)) ^ ((-1)<<7); //sign extension
1072
            if (level == -128) {
1073
                level = get_bits(&s->gb, 8) - 256;
1074
            } else if (level == 0) {
1075
                level = get_bits(&s->gb, 8);
1076
            }
1077
        } else {
1078
            run = rl->table_run[code];
1079
            level = rl->table_level[code];
1080
            if (get_bits1(&s->gb))
1081
                level = -level;
1082
        }
1083
        i += run;
1084
        if (i >= 64)
1085
            return -1;
1086
    add_coef:
1087
        dprintf("%d: run=%d level=%d\n", n, run, level);
1088
        j = scantable[i];
1089
        block[j] = level;
1090
        i++;
1091
    }
1092
    s->block_last_index[n] = i-1;
1093
    return 0;
1094
}
1095

    
1096
/* Also does unquantization here, since I will never support mpeg2
1097
   encoding */
1098
static int mpeg2_decode_block_non_intra(MpegEncContext *s, 
1099
                                        DCTELEM *block, 
1100
                                        int n)
1101
{
1102
    int level, i, j, run;
1103
    int code;
1104
    RLTable *rl = &rl_mpeg1;
1105
    const UINT8 *scan_table;
1106
    const UINT16 *matrix;
1107
    int mismatch;
1108

    
1109
    if (s->alternate_scan)
1110
        scan_table = s->intra_v_scantable.permutated;
1111
    else
1112
        scan_table = s->intra_scantable.permutated;
1113
    mismatch = 1;
1114

    
1115
    {
1116
        int v;
1117
        OPEN_READER(re, &s->gb);
1118
        i = 0;
1119
        if (n < 4)
1120
            matrix = s->inter_matrix;
1121
        else
1122
            matrix = s->chroma_inter_matrix;
1123

    
1124
        /* special case for the first coef. no need to add a second vlc table */
1125
        UPDATE_CACHE(re, &s->gb);
1126
        v= SHOW_UBITS(re, &s->gb, 2);
1127
        if (v & 2) {
1128
            run = 0;
1129
            level = 5 - (v << 1);
1130
            SKIP_BITS(re, &s->gb, 2);
1131
            CLOSE_READER(re, &s->gb);
1132
            goto add_coef;
1133
        }
1134
        CLOSE_READER(re, &s->gb);
1135
    }
1136

    
1137
    /* now quantify & encode AC coefs */
1138
    for(;;) {
1139
        code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1140
        if (code < 0){
1141
            fprintf(stderr, "invalid ac code at %d %d\n", s->mb_x, s->mb_y);
1142
            return -1;
1143
        }
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 + ((-1)<<11)) ^ ((-1)<<11); //sign extension
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
            fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
1160
            return -1;
1161
        }
1162
    add_coef:
1163
        j = scan_table[i];
1164
        dprintf("%d: run=%d level=%d\n", n, run, level);
1165
        /* XXX: optimize */
1166
        if (level > 0) {
1167
            level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1168
        } else {
1169
            level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1170
            level = -level;
1171
        }
1172
        /* XXX: is it really necessary to saturate since the encoder
1173
           knows whats going on ? */
1174
        mismatch ^= level;
1175
        block[j] = level;
1176
        i++;
1177
    }
1178
    block[63] ^= (mismatch & 1);
1179
    s->block_last_index[n] = i;
1180

    
1181
    return 0;
1182
}
1183

    
1184
static int mpeg2_decode_block_intra(MpegEncContext *s, 
1185
                                    DCTELEM *block, 
1186
                                    int n)
1187
{
1188
    int level, dc, diff, i, j, run;
1189
    int code, component;
1190
    RLTable *rl;
1191
    const UINT8 *scan_table;
1192
    const UINT16 *matrix;
1193
    int mismatch;
1194

    
1195
    if (s->alternate_scan)
1196
        scan_table = s->intra_v_scantable.permutated;
1197
    else
1198
        scan_table = s->intra_scantable.permutated;
1199

    
1200
    /* DC coef */
1201
    component = (n <= 3 ? 0 : n - 4 + 1);
1202
    diff = decode_dc(s, component);
1203
    if (diff >= 0xffff)
1204
        return -1;
1205
    dc = s->last_dc[component];
1206
    dc += diff;
1207
    s->last_dc[component] = dc;
1208
    block[0] = dc << (3 - s->intra_dc_precision);
1209
    dprintf("dc=%d\n", block[0]);
1210
    mismatch = block[0] ^ 1;
1211
    i = 1;
1212
    if (s->intra_vlc_format)
1213
        rl = &rl_mpeg2;
1214
    else
1215
        rl = &rl_mpeg1;
1216
    if (n < 4) 
1217
        matrix = s->intra_matrix;
1218
    else
1219
        matrix = s->chroma_intra_matrix;
1220

    
1221
    /* now quantify & encode AC coefs */
1222
    for(;;) {
1223
        code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1224
        if (code < 0){
1225
            fprintf(stderr, "invalid ac code at %d %d\n", s->mb_x, s->mb_y);
1226
            return -1;
1227
        }
1228
        if (code == 112) {
1229
            break;
1230
        } else if (code == 111) {
1231
            /* escape */
1232
            run = get_bits(&s->gb, 6);
1233
            level = get_bits(&s->gb, 12);
1234
            level= (level + ((-1)<<11)) ^ ((-1)<<11); //sign extension
1235
        } else {
1236
            run = rl->table_run[code];
1237
            level = rl->table_level[code];
1238
            if (get_bits1(&s->gb))
1239
                level = -level;
1240
        }
1241
        i += run;
1242
        if (i >= 64){
1243
            fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
1244
            return -1;
1245
        }
1246
        j = scan_table[i];
1247
        dprintf("%d: run=%d level=%d\n", n, run, level);
1248
        level = (level * s->qscale * matrix[j]) / 16;
1249
        /* XXX: is it really necessary to saturate since the encoder
1250
           knows whats going on ? */
1251
        mismatch ^= level;
1252
        block[j] = level;
1253
        i++;
1254
    }
1255
    block[63] ^= (mismatch & 1);
1256
    s->block_last_index[n] = i;
1257
    return 0;
1258
}
1259

    
1260
/* compressed picture size */
1261
#define PICTURE_BUFFER_SIZE 100000
1262

    
1263
typedef struct Mpeg1Context {
1264
    MpegEncContext mpeg_enc_ctx;
1265
    UINT32 header_state;
1266
    int start_code; /* current start code */
1267
    UINT8 buffer[PICTURE_BUFFER_SIZE]; 
1268
    UINT8 *buf_ptr;
1269
    int buffer_size;
1270
    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1271
    int repeat_field; /* true if we must repeat the field */
1272
} Mpeg1Context;
1273

    
1274
static int mpeg_decode_init(AVCodecContext *avctx)
1275
{
1276
    Mpeg1Context *s = avctx->priv_data;
1277
    
1278
    s->mpeg_enc_ctx.flags= avctx->flags;
1279
    common_init(&s->mpeg_enc_ctx);
1280
    init_vlcs(&s->mpeg_enc_ctx);
1281

    
1282
    s->header_state = 0xff;
1283
    s->mpeg_enc_ctx_allocated = 0;
1284
    s->buffer_size = PICTURE_BUFFER_SIZE;
1285
    s->start_code = -1;
1286
    s->buf_ptr = s->buffer;
1287
    s->mpeg_enc_ctx.picture_number = 0;
1288
    s->repeat_field = 0;
1289
    s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1290
    avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1291
    return 0;
1292
}
1293

    
1294
/* return the 8 bit start code value and update the search
1295
   state. Return -1 if no start code found */
1296
static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end, 
1297
                           UINT32 *header_state)
1298
{
1299
    UINT8 *buf_ptr;
1300
    unsigned int state, v;
1301
    int val;
1302

    
1303
    state = *header_state;
1304
    buf_ptr = *pbuf_ptr;
1305
    while (buf_ptr < buf_end) {
1306
        v = *buf_ptr++;
1307
        if (state == 0x000001) {
1308
            state = ((state << 8) | v) & 0xffffff;
1309
            val = state;
1310
            goto found;
1311
        }
1312
        state = ((state << 8) | v) & 0xffffff;
1313
    }
1314
    val = -1;
1315
 found:
1316
    *pbuf_ptr = buf_ptr;
1317
    *header_state = state;
1318
    return val;
1319
}
1320

    
1321
static int mpeg1_decode_picture(AVCodecContext *avctx, 
1322
                                UINT8 *buf, int buf_size)
1323
{
1324
    Mpeg1Context *s1 = avctx->priv_data;
1325
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1326
    int ref, f_code;
1327

    
1328
    init_get_bits(&s->gb, buf, buf_size);
1329

    
1330
    ref = get_bits(&s->gb, 10); /* temporal ref */
1331
    s->pict_type = get_bits(&s->gb, 3);
1332
    dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1333
    skip_bits(&s->gb, 16);
1334
    if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1335
        s->full_pel[0] = get_bits1(&s->gb);
1336
        f_code = get_bits(&s->gb, 3);
1337
        if (f_code == 0)
1338
            return -1;
1339
        s->mpeg_f_code[0][0] = f_code;
1340
        s->mpeg_f_code[0][1] = f_code;
1341
    }
1342
    if (s->pict_type == B_TYPE) {
1343
        s->full_pel[1] = get_bits1(&s->gb);
1344
        f_code = get_bits(&s->gb, 3);
1345
        if (f_code == 0)
1346
            return -1;
1347
        s->mpeg_f_code[1][0] = f_code;
1348
        s->mpeg_f_code[1][1] = f_code;
1349
    }
1350
    s->y_dc_scale = 8;
1351
    s->c_dc_scale = 8;
1352
    s->first_slice = 1;
1353
    return 0;
1354
}
1355

    
1356
static void mpeg_decode_sequence_extension(MpegEncContext *s)
1357
{
1358
    int horiz_size_ext, vert_size_ext;
1359
    int bit_rate_ext, vbv_buf_ext, low_delay;
1360
    int frame_rate_ext_n, frame_rate_ext_d;
1361

    
1362
    skip_bits(&s->gb, 8); /* profil and level */
1363
    s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1364
    skip_bits(&s->gb, 2); /* chroma_format */
1365
    horiz_size_ext = get_bits(&s->gb, 2);
1366
    vert_size_ext = get_bits(&s->gb, 2);
1367
    s->width |= (horiz_size_ext << 12);
1368
    s->height |= (vert_size_ext << 12);
1369
    bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1370
    s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1371
    skip_bits1(&s->gb); /* marker */
1372
    vbv_buf_ext = get_bits(&s->gb, 8);
1373
    low_delay = get_bits1(&s->gb);
1374
    frame_rate_ext_n = get_bits(&s->gb, 2);
1375
    frame_rate_ext_d = get_bits(&s->gb, 5);
1376
    if (frame_rate_ext_d >= 1)
1377
        s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1378
    dprintf("sequence extension\n");
1379
    s->mpeg2 = 1;
1380
    s->avctx->sub_id = 2; /* indicates mpeg2 found */
1381
}
1382

    
1383
static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1384
{
1385
    int i, v, j;
1386

    
1387
    dprintf("matrix extension\n");
1388

    
1389
    if (get_bits1(&s->gb)) {
1390
        for(i=0;i<64;i++) {
1391
            v = get_bits(&s->gb, 8);
1392
            j = s->intra_scantable.permutated[i];
1393
            s->intra_matrix[j] = v;
1394
            s->chroma_intra_matrix[j] = v;
1395
        }
1396
    }
1397
    if (get_bits1(&s->gb)) {
1398
        for(i=0;i<64;i++) {
1399
            v = get_bits(&s->gb, 8);
1400
            j = s->intra_scantable.permutated[i];
1401
            s->inter_matrix[j] = v;
1402
            s->chroma_inter_matrix[j] = v;
1403
        }
1404
    }
1405
    if (get_bits1(&s->gb)) {
1406
        for(i=0;i<64;i++) {
1407
            v = get_bits(&s->gb, 8);
1408
            j = s->intra_scantable.permutated[i];
1409
            s->chroma_intra_matrix[j] = v;
1410
        }
1411
    }
1412
    if (get_bits1(&s->gb)) {
1413
        for(i=0;i<64;i++) {
1414
            v = get_bits(&s->gb, 8);
1415
            j = s->intra_scantable.permutated[i];
1416
            s->chroma_inter_matrix[j] = v;
1417
        }
1418
    }
1419
}
1420

    
1421
static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1422
{
1423
    s->full_pel[0] = s->full_pel[1] = 0;
1424
    s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1425
    s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1426
    s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1427
    s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1428
    s->intra_dc_precision = get_bits(&s->gb, 2);
1429
    s->picture_structure = get_bits(&s->gb, 2);
1430
    s->top_field_first = get_bits1(&s->gb);
1431
    s->frame_pred_frame_dct = get_bits1(&s->gb);
1432
    s->concealment_motion_vectors = get_bits1(&s->gb);
1433
    s->q_scale_type = get_bits1(&s->gb);
1434
    s->intra_vlc_format = get_bits1(&s->gb);
1435
    s->alternate_scan = get_bits1(&s->gb);
1436
    s->repeat_first_field = get_bits1(&s->gb);
1437
    s->chroma_420_type = get_bits1(&s->gb);
1438
    s->progressive_frame = get_bits1(&s->gb);
1439
    /* composite display not parsed */
1440
    dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1441
    dprintf("picture_structure=%d\n", s->picture_structure);
1442
    dprintf("top field first=%d\n", s->top_field_first);
1443
    dprintf("repeat first field=%d\n", s->repeat_first_field);
1444
    dprintf("conceal=%d\n", s->concealment_motion_vectors);
1445
    dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1446
    dprintf("alternate_scan=%d\n", s->alternate_scan);
1447
    dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1448
    dprintf("progressive_frame=%d\n", s->progressive_frame);
1449
}
1450

    
1451
static void mpeg_decode_extension(AVCodecContext *avctx, 
1452
                                  UINT8 *buf, int buf_size)
1453
{
1454
    Mpeg1Context *s1 = avctx->priv_data;
1455
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1456
    int ext_type;
1457

    
1458
    init_get_bits(&s->gb, buf, buf_size);
1459
    
1460
    ext_type = get_bits(&s->gb, 4);
1461
    switch(ext_type) {
1462
    case 0x1:
1463
        /* sequence ext */
1464
        mpeg_decode_sequence_extension(s);
1465
        break;
1466
    case 0x3:
1467
        /* quant matrix extension */
1468
        mpeg_decode_quant_matrix_extension(s);
1469
        break;
1470
    case 0x8:
1471
        /* picture extension */
1472
        mpeg_decode_picture_coding_extension(s);
1473
        break;
1474
    }
1475
}
1476

    
1477
/* return 1 if end of frame */
1478
static int mpeg_decode_slice(AVCodecContext *avctx, 
1479
                              AVPicture *pict,
1480
                              int start_code,
1481
                              UINT8 *buf, int buf_size)
1482
{
1483
    Mpeg1Context *s1 = avctx->priv_data;
1484
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1485
    int ret;
1486

    
1487
    start_code = (start_code - 1) & 0xff;
1488
    if (start_code >= s->mb_height){
1489
        fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);
1490
        return -1;
1491
    }
1492
    s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1493
    s->last_dc[1] = s->last_dc[0];
1494
    s->last_dc[2] = s->last_dc[0];
1495
    memset(s->last_mv, 0, sizeof(s->last_mv));
1496
    s->mb_x = -1;
1497
    s->mb_y = start_code;
1498
    s->mb_incr = 0;
1499
    /* start frame decoding */
1500
    if (s->first_slice) {
1501
        s->first_slice = 0;
1502
        MPV_frame_start(s, avctx);
1503
    }
1504

    
1505
    init_get_bits(&s->gb, buf, buf_size);
1506

    
1507
    s->qscale = get_qscale(s);
1508
    /* extra slice info */
1509
    while (get_bits1(&s->gb) != 0) {
1510
        skip_bits(&s->gb, 8);
1511
    }
1512

    
1513
    for(;;) {
1514
        clear_blocks(s->block[0]);
1515
        emms_c();
1516
        ret = mpeg_decode_mb(s, s->block);
1517
        dprintf("ret=%d\n", ret);
1518
        if (ret < 0)
1519
            return -1;
1520
        if (ret == 1)
1521
            break;
1522
    
1523
        if(s->mb_x==0)
1524
            PRINT_QP("%s", "\n");
1525
        PRINT_QP("%2d", s->qscale);
1526
        
1527
        MPV_decode_mb(s, s->block);
1528
    }
1529
    emms_c();
1530

    
1531
    /* end of slice reached */
1532
    if (s->mb_x == (s->mb_width - 1) &&
1533
        s->mb_y == (s->mb_height - 1)) {
1534
        /* end of image */
1535
        UINT8 **picture;
1536

    
1537
        MPV_frame_end(s);
1538

    
1539
        /* XXX: incorrect reported qscale for mpeg2 */
1540
        if (s->pict_type == B_TYPE) {
1541
            picture = s->current_picture;
1542
            avctx->quality = s->qscale;
1543
        } else {
1544
            /* latency of 1 frame for I and P frames */
1545
            /* XXX: use another variable than picture_number */
1546
            if (s->picture_number == 0) {
1547
                picture = NULL;
1548
            } else {
1549
                picture = s->last_picture;
1550
                avctx->quality = s->last_qscale;
1551
            }
1552
            s->last_qscale = s->qscale;
1553
            s->picture_number++;
1554
        }
1555
        if (picture) {
1556
            pict->data[0] = picture[0];
1557
            pict->data[1] = picture[1];
1558
            pict->data[2] = picture[2];
1559
            pict->linesize[0] = s->linesize;
1560
            pict->linesize[1] = s->uvlinesize;
1561
            pict->linesize[2] = s->uvlinesize;
1562
            return 1;
1563
        } else {
1564
            return 0;
1565
        }
1566
    } else {
1567
        return 0;
1568
    }
1569
}
1570

    
1571
static int mpeg1_decode_sequence(AVCodecContext *avctx, 
1572
                                 UINT8 *buf, int buf_size)
1573
{
1574
    Mpeg1Context *s1 = avctx->priv_data;
1575
    MpegEncContext *s = &s1->mpeg_enc_ctx;
1576
    int width, height, i, v, j;
1577

    
1578
    init_get_bits(&s->gb, buf, buf_size);
1579

    
1580
    width = get_bits(&s->gb, 12);
1581
    height = get_bits(&s->gb, 12);
1582
    skip_bits(&s->gb, 4);
1583
    s->frame_rate_index = get_bits(&s->gb, 4);
1584
    if (s->frame_rate_index == 0)
1585
        return -1;
1586
    s->bit_rate = get_bits(&s->gb, 18) * 400;
1587
    if (get_bits1(&s->gb) == 0) /* marker */
1588
        return -1;
1589
    if (width <= 0 || height <= 0 ||
1590
        (width % 2) != 0 || (height % 2) != 0)
1591
        return -1;
1592
    if (width != s->width ||
1593
        height != s->height) {
1594
        /* start new mpeg1 context decoding */
1595
        s->out_format = FMT_MPEG1;
1596
        if (s1->mpeg_enc_ctx_allocated) {
1597
            MPV_common_end(s);
1598
        }
1599
        s->width = width;
1600
        s->height = height;
1601
        avctx->has_b_frames= s->has_b_frames = 1;
1602
        s->avctx = avctx;
1603
        avctx->width = width;
1604
        avctx->height = height;
1605
        if (s->frame_rate_index >= 9) {
1606
            /* at least give a valid frame rate (some old mpeg1 have this) */
1607
            avctx->frame_rate = 25 * FRAME_RATE_BASE;
1608
        } else {
1609
            avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1610
        }
1611
        s->frame_rate = avctx->frame_rate;
1612
        avctx->bit_rate = s->bit_rate;
1613
        
1614
        if (MPV_common_init(s) < 0)
1615
            return -1;
1616
        s1->mpeg_enc_ctx_allocated = 1;
1617
    }
1618

    
1619
    skip_bits(&s->gb, 10); /* vbv_buffer_size */
1620
    skip_bits(&s->gb, 1);
1621

    
1622
    /* get matrix */
1623
    if (get_bits1(&s->gb)) {
1624
        for(i=0;i<64;i++) {
1625
            v = get_bits(&s->gb, 8);
1626
            j = s->intra_scantable.permutated[i];
1627
            s->intra_matrix[j] = v;
1628
            s->chroma_intra_matrix[j] = v;
1629
        }
1630
#ifdef DEBUG
1631
        dprintf("intra matrix present\n");
1632
        for(i=0;i<64;i++)
1633
            dprintf(" %d", s->intra_matrix[s->intra_scantable.permutated[i]]);
1634
        printf("\n");
1635
#endif
1636
    } else {
1637
        for(i=0;i<64;i++) {
1638
            int j= s->idct_permutation[i];
1639
            v = ff_mpeg1_default_intra_matrix[i];
1640
            s->intra_matrix[j] = v;
1641
            s->chroma_intra_matrix[j] = v;
1642
        }
1643
    }
1644
    if (get_bits1(&s->gb)) {
1645
        for(i=0;i<64;i++) {
1646
            v = get_bits(&s->gb, 8);
1647
            j = s->intra_scantable.permutated[i];
1648
            s->inter_matrix[j] = v;
1649
            s->chroma_inter_matrix[j] = v;
1650
        }
1651
#ifdef DEBUG
1652
        dprintf("non intra matrix present\n");
1653
        for(i=0;i<64;i++)
1654
            dprintf(" %d", s->inter_matrix[s->intra_scantable.permutated[i]]);
1655
        printf("\n");
1656
#endif
1657
    } else {
1658
        for(i=0;i<64;i++) {
1659
            int j= s->idct_permutation[i];
1660
            v = ff_mpeg1_default_non_intra_matrix[i];
1661
            s->inter_matrix[j] = v;
1662
            s->chroma_inter_matrix[j] = v;
1663
        }
1664
    }
1665

    
1666
    /* we set mpeg2 parameters so that it emulates mpeg1 */
1667
    s->progressive_sequence = 1;
1668
    s->progressive_frame = 1;
1669
    s->picture_structure = PICT_FRAME;
1670
    s->frame_pred_frame_dct = 1;
1671
    s->mpeg2 = 0;
1672
    avctx->sub_id = 1; /* indicates mpeg1 */
1673
    return 0;
1674
}
1675

    
1676
/* handle buffering and image synchronisation */
1677
static int mpeg_decode_frame(AVCodecContext *avctx, 
1678
                             void *data, int *data_size,
1679
                             UINT8 *buf, int buf_size)
1680
{
1681
    Mpeg1Context *s = avctx->priv_data;
1682
    UINT8 *buf_end, *buf_ptr, *buf_start;
1683
    int len, start_code_found, ret, code, start_code, input_size;
1684
    AVPicture *picture = data;
1685
    MpegEncContext *s2 = &s->mpeg_enc_ctx;
1686
            
1687
    dprintf("fill_buffer\n");
1688

    
1689
    *data_size = 0;
1690

    
1691
    /* special case for last picture */
1692
    if (buf_size == 0) {
1693
        if (s2->picture_number > 0) {
1694
            picture->data[0] = s2->next_picture[0];
1695
            picture->data[1] = s2->next_picture[1];
1696
            picture->data[2] = s2->next_picture[2];
1697
            picture->linesize[0] = s2->linesize;
1698
            picture->linesize[1] = s2->uvlinesize;
1699
            picture->linesize[2] = s2->uvlinesize;
1700
            *data_size = sizeof(AVPicture);
1701
        }
1702
        return 0;
1703
    }
1704

    
1705
    buf_ptr = buf;
1706
    buf_end = buf + buf_size;
1707

    
1708
#if 0    
1709
    if (s->repeat_field % 2 == 1) { 
1710
        s->repeat_field++;
1711
        //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1712
        //        s2->picture_number, s->repeat_field);
1713
        if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
1714
            *data_size = sizeof(AVPicture);
1715
            goto the_end;
1716
        }
1717
    }
1718
#endif
1719
    while (buf_ptr < buf_end) {
1720
        buf_start = buf_ptr;
1721
        /* find start next code */
1722
        code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1723
        if (code >= 0) {
1724
            start_code_found = 1;
1725
        } else {
1726
            start_code_found = 0;
1727
        }
1728
        /* copy to buffer */
1729
        len = buf_ptr - buf_start;
1730
        if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1731
            /* data too big : flush */
1732
            s->buf_ptr = s->buffer;
1733
            if (start_code_found)
1734
                s->start_code = code;
1735
        } else {
1736
            memcpy(s->buf_ptr, buf_start, len);
1737
            s->buf_ptr += len;
1738
            if(   (s2->flags&CODEC_FLAG_NOT_TRUNCATED) && (!start_code_found) 
1739
               && s->buf_ptr+4<s->buffer+s->buffer_size){
1740
                start_code_found= 1;
1741
                code= 0x1FF;
1742
                s->header_state=0xFF;
1743
                s->buf_ptr[0]=0;
1744
                s->buf_ptr[1]=0;
1745
                s->buf_ptr[2]=1;
1746
                s->buf_ptr[3]=0xFF;
1747
                s->buf_ptr+=4;
1748
            }
1749
            if (start_code_found) {
1750
                /* prepare data for next start code */
1751
                input_size = s->buf_ptr - s->buffer;
1752
                start_code = s->start_code;
1753
                s->buf_ptr = s->buffer;
1754
                s->start_code = code;
1755
                switch(start_code) {
1756
                case SEQ_START_CODE:
1757
                    mpeg1_decode_sequence(avctx, s->buffer, 
1758
                                          input_size);
1759
                    break;
1760
                            
1761
                case PICTURE_START_CODE:
1762
                    /* we have a complete image : we try to decompress it */
1763
                    mpeg1_decode_picture(avctx, 
1764
                                         s->buffer, input_size);
1765
                    break;
1766
                case EXT_START_CODE:
1767
                    mpeg_decode_extension(avctx,
1768
                                          s->buffer, input_size);
1769
                    break;
1770
                default:
1771
                    if (start_code >= SLICE_MIN_START_CODE &&
1772
                        start_code <= SLICE_MAX_START_CODE) {
1773
                        ret = mpeg_decode_slice(avctx, picture,
1774
                                                start_code, s->buffer, input_size);
1775
                        if (ret == 1) {
1776
                            /* got a picture: exit */
1777
                            /* first check if we must repeat the frame */
1778
                            avctx->repeat_pict = 0;
1779
#if 0
1780
                            if (s2->progressive_frame && s2->repeat_first_field) {
1781
                                //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1782
                                //s2->repeat_first_field = 0;
1783
                                //s2->progressive_frame = 0;
1784
                                if (++s->repeat_field > 2)
1785
                                    s->repeat_field = 0;
1786
                                avctx->repeat_pict = 1;
1787
                            }
1788
#endif                      
1789
                            if (s2->repeat_first_field) {
1790
                                if (s2->progressive_sequence) {
1791
                                    if (s2->top_field_first)
1792
                                        avctx->repeat_pict = 4;
1793
                                    else
1794
                                        avctx->repeat_pict = 2;
1795
                                } else if (s2->progressive_frame) {
1796
                                    avctx->repeat_pict = 1;
1797
                                }
1798
                            }         
1799
                            *data_size = sizeof(AVPicture);
1800
                            goto the_end;
1801
                        }else if(ret==-1){
1802
                            printf("Error while decoding slice\n");
1803
                        }
1804
                    }
1805
                    break;
1806
                }
1807
            }
1808
        }
1809
    }
1810
 the_end:
1811
    return buf_ptr - buf;
1812
}
1813

    
1814
static int mpeg_decode_end(AVCodecContext *avctx)
1815
{
1816
    Mpeg1Context *s = avctx->priv_data;
1817

    
1818
    if (s->mpeg_enc_ctx_allocated)
1819
        MPV_common_end(&s->mpeg_enc_ctx);
1820
    return 0;
1821
}
1822

    
1823
AVCodec mpeg_decoder = {
1824
    "mpegvideo",
1825
    CODEC_TYPE_VIDEO,
1826
    CODEC_ID_MPEG1VIDEO,
1827
    sizeof(Mpeg1Context),
1828
    mpeg_decode_init,
1829
    NULL,
1830
    mpeg_decode_end,
1831
    mpeg_decode_frame,
1832
    CODEC_CAP_DR1,
1833
};