2 * MPEG1 encoder / MPEG2 decoder
3 * Copyright (c) 2000,2001 Gerard Lantau.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #include "mpegvideo.h"
24 #include "mpeg12data.h"
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
36 //#define ABS(a) ((a)<0 ? -(a) : (a))
38 static void mpeg1_encode_block(MpegEncContext *s,
41 static void mpeg1_encode_motion(MpegEncContext *s, int val);
42 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
43 static int mpeg1_decode_block(MpegEncContext *s,
46 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
49 static int mpeg2_decode_block_intra(MpegEncContext *s,
52 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
54 static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
55 static UINT8 fcode_tab[MAX_MV*2+1];
57 static void put_header(MpegEncContext *s, int header)
59 align_put_bits(&s->pb);
60 put_bits(&s->pb, 16, header>>16);
61 put_bits(&s->pb, 16, header&0xFFFF);
64 /* put sequence header if needed */
65 static void mpeg1_encode_sequence_header(MpegEncContext *s)
67 unsigned int vbv_buffer_size;
72 if (s->picture_in_gop_number == 0) {
73 /* mpeg1 header repeated every gop */
74 put_header(s, SEQ_START_CODE);
76 /* search closest frame rate */
79 s->frame_rate_index = 0;
82 d = abs(s->frame_rate - frame_rate_tab[i]);
85 s->frame_rate_index = i;
90 put_bits(&s->pb, 12, s->width);
91 put_bits(&s->pb, 12, s->height);
92 put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
93 put_bits(&s->pb, 4, s->frame_rate_index);
94 v = s->bit_rate / 400;
97 put_bits(&s->pb, 18, v);
98 put_bits(&s->pb, 1, 1); /* marker */
99 /* vbv buffer size: slightly greater than an I frame. We add
100 some margin just in case */
101 vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
102 put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
103 put_bits(&s->pb, 1, 1); /* constrained parameter flag */
104 put_bits(&s->pb, 1, 0); /* no custom intra matrix */
105 put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
107 put_header(s, GOP_START_CODE);
108 put_bits(&s->pb, 1, 0); /* do drop frame */
109 /* time code : we must convert from the real frame rate to a
110 fake mpeg frame rate in case of low frame rate */
111 fps = frame_rate_tab[s->frame_rate_index];
112 time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
113 s->gop_picture_number = s->fake_picture_number;
114 put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
115 put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
116 put_bits(&s->pb, 1, 1);
117 put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
118 put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
119 put_bits(&s->pb, 1, 1); /* closed gop */
120 put_bits(&s->pb, 1, 0); /* broken link */
123 if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
124 /* insert empty P pictures to slow down to the desired
125 frame rate. Each fake pictures takes about 20 bytes */
126 fps = frame_rate_tab[s->frame_rate_index];
127 n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
128 while (s->fake_picture_number < n) {
129 mpeg1_skip_picture(s, s->fake_picture_number -
130 s->gop_picture_number);
131 s->fake_picture_number++;
138 /* insert a fake P picture */
139 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
141 unsigned int mb_incr;
143 /* mpeg1 picture header */
144 put_header(s, PICTURE_START_CODE);
145 /* temporal reference */
146 put_bits(&s->pb, 10, pict_num & 0x3ff);
148 put_bits(&s->pb, 3, P_TYPE);
149 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
151 put_bits(&s->pb, 1, 1); /* integer coordinates */
152 put_bits(&s->pb, 3, 1); /* forward_f_code */
154 put_bits(&s->pb, 1, 0); /* extra bit picture */
157 put_header(s, SLICE_MIN_START_CODE);
158 put_bits(&s->pb, 5, 1); /* quantizer scale */
159 put_bits(&s->pb, 1, 0); /* slice extra information */
162 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
163 mbAddrIncrTable[mb_incr - 1][0]);
165 /* empty macroblock */
166 put_bits(&s->pb, 3, 1); /* motion only */
168 /* zero motion x & y */
169 put_bits(&s->pb, 1, 1);
170 put_bits(&s->pb, 1, 1);
172 /* output a number of empty slice */
173 mb_incr = s->mb_width * s->mb_height - 1;
174 while (mb_incr > 33) {
175 put_bits(&s->pb, 11, 0x008);
178 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
179 mbAddrIncrTable[mb_incr - 1][0]);
181 /* empty macroblock */
182 put_bits(&s->pb, 3, 1); /* motion only */
184 /* zero motion x & y */
185 put_bits(&s->pb, 1, 1);
186 put_bits(&s->pb, 1, 1);
189 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
200 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
201 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
204 /* build unified dc encoding tables */
205 for(i=-255; i<256; i++)
213 index = vlc_dc_table[adiff];
215 bits= vlc_dc_lum_bits[index] + index;
216 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
217 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
219 bits= vlc_dc_chroma_bits[index] + index;
220 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
221 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
224 mpeg1_encode_sequence_header(s);
226 /* mpeg1 picture header */
227 put_header(s, PICTURE_START_CODE);
228 /* temporal reference */
229 put_bits(&s->pb, 10, (s->fake_picture_number -
230 s->gop_picture_number) & 0x3ff);
231 s->fake_picture_number++;
233 put_bits(&s->pb, 3, s->pict_type);
234 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
236 if (s->pict_type == P_TYPE) {
237 put_bits(&s->pb, 1, 0); /* half pel coordinates */
238 put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
241 put_bits(&s->pb, 1, 0); /* extra bit picture */
244 put_header(s, SLICE_MIN_START_CODE);
245 put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
246 put_bits(&s->pb, 1, 0); /* slice extra information */
249 void mpeg1_encode_mb(MpegEncContext *s,
250 DCTELEM block[6][64],
251 int motion_x, int motion_y)
253 int mb_incr, i, cbp, mb_x, mb_y;
261 if (s->block_last_index[i] >= 0)
265 /* skip macroblock, except if first or last macroblock of a slice */
266 if ((cbp | motion_x | motion_y) == 0 &&
267 (!((mb_x | mb_y) == 0 ||
268 (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
272 mb_incr = s->mb_incr;
274 while (mb_incr > 33) {
275 put_bits(&s->pb, 11, 0x008);
278 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
279 mbAddrIncrTable[mb_incr - 1][0]);
281 if (s->pict_type == I_TYPE) {
282 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
285 put_bits(&s->pb, 5, 0x03);
288 if (motion_x == 0 && motion_y == 0) {
289 put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
290 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
292 put_bits(&s->pb, 1, 1); /* motion + cbp */
293 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
294 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
295 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
298 put_bits(&s->pb, 3, 1); /* motion only */
299 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
300 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
305 if (cbp & (1 << (5 - i))) {
306 mpeg1_encode_block(s, block[i], i);
311 s->last_mv[0][0][0] = motion_x;
312 s->last_mv[0][0][1] = motion_y;
315 static void mpeg1_encode_motion(MpegEncContext *s, int val)
317 int code, bit_size, l, m, bits, range, sign;
323 mbMotionVectorTable[0][1],
324 mbMotionVectorTable[0][0]);
326 bit_size = s->f_code - 1;
327 range = 1 << bit_size;
328 /* modulo encoding */
333 } else if (val >= l) {
339 code = (val >> bit_size) + 1;
340 bits = val & (range - 1);
345 code = (val >> bit_size) + 1;
346 bits = val & (range - 1);
350 mbMotionVectorTable[code][1],
351 mbMotionVectorTable[code][0]);
352 put_bits(&s->pb, 1, sign);
354 put_bits(&s->pb, bit_size, bits);
359 void mpeg1_encode_init(MpegEncContext *s)
367 for(f_code=1; f_code<=MAX_FCODE; f_code++){
368 for(mv=-MAX_MV; mv<=MAX_MV; mv++){
371 if(mv==0) len= mbMotionVectorTable[0][1];
373 int val, bit_size, range, code;
375 bit_size = s->f_code - 1;
376 range = 1 << bit_size;
382 code = (val >> bit_size) + 1;
384 len= mbMotionVectorTable[code][1] + 1 + bit_size;
386 len= mbMotionVectorTable[16][1] + 2 + bit_size;
390 mv_penalty[f_code][mv+MAX_MV]= len;
395 for(f_code=MAX_FCODE; f_code>0; f_code--){
396 for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
397 fcode_tab[mv+MAX_MV]= f_code;
401 s->mv_penalty= mv_penalty;
402 s->fcode_tab= fcode_tab;
405 s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
406 s->inter_quant_bias= 0;
409 static inline void encode_dc(MpegEncContext *s, int diff, int component)
411 if (component == 0) {
414 mpeg1_lum_dc_uni[diff+255]&0xFF,
415 mpeg1_lum_dc_uni[diff+255]>>8);
419 mpeg1_chr_dc_uni[diff+255]&0xFF,
420 mpeg1_chr_dc_uni[diff+255]>>8);
424 static void mpeg1_encode_block(MpegEncContext *s,
428 int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
430 // RLTable *rl = &rl_mpeg1;
432 last_index = s->block_last_index[n];
436 component = (n <= 3 ? 0 : n - 4 + 1);
437 dc = block[0]; /* overflow is impossible */
438 diff = dc - s->last_dc[component];
439 encode_dc(s, diff, component);
440 s->last_dc[component] = dc;
443 /* encode the first coefficient : needs to be done here because
444 it is handled slightly differently */
446 if (abs(level) == 1) {
447 code = ((UINT32)level >> 31); /* the sign bit */
448 put_bits(&s->pb, 2, code | 0x02);
457 /* now quantify & encode AC coefs */
458 last_non_zero = i - 1;
460 for(;i<=last_index;i++) {
461 j = zigzag_direct[i];
466 dprintf("level[%d]=%d\n", i, level);
468 /* encode using VLC */
470 run = i - last_non_zero - 1;
480 : "=&r" (alevel), "=&r" (sign)
491 // code = get_rl_index(rl, 0, run, alevel);
492 if (alevel > mpeg1_max_level[0][run])
495 code= mpeg1_index_run[0][run] + alevel - 1;
497 if (code < 111 /* rl->n */) {
498 /* store the vlc & sign at once */
499 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
501 /* escape seems to be pretty rare <5% so i dont optimize it */
502 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
503 /* escape: only clip in this case */
504 put_bits(&s->pb, 6, run);
506 put_bits(&s->pb, 8, level & 0xff);
509 put_bits(&s->pb, 16, 0x8001 + level + 255);
511 put_bits(&s->pb, 16, level & 0xffff);
519 put_bits(&s->pb, 2, 0x2);
522 /******************************************/
525 static VLC dc_lum_vlc;
526 static VLC dc_chroma_vlc;
528 static VLC mbincr_vlc;
529 static VLC mb_ptype_vlc;
530 static VLC mb_btype_vlc;
531 static VLC mb_pat_vlc;
533 void mpeg1_init_vlc(MpegEncContext *s)
539 init_vlc(&dc_lum_vlc, 9, 12,
540 vlc_dc_lum_bits, 1, 1,
541 vlc_dc_lum_code, 2, 2);
542 init_vlc(&dc_chroma_vlc, 9, 12,
543 vlc_dc_chroma_bits, 1, 1,
544 vlc_dc_chroma_code, 2, 2);
545 init_vlc(&mv_vlc, 9, 17,
546 &mbMotionVectorTable[0][1], 2, 1,
547 &mbMotionVectorTable[0][0], 2, 1);
548 init_vlc(&mbincr_vlc, 9, 35,
549 &mbAddrIncrTable[0][1], 2, 1,
550 &mbAddrIncrTable[0][0], 2, 1);
551 init_vlc(&mb_pat_vlc, 9, 63,
552 &mbPatTable[0][1], 2, 1,
553 &mbPatTable[0][0], 2, 1);
555 init_vlc(&mb_ptype_vlc, 6, 32,
556 &table_mb_ptype[0][1], 2, 1,
557 &table_mb_ptype[0][0], 2, 1);
558 init_vlc(&mb_btype_vlc, 6, 32,
559 &table_mb_btype[0][1], 2, 1,
560 &table_mb_btype[0][0], 2, 1);
563 /* cannot use generic init because we must add the EOB code */
564 init_vlc(&rl_mpeg1.vlc, 9, rl_mpeg1.n + 2,
565 &rl_mpeg1.table_vlc[0][1], 4, 2,
566 &rl_mpeg1.table_vlc[0][0], 4, 2);
567 init_vlc(&rl_mpeg2.vlc, 9, rl_mpeg2.n + 2,
568 &rl_mpeg2.table_vlc[0][1], 4, 2,
569 &rl_mpeg2.table_vlc[0][0], 4, 2);
573 static inline int get_dmv(MpegEncContext *s)
575 if(get_bits1(&s->gb))
576 return 1 - (get_bits1(&s->gb) << 1);
581 static inline int get_qscale(MpegEncContext *s)
585 if (s->q_scale_type) {
586 qscale = non_linear_qscale[get_bits(&s->gb, 5)];
588 qscale = get_bits(&s->gb, 5) << 1;
591 /* for mpeg1, we use the generic unquant code */
592 qscale = get_bits(&s->gb, 5);
597 /* motion type (for mpeg2) */
603 static int mpeg_decode_mb(MpegEncContext *s,
604 DCTELEM block[6][64])
606 int i, j, k, cbp, val, code, mb_type, motion_type;
608 /* skip mb handling */
609 if (s->mb_incr == 0) {
610 /* read again increment */
613 code = get_vlc(&s->gb, &mbincr_vlc);
615 return 1; /* error = end of slice */
620 /* otherwise, stuffing, nothing to do */
627 if (++s->mb_x >= s->mb_width) {
629 if (s->mb_y >= (s->mb_height - 1))
633 dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
635 if (--s->mb_incr != 0) {
639 s->block_last_index[i] = -1;
640 s->mv_type = MV_TYPE_16X16;
641 if (s->pict_type == P_TYPE) {
642 /* if P type, zero motion vector is implied */
643 s->mv_dir = MV_DIR_FORWARD;
644 s->mv[0][0][0] = s->mv[0][0][1] = 0;
645 s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
646 s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
648 /* if B type, reuse previous vectors and directions */
649 s->mv[0][0][0] = s->last_mv[0][0][0];
650 s->mv[0][0][1] = s->last_mv[0][0][1];
651 s->mv[1][0][0] = s->last_mv[1][0][0];
652 s->mv[1][0][1] = s->last_mv[1][0][1];
658 switch(s->pict_type) {
661 if (get_bits1(&s->gb) == 0) {
662 if (get_bits1(&s->gb) == 0)
664 mb_type = MB_QUANT | MB_INTRA;
670 mb_type = get_vlc(&s->gb, &mb_ptype_vlc);
675 mb_type = get_vlc(&s->gb, &mb_btype_vlc);
680 dprintf("mb_type=%x\n", mb_type);
681 motion_type = 0; /* avoid warning */
682 if (mb_type & (MB_FOR|MB_BACK)) {
683 /* get additionnal motion vector type */
684 if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct)
685 motion_type = MT_FRAME;
687 motion_type = get_bits(&s->gb, 2);
689 /* compute dct type */
690 if (s->picture_structure == PICT_FRAME &&
691 !s->frame_pred_frame_dct &&
692 (mb_type & (MB_PAT | MB_INTRA))) {
693 s->interlaced_dct = get_bits1(&s->gb);
695 if (s->interlaced_dct)
696 printf("interlaced_dct\n");
699 s->interlaced_dct = 0; /* frame based */
702 if (mb_type & MB_QUANT) {
703 s->qscale = get_qscale(s);
705 if (mb_type & MB_INTRA) {
706 if (s->concealment_motion_vectors) {
707 /* just parse them */
708 if (s->picture_structure != PICT_FRAME)
709 skip_bits1(&s->gb); /* field select */
710 mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
711 mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
715 memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
720 /* special case of implicit zero motion vector */
721 if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
722 s->mv_dir = MV_DIR_FORWARD;
723 s->mv_type = MV_TYPE_16X16;
724 s->last_mv[0][0][0] = 0;
725 s->last_mv[0][0][1] = 0;
726 s->last_mv[0][1][0] = 0;
727 s->last_mv[0][1][1] = 0;
730 } else if (mb_type & (MB_FOR | MB_BACK)) {
734 if (mb_type & (MB_FOR >> i)) {
735 s->mv_dir |= (MV_DIR_FORWARD >> i);
736 dprintf("motion_type=%d\n", motion_type);
737 switch(motion_type) {
738 case MT_FRAME: /* or MT_16X8 */
739 if (s->picture_structure == PICT_FRAME) {
741 s->mv_type = MV_TYPE_16X16;
743 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
744 s->last_mv[i][0][k]);
745 s->last_mv[i][0][k] = val;
746 s->last_mv[i][1][k] = val;
747 /* full_pel: only for mpeg1 */
750 s->mv[i][0][k] = val;
751 dprintf("mv%d: %d\n", k, val);
755 s->mv_type = MV_TYPE_16X8;
757 s->field_select[i][j] = get_bits1(&s->gb);
759 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
760 s->last_mv[i][j][k]);
761 s->last_mv[i][j][k] = val;
762 s->mv[i][j][k] = val;
768 if (s->picture_structure == PICT_FRAME) {
769 s->mv_type = MV_TYPE_FIELD;
771 s->field_select[i][j] = get_bits1(&s->gb);
772 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
773 s->last_mv[i][j][0]);
774 s->last_mv[i][j][0] = val;
775 s->mv[i][j][0] = val;
776 dprintf("fmx=%d\n", val);
777 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
778 s->last_mv[i][j][1] >> 1);
779 s->last_mv[i][j][1] = val << 1;
780 s->mv[i][j][1] = val;
781 dprintf("fmy=%d\n", val);
784 s->mv_type = MV_TYPE_16X16;
785 s->field_select[i][0] = get_bits1(&s->gb);
787 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
788 s->last_mv[i][0][k]);
789 s->last_mv[i][0][k] = val;
790 s->last_mv[i][1][k] = val;
791 s->mv[i][0][k] = val;
797 int dmx, dmy, mx, my, m;
799 mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
800 s->last_mv[i][0][0]);
801 s->last_mv[i][0][0] = mx;
802 s->last_mv[i][1][0] = mx;
804 my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
805 s->last_mv[i][0][1] >> 1);
807 s->mv_type = MV_TYPE_DMV;
808 /* XXX: totally broken */
809 if (s->picture_structure == PICT_FRAME) {
810 s->last_mv[i][0][1] = my << 1;
811 s->last_mv[i][1][1] = my << 1;
813 m = s->top_field_first ? 1 : 3;
814 /* top -> top pred */
816 s->mv[i][0][1] = my << 1;
817 s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
818 s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
821 s->mv[i][2][1] = my << 1;
822 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
823 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
825 s->last_mv[i][0][1] = my;
826 s->last_mv[i][1][1] = my;
829 s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
830 s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
831 /* + 2 * cur_field */;
840 if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
841 skip_bits1(&s->gb); /* marker */
844 if (mb_type & MB_PAT) {
845 cbp = get_vlc(&s->gb, &mb_pat_vlc);
850 dprintf("cbp=%x\n", cbp);
855 if (cbp & (1 << (5 - i))) {
856 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
862 if (cbp & (1 << (5 - i))) {
863 if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
870 if (cbp & (1 << (5 - i))) {
871 if (mpeg1_decode_block(s, block[i], i) < 0)
879 /* as h263, but only 17 codes */
880 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
882 int code, sign, val, m, l, shift;
884 code = get_vlc(&s->gb, &mv_vlc);
891 sign = get_bits1(&s->gb);
893 val = (code - 1) << shift;
895 val |= get_bits(&s->gb, shift);
901 /* modulo decoding */
902 l = (1 << shift) * 16;
906 } else if (val >= l) {
912 static inline int decode_dc(MpegEncContext *s, int component)
916 if (component == 0) {
917 code = get_vlc(&s->gb, &dc_lum_vlc);
919 code = get_vlc(&s->gb, &dc_chroma_vlc);
926 diff = get_bits(&s->gb, code);
927 if ((diff & (1 << (code - 1))) == 0)
928 diff = (-1 << code) | (diff + 1);
933 static int mpeg1_decode_block(MpegEncContext *s,
937 int level, dc, diff, i, j, run;
939 RLTable *rl = &rl_mpeg1;
943 component = (n <= 3 ? 0 : n - 4 + 1);
944 diff = decode_dc(s, component);
947 dc = s->last_dc[component];
949 s->last_dc[component] = dc;
951 dprintf("dc=%d diff=%d\n", dc, diff);
958 /* special case for the first coef. no need to add a second vlc table */
960 SHOW_BITS(&s->gb, v, 2);
963 level = 1 - ((v & 1) << 1);
965 RESTORE_BITS(&s->gb);
968 RESTORE_BITS(&s->gb);
971 /* now quantify & encode AC coefs */
973 code = get_vlc(&s->gb, &rl->vlc);
979 } else if (code == 111) {
981 run = get_bits(&s->gb, 6);
982 level = get_bits(&s->gb, 8);
983 level = (level << 24) >> 24;
985 level = get_bits(&s->gb, 8) - 256;
986 } else if (level == 0) {
987 level = get_bits(&s->gb, 8);
990 run = rl->table_run[code];
991 level = rl->table_level[code];
992 if (get_bits1(&s->gb))
999 dprintf("%d: run=%d level=%d\n", n, run, level);
1000 j = zigzag_direct[i];
1004 s->block_last_index[n] = i-1;
1008 /* Also does unquantization here, since I will never support mpeg2
1010 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
1014 int level, i, j, run;
1016 RLTable *rl = &rl_mpeg1;
1017 const UINT8 *scan_table;
1018 const UINT16 *matrix;
1021 if (s->alternate_scan)
1022 scan_table = ff_alternate_vertical_scan;
1024 scan_table = zigzag_direct;
1033 matrix = s->inter_matrix;
1035 matrix = s->chroma_inter_matrix;
1037 /* special case for the first coef. no need to add a second vlc table */
1039 SHOW_BITS(&s->gb, v, 2);
1042 level = 1 - ((v & 1) << 1);
1044 RESTORE_BITS(&s->gb);
1047 RESTORE_BITS(&s->gb);
1050 /* now quantify & encode AC coefs */
1052 code = get_vlc(&s->gb, &rl->vlc);
1057 } else if (code == 111) {
1059 run = get_bits(&s->gb, 6);
1060 level = get_bits(&s->gb, 12);
1061 level = (level << 20) >> 20;
1063 run = rl->table_run[code];
1064 level = rl->table_level[code];
1065 if (get_bits1(&s->gb))
1073 dprintf("%d: run=%d level=%d\n", n, run, level);
1076 level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1078 level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1081 /* XXX: is it really necessary to saturate since the encoder
1082 knows whats going on ? */
1087 block[63] ^= (mismatch & 1);
1088 s->block_last_index[n] = i;
1092 static int mpeg2_decode_block_intra(MpegEncContext *s,
1096 int level, dc, diff, i, j, run;
1097 int code, component;
1099 const UINT8 *scan_table;
1100 const UINT16 *matrix;
1103 if (s->alternate_scan)
1104 scan_table = ff_alternate_vertical_scan;
1106 scan_table = zigzag_direct;
1109 component = (n <= 3 ? 0 : n - 4 + 1);
1110 diff = decode_dc(s, component);
1113 dc = s->last_dc[component];
1115 s->last_dc[component] = dc;
1116 block[0] = dc << (3 - s->intra_dc_precision);
1117 dprintf("dc=%d\n", block[0]);
1118 mismatch = block[0] ^ 1;
1120 if (s->intra_vlc_format)
1125 matrix = s->intra_matrix;
1127 matrix = s->chroma_intra_matrix;
1129 /* now quantify & encode AC coefs */
1131 code = get_vlc(&s->gb, &rl->vlc);
1136 } else if (code == 111) {
1138 run = get_bits(&s->gb, 6);
1139 level = get_bits(&s->gb, 12);
1140 level = (level << 20) >> 20;
1142 run = rl->table_run[code];
1143 level = rl->table_level[code];
1144 if (get_bits1(&s->gb))
1151 dprintf("%d: run=%d level=%d\n", n, run, level);
1152 level = (level * s->qscale * matrix[j]) / 16;
1153 /* XXX: is it really necessary to saturate since the encoder
1154 knows whats going on ? */
1159 block[63] ^= (mismatch & 1);
1160 s->block_last_index[n] = i;
1164 /* compressed picture size */
1165 #define PICTURE_BUFFER_SIZE 100000
1167 typedef struct Mpeg1Context {
1168 MpegEncContext mpeg_enc_ctx;
1169 UINT32 header_state;
1170 int start_code; /* current start code */
1171 UINT8 buffer[PICTURE_BUFFER_SIZE];
1174 int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1175 int repeat_field; /* true if we must repeat the field */
1178 static int mpeg_decode_init(AVCodecContext *avctx)
1180 Mpeg1Context *s = avctx->priv_data;
1182 s->header_state = 0xff;
1183 s->mpeg_enc_ctx_allocated = 0;
1184 s->buffer_size = PICTURE_BUFFER_SIZE;
1186 s->buf_ptr = s->buffer;
1187 s->mpeg_enc_ctx.picture_number = 0;
1188 s->repeat_field = 0;
1189 s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1190 avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1194 /* return the 8 bit start code value and update the search
1195 state. Return -1 if no start code found */
1196 static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end,
1197 UINT32 *header_state)
1200 unsigned int state, v;
1203 state = *header_state;
1204 buf_ptr = *pbuf_ptr;
1205 while (buf_ptr < buf_end) {
1207 if (state == 0x000001) {
1208 state = ((state << 8) | v) & 0xffffff;
1212 state = ((state << 8) | v) & 0xffffff;
1216 *pbuf_ptr = buf_ptr;
1217 *header_state = state;
1221 static int mpeg1_decode_picture(AVCodecContext *avctx,
1222 UINT8 *buf, int buf_size)
1224 Mpeg1Context *s1 = avctx->priv_data;
1225 MpegEncContext *s = &s1->mpeg_enc_ctx;
1228 init_get_bits(&s->gb, buf, buf_size);
1230 ref = get_bits(&s->gb, 10); /* temporal ref */
1231 s->pict_type = get_bits(&s->gb, 3);
1232 dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1233 skip_bits(&s->gb, 16);
1234 if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1235 s->full_pel[0] = get_bits1(&s->gb);
1236 f_code = get_bits(&s->gb, 3);
1239 s->mpeg_f_code[0][0] = f_code;
1240 s->mpeg_f_code[0][1] = f_code;
1242 if (s->pict_type == B_TYPE) {
1243 s->full_pel[1] = get_bits1(&s->gb);
1244 f_code = get_bits(&s->gb, 3);
1247 s->mpeg_f_code[1][0] = f_code;
1248 s->mpeg_f_code[1][1] = f_code;
1256 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1258 int horiz_size_ext, vert_size_ext;
1259 int bit_rate_ext, vbv_buf_ext, low_delay;
1260 int frame_rate_ext_n, frame_rate_ext_d;
1262 skip_bits(&s->gb, 8); /* profil and level */
1263 s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1264 skip_bits(&s->gb, 2); /* chroma_format */
1265 horiz_size_ext = get_bits(&s->gb, 2);
1266 vert_size_ext = get_bits(&s->gb, 2);
1267 s->width |= (horiz_size_ext << 12);
1268 s->height |= (vert_size_ext << 12);
1269 bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */
1270 s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1271 skip_bits1(&s->gb); /* marker */
1272 vbv_buf_ext = get_bits(&s->gb, 8);
1273 low_delay = get_bits1(&s->gb);
1274 frame_rate_ext_n = get_bits(&s->gb, 2);
1275 frame_rate_ext_d = get_bits(&s->gb, 5);
1276 if (frame_rate_ext_d >= 1)
1277 s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1278 dprintf("sequence extension\n");
1282 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1286 dprintf("matrix extension\n");
1288 if (get_bits1(&s->gb)) {
1290 v = get_bits(&s->gb, 8);
1291 j = zigzag_direct[i];
1292 s->intra_matrix[j] = v;
1293 s->chroma_intra_matrix[j] = v;
1296 if (get_bits1(&s->gb)) {
1298 v = get_bits(&s->gb, 8);
1299 j = zigzag_direct[i];
1300 s->inter_matrix[j] = v;
1301 s->chroma_inter_matrix[j] = v;
1304 if (get_bits1(&s->gb)) {
1306 v = get_bits(&s->gb, 8);
1307 j = zigzag_direct[i];
1308 s->chroma_intra_matrix[j] = v;
1311 if (get_bits1(&s->gb)) {
1313 v = get_bits(&s->gb, 8);
1314 j = zigzag_direct[i];
1315 s->chroma_inter_matrix[j] = v;
1320 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1322 s->full_pel[0] = s->full_pel[1] = 0;
1323 s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1324 s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1325 s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1326 s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1327 s->intra_dc_precision = get_bits(&s->gb, 2);
1328 s->picture_structure = get_bits(&s->gb, 2);
1329 s->top_field_first = get_bits1(&s->gb);
1330 s->frame_pred_frame_dct = get_bits1(&s->gb);
1331 s->concealment_motion_vectors = get_bits1(&s->gb);
1332 s->q_scale_type = get_bits1(&s->gb);
1333 s->intra_vlc_format = get_bits1(&s->gb);
1334 s->alternate_scan = get_bits1(&s->gb);
1335 s->repeat_first_field = get_bits1(&s->gb);
1336 s->chroma_420_type = get_bits1(&s->gb);
1337 s->progressive_frame = get_bits1(&s->gb);
1338 /* composite display not parsed */
1339 dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1340 dprintf("picture_structure=%d\n", s->picture_structure);
1341 dprintf("top field first=%d\n", s->top_field_first);
1342 dprintf("repeat first field=%d\n", s->repeat_first_field);
1343 dprintf("conceal=%d\n", s->concealment_motion_vectors);
1344 dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1345 dprintf("alternate_scan=%d\n", s->alternate_scan);
1346 dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1347 dprintf("progressive_frame=%d\n", s->progressive_frame);
1350 static void mpeg_decode_extension(AVCodecContext *avctx,
1351 UINT8 *buf, int buf_size)
1353 Mpeg1Context *s1 = avctx->priv_data;
1354 MpegEncContext *s = &s1->mpeg_enc_ctx;
1357 init_get_bits(&s->gb, buf, buf_size);
1359 ext_type = get_bits(&s->gb, 4);
1363 mpeg_decode_sequence_extension(s);
1366 /* quant matrix extension */
1367 mpeg_decode_quant_matrix_extension(s);
1370 /* picture extension */
1371 mpeg_decode_picture_coding_extension(s);
1376 /* return 1 if end of frame */
1377 static int mpeg_decode_slice(AVCodecContext *avctx,
1380 UINT8 *buf, int buf_size)
1382 Mpeg1Context *s1 = avctx->priv_data;
1383 MpegEncContext *s = &s1->mpeg_enc_ctx;
1386 start_code = (start_code - 1) & 0xff;
1387 if (start_code >= s->mb_height)
1389 s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1390 s->last_dc[1] = s->last_dc[0];
1391 s->last_dc[2] = s->last_dc[0];
1392 memset(s->last_mv, 0, sizeof(s->last_mv));
1394 s->mb_y = start_code;
1396 /* start frame decoding */
1397 if (s->first_slice) {
1402 init_get_bits(&s->gb, buf, buf_size);
1404 s->qscale = get_qscale(s);
1405 /* extra slice info */
1406 while (get_bits1(&s->gb) != 0) {
1407 skip_bits(&s->gb, 8);
1411 clear_blocks(s->block[0]);
1413 ret = mpeg_decode_mb(s, s->block);
1414 dprintf("ret=%d\n", ret);
1419 MPV_decode_mb(s, s->block);
1423 /* end of slice reached */
1424 if (s->mb_x == (s->mb_width - 1) &&
1425 s->mb_y == (s->mb_height - 1)) {
1431 /* XXX: incorrect reported qscale for mpeg2 */
1432 if (s->pict_type == B_TYPE) {
1433 picture = s->current_picture;
1434 avctx->quality = s->qscale;
1436 /* latency of 1 frame for I and P frames */
1437 /* XXX: use another variable than picture_number */
1438 if (s->picture_number == 0) {
1441 picture = s->last_picture;
1442 avctx->quality = s->last_qscale;
1444 s->last_qscale = s->qscale;
1445 s->picture_number++;
1448 pict->data[0] = picture[0];
1449 pict->data[1] = picture[1];
1450 pict->data[2] = picture[2];
1451 pict->linesize[0] = s->linesize;
1452 pict->linesize[1] = s->linesize / 2;
1453 pict->linesize[2] = s->linesize / 2;
1463 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1464 UINT8 *buf, int buf_size)
1466 Mpeg1Context *s1 = avctx->priv_data;
1467 MpegEncContext *s = &s1->mpeg_enc_ctx;
1468 int width, height, i, v, j;
1470 init_get_bits(&s->gb, buf, buf_size);
1472 width = get_bits(&s->gb, 12);
1473 height = get_bits(&s->gb, 12);
1474 skip_bits(&s->gb, 4);
1475 s->frame_rate_index = get_bits(&s->gb, 4);
1476 if (s->frame_rate_index == 0)
1478 s->bit_rate = get_bits(&s->gb, 18) * 400;
1479 if (get_bits1(&s->gb) == 0) /* marker */
1481 if (width <= 0 || height <= 0 ||
1482 (width % 2) != 0 || (height % 2) != 0)
1484 if (width != s->width ||
1485 height != s->height) {
1486 /* start new mpeg1 context decoding */
1487 s->out_format = FMT_MPEG1;
1488 if (s1->mpeg_enc_ctx_allocated) {
1493 s->has_b_frames = 1;
1495 avctx->width = width;
1496 avctx->height = height;
1497 avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1498 s->frame_rate = avctx->frame_rate;
1499 avctx->bit_rate = s->bit_rate;
1501 if (MPV_common_init(s) < 0)
1504 s1->mpeg_enc_ctx_allocated = 1;
1507 skip_bits(&s->gb, 10); /* vbv_buffer_size */
1508 skip_bits(&s->gb, 1);
1511 if (get_bits1(&s->gb)) {
1513 v = get_bits(&s->gb, 8);
1514 j = zigzag_direct[i];
1515 s->intra_matrix[j] = v;
1516 s->chroma_intra_matrix[j] = v;
1519 dprintf("intra matrix present\n");
1521 dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1526 v = default_intra_matrix[i];
1527 s->intra_matrix[i] = v;
1528 s->chroma_intra_matrix[i] = v;
1531 if (get_bits1(&s->gb)) {
1533 v = get_bits(&s->gb, 8);
1534 j = zigzag_direct[i];
1535 s->inter_matrix[j] = v;
1536 s->chroma_inter_matrix[j] = v;
1539 dprintf("non intra matrix present\n");
1541 dprintf(" %d", s->inter_matrix[zigzag_direct[i]]);
1546 v = default_non_intra_matrix[i];
1547 s->inter_matrix[i] = v;
1548 s->chroma_inter_matrix[i] = v;
1552 /* we set mpeg2 parameters so that it emulates mpeg1 */
1553 s->progressive_sequence = 1;
1554 s->progressive_frame = 1;
1555 s->picture_structure = PICT_FRAME;
1556 s->frame_pred_frame_dct = 1;
1561 /* handle buffering and image synchronisation */
1562 static int mpeg_decode_frame(AVCodecContext *avctx,
1563 void *data, int *data_size,
1564 UINT8 *buf, int buf_size)
1566 Mpeg1Context *s = avctx->priv_data;
1567 UINT8 *buf_end, *buf_ptr, *buf_start;
1568 int len, start_code_found, ret, code, start_code, input_size;
1569 AVPicture *picture = data;
1570 MpegEncContext *s2 = &s->mpeg_enc_ctx;
1572 dprintf("fill_buffer\n");
1576 /* special case for last picture */
1577 if (buf_size == 0) {
1578 if (s2->picture_number > 0) {
1579 picture->data[0] = s2->next_picture[0];
1580 picture->data[1] = s2->next_picture[1];
1581 picture->data[2] = s2->next_picture[2];
1582 picture->linesize[0] = s2->linesize;
1583 picture->linesize[1] = s2->linesize / 2;
1584 picture->linesize[2] = s2->linesize / 2;
1585 *data_size = sizeof(AVPicture);
1591 buf_end = buf + buf_size;
1594 if (s->repeat_field % 2 == 1) {
1596 //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1597 // s2->picture_number, s->repeat_field);
1598 if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
1599 *data_size = sizeof(AVPicture);
1604 while (buf_ptr < buf_end) {
1605 buf_start = buf_ptr;
1606 /* find start next code */
1607 code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1609 start_code_found = 1;
1611 start_code_found = 0;
1613 /* copy to buffer */
1614 len = buf_ptr - buf_start;
1615 if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1616 /* data too big : flush */
1617 s->buf_ptr = s->buffer;
1618 if (start_code_found)
1619 s->start_code = code;
1621 memcpy(s->buf_ptr, buf_start, len);
1624 if (start_code_found) {
1625 /* prepare data for next start code */
1626 input_size = s->buf_ptr - s->buffer;
1627 start_code = s->start_code;
1628 s->buf_ptr = s->buffer;
1629 s->start_code = code;
1630 switch(start_code) {
1631 case SEQ_START_CODE:
1632 mpeg1_decode_sequence(avctx, s->buffer,
1636 case PICTURE_START_CODE:
1637 /* we have a complete image : we try to decompress it */
1638 mpeg1_decode_picture(avctx,
1639 s->buffer, input_size);
1641 case EXT_START_CODE:
1642 mpeg_decode_extension(avctx,
1643 s->buffer, input_size);
1646 if (start_code >= SLICE_MIN_START_CODE &&
1647 start_code <= SLICE_MAX_START_CODE) {
1648 ret = mpeg_decode_slice(avctx, picture,
1649 start_code, s->buffer, input_size);
1651 /* got a picture: exit */
1652 /* first check if we must repeat the frame */
1653 avctx->repeat_pict = 0;
1655 if (s2->progressive_frame && s2->repeat_first_field) {
1656 //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1657 //s2->repeat_first_field = 0;
1658 //s2->progressive_frame = 0;
1659 if (++s->repeat_field > 2)
1660 s->repeat_field = 0;
1661 avctx->repeat_pict = 1;
1664 if (s2->repeat_first_field) {
1665 if (s2->progressive_sequence) {
1666 if (s2->top_field_first)
1667 avctx->repeat_pict = 4;
1669 avctx->repeat_pict = 2;
1670 } else if (s2->progressive_frame) {
1671 avctx->repeat_pict = 1;
1674 *data_size = sizeof(AVPicture);
1684 return buf_ptr - buf;
1687 static int mpeg_decode_end(AVCodecContext *avctx)
1689 Mpeg1Context *s = avctx->priv_data;
1691 if (s->mpeg_enc_ctx_allocated)
1692 MPV_common_end(&s->mpeg_enc_ctx);
1696 AVCodec mpeg_decoder = {
1699 CODEC_ID_MPEG1VIDEO,
1700 sizeof(Mpeg1Context),