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.
21 #include "mpegvideo.h"
23 #include "mpeg12data.h"
30 #define dprintf(fmt,args...) printf(fmt, ## args)
32 #define dprintf(fmt,args...)
37 inline void dprintf(const char* fmt,...) {}
42 #define SEQ_END_CODE 0x000001b7
43 #define SEQ_START_CODE 0x000001b3
44 #define GOP_START_CODE 0x000001b8
45 #define PICTURE_START_CODE 0x00000100
46 #define SLICE_MIN_START_CODE 0x00000101
47 #define SLICE_MAX_START_CODE 0x000001af
48 #define EXT_START_CODE 0x000001b5
49 #define USER_START_CODE 0x000001b2
51 static void mpeg1_encode_block(MpegEncContext *s,
54 static void mpeg1_encode_motion(MpegEncContext *s, int val);
55 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
56 static int mpeg1_decode_block(MpegEncContext *s,
59 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
62 static int mpeg2_decode_block_intra(MpegEncContext *s,
65 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
67 static void put_header(MpegEncContext *s, int header)
69 align_put_bits(&s->pb);
70 put_bits(&s->pb, 32, header);
73 /* put sequence header if needed */
74 static void mpeg1_encode_sequence_header(MpegEncContext *s)
76 unsigned int vbv_buffer_size;
81 if ((s->picture_number % s->gop_size) == 0) {
82 /* mpeg1 header repeated every gop */
83 put_header(s, SEQ_START_CODE);
85 /* search closest frame rate */
88 s->frame_rate_index = 0;
91 d = abs(s->frame_rate - frame_rate_tab[i]);
94 s->frame_rate_index = i;
99 put_bits(&s->pb, 12, s->width);
100 put_bits(&s->pb, 12, s->height);
101 put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
102 put_bits(&s->pb, 4, s->frame_rate_index);
103 v = s->bit_rate / 400;
106 put_bits(&s->pb, 18, v);
107 put_bits(&s->pb, 1, 1); /* marker */
108 /* vbv buffer size: slightly greater than an I frame. We add
109 some margin just in case */
110 vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
111 put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
112 put_bits(&s->pb, 1, 1); /* constrained parameter flag */
113 put_bits(&s->pb, 1, 0); /* no custom intra matrix */
114 put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
116 put_header(s, GOP_START_CODE);
117 put_bits(&s->pb, 1, 0); /* do drop frame */
118 /* time code : we must convert from the real frame rate to a
119 fake mpeg frame rate in case of low frame rate */
120 fps = frame_rate_tab[s->frame_rate_index];
121 time_code = s->fake_picture_number * FRAME_RATE_BASE;
122 s->gop_picture_number = s->fake_picture_number;
123 put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
124 put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
125 put_bits(&s->pb, 1, 1);
126 put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
127 put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
128 put_bits(&s->pb, 1, 1); /* closed gop */
129 put_bits(&s->pb, 1, 0); /* broken link */
132 if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
133 /* insert empty P pictures to slow down to the desired
134 frame rate. Each fake pictures takes about 20 bytes */
135 fps = frame_rate_tab[s->frame_rate_index];
136 n = ((s->picture_number * fps) / s->frame_rate) - 1;
137 while (s->fake_picture_number < n) {
138 mpeg1_skip_picture(s, s->fake_picture_number -
139 s->gop_picture_number);
140 s->fake_picture_number++;
144 s->fake_picture_number++;
148 /* insert a fake P picture */
149 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
151 unsigned int mb_incr;
153 /* mpeg1 picture header */
154 put_header(s, PICTURE_START_CODE);
155 /* temporal reference */
156 put_bits(&s->pb, 10, pict_num & 0x3ff);
158 put_bits(&s->pb, 3, P_TYPE);
159 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
161 put_bits(&s->pb, 1, 1); /* integer coordinates */
162 put_bits(&s->pb, 3, 1); /* forward_f_code */
164 put_bits(&s->pb, 1, 0); /* extra bit picture */
167 put_header(s, SLICE_MIN_START_CODE);
168 put_bits(&s->pb, 5, 1); /* quantizer scale */
169 put_bits(&s->pb, 1, 0); /* slice extra information */
172 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
173 mbAddrIncrTable[mb_incr - 1][0]);
175 /* empty macroblock */
176 put_bits(&s->pb, 3, 1); /* motion only */
178 /* zero motion x & y */
179 put_bits(&s->pb, 1, 1);
180 put_bits(&s->pb, 1, 1);
182 /* output a number of empty slice */
183 mb_incr = s->mb_width * s->mb_height - 1;
184 while (mb_incr > 33) {
185 put_bits(&s->pb, 11, 0x008);
188 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
189 mbAddrIncrTable[mb_incr - 1][0]);
191 /* empty macroblock */
192 put_bits(&s->pb, 3, 1); /* motion only */
194 /* zero motion x & y */
195 put_bits(&s->pb, 1, 1);
196 put_bits(&s->pb, 1, 1);
199 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
207 mpeg1_encode_sequence_header(s);
209 /* mpeg1 picture header */
210 put_header(s, PICTURE_START_CODE);
211 /* temporal reference */
212 put_bits(&s->pb, 10, (s->fake_picture_number -
213 s->gop_picture_number) & 0x3ff);
215 put_bits(&s->pb, 3, s->pict_type);
216 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
218 if (s->pict_type == P_TYPE) {
219 put_bits(&s->pb, 1, 0); /* half pel coordinates */
220 put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
223 put_bits(&s->pb, 1, 0); /* extra bit picture */
226 put_header(s, SLICE_MIN_START_CODE);
227 put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
228 put_bits(&s->pb, 1, 0); /* slice extra information */
231 void mpeg1_encode_mb(MpegEncContext *s,
232 DCTELEM block[6][64],
233 int motion_x, int motion_y)
235 int mb_incr, i, cbp, mb_x, mb_y;
243 if (s->block_last_index[i] >= 0)
247 /* skip macroblock, except if first or last macroblock of a slice */
248 if ((cbp | motion_x | motion_y) == 0 &&
249 (!((mb_x | mb_y) == 0 ||
250 (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
254 mb_incr = s->mb_incr;
256 while (mb_incr > 33) {
257 put_bits(&s->pb, 11, 0x008);
260 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
261 mbAddrIncrTable[mb_incr - 1][0]);
263 if (s->pict_type == I_TYPE) {
264 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
267 put_bits(&s->pb, 5, 0x03);
270 if (motion_x == 0 && motion_y == 0) {
271 put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
272 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
274 put_bits(&s->pb, 1, 1); /* motion + cbp */
275 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
276 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
277 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
280 put_bits(&s->pb, 3, 1); /* motion only */
281 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
282 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
287 if (cbp & (1 << (5 - i))) {
288 mpeg1_encode_block(s, block[i], i);
293 s->last_mv[0][0][0] = motion_x;
294 s->last_mv[0][0][1] = motion_y;
297 static void mpeg1_encode_motion(MpegEncContext *s, int val)
299 int code, bit_size, l, m, bits, range, sign;
305 mbMotionVectorTable[0][1],
306 mbMotionVectorTable[0][0]);
308 bit_size = s->f_code - 1;
309 range = 1 << bit_size;
310 /* modulo encoding */
315 } else if (val >= l) {
321 code = (val >> bit_size) + 1;
322 bits = val & (range - 1);
327 code = (val >> bit_size) + 1;
328 bits = val & (range - 1);
332 mbMotionVectorTable[code][1],
333 mbMotionVectorTable[code][0]);
334 put_bits(&s->pb, 1, sign);
336 put_bits(&s->pb, bit_size, bits);
341 static inline void encode_dc(MpegEncContext *s, int diff, int component)
346 index = vlc_dc_table[adiff];
347 if (component == 0) {
348 put_bits(&s->pb, vlc_dc_lum_bits[index], vlc_dc_lum_code[index]);
350 put_bits(&s->pb, vlc_dc_chroma_bits[index], vlc_dc_chroma_code[index]);
353 put_bits(&s->pb, index, (diff & ((1 << index) - 1)));
354 } else if (diff < 0) {
355 put_bits(&s->pb, index, ((diff - 1) & ((1 << index) - 1)));
359 static void mpeg1_encode_block(MpegEncContext *s,
363 int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
365 RLTable *rl = &rl_mpeg1;
367 last_index = s->block_last_index[n];
371 component = (n <= 3 ? 0 : n - 4 + 1);
372 dc = block[0]; /* overflow is impossible */
373 diff = dc - s->last_dc[component];
374 encode_dc(s, diff, component);
375 s->last_dc[component] = dc;
378 /* encode the first coefficient : needs to be done here because
379 it is handled slightly differently */
381 if (abs(level) == 1) {
382 code = ((UINT32)level >> 31); /* the sign bit */
383 put_bits(&s->pb, 2, code | 0x02);
392 /* now quantify & encode AC coefs */
393 last_non_zero = i - 1;
394 for(;i<=last_index;i++) {
395 j = zigzag_direct[i];
400 dprintf("level[%d]=%d\n", i, level);
402 /* encode using VLC */
404 run = i - last_non_zero - 1;
411 code = get_rl_index(rl, 0, run, alevel);
412 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
414 put_bits(&s->pb, 1, sign);
416 /* escape: only clip in this case */
417 put_bits(&s->pb, 6, run);
419 put_bits(&s->pb, 8, level & 0xff);
422 put_bits(&s->pb, 16, 0x8001 + level + 255);
424 put_bits(&s->pb, 16, level & 0xffff);
432 put_bits(&s->pb, 2, 0x2);
435 /******************************************/
438 static VLC dc_lum_vlc;
439 static VLC dc_chroma_vlc;
441 static VLC mbincr_vlc;
442 static VLC mb_ptype_vlc;
443 static VLC mb_btype_vlc;
444 static VLC mb_pat_vlc;
446 void mpeg1_init_vlc(MpegEncContext *s)
452 init_vlc(&dc_lum_vlc, 9, 12,
453 vlc_dc_lum_bits, 1, 1,
454 vlc_dc_lum_code, 2, 2);
455 init_vlc(&dc_chroma_vlc, 9, 12,
456 vlc_dc_chroma_bits, 1, 1,
457 vlc_dc_chroma_code, 2, 2);
458 init_vlc(&mv_vlc, 9, 17,
459 &mbMotionVectorTable[0][1], 2, 1,
460 &mbMotionVectorTable[0][0], 2, 1);
461 init_vlc(&mbincr_vlc, 9, 35,
462 &mbAddrIncrTable[0][1], 2, 1,
463 &mbAddrIncrTable[0][0], 2, 1);
464 init_vlc(&mb_pat_vlc, 9, 63,
465 &mbPatTable[0][1], 2, 1,
466 &mbPatTable[0][0], 2, 1);
468 init_vlc(&mb_ptype_vlc, 6, 32,
469 &table_mb_ptype[0][1], 2, 1,
470 &table_mb_ptype[0][0], 2, 1);
471 init_vlc(&mb_btype_vlc, 6, 32,
472 &table_mb_btype[0][1], 2, 1,
473 &table_mb_btype[0][0], 2, 1);
476 /* cannot use generic init because we must add the EOB code */
477 init_vlc(&rl_mpeg1.vlc, 9, rl_mpeg1.n + 2,
478 &rl_mpeg1.table_vlc[0][1], 4, 2,
479 &rl_mpeg1.table_vlc[0][0], 4, 2);
480 init_vlc(&rl_mpeg2.vlc, 9, rl_mpeg2.n + 2,
481 &rl_mpeg2.table_vlc[0][1], 4, 2,
482 &rl_mpeg2.table_vlc[0][0], 4, 2);
486 static inline int get_dmv(MpegEncContext *s)
488 if(get_bits1(&s->gb))
489 return 1 - (get_bits1(&s->gb) << 1);
494 static inline int get_qscale(MpegEncContext *s)
498 if (s->q_scale_type) {
499 qscale = non_linear_qscale[get_bits(&s->gb, 5)];
501 qscale = get_bits(&s->gb, 5) << 1;
504 /* for mpeg1, we use the generic unquant code */
505 qscale = get_bits(&s->gb, 5);
510 /* motion type (for mpeg2) */
516 static int mpeg_decode_mb(MpegEncContext *s,
517 DCTELEM block[6][64])
519 int i, j, k, cbp, val, code, mb_type, motion_type;
521 /* skip mb handling */
522 if (s->mb_incr == 0) {
523 /* read again increment */
526 code = get_vlc(&s->gb, &mbincr_vlc);
528 return 1; /* error = end of slice */
533 /* otherwise, stuffing, nothing to do */
540 if (++s->mb_x >= s->mb_width) {
542 if (s->mb_y >= (s->mb_height - 1))
546 dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
548 if (--s->mb_incr != 0) {
552 s->block_last_index[i] = -1;
553 s->mv_type = MV_TYPE_16X16;
554 if (s->pict_type == P_TYPE) {
555 /* if P type, zero motion vector is implied */
556 s->mv_dir = MV_DIR_FORWARD;
557 s->mv[0][0][0] = s->mv[0][0][1] = 0;
558 s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
559 s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
561 /* if B type, reuse previous vectors and directions */
562 s->mv[0][0][0] = s->last_mv[0][0][0];
563 s->mv[0][0][1] = s->last_mv[0][0][1];
564 s->mv[1][0][0] = s->last_mv[1][0][0];
565 s->mv[1][0][1] = s->last_mv[1][0][1];
571 switch(s->pict_type) {
574 if (get_bits1(&s->gb) == 0) {
575 if (get_bits1(&s->gb) == 0)
577 mb_type = MB_QUANT | MB_INTRA;
583 mb_type = get_vlc(&s->gb, &mb_ptype_vlc);
588 mb_type = get_vlc(&s->gb, &mb_btype_vlc);
593 dprintf("mb_type=%x\n", mb_type);
594 motion_type = 0; /* avoid warning */
595 if (mb_type & (MB_FOR|MB_BACK)) {
596 /* get additionnal motion vector type */
597 if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct)
598 motion_type = MT_FRAME;
600 motion_type = get_bits(&s->gb, 2);
602 /* compute dct type */
603 if (s->picture_structure == PICT_FRAME &&
604 !s->frame_pred_frame_dct &&
605 (mb_type & (MB_PAT | MB_INTRA))) {
606 s->interlaced_dct = get_bits1(&s->gb);
608 if (s->interlaced_dct)
609 printf("interlaced_dct\n");
612 s->interlaced_dct = 0; /* frame based */
615 if (mb_type & MB_QUANT) {
616 s->qscale = get_qscale(s);
618 if (mb_type & MB_INTRA) {
619 if (s->concealment_motion_vectors) {
620 /* just parse them */
621 if (s->picture_structure != PICT_FRAME)
622 skip_bits1(&s->gb); /* field select */
623 mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
624 mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
628 memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
633 /* special case of implicit zero motion vector */
634 if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
635 s->mv_dir = MV_DIR_FORWARD;
636 s->mv_type = MV_TYPE_16X16;
637 s->last_mv[0][0][0] = 0;
638 s->last_mv[0][0][1] = 0;
639 s->last_mv[0][1][0] = 0;
640 s->last_mv[0][1][1] = 0;
643 } else if (mb_type & (MB_FOR | MB_BACK)) {
647 if (mb_type & (MB_FOR >> i)) {
648 s->mv_dir |= (MV_DIR_FORWARD >> i);
649 dprintf("motion_type=%d\n", motion_type);
650 switch(motion_type) {
651 case MT_FRAME: /* or MT_16X8 */
652 if (s->picture_structure == PICT_FRAME) {
654 s->mv_type = MV_TYPE_16X16;
656 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
657 s->last_mv[i][0][k]);
658 s->last_mv[i][0][k] = val;
659 s->last_mv[i][1][k] = val;
660 /* full_pel: only for mpeg1 */
663 s->mv[i][0][k] = val;
664 dprintf("mv%d: %d\n", k, val);
668 s->mv_type = MV_TYPE_16X8;
670 s->field_select[i][j] = get_bits1(&s->gb);
672 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
673 s->last_mv[i][j][k]);
674 s->last_mv[i][j][k] = val;
675 s->mv[i][j][k] = val;
681 if (s->picture_structure == PICT_FRAME) {
682 s->mv_type = MV_TYPE_FIELD;
684 s->field_select[i][j] = get_bits1(&s->gb);
685 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
686 s->last_mv[i][j][0]);
687 s->last_mv[i][j][0] = val;
688 s->mv[i][j][0] = val;
689 dprintf("fmx=%d\n", val);
690 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
691 s->last_mv[i][j][1] >> 1);
692 s->last_mv[i][j][1] = val << 1;
693 s->mv[i][j][1] = val;
694 dprintf("fmy=%d\n", val);
697 s->mv_type = MV_TYPE_16X16;
698 s->field_select[i][0] = get_bits1(&s->gb);
700 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
701 s->last_mv[i][0][k]);
702 s->last_mv[i][0][k] = val;
703 s->last_mv[i][1][k] = val;
704 s->mv[i][0][k] = val;
710 int dmx, dmy, mx, my, m;
712 mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
713 s->last_mv[i][0][0]);
714 s->last_mv[i][0][0] = mx;
715 s->last_mv[i][1][0] = mx;
717 my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
718 s->last_mv[i][0][1] >> 1);
720 s->mv_type = MV_TYPE_DMV;
721 /* XXX: totally broken */
722 if (s->picture_structure == PICT_FRAME) {
723 s->last_mv[i][0][1] = my << 1;
724 s->last_mv[i][1][1] = my << 1;
726 m = s->top_field_first ? 1 : 3;
727 /* top -> top pred */
729 s->mv[i][0][1] = my << 1;
730 s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
731 s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
734 s->mv[i][2][1] = my << 1;
735 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
736 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
738 s->last_mv[i][0][1] = my;
739 s->last_mv[i][1][1] = my;
742 s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
743 s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
744 /* + 2 * cur_field */;
753 if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
754 skip_bits1(&s->gb); /* marker */
757 if (mb_type & MB_PAT) {
758 cbp = get_vlc(&s->gb, &mb_pat_vlc);
763 dprintf("cbp=%x\n", cbp);
768 if (cbp & (1 << (5 - i))) {
769 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
775 if (cbp & (1 << (5 - i))) {
776 if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
783 if (cbp & (1 << (5 - i))) {
784 if (mpeg1_decode_block(s, block[i], i) < 0)
792 /* as h263, but only 17 codes */
793 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
795 int code, sign, val, m, l, shift;
797 code = get_vlc(&s->gb, &mv_vlc);
804 sign = get_bits1(&s->gb);
806 val = (code - 1) << shift;
808 val |= get_bits(&s->gb, shift);
814 /* modulo decoding */
815 l = (1 << shift) * 16;
819 } else if (val >= l) {
825 static inline int decode_dc(MpegEncContext *s, int component)
829 if (component == 0) {
830 code = get_vlc(&s->gb, &dc_lum_vlc);
832 code = get_vlc(&s->gb, &dc_chroma_vlc);
839 diff = get_bits(&s->gb, code);
840 if ((diff & (1 << (code - 1))) == 0)
841 diff = (-1 << code) | (diff + 1);
846 static int mpeg1_decode_block(MpegEncContext *s,
850 int level, dc, diff, i, j, run;
852 RLTable *rl = &rl_mpeg1;
856 component = (n <= 3 ? 0 : n - 4 + 1);
857 diff = decode_dc(s, component);
860 dc = s->last_dc[component];
862 s->last_dc[component] = dc;
864 dprintf("dc=%d diff=%d\n", dc, diff);
871 /* special case for the first coef. no need to add a second vlc table */
873 SHOW_BITS(&s->gb, v, 2);
876 level = 1 - ((v & 1) << 1);
878 RESTORE_BITS(&s->gb);
881 RESTORE_BITS(&s->gb);
884 /* now quantify & encode AC coefs */
886 code = get_vlc(&s->gb, &rl->vlc);
892 } else if (code == 111) {
894 run = get_bits(&s->gb, 6);
895 level = get_bits(&s->gb, 8);
896 level = (level << 24) >> 24;
898 level = get_bits(&s->gb, 8) - 256;
899 } else if (level == 0) {
900 level = get_bits(&s->gb, 8);
903 run = rl->table_run[code];
904 level = rl->table_level[code];
905 if (get_bits1(&s->gb))
912 dprintf("%d: run=%d level=%d\n", n, run, level);
913 j = zigzag_direct[i];
917 s->block_last_index[n] = i;
921 /* Also does unquantization here, since I will never support mpeg2
923 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
927 int level, i, j, run;
929 RLTable *rl = &rl_mpeg1;
930 const UINT8 *scan_table;
931 const UINT16 *matrix;
934 if (s->alternate_scan)
935 scan_table = ff_alternate_vertical_scan;
937 scan_table = zigzag_direct;
946 matrix = s->non_intra_matrix;
948 matrix = s->chroma_non_intra_matrix;
950 /* special case for the first coef. no need to add a second vlc table */
952 SHOW_BITS(&s->gb, v, 2);
955 level = 1 - ((v & 1) << 1);
957 RESTORE_BITS(&s->gb);
960 RESTORE_BITS(&s->gb);
963 /* now quantify & encode AC coefs */
965 code = get_vlc(&s->gb, &rl->vlc);
970 } else if (code == 111) {
972 run = get_bits(&s->gb, 6);
973 level = get_bits(&s->gb, 12);
974 level = (level << 20) >> 20;
976 run = rl->table_run[code];
977 level = rl->table_level[code];
978 if (get_bits1(&s->gb))
986 dprintf("%d: run=%d level=%d\n", n, run, level);
989 level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
991 level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
994 /* XXX: is it really necessary to saturate since the encoder
995 knows whats going on ? */
1000 block[63] ^= (mismatch & 1);
1001 s->block_last_index[n] = i;
1005 static int mpeg2_decode_block_intra(MpegEncContext *s,
1009 int level, dc, diff, i, j, run;
1010 int code, component;
1012 const UINT8 *scan_table;
1013 const UINT16 *matrix;
1016 if (s->alternate_scan)
1017 scan_table = ff_alternate_vertical_scan;
1019 scan_table = zigzag_direct;
1022 component = (n <= 3 ? 0 : n - 4 + 1);
1023 diff = decode_dc(s, component);
1026 dc = s->last_dc[component];
1028 s->last_dc[component] = dc;
1029 block[0] = dc << (3 - s->intra_dc_precision);
1030 dprintf("dc=%d\n", block[0]);
1031 mismatch = block[0] ^ 1;
1033 if (s->intra_vlc_format)
1038 matrix = s->intra_matrix;
1040 matrix = s->chroma_intra_matrix;
1042 /* now quantify & encode AC coefs */
1044 code = get_vlc(&s->gb, &rl->vlc);
1049 } else if (code == 111) {
1051 run = get_bits(&s->gb, 6);
1052 level = get_bits(&s->gb, 12);
1053 level = (level << 20) >> 20;
1055 run = rl->table_run[code];
1056 level = rl->table_level[code];
1057 if (get_bits1(&s->gb))
1064 dprintf("%d: run=%d level=%d\n", n, run, level);
1065 level = (level * s->qscale * matrix[j]) / 16;
1066 /* XXX: is it really necessary to saturate since the encoder
1067 knows whats going on ? */
1072 block[63] ^= (mismatch & 1);
1073 s->block_last_index[n] = i;
1077 /* compressed picture size */
1078 #define PICTURE_BUFFER_SIZE 100000
1080 typedef struct Mpeg1Context {
1081 MpegEncContext mpeg_enc_ctx;
1082 UINT32 header_state;
1083 int start_code; /* current start code */
1084 UINT8 buffer[PICTURE_BUFFER_SIZE];
1087 int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1090 static int mpeg_decode_init(AVCodecContext *avctx)
1092 Mpeg1Context *s = avctx->priv_data;
1094 s->header_state = 0xff;
1095 s->mpeg_enc_ctx_allocated = 0;
1096 s->buffer_size = PICTURE_BUFFER_SIZE;
1098 s->buf_ptr = s->buffer;
1099 s->mpeg_enc_ctx.picture_number = 0;
1103 /* return the 8 bit start code value and update the search
1104 state. Return -1 if no start code found */
1105 static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end,
1106 UINT32 *header_state)
1109 unsigned int state, v;
1112 state = *header_state;
1113 buf_ptr = *pbuf_ptr;
1114 while (buf_ptr < buf_end) {
1116 if (state == 0x000001) {
1117 state = ((state << 8) | v) & 0xffffff;
1121 state = ((state << 8) | v) & 0xffffff;
1125 *pbuf_ptr = buf_ptr;
1126 *header_state = state;
1130 static int mpeg1_decode_picture(AVCodecContext *avctx,
1131 UINT8 *buf, int buf_size)
1133 Mpeg1Context *s1 = avctx->priv_data;
1134 MpegEncContext *s = &s1->mpeg_enc_ctx;
1137 init_get_bits(&s->gb, buf, buf_size);
1139 ref = get_bits(&s->gb, 10); /* temporal ref */
1140 s->pict_type = get_bits(&s->gb, 3);
1141 dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1142 skip_bits(&s->gb, 16);
1143 if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1144 s->full_pel[0] = get_bits1(&s->gb);
1145 f_code = get_bits(&s->gb, 3);
1148 s->mpeg_f_code[0][0] = f_code;
1149 s->mpeg_f_code[0][1] = f_code;
1151 if (s->pict_type == B_TYPE) {
1152 s->full_pel[1] = get_bits1(&s->gb);
1153 f_code = get_bits(&s->gb, 3);
1156 s->mpeg_f_code[1][0] = f_code;
1157 s->mpeg_f_code[1][1] = f_code;
1165 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1167 int horiz_size_ext, vert_size_ext;
1168 int bit_rate_ext, vbv_buf_ext, low_delay;
1169 int frame_rate_ext_n, frame_rate_ext_d;
1171 skip_bits(&s->gb, 8); /* profil and level */
1172 skip_bits(&s->gb, 1); /* progressive_sequence */
1173 skip_bits(&s->gb, 2); /* chroma_format */
1174 horiz_size_ext = get_bits(&s->gb, 2);
1175 vert_size_ext = get_bits(&s->gb, 2);
1176 s->width |= (horiz_size_ext << 12);
1177 s->height |= (vert_size_ext << 12);
1178 bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */
1179 s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1180 skip_bits1(&s->gb); /* marker */
1181 vbv_buf_ext = get_bits(&s->gb, 8);
1182 low_delay = get_bits1(&s->gb);
1183 frame_rate_ext_n = get_bits(&s->gb, 2);
1184 frame_rate_ext_d = get_bits(&s->gb, 5);
1185 if (frame_rate_ext_d >= 1)
1186 s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1187 dprintf("sequence extension\n");
1191 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1195 dprintf("matrix extension\n");
1197 if (get_bits1(&s->gb)) {
1199 v = get_bits(&s->gb, 8);
1200 j = zigzag_direct[i];
1201 s->intra_matrix[j] = v;
1202 s->chroma_intra_matrix[j] = v;
1205 if (get_bits1(&s->gb)) {
1207 v = get_bits(&s->gb, 8);
1208 j = zigzag_direct[i];
1209 s->non_intra_matrix[j] = v;
1210 s->chroma_non_intra_matrix[j] = v;
1213 if (get_bits1(&s->gb)) {
1215 v = get_bits(&s->gb, 8);
1216 j = zigzag_direct[i];
1217 s->chroma_intra_matrix[j] = v;
1220 if (get_bits1(&s->gb)) {
1222 v = get_bits(&s->gb, 8);
1223 j = zigzag_direct[i];
1224 s->chroma_non_intra_matrix[j] = v;
1229 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1231 s->full_pel[0] = s->full_pel[1] = 0;
1232 s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1233 s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1234 s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1235 s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1236 s->intra_dc_precision = get_bits(&s->gb, 2);
1237 s->picture_structure = get_bits(&s->gb, 2);
1238 s->top_field_first = get_bits1(&s->gb);
1239 s->frame_pred_frame_dct = get_bits1(&s->gb);
1240 s->concealment_motion_vectors = get_bits1(&s->gb);
1241 s->q_scale_type = get_bits1(&s->gb);
1242 s->intra_vlc_format = get_bits1(&s->gb);
1243 s->alternate_scan = get_bits1(&s->gb);
1244 s->repeat_first_field = get_bits1(&s->gb);
1245 s->chroma_420_type = get_bits1(&s->gb);
1246 s->progressive_frame = get_bits1(&s->gb);
1247 /* composite display not parsed */
1248 dprintf("intra_dc_precion=%d\n", s->intra_dc_precision);
1249 dprintf("picture_structure=%d\n", s->picture_structure);
1250 dprintf("conceal=%d\n", s->concealment_motion_vectors);
1251 dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1252 dprintf("alternate_scan=%d\n", s->alternate_scan);
1253 dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1256 static void mpeg_decode_extension(AVCodecContext *avctx,
1257 UINT8 *buf, int buf_size)
1259 Mpeg1Context *s1 = avctx->priv_data;
1260 MpegEncContext *s = &s1->mpeg_enc_ctx;
1263 init_get_bits(&s->gb, buf, buf_size);
1265 ext_type = get_bits(&s->gb, 4);
1269 mpeg_decode_sequence_extension(s);
1272 /* quant matrix extension */
1273 mpeg_decode_quant_matrix_extension(s);
1276 /* picture extension */
1277 mpeg_decode_picture_coding_extension(s);
1282 /* return 1 if end of frame */
1283 static int mpeg_decode_slice(AVCodecContext *avctx,
1286 UINT8 *buf, int buf_size)
1288 Mpeg1Context *s1 = avctx->priv_data;
1289 MpegEncContext *s = &s1->mpeg_enc_ctx;
1292 start_code = (start_code - 1) & 0xff;
1293 if (start_code >= s->mb_height)
1295 s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1296 s->last_dc[1] = s->last_dc[0];
1297 s->last_dc[2] = s->last_dc[0];
1298 memset(s->last_mv, 0, sizeof(s->last_mv));
1300 s->mb_y = start_code;
1303 /* start frame decoding */
1304 if (s->first_slice) {
1309 init_get_bits(&s->gb, buf, buf_size);
1311 s->qscale = get_qscale(s);
1312 /* extra slice info */
1313 while (get_bits1(&s->gb) != 0) {
1314 skip_bits(&s->gb, 8);
1318 memset(s->block, 0, sizeof(s->block));
1319 ret = mpeg_decode_mb(s, s->block);
1320 dprintf("ret=%d\n", ret);
1325 MPV_decode_mb(s, s->block);
1328 /* end of slice reached */
1329 if (s->mb_x == (s->mb_width - 1) &&
1330 s->mb_y == (s->mb_height - 1)) {
1336 /* XXX: incorrect reported qscale for mpeg2 */
1337 if (s->pict_type == B_TYPE) {
1338 picture = s->current_picture;
1339 avctx->quality = s->qscale;
1341 /* latency of 1 frame for I and P frames */
1342 /* XXX: use another variable than picture_number */
1343 if (s->picture_number == 0) {
1346 picture = s->last_picture;
1347 avctx->quality = s->last_qscale;
1349 s->last_qscale = s->qscale;
1350 s->picture_number++;
1353 pict->data[0] = picture[0];
1354 pict->data[1] = picture[1];
1355 pict->data[2] = picture[2];
1356 pict->linesize[0] = s->linesize;
1357 pict->linesize[1] = s->linesize / 2;
1358 pict->linesize[2] = s->linesize / 2;
1368 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1369 UINT8 *buf, int buf_size)
1371 Mpeg1Context *s1 = avctx->priv_data;
1372 MpegEncContext *s = &s1->mpeg_enc_ctx;
1373 int width, height, i, v, j;
1375 init_get_bits(&s->gb, buf, buf_size);
1377 width = get_bits(&s->gb, 12);
1378 height = get_bits(&s->gb, 12);
1379 skip_bits(&s->gb, 4);
1380 s->frame_rate_index = get_bits(&s->gb, 4);
1381 if (s->frame_rate_index == 0)
1383 s->bit_rate = get_bits(&s->gb, 18) * 400;
1384 if (get_bits1(&s->gb) == 0) /* marker */
1386 if (width <= 0 || height <= 0 ||
1387 (width % 2) != 0 || (height % 2) != 0)
1389 if (width != s->width ||
1390 height != s->height) {
1391 /* start new mpeg1 context decoding */
1392 s->out_format = FMT_MPEG1;
1393 if (s1->mpeg_enc_ctx_allocated) {
1398 s->has_b_frames = 1;
1399 avctx->width = width;
1400 avctx->height = height;
1401 avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1402 avctx->bit_rate = s->bit_rate;
1404 if (MPV_common_init(s) < 0)
1407 s1->mpeg_enc_ctx_allocated = 1;
1410 skip_bits(&s->gb, 10); /* vbv_buffer_size */
1411 skip_bits(&s->gb, 1);
1414 if (get_bits1(&s->gb)) {
1416 v = get_bits(&s->gb, 8);
1417 j = zigzag_direct[i];
1418 s->intra_matrix[j] = v;
1419 s->chroma_intra_matrix[j] = v;
1422 dprintf("intra matrix present\n");
1424 dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1429 v = default_intra_matrix[i];
1430 s->intra_matrix[i] = v;
1431 s->chroma_intra_matrix[i] = v;
1434 if (get_bits1(&s->gb)) {
1436 v = get_bits(&s->gb, 8);
1437 j = zigzag_direct[i];
1438 s->non_intra_matrix[j] = v;
1439 s->chroma_non_intra_matrix[j] = v;
1442 dprintf("non intra matrix present\n");
1444 dprintf(" %d", s->non_intra_matrix[zigzag_direct[i]]);
1449 v = default_non_intra_matrix[i];
1450 s->non_intra_matrix[i] = v;
1451 s->chroma_non_intra_matrix[i] = v;
1455 /* we set mpeg2 parameters so that it emulates mpeg1 */
1456 s->progressive_sequence = 1;
1457 s->progressive_frame = 1;
1458 s->picture_structure = PICT_FRAME;
1459 s->frame_pred_frame_dct = 1;
1464 /* handle buffering and image synchronisation */
1465 static int mpeg_decode_frame(AVCodecContext *avctx,
1466 void *data, int *data_size,
1467 UINT8 *buf, int buf_size)
1469 Mpeg1Context *s = avctx->priv_data;
1470 UINT8 *buf_end, *buf_ptr, *buf_start;
1471 int len, start_code_found, ret, code, start_code, input_size;
1472 AVPicture *picture = data;
1474 dprintf("fill_buffer\n");
1477 /* special case for last picture */
1478 if (buf_size == 0) {
1479 MpegEncContext *s2 = &s->mpeg_enc_ctx;
1480 if (s2->picture_number > 0) {
1481 picture->data[0] = s2->next_picture[0];
1482 picture->data[1] = s2->next_picture[1];
1483 picture->data[2] = s2->next_picture[2];
1484 picture->linesize[0] = s2->linesize;
1485 picture->linesize[1] = s2->linesize / 2;
1486 picture->linesize[2] = s2->linesize / 2;
1487 *data_size = sizeof(AVPicture);
1493 buf_end = buf + buf_size;
1494 while (buf_ptr < buf_end) {
1495 buf_start = buf_ptr;
1496 /* find start next code */
1497 code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1499 start_code_found = 1;
1501 start_code_found = 0;
1503 /* copy to buffer */
1504 len = buf_ptr - buf_start;
1505 if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1506 /* data too big : flush */
1507 s->buf_ptr = s->buffer;
1508 if (start_code_found)
1509 s->start_code = code;
1511 memcpy(s->buf_ptr, buf_start, len);
1514 if (start_code_found) {
1515 /* prepare data for next start code */
1516 input_size = s->buf_ptr - s->buffer;
1517 start_code = s->start_code;
1518 s->buf_ptr = s->buffer;
1519 s->start_code = code;
1520 switch(start_code) {
1521 case SEQ_START_CODE:
1522 mpeg1_decode_sequence(avctx, s->buffer,
1526 case PICTURE_START_CODE:
1527 /* we have a complete image : we try to decompress it */
1528 mpeg1_decode_picture(avctx,
1529 s->buffer, input_size);
1531 case EXT_START_CODE:
1532 mpeg_decode_extension(avctx,
1533 s->buffer, input_size);
1536 if (start_code >= SLICE_MIN_START_CODE &&
1537 start_code <= SLICE_MAX_START_CODE) {
1538 ret = mpeg_decode_slice(avctx, picture,
1539 start_code, s->buffer, input_size);
1541 /* got a picture: exit */
1542 *data_size = sizeof(AVPicture);
1552 return buf_ptr - buf;
1555 static int mpeg_decode_end(AVCodecContext *avctx)
1557 Mpeg1Context *s = avctx->priv_data;
1559 if (s->mpeg_enc_ctx_allocated)
1560 MPV_common_end(&s->mpeg_enc_ctx);
1564 AVCodec mpeg_decoder = {
1567 CODEC_ID_MPEG1VIDEO,
1568 sizeof(Mpeg1Context),