3 * Copyright (c) 2002 Fabrice Bellard.
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.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include "mpegvideo.h"
22 #include "simple_idct.h"
24 #define NTSC_FRAME_SIZE 120000
25 #define PAL_FRAME_SIZE 144000
27 #define TEX_VLC_BITS 9
29 typedef struct DVVideoDecodeContext {
30 AVCodecContext *avctx;
33 int sampling_411; /* 0 = 420, 1 = 411 */
35 UINT8 *current_picture[3]; /* picture structure */
37 DCTELEM block[5*6][64] __align8;
38 UINT8 dv_zigzag[2][64];
39 UINT8 idct_permutation[64];
40 /* XXX: move it to static storage ? */
41 UINT8 dv_shift[2][22][64];
42 void (*idct_put[2])(UINT8 *dest, int line_size, DCTELEM *block);
43 } DVVideoDecodeContext;
48 /* XXX: also include quantization */
49 static RL_VLC_ELEM *dv_rl_vlc[1];
51 static void dv_build_unquantize_tables(DVVideoDecodeContext *s)
55 /* NOTE: max left shift is 6 */
56 for(q = 0; q < 22; q++) {
58 for(i = 1; i < 64; i++) {
60 j = s->idct_permutation[i];
61 s->dv_shift[0][q][j] =
62 dv_quant_shifts[q][dv_88_areas[i]] + 1;
66 for(i = 1; i < 64; i++) {
68 s->dv_shift[1][q][i] =
69 dv_quant_shifts[q][dv_248_areas[i]] + 1;
74 static int dvvideo_decode_init(AVCodecContext *avctx)
76 DVVideoDecodeContext *s = avctx->priv_data;
85 /* NOTE: as a trick, we use the fact the no codes are unused
86 to accelerate the parsing of partial codes */
87 init_vlc(&dv_vlc, TEX_VLC_BITS, NB_DV_VLC,
88 dv_vlc_len, 1, 1, dv_vlc_bits, 2, 2);
90 dv_rl_vlc[0] = av_malloc(dv_vlc.table_size * sizeof(RL_VLC_ELEM));
91 for(i = 0; i < dv_vlc.table_size; i++){
92 int code= dv_vlc.table[i][0];
93 int len = dv_vlc.table[i][1];
96 if(len<0){ //more bits needed
99 } else if (code == (NB_DV_VLC - 1)) {
104 run= dv_vlc_run[code] + 1;
105 level= dv_vlc_level[code];
107 dv_rl_vlc[0][i].len = len;
108 dv_rl_vlc[0][i].level = level;
109 dv_rl_vlc[0][i].run = run;
113 /* ugly way to get the idct & scantable */
115 memset(&s2, 0, sizeof(MpegEncContext));
117 if (DCT_common_init(&s2) < 0)
120 s->idct_put[0] = s2.idct_put;
121 memcpy(s->idct_permutation, s2.idct_permutation, 64);
122 memcpy(s->dv_zigzag[0], s2.intra_scantable.permutated, 64);
124 /* XXX: use MMX also for idct248 */
125 s->idct_put[1] = simple_idct248_put;
126 memcpy(s->dv_zigzag[1], dv_248_zigzag, 64);
128 /* XXX: do it only for constant case */
129 dv_build_unquantize_tables(s);
136 typedef struct BlockInfo {
137 const UINT8 *shift_table;
138 const UINT8 *scan_table;
139 UINT8 pos; /* position in block */
140 UINT8 eob_reached; /* true if EOB has been reached */
142 UINT8 partial_bit_count;
143 UINT16 partial_bit_buffer;
147 /* block size in bits */
148 static const UINT16 block_sizes[6] = {
149 112, 112, 112, 112, 80, 80
152 #ifndef ALT_BITSTREAM_READER
153 #error only works with ALT_BITSTREAM_READER
156 /* decode ac coefs */
157 static void dv_decode_ac(DVVideoDecodeContext *s,
158 BlockInfo *mb, INT16 *block, int last_index)
161 int shift_offset = mb->shift_offset;
162 const UINT8 *scan_table = mb->scan_table;
163 const UINT8 *shift_table = mb->shift_table;
165 int level, pos1, sign, run;
166 int partial_bit_count;
168 OPEN_READER(re, &s->gb);
174 /* if we must parse a partial vlc, we do it here */
175 partial_bit_count = mb->partial_bit_count;
176 if (partial_bit_count > 0) {
182 /* build the dummy bit buffer */
183 l = 16 - partial_bit_count;
184 UPDATE_CACHE(re, &s->gb);
186 printf("show=%04x\n", SHOW_UBITS(re, &s->gb, 16));
188 v = (mb->partial_bit_buffer << l) | SHOW_UBITS(re, &s->gb, l);
192 printf("v=%04x cnt=%d %04x\n",
193 v, partial_bit_count, (mb->partial_bit_buffer << l));
195 /* try to read the codeword */
196 init_get_bits(&gb1, buf, 4);
198 OPEN_READER(re1, &gb1);
199 UPDATE_CACHE(re1, &gb1);
200 GET_RL_VLC(level, run, re1, &gb1, dv_rl_vlc[0],
203 CLOSE_READER(re1, &gb1);
206 printf("****run=%d level=%d size=%d\n", run, level, l);
208 /* compute codeword length */
209 l1 = (level != 256 && level != 0);
210 /* if too long, we cannot parse */
211 l -= partial_bit_count;
212 if ((re_index + l + l1) > last_index)
215 last_re_index = 0; /* avoid warning */
217 /* by definition, if we can read the vlc, all partial bits
218 will be read (otherwise we could have read the vlc before) */
219 mb->partial_bit_count = 0;
220 UPDATE_CACHE(re, &s->gb);
224 /* get the AC coefficients until last_index is reached */
226 UPDATE_CACHE(re, &s->gb);
228 printf("%2d: bits=%04x index=%d\n",
229 pos, SHOW_UBITS(re, &s->gb, 16), re_index);
231 last_re_index = re_index;
232 GET_RL_VLC(level, run, re, &s->gb, dv_rl_vlc[0],
236 printf("run=%d level=%d\n", run, level);
239 if (re_index > last_index) {
241 /* put position before read code */
242 re_index = last_re_index;
249 } else if (level != 0) {
250 if ((re_index + 1) > last_index)
252 sign = SHOW_SBITS(re, &s->gb, 1);
253 level = (level ^ sign) - sign;
254 LAST_SKIP_BITS(re, &s->gb, 1);
260 pos1 = scan_table[pos];
261 level = level << (shift_table[pos1] + shift_offset);
263 // printf("run=%d level=%d shift=%d\n", run, level, shift_table[pos1]);
265 if (re_index > last_index)
267 /* level is zero: means run without coding. No
273 #if defined(VLC_DEBUG) || 1
274 printf("error pos=%d\n", pos);
276 /* for errors, we consider the eob is reached */
282 CLOSE_READER(re, &s->gb);
286 static inline void bit_copy(PutBitContext *pb, GetBitContext *gb, int bits_left)
288 while (bits_left >= 16) {
289 put_bits(pb, 16, get_bits(gb, 16));
293 put_bits(pb, bits_left, get_bits(gb, bits_left));
297 /* mb_x and mb_y are in units of 8 pixels */
298 static inline void dv_decode_video_segment(DVVideoDecodeContext *s,
300 const UINT16 *mb_pos_ptr)
302 int quant, dc, dct_mode, class1, j;
303 int mb_index, mb_x, mb_y, v, last_index;
304 DCTELEM *block, *block1;
305 int c_offset, bits_left;
307 BlockInfo mb_data[5 * 6], *mb, *mb1;
308 void (*idct_put)(UINT8 *dest, int line_size, DCTELEM *block);
310 PutBitContext pb, vs_pb;
311 UINT8 mb_bit_buffer[80 + 4]; /* allow some slack */
313 UINT8 vs_bit_buffer[5 * 80 + 4]; /* allow some slack */
316 memset(s->block, 0, sizeof(s->block));
318 /* pass 1 : read DC and AC coefficients in blocks */
320 block1 = &s->block[0][0];
322 init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80, NULL, NULL);
324 for(mb_index = 0; mb_index < 5; mb_index++) {
326 quant = buf_ptr[3] & 0x0f;
328 init_put_bits(&pb, mb_bit_buffer, 80, NULL, NULL);
332 for(j = 0;j < 6; j++) {
333 /* NOTE: size is not important here */
334 init_get_bits(&s->gb, buf_ptr, 14);
337 dc = get_bits(&s->gb, 9);
338 dc = (dc << (32 - 9)) >> (32 - 9);
339 dct_mode = get_bits1(&s->gb);
340 mb->dct_mode = dct_mode;
341 mb->scan_table = s->dv_zigzag[dct_mode];
342 class1 = get_bits(&s->gb, 2);
343 mb->shift_offset = (class1 == 3);
344 mb->shift_table = s->dv_shift[dct_mode]
345 [quant + dv_quant_offset[class1]];
347 /* convert to unsigned because 128 is not added in the
351 last_index = block_sizes[j];
352 buf_ptr += last_index >> 3;
354 mb->partial_bit_count = 0;
356 dv_decode_ac(s, mb, block, last_index);
358 /* write the remaining bits in a new buffer only if the
360 bits_left = last_index - s->gb.index;
361 if (mb->eob_reached) {
362 mb->partial_bit_count = 0;
363 mb_bit_count += bits_left;
364 bit_copy(&pb, &s->gb, bits_left);
366 /* should be < 16 bits otherwise a codeword could have
368 mb->partial_bit_count = bits_left;
369 mb->partial_bit_buffer = get_bits(&s->gb, bits_left);
377 /* pass 2 : we can do it just after */
379 printf("***pass 2 size=%d\n", mb_bit_count);
383 init_get_bits(&s->gb, mb_bit_buffer, 80);
384 for(j = 0;j < 6; j++) {
385 if (!mb->eob_reached && s->gb.index < mb_bit_count) {
386 dv_decode_ac(s, mb, block, mb_bit_count);
387 /* if still not finished, no need to parse other blocks */
388 if (!mb->eob_reached) {
389 /* we could not parse the current AC coefficient,
390 so we add the remaining bytes */
391 bits_left = mb_bit_count - s->gb.index;
393 mb->partial_bit_count += bits_left;
394 mb->partial_bit_buffer =
395 (mb->partial_bit_buffer << bits_left) |
396 get_bits(&s->gb, bits_left);
404 /* all blocks are finished, so the extra bytes can be used at
405 the video segment level */
406 bits_left = mb_bit_count - s->gb.index;
407 vs_bit_count += bits_left;
408 bit_copy(&vs_pb, &s->gb, bits_left);
414 /* we need a pass other the whole video segment */
415 flush_put_bits(&vs_pb);
418 printf("***pass 3 size=%d\n", vs_bit_count);
420 block = &s->block[0][0];
422 init_get_bits(&s->gb, vs_bit_buffer, 5 * 80);
423 for(mb_index = 0; mb_index < 5; mb_index++) {
424 for(j = 0;j < 6; j++) {
425 if (!mb->eob_reached) {
427 printf("start %d:%d\n", mb_index, j);
429 dv_decode_ac(s, mb, block, vs_bit_count);
436 /* compute idct and place blocks */
437 block = &s->block[0][0];
439 for(mb_index = 0; mb_index < 5; mb_index++) {
443 y_ptr = s->current_picture[0] + (mb_y * s->linesize[0] * 8) + (mb_x * 8);
445 c_offset = (mb_y * s->linesize[1] * 8) + ((mb_x >> 2) * 8);
447 c_offset = ((mb_y >> 1) * s->linesize[1] * 8) + ((mb_x >> 1) * 8);
448 for(j = 0;j < 6; j++) {
449 idct_put = s->idct_put[mb->dct_mode];
451 if (s->sampling_411 && mb_x < (704 / 8)) {
452 /* NOTE: at end of line, the macroblock is handled as 420 */
453 idct_put(y_ptr + (j * 8), s->linesize[0], block);
455 idct_put(y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->linesize[0]),
456 s->linesize[0], block);
459 if (s->sampling_411 && mb_x >= (704 / 8)) {
460 uint8_t pixels[64], *c_ptr, *c_ptr1, *ptr;
462 /* NOTE: at end of line, the macroblock is handled as 420 */
463 idct_put(pixels, 8, block);
464 linesize = s->linesize[6 - j];
465 c_ptr = s->current_picture[6 - j] + c_offset;
467 for(y = 0;y < 8; y++) {
468 /* convert to 411P */
469 c_ptr1 = c_ptr + linesize;
470 c_ptr1[0] = c_ptr[0] = (ptr[0] + ptr[1]) >> 1;
471 c_ptr1[1] = c_ptr[1] = (ptr[2] + ptr[3]) >> 1;
472 c_ptr1[2] = c_ptr[2] = (ptr[4] + ptr[5]) >> 1;
473 c_ptr1[3] = c_ptr[3] = (ptr[6] + ptr[7]) >> 1;
474 c_ptr += linesize * 2;
478 /* don't ask me why they inverted Cb and Cr ! */
479 idct_put(s->current_picture[6 - j] + c_offset,
480 s->linesize[6 - j], block);
490 /* NOTE: exactly one frame must be given (120000 bytes for NTSC,
491 144000 bytes for PAL) */
492 static int dvvideo_decode_frame(AVCodecContext *avctx,
493 void *data, int *data_size,
494 UINT8 *buf, int buf_size)
496 DVVideoDecodeContext *s = avctx->priv_data;
497 int sct, dsf, apt, ds, nb_dif_segs, vs, size, width, height, i, packet_size;
499 const UINT16 *mb_pos_ptr;
503 init_get_bits(&s->gb, buf, buf_size);
504 sct = get_bits(&s->gb, 3);
507 skip_bits(&s->gb, 5);
508 get_bits(&s->gb, 4); /* dsn (sequence number */
509 get_bits(&s->gb, 1); /* fsc (channel number) */
510 skip_bits(&s->gb, 3);
511 get_bits(&s->gb, 8); /* dbn (diff block number 0-134) */
513 dsf = get_bits(&s->gb, 1); /* 0 = NTSC 1 = PAL */
514 if (get_bits(&s->gb, 1) != 0)
516 skip_bits(&s->gb, 11);
517 apt = get_bits(&s->gb, 3); /* apt */
519 get_bits(&s->gb, 1); /* tf1 */
520 skip_bits(&s->gb, 4);
521 get_bits(&s->gb, 3); /* ap1 */
523 get_bits(&s->gb, 1); /* tf2 */
524 skip_bits(&s->gb, 4);
525 get_bits(&s->gb, 3); /* ap2 */
527 get_bits(&s->gb, 1); /* tf3 */
528 skip_bits(&s->gb, 4);
529 get_bits(&s->gb, 3); /* ap3 */
534 avctx->frame_rate = 25 * FRAME_RATE_BASE;
535 packet_size = PAL_FRAME_SIZE;
539 avctx->frame_rate = 30 * FRAME_RATE_BASE;
540 packet_size = NTSC_FRAME_SIZE;
544 /* NOTE: we only accept several full frames */
545 if (buf_size < packet_size)
548 /* XXX: is it correct to assume that 420 is always used in PAL
550 s->sampling_411 = !dsf;
551 if (s->sampling_411) {
552 mb_pos_ptr = dv_place_411;
553 avctx->pix_fmt = PIX_FMT_YUV411P;
555 mb_pos_ptr = dv_place_420;
556 avctx->pix_fmt = PIX_FMT_YUV420P;
559 avctx->width = width;
560 avctx->height = height;
562 if (avctx->flags & CODEC_FLAG_DR1 && avctx->get_buffer_callback)
565 avctx->dr_buffer[0] = avctx->dr_buffer[1] = avctx->dr_buffer[2] = 0;
566 if(avctx->get_buffer_callback(avctx, width, height, I_TYPE) < 0){
567 fprintf(stderr, "get_buffer() failed\n");
572 /* (re)alloc picture if needed */
573 if (s->width != width || s->height != height) {
574 if (!(avctx->flags & CODEC_FLAG_DR1))
576 if (avctx->dr_buffer[i] != s->current_picture[i])
577 av_freep(&s->current_picture[i]);
578 avctx->dr_buffer[i] = 0;
582 if (avctx->dr_buffer[i]) {
583 s->current_picture[i] = avctx->dr_buffer[i];
584 s->linesize[i] = (i == 0) ? avctx->dr_stride : avctx->dr_uvstride;
586 size = width * height;
587 s->linesize[i] = width;
590 s->linesize[i] >>= s->sampling_411 ? 2 : 1;
592 s->current_picture[i] = av_malloc(size);
594 if (!s->current_picture[i])
601 /* for each DIF segment */
603 for (ds = 0; ds < nb_dif_segs; ds++) {
604 buf_ptr += 6 * 80; /* skip DIF segment header */
606 for(vs = 0; vs < 27; vs++) {
608 /* skip audio block */
611 dv_decode_video_segment(s, buf_ptr, mb_pos_ptr);
620 *data_size = sizeof(AVPicture);
623 picture->data[i] = s->current_picture[i];
624 picture->linesize[i] = s->linesize[i];
629 static int dvvideo_decode_end(AVCodecContext *avctx)
631 DVVideoDecodeContext *s = avctx->priv_data;
635 if (avctx->dr_buffer[i] != s->current_picture[i])
636 av_freep(&s->current_picture[i]);
640 AVCodec dvvideo_decoder = {
644 sizeof(DVVideoDecodeContext),
648 dvvideo_decode_frame,
653 typedef struct DVAudioDecodeContext {
654 AVCodecContext *avctx;
657 } DVAudioDecodeContext;
659 static int dvaudio_decode_init(AVCodecContext *avctx)
661 // DVAudioDecodeContext *s = avctx->priv_data;
665 /* NOTE: exactly one frame must be given (120000 bytes for NTSC,
666 144000 bytes for PAL) */
667 static int dvaudio_decode_frame(AVCodecContext *avctx,
668 void *data, int *data_size,
669 UINT8 *buf, int buf_size)
671 // DVAudioDecodeContext *s = avctx->priv_data;
675 static int dvaudio_decode_end(AVCodecContext *avctx)
677 // DVAudioDecodeContext *s = avctx->priv_data;
681 AVCodec dvaudio_decoder = {
685 sizeof(DVAudioDecodeContext),
689 dvaudio_decode_frame,