3 * Copyright (c) 2000,2001 Fabrice Bellard
4 * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
6 * This file is part of Libav.
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "error_resilience.h"
25 #include "mpegvideo.h"
26 #include "mpeg4video.h"
30 /* The defines below define the number of bits that are read at once for
31 * reading vlc values. Changing these may improve speed and data cache needs
32 * be aware though that decreasing them may need the number of stages that is
33 * passed to get_vlc* to be increased. */
34 #define SPRITE_TRAJ_VLC_BITS 6
36 #define MB_TYPE_B_VLC_BITS 4
38 static VLC dc_lum, dc_chrom;
39 static VLC sprite_trajectory;
40 static VLC mb_type_b_vlc;
42 static const int mb_type_b_map[4] = {
43 MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
44 MB_TYPE_L0L1 | MB_TYPE_16x16,
45 MB_TYPE_L1 | MB_TYPE_16x16,
46 MB_TYPE_L0 | MB_TYPE_16x16,
51 * @param n block index (0-3 are luma, 4-5 are chroma)
52 * @param dir the ac prediction direction
54 void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n, int dir)
57 int16_t *ac_val, *ac_val1;
58 int8_t *const qscale_table = s->current_picture.qscale_table;
61 ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
65 const int xy = s->mb_x - 1 + s->mb_y * s->mb_stride;
69 if (s->mb_x == 0 || s->qscale == qscale_table[xy] ||
72 for (i = 1; i < 8; i++)
73 block[s->dsp.idct_permutation[i << 3]] += ac_val[i];
75 /* different qscale, we must rescale */
76 for (i = 1; i < 8; i++)
77 block[s->dsp.idct_permutation[i << 3]] += ROUNDED_DIV(ac_val[i] * qscale_table[xy], s->qscale);
80 const int xy = s->mb_x + s->mb_y * s->mb_stride - s->mb_stride;
82 ac_val -= 16 * s->block_wrap[n];
84 if (s->mb_y == 0 || s->qscale == qscale_table[xy] ||
87 for (i = 1; i < 8; i++)
88 block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
90 /* different qscale, we must rescale */
91 for (i = 1; i < 8; i++)
92 block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8] * qscale_table[xy], s->qscale);
97 for (i = 1; i < 8; i++)
98 ac_val1[i] = block[s->dsp.idct_permutation[i << 3]];
101 for (i = 1; i < 8; i++)
102 ac_val1[8 + i] = block[s->dsp.idct_permutation[i]];
106 * check if the next stuff is a resync marker or the end.
109 static inline int mpeg4_is_resync(MpegEncContext *s)
111 int bits_count = get_bits_count(&s->gb);
112 int v = show_bits(&s->gb, 16);
114 if (s->workaround_bugs & FF_BUG_NO_PADDING)
118 if (s->pict_type == AV_PICTURE_TYPE_B ||
119 (v >> (8 - s->pict_type) != 1) || s->partitioned_frame)
121 skip_bits(&s->gb, 8 + s->pict_type);
122 bits_count += 8 + s->pict_type;
123 v = show_bits(&s->gb, 16);
126 if (bits_count + 8 >= s->gb.size_in_bits) {
128 v |= 0x7F >> (7 - (bits_count & 7));
133 if (v == ff_mpeg4_resync_prefix[bits_count & 7]) {
135 GetBitContext gb = s->gb;
137 skip_bits(&s->gb, 1);
138 align_get_bits(&s->gb);
140 for (len = 0; len < 32; len++)
141 if (get_bits1(&s->gb))
146 if (len >= ff_mpeg4_get_video_packet_prefix_length(s))
153 static int mpeg4_decode_sprite_trajectory(MpegEncContext *s, GetBitContext *gb)
155 int a = 2 << s->sprite_warping_accuracy;
156 int rho = 3 - s->sprite_warping_accuracy;
162 int min_ab, i, w2, h2, w3, h3;
163 int sprite_ref[4][2];
164 int virtual_ref[2][2];
166 // only true for rectangle shapes
167 const int vop_ref[4][2] = { { 0, 0 }, { s->width, 0 },
168 { 0, s->height }, { s->width, s->height } };
169 int d[4][2] = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } };
171 if (w <= 0 || h <= 0)
172 return AVERROR_INVALIDDATA;
174 for (i = 0; i < s->num_sprite_warping_points; i++) {
178 length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
180 x = get_xbits(gb, length);
182 if (!(s->divx_version == 500 && s->divx_build == 413))
183 skip_bits1(gb); /* marker bit */
185 length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
187 y = get_xbits(gb, length);
189 skip_bits1(gb); /* marker bit */
190 s->sprite_traj[i][0] = d[i][0] = x;
191 s->sprite_traj[i][1] = d[i][1] = y;
194 s->sprite_traj[i][0] = s->sprite_traj[i][1] = 0;
196 while ((1 << alpha) < w)
198 while ((1 << beta) < h)
199 beta++; /* typo in the mpeg4 std for the definition of w' and h' */
203 // Note, the 4th point isn't used for GMC
204 if (s->divx_version == 500 && s->divx_build == 413) {
205 sprite_ref[0][0] = a * vop_ref[0][0] + d[0][0];
206 sprite_ref[0][1] = a * vop_ref[0][1] + d[0][1];
207 sprite_ref[1][0] = a * vop_ref[1][0] + d[0][0] + d[1][0];
208 sprite_ref[1][1] = a * vop_ref[1][1] + d[0][1] + d[1][1];
209 sprite_ref[2][0] = a * vop_ref[2][0] + d[0][0] + d[2][0];
210 sprite_ref[2][1] = a * vop_ref[2][1] + d[0][1] + d[2][1];
212 sprite_ref[0][0] = (a >> 1) * (2 * vop_ref[0][0] + d[0][0]);
213 sprite_ref[0][1] = (a >> 1) * (2 * vop_ref[0][1] + d[0][1]);
214 sprite_ref[1][0] = (a >> 1) * (2 * vop_ref[1][0] + d[0][0] + d[1][0]);
215 sprite_ref[1][1] = (a >> 1) * (2 * vop_ref[1][1] + d[0][1] + d[1][1]);
216 sprite_ref[2][0] = (a >> 1) * (2 * vop_ref[2][0] + d[0][0] + d[2][0]);
217 sprite_ref[2][1] = (a >> 1) * (2 * vop_ref[2][1] + d[0][1] + d[2][1]);
219 /* sprite_ref[3][0] = (a >> 1) * (2 * vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
220 * sprite_ref[3][1] = (a >> 1) * (2 * vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
222 /* this is mostly identical to the mpeg4 std (and is totally unreadable
223 * because of that...). Perhaps it should be reordered to be more readable.
224 * The idea behind this virtual_ref mess is to be able to use shifts later
225 * per pixel instead of divides so the distance between points is converted
226 * from w&h based to w2&h2 based which are of the 2^x form. */
227 virtual_ref[0][0] = 16 * (vop_ref[0][0] + w2) +
228 ROUNDED_DIV(((w - w2) *
229 (r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
230 w2 * (r * sprite_ref[1][0] - 16 * vop_ref[1][0])), w);
231 virtual_ref[0][1] = 16 * vop_ref[0][1] +
232 ROUNDED_DIV(((w - w2) *
233 (r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
234 w2 * (r * sprite_ref[1][1] - 16 * vop_ref[1][1])), w);
235 virtual_ref[1][0] = 16 * vop_ref[0][0] +
236 ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
237 h2 * (r * sprite_ref[2][0] - 16 * vop_ref[2][0])), h);
238 virtual_ref[1][1] = 16 * (vop_ref[0][1] + h2) +
239 ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
240 h2 * (r * sprite_ref[2][1] - 16 * vop_ref[2][1])), h);
242 switch (s->num_sprite_warping_points) {
244 s->sprite_offset[0][0] =
245 s->sprite_offset[0][1] =
246 s->sprite_offset[1][0] =
247 s->sprite_offset[1][1] = 0;
248 s->sprite_delta[0][0] = a;
249 s->sprite_delta[0][1] =
250 s->sprite_delta[1][0] = 0;
251 s->sprite_delta[1][1] = a;
253 s->sprite_shift[1] = 0;
256 s->sprite_offset[0][0] = sprite_ref[0][0] - a * vop_ref[0][0];
257 s->sprite_offset[0][1] = sprite_ref[0][1] - a * vop_ref[0][1];
258 s->sprite_offset[1][0] = ((sprite_ref[0][0] >> 1) | (sprite_ref[0][0] & 1)) -
259 a * (vop_ref[0][0] / 2);
260 s->sprite_offset[1][1] = ((sprite_ref[0][1] >> 1) | (sprite_ref[0][1] & 1)) -
261 a * (vop_ref[0][1] / 2);
262 s->sprite_delta[0][0] = a;
263 s->sprite_delta[0][1] =
264 s->sprite_delta[1][0] = 0;
265 s->sprite_delta[1][1] = a;
267 s->sprite_shift[1] = 0;
270 s->sprite_offset[0][0] = (sprite_ref[0][0] << (alpha + rho)) +
271 (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
273 (r * sprite_ref[0][1] - virtual_ref[0][1]) *
274 (-vop_ref[0][1]) + (1 << (alpha + rho - 1));
275 s->sprite_offset[0][1] = (sprite_ref[0][1] << (alpha + rho)) +
276 (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
278 (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
279 (-vop_ref[0][1]) + (1 << (alpha + rho - 1));
280 s->sprite_offset[1][0] = ((-r * sprite_ref[0][0] + virtual_ref[0][0]) *
281 (-2 * vop_ref[0][0] + 1) +
282 (r * sprite_ref[0][1] - virtual_ref[0][1]) *
283 (-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
284 sprite_ref[0][0] - 16 * w2 + (1 << (alpha + rho + 1)));
285 s->sprite_offset[1][1] = ((-r * sprite_ref[0][1] + virtual_ref[0][1]) *
286 (-2 * vop_ref[0][0] + 1) +
287 (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
288 (-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
289 sprite_ref[0][1] - 16 * w2 + (1 << (alpha + rho + 1)));
290 s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
291 s->sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
292 s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
293 s->sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
295 s->sprite_shift[0] = alpha + rho;
296 s->sprite_shift[1] = alpha + rho + 2;
299 min_ab = FFMIN(alpha, beta);
302 s->sprite_offset[0][0] = (sprite_ref[0][0] << (alpha + beta + rho - min_ab)) +
303 (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
304 h3 * (-vop_ref[0][0]) +
305 (-r * sprite_ref[0][0] + virtual_ref[1][0]) *
306 w3 * (-vop_ref[0][1]) +
307 (1 << (alpha + beta + rho - min_ab - 1));
308 s->sprite_offset[0][1] = (sprite_ref[0][1] << (alpha + beta + rho - min_ab)) +
309 (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
310 h3 * (-vop_ref[0][0]) +
311 (-r * sprite_ref[0][1] + virtual_ref[1][1]) *
312 w3 * (-vop_ref[0][1]) +
313 (1 << (alpha + beta + rho - min_ab - 1));
314 s->sprite_offset[1][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
315 h3 * (-2 * vop_ref[0][0] + 1) +
316 (-r * sprite_ref[0][0] + virtual_ref[1][0]) *
317 w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
318 r * sprite_ref[0][0] - 16 * w2 * h3 +
319 (1 << (alpha + beta + rho - min_ab + 1));
320 s->sprite_offset[1][1] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
321 h3 * (-2 * vop_ref[0][0] + 1) +
322 (-r * sprite_ref[0][1] + virtual_ref[1][1]) *
323 w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
324 r * sprite_ref[0][1] - 16 * w2 * h3 +
325 (1 << (alpha + beta + rho - min_ab + 1));
326 s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3;
327 s->sprite_delta[0][1] = (-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3;
328 s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3;
329 s->sprite_delta[1][1] = (-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3;
331 s->sprite_shift[0] = alpha + beta + rho - min_ab;
332 s->sprite_shift[1] = alpha + beta + rho - min_ab + 2;
335 /* try to simplify the situation */
336 if (s->sprite_delta[0][0] == a << s->sprite_shift[0] &&
337 s->sprite_delta[0][1] == 0 &&
338 s->sprite_delta[1][0] == 0 &&
339 s->sprite_delta[1][1] == a << s->sprite_shift[0]) {
340 s->sprite_offset[0][0] >>= s->sprite_shift[0];
341 s->sprite_offset[0][1] >>= s->sprite_shift[0];
342 s->sprite_offset[1][0] >>= s->sprite_shift[1];
343 s->sprite_offset[1][1] >>= s->sprite_shift[1];
344 s->sprite_delta[0][0] = a;
345 s->sprite_delta[0][1] = 0;
346 s->sprite_delta[1][0] = 0;
347 s->sprite_delta[1][1] = a;
348 s->sprite_shift[0] = 0;
349 s->sprite_shift[1] = 0;
350 s->real_sprite_warping_points = 1;
352 int shift_y = 16 - s->sprite_shift[0];
353 int shift_c = 16 - s->sprite_shift[1];
354 for (i = 0; i < 2; i++) {
355 s->sprite_offset[0][i] <<= shift_y;
356 s->sprite_offset[1][i] <<= shift_c;
357 s->sprite_delta[0][i] <<= shift_y;
358 s->sprite_delta[1][i] <<= shift_y;
359 s->sprite_shift[i] = 16;
361 s->real_sprite_warping_points = s->num_sprite_warping_points;
368 * Decode the next video packet.
369 * @return <0 if something went wrong
371 int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
373 MpegEncContext *s = &ctx->m;
375 int mb_num_bits = av_log2(s->mb_num - 1) + 1;
376 int header_extension = 0, mb_num, len;
378 /* is there enough space left for a video packet + header */
379 if (get_bits_count(&s->gb) > s->gb.size_in_bits - 20)
382 for (len = 0; len < 32; len++)
383 if (get_bits1(&s->gb))
386 if (len != ff_mpeg4_get_video_packet_prefix_length(s)) {
387 av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
391 if (ctx->shape != RECT_SHAPE) {
392 header_extension = get_bits1(&s->gb);
393 // FIXME more stuff here
396 mb_num = get_bits(&s->gb, mb_num_bits);
397 if (mb_num >= s->mb_num) {
398 av_log(s->avctx, AV_LOG_ERROR,
399 "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
402 if (s->pict_type == AV_PICTURE_TYPE_B) {
403 int mb_x = 0, mb_y = 0;
405 while (s->next_picture.mbskip_table[s->mb_index2xy[mb_num]]) {
407 ff_thread_await_progress(&s->next_picture_ptr->tf, mb_y++, 0);
409 if (++mb_x == s->mb_width)
412 if (mb_num >= s->mb_num)
413 return -1; // slice contains just skipped MBs (already decoded)
416 s->mb_x = mb_num % s->mb_width;
417 s->mb_y = mb_num / s->mb_width;
419 if (ctx->shape != BIN_ONLY_SHAPE) {
420 int qscale = get_bits(&s->gb, s->quant_precision);
422 s->chroma_qscale = s->qscale = qscale;
425 if (ctx->shape == RECT_SHAPE)
426 header_extension = get_bits1(&s->gb);
428 if (header_extension) {
431 while (get_bits1(&s->gb) != 0)
434 check_marker(&s->gb, "before time_increment in video packed header");
435 skip_bits(&s->gb, ctx->time_increment_bits); /* time_increment */
436 check_marker(&s->gb, "before vop_coding_type in video packed header");
438 skip_bits(&s->gb, 2); /* vop coding type */
439 // FIXME not rect stuff here
441 if (ctx->shape != BIN_ONLY_SHAPE) {
442 skip_bits(&s->gb, 3); /* intra dc vlc threshold */
443 // FIXME don't just ignore everything
444 if (s->pict_type == AV_PICTURE_TYPE_S &&
445 ctx->vol_sprite_usage == GMC_SPRITE) {
446 if (mpeg4_decode_sprite_trajectory(s, &s->gb) < 0)
447 return AVERROR_INVALIDDATA;
448 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
451 // FIXME reduced res stuff here
453 if (s->pict_type != AV_PICTURE_TYPE_I) {
454 int f_code = get_bits(&s->gb, 3); /* fcode_for */
456 av_log(s->avctx, AV_LOG_ERROR,
457 "Error, video packet header damaged (f_code=0)\n");
459 if (s->pict_type == AV_PICTURE_TYPE_B) {
460 int b_code = get_bits(&s->gb, 3);
462 av_log(s->avctx, AV_LOG_ERROR,
463 "Error, video packet header damaged (b_code=0)\n");
467 // FIXME new-pred stuff
473 * Get the average motion vector for a GMC MB.
474 * @param n either 0 for the x component or 1 for y
475 * @return the average MV for a GMC MB
477 static inline int get_amv(MpegEncContext *s, int n)
479 int x, y, mb_v, sum, dx, dy, shift;
480 int len = 1 << (s->f_code + 4);
481 const int a = s->sprite_warping_accuracy;
483 if (s->workaround_bugs & FF_BUG_AMV)
484 len >>= s->quarter_sample;
486 if (s->real_sprite_warping_points == 1) {
487 if (s->divx_version == 500 && s->divx_build == 413)
488 sum = s->sprite_offset[0][n] / (1 << (a - s->quarter_sample));
490 sum = RSHIFT(s->sprite_offset[0][n] << s->quarter_sample, a);
492 dx = s->sprite_delta[n][0];
493 dy = s->sprite_delta[n][1];
494 shift = s->sprite_shift[0];
496 dy -= 1 << (shift + a + 1);
498 dx -= 1 << (shift + a + 1);
499 mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16 + dy * s->mb_y * 16;
502 for (y = 0; y < 16; y++) {
507 for (x = 0; x < 16; x++) {
512 sum = RSHIFT(sum, a + 8 - s->quarter_sample);
524 * Decode the dc value.
525 * @param n block index (0-3 are luma, 4-5 are chroma)
526 * @param dir_ptr the prediction direction will be stored here
527 * @return the quantized dc
529 static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
534 code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
536 code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
538 if (code < 0 || code > 9 /* && s->nbit < 9 */) {
539 av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
548 level = 2 * get_bits1(&s->gb) - 1;
550 if (get_bits1(&s->gb))
551 level = get_bits(&s->gb, code - 1) + (1 << (code - 1));
553 level = -get_bits(&s->gb, code - 1) - (1 << (code - 1));
556 level = get_xbits(&s->gb, code);
560 if (get_bits1(&s->gb) == 0) { /* marker */
561 if (s->err_recognition & AV_EF_BITSTREAM) {
562 av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
569 return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
573 * Decode first partition.
574 * @return number of MBs decoded or <0 if an error occurred
576 static int mpeg4_decode_partition_a(Mpeg4DecContext *ctx)
578 MpegEncContext *s = &ctx->m;
580 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
582 /* decode first partition */
583 s->first_slice_line = 1;
584 for (; s->mb_y < s->mb_height; s->mb_y++) {
585 ff_init_block_index(s);
586 for (; s->mb_x < s->mb_width; s->mb_x++) {
587 const int xy = s->mb_x + s->mb_y * s->mb_stride;
592 ff_update_block_index(s);
593 if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
594 s->first_slice_line = 0;
596 if (s->pict_type == AV_PICTURE_TYPE_I) {
600 if (show_bits_long(&s->gb, 19) == DC_MARKER)
603 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
605 av_log(s->avctx, AV_LOG_ERROR,
606 "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
611 s->cbp_table[xy] = cbpc & 3;
612 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
616 ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
618 s->current_picture.qscale_table[xy] = s->qscale;
620 s->mbintra_table[xy] = 1;
621 for (i = 0; i < 6; i++) {
623 int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
625 av_log(s->avctx, AV_LOG_ERROR,
626 "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
633 s->pred_dir_table[xy] = dir;
634 } else { /* P/S_TYPE */
635 int mx, my, pred_x, pred_y, bits;
636 int16_t *const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
637 const int stride = s->b8_stride * 2;
640 bits = show_bits(&s->gb, 17);
641 if (bits == MOTION_MARKER)
645 if (bits & 0x10000) {
647 if (s->pict_type == AV_PICTURE_TYPE_S &&
648 ctx->vol_sprite_usage == GMC_SPRITE) {
649 s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
656 s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
663 mot_val[0 + stride] =
664 mot_val[2 + stride] = mx;
667 mot_val[1 + stride] =
668 mot_val[3 + stride] = my;
670 if (s->mbintra_table[xy])
671 ff_clean_intra_table_entries(s);
675 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
677 av_log(s->avctx, AV_LOG_ERROR,
678 "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
684 s->cbp_table[xy] = cbpc & (8 + 3); // 8 is dquant
686 s->mb_intra = ((cbpc & 4) != 0);
689 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
690 s->mbintra_table[xy] = 1;
693 mot_val[0 + stride] =
694 mot_val[2 + stride] = 0;
697 mot_val[1 + stride] =
698 mot_val[3 + stride] = 0;
700 if (s->mbintra_table[xy])
701 ff_clean_intra_table_entries(s);
703 if (s->pict_type == AV_PICTURE_TYPE_S &&
704 ctx->vol_sprite_usage == GMC_SPRITE &&
706 s->mcsel = get_bits1(&s->gb);
710 if ((cbpc & 16) == 0) {
711 /* 16x16 motion prediction */
713 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
715 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
719 my = ff_h263_decode_motion(s, pred_y, s->f_code);
722 s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
727 s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
734 mot_val[0 + stride] =
735 mot_val[2 + stride] = mx;
738 mot_val[1 + stride] =
739 mot_val[3 + stride] = my;
742 s->current_picture.mb_type[xy] = MB_TYPE_8x8 |
744 for (i = 0; i < 4; i++) {
745 int16_t *mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
746 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
750 my = ff_h263_decode_motion(s, pred_y, s->f_code);
767 * decode second partition.
768 * @return <0 if an error occurred
770 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count)
773 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
775 s->mb_x = s->resync_mb_x;
776 s->first_slice_line = 1;
777 for (s->mb_y = s->resync_mb_y; mb_num < mb_count; s->mb_y++) {
778 ff_init_block_index(s);
779 for (; mb_num < mb_count && s->mb_x < s->mb_width; s->mb_x++) {
780 const int xy = s->mb_x + s->mb_y * s->mb_stride;
783 ff_update_block_index(s);
784 if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
785 s->first_slice_line = 0;
787 if (s->pict_type == AV_PICTURE_TYPE_I) {
788 int ac_pred = get_bits1(&s->gb);
789 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
791 av_log(s->avctx, AV_LOG_ERROR,
792 "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
796 s->cbp_table[xy] |= cbpy << 2;
797 s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
798 } else { /* P || S_TYPE */
799 if (IS_INTRA(s->current_picture.mb_type[xy])) {
802 int ac_pred = get_bits1(&s->gb);
803 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
806 av_log(s->avctx, AV_LOG_ERROR,
807 "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
811 if (s->cbp_table[xy] & 8)
812 ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
813 s->current_picture.qscale_table[xy] = s->qscale;
815 for (i = 0; i < 6; i++) {
817 int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
819 av_log(s->avctx, AV_LOG_ERROR,
820 "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
827 s->cbp_table[xy] &= 3; // remove dquant
828 s->cbp_table[xy] |= cbpy << 2;
829 s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
830 s->pred_dir_table[xy] = dir;
831 } else if (IS_SKIP(s->current_picture.mb_type[xy])) {
832 s->current_picture.qscale_table[xy] = s->qscale;
833 s->cbp_table[xy] = 0;
835 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
838 av_log(s->avctx, AV_LOG_ERROR,
839 "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
843 if (s->cbp_table[xy] & 8)
844 ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
845 s->current_picture.qscale_table[xy] = s->qscale;
847 s->cbp_table[xy] &= 3; // remove dquant
848 s->cbp_table[xy] |= (cbpy ^ 0xf) << 2;
852 if (mb_num >= mb_count)
860 * Decode the first and second partition.
861 * @return <0 if error (and sets error type in the error_status_table)
863 int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx)
865 MpegEncContext *s = &ctx->m;
867 const int part_a_error = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_ERROR | ER_MV_ERROR) : ER_MV_ERROR;
868 const int part_a_end = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_END | ER_MV_END) : ER_MV_END;
870 mb_num = mpeg4_decode_partition_a(ctx);
872 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
873 s->mb_x, s->mb_y, part_a_error);
877 if (s->resync_mb_x + s->resync_mb_y * s->mb_width + mb_num > s->mb_num) {
878 av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
879 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
880 s->mb_x, s->mb_y, part_a_error);
884 s->mb_num_left = mb_num;
886 if (s->pict_type == AV_PICTURE_TYPE_I) {
887 while (show_bits(&s->gb, 9) == 1)
888 skip_bits(&s->gb, 9);
889 if (get_bits_long(&s->gb, 19) != DC_MARKER) {
890 av_log(s->avctx, AV_LOG_ERROR,
891 "marker missing after first I partition at %d %d\n",
896 while (show_bits(&s->gb, 10) == 1)
897 skip_bits(&s->gb, 10);
898 if (get_bits(&s->gb, 17) != MOTION_MARKER) {
899 av_log(s->avctx, AV_LOG_ERROR,
900 "marker missing after first P partition at %d %d\n",
905 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
906 s->mb_x - 1, s->mb_y, part_a_end);
908 if (mpeg4_decode_partition_b(s, mb_num) < 0) {
909 if (s->pict_type == AV_PICTURE_TYPE_P)
910 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
911 s->mb_x, s->mb_y, ER_DC_ERROR);
914 if (s->pict_type == AV_PICTURE_TYPE_P)
915 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
916 s->mb_x - 1, s->mb_y, ER_DC_END);
924 * @return <0 if an error occurred
926 static inline int mpeg4_decode_block(MpegEncContext *s, int16_t *block,
927 int n, int coded, int intra, int rvlc)
929 int level, i, last, run, qmul, qadd, dc_pred_dir;
932 const uint8_t *scan_table;
934 // Note intra & rvlc should be optimized away if this is inlined
937 if (s->use_intra_dc_vlc) {
939 if (s->partitioned_frame) {
940 level = s->dc_val[0][s->block_index[n]];
942 level = FASTDIV((level + (s->y_dc_scale >> 1)), s->y_dc_scale);
944 level = FASTDIV((level + (s->c_dc_scale >> 1)), s->c_dc_scale);
945 dc_pred_dir = (s->pred_dir_table[s->mb_x + s->mb_y * s->mb_stride] << n) & 32;
947 level = mpeg4_decode_dc(s, n, &dc_pred_dir);
955 ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
961 rl = &ff_rvlc_rl_intra;
962 rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
964 rl = &ff_mpeg4_rl_intra;
965 rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
968 if (dc_pred_dir == 0)
969 scan_table = s->intra_v_scantable.permutated; /* left */
971 scan_table = s->intra_h_scantable.permutated; /* top */
973 scan_table = s->intra_scantable.permutated;
980 s->block_last_index[n] = i;
984 rl = &ff_rvlc_rl_inter;
986 rl = &ff_h263_rl_inter;
988 scan_table = s->intra_scantable.permutated;
994 rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
996 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
998 qmul = s->qscale << 1;
999 qadd = (s->qscale - 1) | 1;
1001 rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
1003 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
1007 OPEN_READER(re, &s->gb);
1009 UPDATE_CACHE(re, &s->gb);
1010 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
1014 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1015 av_log(s->avctx, AV_LOG_ERROR,
1016 "1. marker bit missing in rvlc esc\n");
1019 SKIP_CACHE(re, &s->gb, 1);
1021 last = SHOW_UBITS(re, &s->gb, 1);
1022 SKIP_CACHE(re, &s->gb, 1);
1023 run = SHOW_UBITS(re, &s->gb, 6);
1024 SKIP_COUNTER(re, &s->gb, 1 + 1 + 6);
1025 UPDATE_CACHE(re, &s->gb);
1027 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1028 av_log(s->avctx, AV_LOG_ERROR,
1029 "2. marker bit missing in rvlc esc\n");
1032 SKIP_CACHE(re, &s->gb, 1);
1034 level = SHOW_UBITS(re, &s->gb, 11);
1035 SKIP_CACHE(re, &s->gb, 11);
1037 if (SHOW_UBITS(re, &s->gb, 5) != 0x10) {
1038 av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
1041 SKIP_CACHE(re, &s->gb, 5);
1043 level = level * qmul + qadd;
1044 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1045 SKIP_COUNTER(re, &s->gb, 1 + 11 + 5 + 1);
1052 cache = GET_CACHE(re, &s->gb);
1055 cache ^= 0xC0000000;
1057 if (cache & 0x80000000) {
1058 if (cache & 0x40000000) {
1060 SKIP_CACHE(re, &s->gb, 2);
1061 last = SHOW_UBITS(re, &s->gb, 1);
1062 SKIP_CACHE(re, &s->gb, 1);
1063 run = SHOW_UBITS(re, &s->gb, 6);
1064 SKIP_COUNTER(re, &s->gb, 2 + 1 + 6);
1065 UPDATE_CACHE(re, &s->gb);
1068 level = SHOW_SBITS(re, &s->gb, 12);
1069 LAST_SKIP_BITS(re, &s->gb, 12);
1071 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1072 av_log(s->avctx, AV_LOG_ERROR,
1073 "1. marker bit missing in 3. esc\n");
1076 SKIP_CACHE(re, &s->gb, 1);
1078 level = SHOW_SBITS(re, &s->gb, 12);
1079 SKIP_CACHE(re, &s->gb, 12);
1081 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1082 av_log(s->avctx, AV_LOG_ERROR,
1083 "2. marker bit missing in 3. esc\n");
1087 SKIP_COUNTER(re, &s->gb, 1 + 12 + 1);
1091 level = level * qmul + qadd;
1093 level = level * qmul - qadd;
1095 if ((unsigned)(level + 2048) > 4095) {
1096 if (s->err_recognition & AV_EF_BITSTREAM) {
1097 if (level > 2560 || level < -2560) {
1098 av_log(s->avctx, AV_LOG_ERROR,
1099 "|level| overflow in 3. esc, qp=%d\n",
1104 level = level < 0 ? -2048 : 2047;
1112 SKIP_BITS(re, &s->gb, 2);
1113 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1114 i += run + rl->max_run[run >> 7][level / qmul] + 1; // FIXME opt indexing
1115 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1116 LAST_SKIP_BITS(re, &s->gb, 1);
1120 SKIP_BITS(re, &s->gb, 1);
1121 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1123 level = level + rl->max_level[run >> 7][(run - 1) & 63] * qmul; // FIXME opt indexing
1124 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1125 LAST_SKIP_BITS(re, &s->gb, 1);
1130 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1131 LAST_SKIP_BITS(re, &s->gb, 1);
1136 av_log(s->avctx, AV_LOG_ERROR,
1137 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1141 block[scan_table[i]] = level;
1145 block[scan_table[i]] = level;
1147 CLOSE_READER(re, &s->gb);
1152 if (!s->use_intra_dc_vlc) {
1153 block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1155 i -= i >> 31; // if (i == -1) i = 0;
1158 ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1160 i = 63; // FIXME not optimal
1162 s->block_last_index[n] = i;
1167 * decode partition C of one MB.
1168 * @return <0 if an error occurred
1170 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1172 Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1174 const int xy = s->mb_x + s->mb_y * s->mb_stride;
1176 mb_type = s->current_picture.mb_type[xy];
1177 cbp = s->cbp_table[xy];
1179 s->use_intra_dc_vlc = s->qscale < s->intra_dc_threshold;
1181 if (s->current_picture.qscale_table[xy] != s->qscale)
1182 ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1184 if (s->pict_type == AV_PICTURE_TYPE_P ||
1185 s->pict_type == AV_PICTURE_TYPE_S) {
1187 for (i = 0; i < 4; i++) {
1188 s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1189 s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1191 s->mb_intra = IS_INTRA(mb_type);
1193 if (IS_SKIP(mb_type)) {
1195 for (i = 0; i < 6; i++)
1196 s->block_last_index[i] = -1;
1197 s->mv_dir = MV_DIR_FORWARD;
1198 s->mv_type = MV_TYPE_16X16;
1199 if (s->pict_type == AV_PICTURE_TYPE_S
1200 && ctx->vol_sprite_usage == GMC_SPRITE) {
1207 } else if (s->mb_intra) {
1208 s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1209 } else if (!s->mb_intra) {
1210 // s->mcsel = 0; // FIXME do we need to init that?
1212 s->mv_dir = MV_DIR_FORWARD;
1213 if (IS_8X8(mb_type)) {
1214 s->mv_type = MV_TYPE_8X8;
1216 s->mv_type = MV_TYPE_16X16;
1219 } else { /* I-Frame */
1221 s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1224 if (!IS_SKIP(mb_type)) {
1226 s->dsp.clear_blocks(s->block[0]);
1227 /* decode each block */
1228 for (i = 0; i < 6; i++) {
1229 if (mpeg4_decode_block(s, block[i], i, cbp & 32, s->mb_intra, ctx->rvlc) < 0) {
1230 av_log(s->avctx, AV_LOG_ERROR,
1231 "texture corrupted at %d %d %d\n",
1232 s->mb_x, s->mb_y, s->mb_intra);
1239 /* per-MB end of slice check */
1240 if (--s->mb_num_left <= 0) {
1241 if (mpeg4_is_resync(s))
1246 if (mpeg4_is_resync(s)) {
1247 const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1248 if (s->cbp_table[xy + delta])
1255 static int mpeg4_decode_mb(MpegEncContext *s, int16_t block[6][64])
1257 Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1258 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1260 static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1261 const int xy = s->mb_x + s->mb_y * s->mb_stride;
1263 assert(s->h263_pred);
1265 if (s->pict_type == AV_PICTURE_TYPE_P ||
1266 s->pict_type == AV_PICTURE_TYPE_S) {
1268 if (get_bits1(&s->gb)) {
1271 for (i = 0; i < 6; i++)
1272 s->block_last_index[i] = -1;
1273 s->mv_dir = MV_DIR_FORWARD;
1274 s->mv_type = MV_TYPE_16X16;
1275 if (s->pict_type == AV_PICTURE_TYPE_S &&
1276 ctx->vol_sprite_usage == GMC_SPRITE) {
1277 s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1282 s->mv[0][0][0] = get_amv(s, 0);
1283 s->mv[0][0][1] = get_amv(s, 1);
1286 s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1296 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1298 av_log(s->avctx, AV_LOG_ERROR,
1299 "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1302 } while (cbpc == 20);
1304 s->dsp.clear_blocks(s->block[0]);
1306 s->mb_intra = ((cbpc & 4) != 0);
1310 if (s->pict_type == AV_PICTURE_TYPE_S &&
1311 ctx->vol_sprite_usage == GMC_SPRITE && (cbpc & 16) == 0)
1312 s->mcsel = get_bits1(&s->gb);
1315 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1317 cbp = (cbpc & 3) | (cbpy << 2);
1319 ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1320 if ((!s->progressive_sequence) &&
1321 (cbp || (s->workaround_bugs & FF_BUG_XVID_ILACE)))
1322 s->interlaced_dct = get_bits1(&s->gb);
1324 s->mv_dir = MV_DIR_FORWARD;
1325 if ((cbpc & 16) == 0) {
1327 s->current_picture.mb_type[xy] = MB_TYPE_GMC |
1330 /* 16x16 global motion prediction */
1331 s->mv_type = MV_TYPE_16X16;
1334 s->mv[0][0][0] = mx;
1335 s->mv[0][0][1] = my;
1336 } else if ((!s->progressive_sequence) && get_bits1(&s->gb)) {
1337 s->current_picture.mb_type[xy] = MB_TYPE_16x8 |
1340 /* 16x8 field motion prediction */
1341 s->mv_type = MV_TYPE_FIELD;
1343 s->field_select[0][0] = get_bits1(&s->gb);
1344 s->field_select[0][1] = get_bits1(&s->gb);
1346 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1348 for (i = 0; i < 2; i++) {
1349 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1353 my = ff_h263_decode_motion(s, pred_y / 2, s->f_code);
1357 s->mv[0][i][0] = mx;
1358 s->mv[0][i][1] = my;
1361 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1362 /* 16x16 motion prediction */
1363 s->mv_type = MV_TYPE_16X16;
1364 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1365 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1370 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1374 s->mv[0][0][0] = mx;
1375 s->mv[0][0][1] = my;
1378 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1379 s->mv_type = MV_TYPE_8X8;
1380 for (i = 0; i < 4; i++) {
1381 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1382 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1386 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1389 s->mv[0][i][0] = mx;
1390 s->mv[0][i][1] = my;
1395 } else if (s->pict_type == AV_PICTURE_TYPE_B) {
1396 int modb1; // first bit of modb
1397 int modb2; // second bit of modb
1400 s->mb_intra = 0; // B-frames never contain intra blocks
1401 s->mcsel = 0; // ... true gmc blocks
1404 for (i = 0; i < 2; i++) {
1405 s->last_mv[i][0][0] =
1406 s->last_mv[i][0][1] =
1407 s->last_mv[i][1][0] =
1408 s->last_mv[i][1][1] = 0;
1411 ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1414 /* if we skipped it in the future P Frame than skip it now too */
1415 s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
1417 if (s->mb_skipped) {
1419 for (i = 0; i < 6; i++)
1420 s->block_last_index[i] = -1;
1422 s->mv_dir = MV_DIR_FORWARD;
1423 s->mv_type = MV_TYPE_16X16;
1428 s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1434 modb1 = get_bits1(&s->gb);
1436 // like MB_TYPE_B_DIRECT but no vectors coded
1437 mb_type = MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1;
1440 modb2 = get_bits1(&s->gb);
1441 mb_type = get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1443 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1446 mb_type = mb_type_b_map[mb_type];
1450 s->dsp.clear_blocks(s->block[0]);
1451 cbp = get_bits(&s->gb, 6);
1454 if ((!IS_DIRECT(mb_type)) && cbp) {
1455 if (get_bits1(&s->gb))
1456 ff_set_qscale(s, s->qscale + get_bits1(&s->gb) * 4 - 2);
1459 if (!s->progressive_sequence) {
1461 s->interlaced_dct = get_bits1(&s->gb);
1463 if (!IS_DIRECT(mb_type) && get_bits1(&s->gb)) {
1464 mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1465 mb_type &= ~MB_TYPE_16x16;
1467 if (USES_LIST(mb_type, 0)) {
1468 s->field_select[0][0] = get_bits1(&s->gb);
1469 s->field_select[0][1] = get_bits1(&s->gb);
1471 if (USES_LIST(mb_type, 1)) {
1472 s->field_select[1][0] = get_bits1(&s->gb);
1473 s->field_select[1][1] = get_bits1(&s->gb);
1479 if ((mb_type & (MB_TYPE_DIRECT2 | MB_TYPE_INTERLACED)) == 0) {
1480 s->mv_type = MV_TYPE_16X16;
1482 if (USES_LIST(mb_type, 0)) {
1483 s->mv_dir = MV_DIR_FORWARD;
1485 mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1486 my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1487 s->last_mv[0][1][0] =
1488 s->last_mv[0][0][0] =
1489 s->mv[0][0][0] = mx;
1490 s->last_mv[0][1][1] =
1491 s->last_mv[0][0][1] =
1492 s->mv[0][0][1] = my;
1495 if (USES_LIST(mb_type, 1)) {
1496 s->mv_dir |= MV_DIR_BACKWARD;
1498 mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1499 my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1500 s->last_mv[1][1][0] =
1501 s->last_mv[1][0][0] =
1502 s->mv[1][0][0] = mx;
1503 s->last_mv[1][1][1] =
1504 s->last_mv[1][0][1] =
1505 s->mv[1][0][1] = my;
1507 } else if (!IS_DIRECT(mb_type)) {
1508 s->mv_type = MV_TYPE_FIELD;
1510 if (USES_LIST(mb_type, 0)) {
1511 s->mv_dir = MV_DIR_FORWARD;
1513 for (i = 0; i < 2; i++) {
1514 mx = ff_h263_decode_motion(s, s->last_mv[0][i][0], s->f_code);
1515 my = ff_h263_decode_motion(s, s->last_mv[0][i][1] / 2, s->f_code);
1516 s->last_mv[0][i][0] =
1517 s->mv[0][i][0] = mx;
1518 s->last_mv[0][i][1] = (s->mv[0][i][1] = my) * 2;
1522 if (USES_LIST(mb_type, 1)) {
1523 s->mv_dir |= MV_DIR_BACKWARD;
1525 for (i = 0; i < 2; i++) {
1526 mx = ff_h263_decode_motion(s, s->last_mv[1][i][0], s->b_code);
1527 my = ff_h263_decode_motion(s, s->last_mv[1][i][1] / 2, s->b_code);
1528 s->last_mv[1][i][0] =
1529 s->mv[1][i][0] = mx;
1530 s->last_mv[1][i][1] = (s->mv[1][i][1] = my) * 2;
1536 if (IS_DIRECT(mb_type)) {
1537 if (IS_SKIP(mb_type)) {
1541 mx = ff_h263_decode_motion(s, 0, 1);
1542 my = ff_h263_decode_motion(s, 0, 1);
1545 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1546 mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1548 s->current_picture.mb_type[xy] = mb_type;
1549 } else { /* I-Frame */
1551 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1553 av_log(s->avctx, AV_LOG_ERROR,
1554 "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1557 } while (cbpc == 8);
1563 s->ac_pred = get_bits1(&s->gb);
1565 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1567 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1569 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1571 av_log(s->avctx, AV_LOG_ERROR,
1572 "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1575 cbp = (cbpc & 3) | (cbpy << 2);
1577 s->use_intra_dc_vlc = s->qscale < s->intra_dc_threshold;
1580 ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1582 if (!s->progressive_sequence)
1583 s->interlaced_dct = get_bits1(&s->gb);
1585 s->dsp.clear_blocks(s->block[0]);
1586 /* decode each block */
1587 for (i = 0; i < 6; i++) {
1588 if (mpeg4_decode_block(s, block[i], i, cbp & 32, 1, 0) < 0)
1595 /* decode each block */
1596 for (i = 0; i < 6; i++) {
1597 if (mpeg4_decode_block(s, block[i], i, cbp & 32, 0, 0) < 0)
1603 /* per-MB end of slice check */
1604 if (s->codec_id == AV_CODEC_ID_MPEG4) {
1605 if (mpeg4_is_resync(s)) {
1606 const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1608 if (s->pict_type == AV_PICTURE_TYPE_B &&
1609 s->next_picture.mbskip_table[xy + delta]) {
1610 ff_thread_await_progress(&s->next_picture_ptr->tf,
1611 (s->mb_x + delta >= s->mb_width)
1612 ? FFMIN(s->mb_y + 1, s->mb_height - 1)
1616 if (s->pict_type == AV_PICTURE_TYPE_B &&
1617 s->next_picture.mbskip_table[xy + delta])
1626 static int mpeg4_decode_gop_header(MpegEncContext *s, GetBitContext *gb)
1628 int hours, minutes, seconds;
1629 unsigned time_code = show_bits(gb, 18);
1631 if (time_code & 0x40) { /* marker_bit */
1632 hours = time_code >> 13;
1633 minutes = time_code >> 7 & 0x3f;
1634 seconds = time_code & 0x3f;
1635 s->time_base = seconds + 60 * (minutes + 60 * hours);
1636 skip_bits(gb, 20); /* time_code, closed_gov, broken_link */
1638 av_log(s->avctx, AV_LOG_WARNING, "GOP header missing marker_bit\n");
1644 static int mpeg4_decode_profile_level(MpegEncContext *s, GetBitContext *gb)
1646 int profile_and_level_indication;
1648 profile_and_level_indication = get_bits(gb, 8);
1650 s->avctx->profile = (profile_and_level_indication & 0xf0) >> 4;
1651 s->avctx->level = (profile_and_level_indication & 0x0f);
1653 // for Simple profile, level 0
1654 if (s->avctx->profile == 0 && s->avctx->level == 8) {
1655 s->avctx->level = 0;
1661 static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
1663 MpegEncContext *s = &ctx->m;
1664 int width, height, vo_ver_id;
1667 skip_bits(gb, 1); /* random access */
1668 s->vo_type = get_bits(gb, 8);
1669 if (get_bits1(gb) != 0) { /* is_ol_id */
1670 vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1671 skip_bits(gb, 3); /* vo_priority */
1675 s->aspect_ratio_info = get_bits(gb, 4);
1676 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1677 s->avctx->sample_aspect_ratio.num = get_bits(gb, 8); // par_width
1678 s->avctx->sample_aspect_ratio.den = get_bits(gb, 8); // par_height
1680 s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[s->aspect_ratio_info];
1683 if ((s->vol_control_parameters = get_bits1(gb))) { /* vol control parameter */
1684 int chroma_format = get_bits(gb, 2);
1685 if (chroma_format != CHROMA_420)
1686 av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1688 s->low_delay = get_bits1(gb);
1689 if (get_bits1(gb)) { /* vbv parameters */
1690 get_bits(gb, 15); /* first_half_bitrate */
1691 skip_bits1(gb); /* marker */
1692 get_bits(gb, 15); /* latter_half_bitrate */
1693 skip_bits1(gb); /* marker */
1694 get_bits(gb, 15); /* first_half_vbv_buffer_size */
1695 skip_bits1(gb); /* marker */
1696 get_bits(gb, 3); /* latter_half_vbv_buffer_size */
1697 get_bits(gb, 11); /* first_half_vbv_occupancy */
1698 skip_bits1(gb); /* marker */
1699 get_bits(gb, 15); /* latter_half_vbv_occupancy */
1700 skip_bits1(gb); /* marker */
1703 /* is setting low delay flag only once the smartest thing to do?
1704 * low delay detection won't be overriden. */
1705 if (s->picture_number == 0)
1709 ctx->shape = get_bits(gb, 2); /* vol shape */
1710 if (ctx->shape != RECT_SHAPE)
1711 av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1712 if (ctx->shape == GRAY_SHAPE && vo_ver_id != 1) {
1713 av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1714 skip_bits(gb, 4); /* video_object_layer_shape_extension */
1717 check_marker(gb, "before time_increment_resolution");
1719 s->avctx->time_base.den = get_bits(gb, 16);
1720 if (!s->avctx->time_base.den) {
1721 av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
1722 s->avctx->time_base.num = 0;
1726 ctx->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
1727 if (ctx->time_increment_bits < 1)
1728 ctx->time_increment_bits = 1;
1730 check_marker(gb, "before fixed_vop_rate");
1732 if (get_bits1(gb) != 0) /* fixed_vop_rate */
1733 s->avctx->time_base.num = get_bits(gb, ctx->time_increment_bits);
1735 s->avctx->time_base.num = 1;
1739 if (ctx->shape != BIN_ONLY_SHAPE) {
1740 if (ctx->shape == RECT_SHAPE) {
1741 skip_bits1(gb); /* marker */
1742 width = get_bits(gb, 13);
1743 skip_bits1(gb); /* marker */
1744 height = get_bits(gb, 13);
1745 skip_bits1(gb); /* marker */
1746 if (width && height && /* they should be non zero but who knows */
1747 !(s->width && s->codec_tag == AV_RL32("MP4S"))) {
1748 if (s->width && s->height &&
1749 (s->width != width || s->height != height))
1750 s->context_reinit = 1;
1756 s->progressive_sequence =
1757 s->progressive_frame = get_bits1(gb) ^ 1;
1758 s->interlaced_dct = 0;
1759 if (!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1760 av_log(s->avctx, AV_LOG_INFO, /* OBMC Disable */
1761 "MPEG4 OBMC not supported (very likely buggy encoder)\n");
1763 ctx->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1765 ctx->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1767 if (ctx->vol_sprite_usage == STATIC_SPRITE)
1768 av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1769 if (ctx->vol_sprite_usage == STATIC_SPRITE ||
1770 ctx->vol_sprite_usage == GMC_SPRITE) {
1771 if (ctx->vol_sprite_usage == STATIC_SPRITE) {
1772 skip_bits(gb, 13); // sprite_width
1773 skip_bits1(gb); /* marker */
1774 skip_bits(gb, 13); // sprite_height
1775 skip_bits1(gb); /* marker */
1776 skip_bits(gb, 13); // sprite_left
1777 skip_bits1(gb); /* marker */
1778 skip_bits(gb, 13); // sprite_top
1779 skip_bits1(gb); /* marker */
1781 s->num_sprite_warping_points = get_bits(gb, 6);
1782 if (s->num_sprite_warping_points > 3) {
1783 av_log(s->avctx, AV_LOG_ERROR,
1784 "%d sprite_warping_points\n",
1785 s->num_sprite_warping_points);
1786 s->num_sprite_warping_points = 0;
1789 s->sprite_warping_accuracy = get_bits(gb, 2);
1790 s->sprite_brightness_change = get_bits1(gb);
1791 if (ctx->vol_sprite_usage == STATIC_SPRITE)
1792 s->low_latency_sprite = get_bits1(gb);
1794 // FIXME sadct disable bit if verid!=1 && shape not rect
1796 if (get_bits1(gb) == 1) { /* not_8_bit */
1797 s->quant_precision = get_bits(gb, 4); /* quant_precision */
1798 if (get_bits(gb, 4) != 8) /* bits_per_pixel */
1799 av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n");
1800 if (s->quant_precision != 5)
1801 av_log(s->avctx, AV_LOG_ERROR,
1802 "quant precision %d\n", s->quant_precision);
1804 s->quant_precision = 5;
1807 // FIXME a bunch of grayscale shape things
1809 if ((s->mpeg_quant = get_bits1(gb))) { /* vol_quant_type */
1812 /* load default matrixes */
1813 for (i = 0; i < 64; i++) {
1814 int j = s->dsp.idct_permutation[i];
1815 v = ff_mpeg4_default_intra_matrix[i];
1816 s->intra_matrix[j] = v;
1817 s->chroma_intra_matrix[j] = v;
1819 v = ff_mpeg4_default_non_intra_matrix[i];
1820 s->inter_matrix[j] = v;
1821 s->chroma_inter_matrix[j] = v;
1824 /* load custom intra matrix */
1825 if (get_bits1(gb)) {
1827 for (i = 0; i < 64; i++) {
1829 v = get_bits(gb, 8);
1834 j = s->dsp.idct_permutation[ff_zigzag_direct[i]];
1835 s->intra_matrix[j] = last;
1836 s->chroma_intra_matrix[j] = last;
1839 /* replicate last value */
1840 for (; i < 64; i++) {
1841 int j = s->dsp.idct_permutation[ff_zigzag_direct[i]];
1842 s->intra_matrix[j] = last;
1843 s->chroma_intra_matrix[j] = last;
1847 /* load custom non intra matrix */
1848 if (get_bits1(gb)) {
1850 for (i = 0; i < 64; i++) {
1852 v = get_bits(gb, 8);
1857 j = s->dsp.idct_permutation[ff_zigzag_direct[i]];
1858 s->inter_matrix[j] = v;
1859 s->chroma_inter_matrix[j] = v;
1862 /* replicate last value */
1863 for (; i < 64; i++) {
1864 int j = s->dsp.idct_permutation[ff_zigzag_direct[i]];
1865 s->inter_matrix[j] = last;
1866 s->chroma_inter_matrix[j] = last;
1870 // FIXME a bunch of grayscale shape things
1874 s->quarter_sample = get_bits1(gb);
1876 s->quarter_sample = 0;
1878 if (!get_bits1(gb)) {
1879 int pos = get_bits_count(gb);
1880 int estimation_method = get_bits(gb, 2);
1881 if (estimation_method < 2) {
1882 if (!get_bits1(gb)) {
1883 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* opaque */
1884 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* transparent */
1885 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* intra_cae */
1886 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* inter_cae */
1887 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* no_update */
1888 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* upampling */
1890 if (!get_bits1(gb)) {
1891 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* intra_blocks */
1892 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* inter_blocks */
1893 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* inter4v_blocks */
1894 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* not coded blocks */
1896 if (!check_marker(gb, "in complexity estimation part 1")) {
1897 skip_bits_long(gb, pos - get_bits_count(gb));
1900 if (!get_bits1(gb)) {
1901 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* dct_coeffs */
1902 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* dct_lines */
1903 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* vlc_syms */
1904 s->cplx_estimation_trash_i += 4 * get_bits1(gb); /* vlc_bits */
1906 if (!get_bits1(gb)) {
1907 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* apm */
1908 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* npm */
1909 s->cplx_estimation_trash_b += 8 * get_bits1(gb); /* interpolate_mc_q */
1910 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* forwback_mc_q */
1911 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* halfpel2 */
1912 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* halfpel4 */
1914 if (!check_marker(gb, "in complexity estimation part 2")) {
1915 skip_bits_long(gb, pos - get_bits_count(gb));
1918 if (estimation_method == 1) {
1919 s->cplx_estimation_trash_i += 8 * get_bits1(gb); /* sadct */
1920 s->cplx_estimation_trash_p += 8 * get_bits1(gb); /* qpel */
1923 av_log(s->avctx, AV_LOG_ERROR,
1924 "Invalid Complexity estimation method %d\n",
1929 s->cplx_estimation_trash_i =
1930 s->cplx_estimation_trash_p =
1931 s->cplx_estimation_trash_b = 0;
1934 ctx->resync_marker = !get_bits1(gb); /* resync_marker_disabled */
1936 s->data_partitioning = get_bits1(gb);
1937 if (s->data_partitioning)
1938 ctx->rvlc = get_bits1(gb);
1940 if (vo_ver_id != 1) {
1941 s->new_pred = get_bits1(gb);
1943 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1944 skip_bits(gb, 2); /* requested upstream message type */
1945 skip_bits1(gb); /* newpred segment type */
1947 s->reduced_res_vop = get_bits1(gb);
1948 if (s->reduced_res_vop)
1949 av_log(s->avctx, AV_LOG_ERROR,
1950 "reduced resolution VOP not supported\n");
1953 s->reduced_res_vop = 0;
1956 s->scalability = get_bits1(gb);
1958 if (s->scalability) {
1959 GetBitContext bak = *gb;
1960 int h_sampling_factor_n;
1961 int h_sampling_factor_m;
1962 int v_sampling_factor_n;
1963 int v_sampling_factor_m;
1965 s->hierachy_type = get_bits1(gb);
1966 skip_bits(gb, 4); /* ref_layer_id */
1967 skip_bits1(gb); /* ref_layer_sampling_dir */
1968 h_sampling_factor_n = get_bits(gb, 5);
1969 h_sampling_factor_m = get_bits(gb, 5);
1970 v_sampling_factor_n = get_bits(gb, 5);
1971 v_sampling_factor_m = get_bits(gb, 5);
1972 s->enhancement_type = get_bits1(gb);
1974 if (h_sampling_factor_n == 0 || h_sampling_factor_m == 0 ||
1975 v_sampling_factor_n == 0 || v_sampling_factor_m == 0) {
1976 /* illegal scalability header (VERY broken encoder),
1977 * trying to workaround */
1981 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1983 // bin shape stuff FIXME
1991 * Decode the user data stuff in the header.
1992 * Also initializes divx/xvid/lavc_version/build.
1994 static int decode_user_data(MpegEncContext *s, GetBitContext *gb)
1999 int ver = 0, build = 0, ver2 = 0, ver3 = 0;
2002 for (i = 0; i < 255 && get_bits_count(gb) < gb->size_in_bits; i++) {
2003 if (show_bits(gb, 23) == 0)
2005 buf[i] = get_bits(gb, 8);
2009 /* divx detection */
2010 e = sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
2012 e = sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
2014 s->divx_version = ver;
2015 s->divx_build = build;
2016 s->divx_packed = e == 3 && last == 'p';
2017 if (s->divx_packed && !s->showed_packed_warning) {
2018 av_log(s->avctx, AV_LOG_WARNING,
2019 "Invalid and inefficient vfw-avi packed B frames detected\n");
2020 s->showed_packed_warning = 1;
2024 /* libavcodec detection */
2025 e = sscanf(buf, "FFmpe%*[^b]b%d", &build) + 3;
2027 e = sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
2029 e = sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3) + 1;
2031 build = (ver << 16) + (ver2 << 8) + ver3;
2034 if (strcmp(buf, "ffmpeg") == 0)
2035 s->lavc_build = 4600;
2038 s->lavc_build = build;
2040 /* Xvid detection */
2041 e = sscanf(buf, "XviD%d", &build);
2043 s->xvid_build = build;
2048 static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2050 MpegEncContext *s = &ctx->m;
2051 int time_incr, time_increment;
2053 s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I; /* pict type: I = 0 , P = 1 */
2054 if (s->pict_type == AV_PICTURE_TYPE_B && s->low_delay &&
2055 s->vol_control_parameters == 0 && !(s->flags & CODEC_FLAG_LOW_DELAY)) {
2056 av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
2060 s->partitioned_frame = s->data_partitioning && s->pict_type != AV_PICTURE_TYPE_B;
2061 if (s->partitioned_frame)
2062 s->decode_mb = mpeg4_decode_partitioned_mb;
2064 s->decode_mb = mpeg4_decode_mb;
2067 while (get_bits1(gb) != 0)
2070 check_marker(gb, "before time_increment");
2072 if (ctx->time_increment_bits == 0 ||
2073 !(show_bits(gb, ctx->time_increment_bits + 1) & 1)) {
2074 av_log(s->avctx, AV_LOG_ERROR,
2075 "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
2077 for (ctx->time_increment_bits = 1;
2078 ctx->time_increment_bits < 16;
2079 ctx->time_increment_bits++) {
2080 if (s->pict_type == AV_PICTURE_TYPE_P ||
2081 (s->pict_type == AV_PICTURE_TYPE_S &&
2082 ctx->vol_sprite_usage == GMC_SPRITE)) {
2083 if ((show_bits(gb, ctx->time_increment_bits + 6) & 0x37) == 0x30)
2085 } else if ((show_bits(gb, ctx->time_increment_bits + 5) & 0x1F) == 0x18)
2089 av_log(s->avctx, AV_LOG_ERROR,
2090 "my guess is %d bits ;)\n", ctx->time_increment_bits);
2094 time_increment = get_bits1(gb); // FIXME investigate further
2096 time_increment = get_bits(gb, ctx->time_increment_bits);
2098 if (s->pict_type != AV_PICTURE_TYPE_B) {
2099 s->last_time_base = s->time_base;
2100 s->time_base += time_incr;
2101 s->time = s->time_base * s->avctx->time_base.den + time_increment;
2102 if (s->workaround_bugs & FF_BUG_UMP4) {
2103 if (s->time < s->last_non_b_time) {
2104 /* header is not mpeg-4-compatible, broken encoder,
2105 * trying to workaround */
2107 s->time += s->avctx->time_base.den;
2110 s->pp_time = s->time - s->last_non_b_time;
2111 s->last_non_b_time = s->time;
2113 s->time = (s->last_time_base + time_incr) * s->avctx->time_base.den + time_increment;
2114 s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
2115 if (s->pp_time <= s->pb_time ||
2116 s->pp_time <= s->pp_time - s->pb_time ||
2118 /* messed up order, maybe after seeking? skipping current b-frame */
2119 return FRAME_SKIPPED;
2121 ff_mpeg4_init_direct_mv(s);
2123 if (s->t_frame == 0)
2124 s->t_frame = s->pb_time;
2125 if (s->t_frame == 0)
2126 s->t_frame = 1; // 1/0 protection
2127 s->pp_field_time = (ROUNDED_DIV(s->last_non_b_time, s->t_frame) -
2128 ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame)) * 2;
2129 s->pb_field_time = (ROUNDED_DIV(s->time, s->t_frame) -
2130 ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame)) * 2;
2131 if (!s->progressive_sequence) {
2132 if (s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
2133 return FRAME_SKIPPED;
2137 check_marker(gb, "before vop_coded");
2140 if (get_bits1(gb) != 1) {
2141 if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2142 av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
2143 return FRAME_SKIPPED;
2145 if (ctx->shape != BIN_ONLY_SHAPE &&
2146 (s->pict_type == AV_PICTURE_TYPE_P ||
2147 (s->pict_type == AV_PICTURE_TYPE_S &&
2148 ctx->vol_sprite_usage == GMC_SPRITE))) {
2149 /* rounding type for motion estimation */
2150 s->no_rounding = get_bits1(gb);
2154 // FIXME reduced res stuff
2156 if (ctx->shape != RECT_SHAPE) {
2157 if (ctx->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2158 skip_bits(gb, 13); /* width */
2159 skip_bits1(gb); /* marker */
2160 skip_bits(gb, 13); /* height */
2161 skip_bits1(gb); /* marker */
2162 skip_bits(gb, 13); /* hor_spat_ref */
2163 skip_bits1(gb); /* marker */
2164 skip_bits(gb, 13); /* ver_spat_ref */
2166 skip_bits1(gb); /* change_CR_disable */
2168 if (get_bits1(gb) != 0)
2169 skip_bits(gb, 8); /* constant_alpha_value */
2172 // FIXME complexity estimation stuff
2174 if (ctx->shape != BIN_ONLY_SHAPE) {
2175 skip_bits_long(gb, s->cplx_estimation_trash_i);
2176 if (s->pict_type != AV_PICTURE_TYPE_I)
2177 skip_bits_long(gb, s->cplx_estimation_trash_p);
2178 if (s->pict_type == AV_PICTURE_TYPE_B)
2179 skip_bits_long(gb, s->cplx_estimation_trash_b);
2181 s->intra_dc_threshold = ff_mpeg4_dc_threshold[get_bits(gb, 3)];
2182 if (!s->progressive_sequence) {
2183 s->top_field_first = get_bits1(gb);
2184 s->alternate_scan = get_bits1(gb);
2186 s->alternate_scan = 0;
2189 if (s->alternate_scan) {
2190 ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
2191 ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
2192 ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2193 ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2195 ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
2196 ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
2197 ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2198 ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2201 if (s->pict_type == AV_PICTURE_TYPE_S &&
2202 (ctx->vol_sprite_usage == STATIC_SPRITE ||
2203 ctx->vol_sprite_usage == GMC_SPRITE)) {
2204 if (mpeg4_decode_sprite_trajectory(s, gb) < 0)
2205 return AVERROR_INVALIDDATA;
2206 if (s->sprite_brightness_change)
2207 av_log(s->avctx, AV_LOG_ERROR,
2208 "sprite_brightness_change not supported\n");
2209 if (ctx->vol_sprite_usage == STATIC_SPRITE)
2210 av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2213 if (ctx->shape != BIN_ONLY_SHAPE) {
2214 s->chroma_qscale = s->qscale = get_bits(gb, s->quant_precision);
2215 if (s->qscale == 0) {
2216 av_log(s->avctx, AV_LOG_ERROR,
2217 "Error, header damaged or not MPEG4 header (qscale=0)\n");
2218 return -1; // makes no sense to continue, as there is nothing left from the image then
2221 if (s->pict_type != AV_PICTURE_TYPE_I) {
2222 s->f_code = get_bits(gb, 3); /* fcode_for */
2223 if (s->f_code == 0) {
2224 av_log(s->avctx, AV_LOG_ERROR,
2225 "Error, header damaged or not MPEG4 header (f_code=0)\n");
2226 return -1; // makes no sense to continue, as there is nothing left from the image then
2231 if (s->pict_type == AV_PICTURE_TYPE_B) {
2232 s->b_code = get_bits(gb, 3);
2236 if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2237 av_log(s->avctx, AV_LOG_DEBUG,
2238 "qp:%d fc:%d,%d %s size:%d pro:%d alt:%d top:%d %spel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d\n",
2239 s->qscale, s->f_code, s->b_code,
2240 s->pict_type == AV_PICTURE_TYPE_I ? "I" : (s->pict_type == AV_PICTURE_TYPE_P ? "P" : (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
2241 gb->size_in_bits, s->progressive_sequence, s->alternate_scan,
2242 s->top_field_first, s->quarter_sample ? "q" : "h",
2243 s->data_partitioning, ctx->resync_marker,
2244 s->num_sprite_warping_points, s->sprite_warping_accuracy,
2245 1 - s->no_rounding, s->vo_type,
2246 s->vol_control_parameters ? " VOLC" : " ", s->intra_dc_threshold,
2247 s->cplx_estimation_trash_i, s->cplx_estimation_trash_p,
2248 s->cplx_estimation_trash_b);
2251 if (!s->scalability) {
2252 if (ctx->shape != RECT_SHAPE && s->pict_type != AV_PICTURE_TYPE_I)
2253 skip_bits1(gb); // vop shape coding type
2255 if (s->enhancement_type) {
2256 int load_backward_shape = get_bits1(gb);
2257 if (load_backward_shape)
2258 av_log(s->avctx, AV_LOG_ERROR,
2259 "load backward shape isn't supported\n");
2261 skip_bits(gb, 2); // ref_select_code
2264 /* detect buggy encoders which don't set the low_delay flag
2265 * (divx4/xvid/opendivx). Note we cannot detect divx5 without b-frames
2266 * easily (although it's buggy too) */
2267 if (s->vo_type == 0 && s->vol_control_parameters == 0 &&
2268 s->divx_version == -1 && s->picture_number == 0) {
2269 av_log(s->avctx, AV_LOG_WARNING,
2270 "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2274 s->picture_number++; // better than pic number==0 always ;)
2276 // FIXME add short header support
2277 s->y_dc_scale_table = ff_mpeg4_y_dc_scale_table;
2278 s->c_dc_scale_table = ff_mpeg4_c_dc_scale_table;
2280 if (s->workaround_bugs & FF_BUG_EDGE) {
2281 s->h_edge_pos = s->width;
2282 s->v_edge_pos = s->height;
2288 * Decode mpeg4 headers.
2289 * @return <0 if no VOP found (or a damaged one)
2290 * FRAME_SKIPPED if a not coded VOP is found
2291 * 0 if a VOP is found
2293 int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2295 MpegEncContext *s = &ctx->m;
2296 unsigned startcode, v;
2298 /* search next start code */
2301 if (s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630) {
2303 if (get_bits(gb, 8) == 0xF0)
2309 if (get_bits_count(gb) >= gb->size_in_bits) {
2310 if (gb->size_in_bits == 8 &&
2311 (s->divx_version >= 0 || s->xvid_build >= 0)) {
2312 av_log(s->avctx, AV_LOG_WARNING, "frame skip %d\n", gb->size_in_bits);
2313 return FRAME_SKIPPED; // divx bug
2315 return -1; // end of stream
2318 /* use the bits after the test */
2319 v = get_bits(gb, 8);
2320 startcode = ((startcode << 8) | v) & 0xffffffff;
2322 if ((startcode & 0xFFFFFF00) != 0x100)
2323 continue; // no startcode
2325 if (s->avctx->debug & FF_DEBUG_STARTCODE) {
2326 av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2327 if (startcode <= 0x11F)
2328 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2329 else if (startcode <= 0x12F)
2330 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2331 else if (startcode <= 0x13F)
2332 av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2333 else if (startcode <= 0x15F)
2334 av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2335 else if (startcode <= 0x1AF)
2336 av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2337 else if (startcode == 0x1B0)
2338 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2339 else if (startcode == 0x1B1)
2340 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2341 else if (startcode == 0x1B2)
2342 av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2343 else if (startcode == 0x1B3)
2344 av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2345 else if (startcode == 0x1B4)
2346 av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2347 else if (startcode == 0x1B5)
2348 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2349 else if (startcode == 0x1B6)
2350 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2351 else if (startcode == 0x1B7)
2352 av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2353 else if (startcode == 0x1B8)
2354 av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2355 else if (startcode == 0x1B9)
2356 av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2357 else if (startcode == 0x1BA)
2358 av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2359 else if (startcode == 0x1BB)
2360 av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2361 else if (startcode == 0x1BC)
2362 av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2363 else if (startcode == 0x1BD)
2364 av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2365 else if (startcode == 0x1BE)
2366 av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2367 else if (startcode == 0x1BF)
2368 av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2369 else if (startcode == 0x1C0)
2370 av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2371 else if (startcode == 0x1C1)
2372 av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2373 else if (startcode == 0x1C2)
2374 av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2375 else if (startcode == 0x1C3)
2376 av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2377 else if (startcode <= 0x1C5)
2378 av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2379 else if (startcode <= 0x1FF)
2380 av_log(s->avctx, AV_LOG_DEBUG, "System start");
2381 av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2384 if (startcode >= 0x120 && startcode <= 0x12F) {
2385 if (decode_vol_header(ctx, gb) < 0)
2387 } else if (startcode == USER_DATA_STARTCODE) {
2388 decode_user_data(s, gb);
2389 } else if (startcode == GOP_STARTCODE) {
2390 mpeg4_decode_gop_header(s, gb);
2391 } else if (startcode == VOS_STARTCODE) {
2392 mpeg4_decode_profile_level(s, gb);
2393 } else if (startcode == VOP_STARTCODE) {
2402 if (s->flags & CODEC_FLAG_LOW_DELAY)
2404 s->avctx->has_b_frames = !s->low_delay;
2406 if (s->xvid_build == -1 && s->divx_version == -1 && s->lavc_build == -1) {
2407 if (s->stream_codec_tag == AV_RL32("XVID") ||
2408 s->codec_tag == AV_RL32("XVID") ||
2409 s->codec_tag == AV_RL32("XVIX") ||
2410 s->codec_tag == AV_RL32("RMP4") ||
2411 s->codec_tag == AV_RL32("ZMP4") ||
2412 s->codec_tag == AV_RL32("SIPP"))
2416 if (s->xvid_build == -1 && s->divx_version == -1 && s->lavc_build == -1)
2417 if (s->codec_tag == AV_RL32("DIVX") && s->vo_type == 0 &&
2418 s->vol_control_parameters == 0)
2419 s->divx_version = 400; // divx 4
2421 if (s->xvid_build >= 0 && s->divx_version >= 0) {
2426 if (s->workaround_bugs & FF_BUG_AUTODETECT) {
2427 if (s->codec_tag == AV_RL32("XVIX"))
2428 s->workaround_bugs |= FF_BUG_XVID_ILACE;
2430 if (s->codec_tag == AV_RL32("UMP4"))
2431 s->workaround_bugs |= FF_BUG_UMP4;
2433 if (s->divx_version >= 500 && s->divx_build < 1814)
2434 s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2436 if (s->divx_version > 502 && s->divx_build < 1814)
2437 s->workaround_bugs |= FF_BUG_QPEL_CHROMA2;
2439 if (s->xvid_build <= 3U)
2440 s->padding_bug_score = 256 * 256 * 256 * 64;
2442 if (s->xvid_build <= 1U)
2443 s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2445 if (s->xvid_build <= 12U)
2446 s->workaround_bugs |= FF_BUG_EDGE;
2448 if (s->xvid_build <= 32U)
2449 s->workaround_bugs |= FF_BUG_DC_CLIP;
2451 if (s->lavc_build < 4653U)
2452 s->workaround_bugs |= FF_BUG_STD_QPEL;
2454 if (s->lavc_build < 4655U)
2455 s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2457 if (s->lavc_build < 4670U)
2458 s->workaround_bugs |= FF_BUG_EDGE;
2460 if (s->lavc_build <= 4712U)
2461 s->workaround_bugs |= FF_BUG_DC_CLIP;
2463 if (s->divx_version >= 0)
2464 s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2466 if (s->divx_version == 501 && s->divx_build == 20020416)
2467 s->padding_bug_score = 256 * 256 * 256 * 64;
2469 if (s->divx_version < 500U)
2470 s->workaround_bugs |= FF_BUG_EDGE;
2472 if (s->divx_version >= 0)
2473 s->workaround_bugs |= FF_BUG_HPEL_CHROMA;
2477 if (s->codec_id == AV_CODEC_ID_MPEG4 && s->xvid_build >= 0 &&
2478 s->avctx->idct_algo == FF_IDCT_AUTO &&
2479 (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
2480 s->avctx->idct_algo = FF_IDCT_XVIDMMX;
2481 ff_dct_common_init(s);
2482 s->picture_number = 0;
2486 if (s->avctx->debug & FF_DEBUG_BUGS)
2487 av_log(s->avctx, AV_LOG_DEBUG,
2488 "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
2489 s->workaround_bugs, s->lavc_build, s->xvid_build,
2490 s->divx_version, s->divx_build, s->divx_packed ? "p" : "");
2492 return decode_vop_header(ctx, gb);
2495 static int mpeg4_update_thread_context(AVCodecContext *dst,
2496 const AVCodecContext *src)
2498 Mpeg4DecContext *s = dst->priv_data;
2499 const Mpeg4DecContext *s1 = src->priv_data;
2501 int ret = ff_mpeg_update_thread_context(dst, src);
2506 s->shape = s1->shape;
2507 s->time_increment_bits = s1->time_increment_bits;
2512 static av_cold int decode_init(AVCodecContext *avctx)
2514 Mpeg4DecContext *ctx = avctx->priv_data;
2515 MpegEncContext *s = &ctx->m;
2517 static int done = 0;
2524 if ((ret = ff_h263_decode_init(avctx)) < 0)
2530 ff_init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2531 ff_init_rl(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2532 ff_init_rl(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2533 INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2534 INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
2535 INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
2536 INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2537 &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2538 &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2539 INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2540 &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2541 &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2542 INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2543 &ff_sprite_trajectory_tab[0][1], 4, 2,
2544 &ff_sprite_trajectory_tab[0][0], 4, 2, 128);
2545 INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2546 &ff_mb_type_b_tab[0][1], 2, 1,
2547 &ff_mb_type_b_tab[0][0], 2, 1, 16);
2551 s->low_delay = 0; /* default, might be overriden in the vol header during header parsing */
2552 s->decode_mb = mpeg4_decode_mb;
2553 ctx->time_increment_bits = 4; /* default value for broken headers */
2555 avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2556 avctx->internal->allocate_progress = 1;
2561 static const AVProfile mpeg4_video_profiles[] = {
2562 { FF_PROFILE_MPEG4_SIMPLE, "Simple Profile" },
2563 { FF_PROFILE_MPEG4_SIMPLE_SCALABLE, "Simple Scalable Profile" },
2564 { FF_PROFILE_MPEG4_CORE, "Core Profile" },
2565 { FF_PROFILE_MPEG4_MAIN, "Main Profile" },
2566 { FF_PROFILE_MPEG4_N_BIT, "N-bit Profile" },
2567 { FF_PROFILE_MPEG4_SCALABLE_TEXTURE, "Scalable Texture Profile" },
2568 { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION, "Simple Face Animation Profile" },
2569 { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE, "Basic Animated Texture Profile" },
2570 { FF_PROFILE_MPEG4_HYBRID, "Hybrid Profile" },
2571 { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME, "Advanced Real Time Simple Profile" },
2572 { FF_PROFILE_MPEG4_CORE_SCALABLE, "Code Scalable Profile" },
2573 { FF_PROFILE_MPEG4_ADVANCED_CODING, "Advanced Coding Profile" },
2574 { FF_PROFILE_MPEG4_ADVANCED_CORE, "Advanced Core Profile" },
2575 { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2576 { FF_PROFILE_MPEG4_SIMPLE_STUDIO, "Simple Studio Profile" },
2577 { FF_PROFILE_MPEG4_ADVANCED_SIMPLE, "Advanced Simple Profile" },
2580 AVCodec ff_mpeg4_decoder = {
2582 .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2583 .type = AVMEDIA_TYPE_VIDEO,
2584 .id = AV_CODEC_ID_MPEG4,
2585 .priv_data_size = sizeof(Mpeg4DecContext),
2586 .init = decode_init,
2587 .close = ff_h263_decode_end,
2588 .decode = ff_h263_decode_frame,
2589 .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2590 CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2591 CODEC_CAP_FRAME_THREADS,
2592 .flush = ff_mpeg_flush,
2593 .pix_fmts = ff_h263_hwaccel_pixfmt_list_420,
2594 .profiles = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2595 .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg4_update_thread_context),