path: root/libavcodec/mpeg4videodec.c (plain)
blob: 791a07bbbb7dbb31039912b8a5a1dfb26b5f89bd

1	/*
2	* MPEG-4 decoder
3	* Copyright (c) 2000,2001 Fabrice Bellard
4	* Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
5	*
6	* This file is part of FFmpeg.
7	*
8	* FFmpeg 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.
12	*
13	* FFmpeg 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.
17	*
18	* You should have received a copy of the GNU Lesser General Public
19	* License along with FFmpeg; if not, write to the Free Software
20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21	*/
22
23	#define UNCHECKED_BITSTREAM_READER 1
24
25	#include "libavutil/internal.h"
26	#include "libavutil/opt.h"
27	#include "error_resilience.h"
28	#include "idctdsp.h"
29	#include "internal.h"
30	#include "mpegutils.h"
31	#include "mpegvideo.h"
32	#include "mpegvideodata.h"
33	#include "mpeg4video.h"
34	#include "h263.h"
35	#include "profiles.h"
36	#include "thread.h"
37	#include "xvididct.h"
38
39	/* The defines below define the number of bits that are read at once for
40	* reading vlc values. Changing these may improve speed and data cache needs
41	* be aware though that decreasing them may need the number of stages that is
42	* passed to get_vlc* to be increased. */
43	#define SPRITE_TRAJ_VLC_BITS 6
44	#define DC_VLC_BITS 9
45	#define MB_TYPE_B_VLC_BITS 4
46
47	static VLC dc_lum, dc_chrom;
48	static VLC sprite_trajectory;
49	static VLC mb_type_b_vlc;
50
51	static const int mb_type_b_map[4] = {
52	MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
53	MB_TYPE_L0L1 | MB_TYPE_16x16,
54	MB_TYPE_L1 | MB_TYPE_16x16,
55	MB_TYPE_L0 | MB_TYPE_16x16,
56	};
57
58	/**
59	* Predict the ac.
60	* @param n block index (0-3 are luma, 4-5 are chroma)
61	* @param dir the ac prediction direction
62	*/
63	void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n, int dir)
64	{
65	int i;
66	int16_t *ac_val, *ac_val1;
67	int8_t *const qscale_table = s->current_picture.qscale_table;
68
69	/* find prediction */
70	ac_val = &s->ac_val[0][0][0] + s->block_index[n] * 16;
71	ac_val1 = ac_val;
72	if (s->ac_pred) {
73	if (dir == 0) {
74	const int xy = s->mb_x - 1 + s->mb_y * s->mb_stride;
75	/* left prediction */
76	ac_val -= 16;
77
78	if (s->mb_x == 0 || s->qscale == qscale_table[xy] ||
79	n == 1 || n == 3) {
80	/* same qscale */
81	for (i = 1; i < 8; i++)
82	block[s->idsp.idct_permutation[i << 3]] += ac_val[i];
83	} else {
84	/* different qscale, we must rescale */
85	for (i = 1; i < 8; i++)
86	block[s->idsp.idct_permutation[i << 3]] += ROUNDED_DIV(ac_val[i] * qscale_table[xy], s->qscale);
87	}
88	} else {
89	const int xy = s->mb_x + s->mb_y * s->mb_stride - s->mb_stride;
90	/* top prediction */
91	ac_val -= 16 * s->block_wrap[n];
92
93	if (s->mb_y == 0 || s->qscale == qscale_table[xy] ||
94	n == 2 || n == 3) {
95	/* same qscale */
96	for (i = 1; i < 8; i++)
97	block[s->idsp.idct_permutation[i]] += ac_val[i + 8];
98	} else {
99	/* different qscale, we must rescale */
100	for (i = 1; i < 8; i++)
101	block[s->idsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8] * qscale_table[xy], s->qscale);
102	}
103	}
104	}
105	/* left copy */
106	for (i = 1; i < 8; i++)
107	ac_val1[i] = block[s->idsp.idct_permutation[i << 3]];
108
109	/* top copy */
110	for (i = 1; i < 8; i++)
111	ac_val1[8 + i] = block[s->idsp.idct_permutation[i]];
112	}
113
114	/**
115	* check if the next stuff is a resync marker or the end.
116	* @return 0 if not
117	*/
118	static inline int mpeg4_is_resync(Mpeg4DecContext *ctx)
119	{
120	MpegEncContext *s = &ctx->m;
121	int bits_count = get_bits_count(&s->gb);
122	int v = show_bits(&s->gb, 16);
123
124	if (s->workaround_bugs & FF_BUG_NO_PADDING && !ctx->resync_marker)
125	return 0;
126
127	while (v <= 0xFF) {
128	if (s->pict_type == AV_PICTURE_TYPE_B ||
129	(v >> (8 - s->pict_type) != 1) || s->partitioned_frame)
130	break;
131	skip_bits(&s->gb, 8 + s->pict_type);
132	bits_count += 8 + s->pict_type;
133	v = show_bits(&s->gb, 16);
134	}
135
136	if (bits_count + 8 >= s->gb.size_in_bits) {
137	v >>= 8;
138	v |= 0x7F >> (7 - (bits_count & 7));
139
140	if (v == 0x7F)
141	return s->mb_num;
142	} else {
143	if (v == ff_mpeg4_resync_prefix[bits_count & 7]) {
144	int len, mb_num;
145	int mb_num_bits = av_log2(s->mb_num - 1) + 1;
146	GetBitContext gb = s->gb;
147
148	skip_bits(&s->gb, 1);
149	align_get_bits(&s->gb);
150
151	for (len = 0; len < 32; len++)
152	if (get_bits1(&s->gb))
153	break;
154
155	mb_num = get_bits(&s->gb, mb_num_bits);
156	if (!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
157	mb_num= -1;
158
159	s->gb = gb;
160
161	if (len >= ff_mpeg4_get_video_packet_prefix_length(s))
162	return mb_num;
163	}
164	}
165	return 0;
166	}
167
168	static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *gb)
169	{
170	MpegEncContext *s = &ctx->m;
171	int a = 2 << s->sprite_warping_accuracy;
172	int rho = 3 - s->sprite_warping_accuracy;
173	int r = 16 / a;
174	int alpha = 0;
175	int beta = 0;
176	int w = s->width;
177	int h = s->height;
178	int min_ab, i, w2, h2, w3, h3;
179	int sprite_ref[4][2];
180	int virtual_ref[2][2];
181
182	// only true for rectangle shapes
183	const int vop_ref[4][2] = { { 0, 0 }, { s->width, 0 },
184	{ 0, s->height }, { s->width, s->height } };
185	int d[4][2] = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } };
186
187	if (w <= 0 || h <= 0)
188	return AVERROR_INVALIDDATA;
189
190	for (i = 0; i < ctx->num_sprite_warping_points; i++) {
191	int length;
192	int x = 0, y = 0;
193
194	length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
195	if (length > 0)
196	x = get_xbits(gb, length);
197
198	if (!(ctx->divx_version == 500 && ctx->divx_build == 413))
199	check_marker(s->avctx, gb, "before sprite_trajectory");
200
201	length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
202	if (length > 0)
203	y = get_xbits(gb, length);
204
205	check_marker(s->avctx, gb, "after sprite_trajectory");
206	ctx->sprite_traj[i][0] = d[i][0] = x;
207	ctx->sprite_traj[i][1] = d[i][1] = y;
208	}
209	for (; i < 4; i++)
210	ctx->sprite_traj[i][0] = ctx->sprite_traj[i][1] = 0;
211
212	while ((1 << alpha) < w)
213	alpha++;
214	while ((1 << beta) < h)
215	beta++; /* typo in the MPEG-4 std for the definition of w' and h' */
216	w2 = 1 << alpha;
217	h2 = 1 << beta;
218
219	// Note, the 4th point isn't used for GMC
220	if (ctx->divx_version == 500 && ctx->divx_build == 413) {
221	sprite_ref[0][0] = a * vop_ref[0][0] + d[0][0];
222	sprite_ref[0][1] = a * vop_ref[0][1] + d[0][1];
223	sprite_ref[1][0] = a * vop_ref[1][0] + d[0][0] + d[1][0];
224	sprite_ref[1][1] = a * vop_ref[1][1] + d[0][1] + d[1][1];
225	sprite_ref[2][0] = a * vop_ref[2][0] + d[0][0] + d[2][0];
226	sprite_ref[2][1] = a * vop_ref[2][1] + d[0][1] + d[2][1];
227	} else {
228	sprite_ref[0][0] = (a >> 1) * (2 * vop_ref[0][0] + d[0][0]);
229	sprite_ref[0][1] = (a >> 1) * (2 * vop_ref[0][1] + d[0][1]);
230	sprite_ref[1][0] = (a >> 1) * (2 * vop_ref[1][0] + d[0][0] + d[1][0]);
231	sprite_ref[1][1] = (a >> 1) * (2 * vop_ref[1][1] + d[0][1] + d[1][1]);
232	sprite_ref[2][0] = (a >> 1) * (2 * vop_ref[2][0] + d[0][0] + d[2][0]);
233	sprite_ref[2][1] = (a >> 1) * (2 * vop_ref[2][1] + d[0][1] + d[2][1]);
234	}
235	/* sprite_ref[3][0] = (a >> 1) * (2 * vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
236	* sprite_ref[3][1] = (a >> 1) * (2 * vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
237
238	/* This is mostly identical to the MPEG-4 std (and is totally unreadable
239	* because of that...). Perhaps it should be reordered to be more readable.
240	* The idea behind this virtual_ref mess is to be able to use shifts later
241	* per pixel instead of divides so the distance between points is converted
242	* from w&h based to w2&h2 based which are of the 2^x form. */
243	virtual_ref[0][0] = 16 * (vop_ref[0][0] + w2) +
244	ROUNDED_DIV(((w - w2) *
245	(r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
246	w2 * (r * sprite_ref[1][0] - 16 * vop_ref[1][0])), w);
247	virtual_ref[0][1] = 16 * vop_ref[0][1] +
248	ROUNDED_DIV(((w - w2) *
249	(r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
250	w2 * (r * sprite_ref[1][1] - 16 * vop_ref[1][1])), w);
251	virtual_ref[1][0] = 16 * vop_ref[0][0] +
252	ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
253	h2 * (r * sprite_ref[2][0] - 16 * vop_ref[2][0])), h);
254	virtual_ref[1][1] = 16 * (vop_ref[0][1] + h2) +
255	ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
256	h2 * (r * sprite_ref[2][1] - 16 * vop_ref[2][1])), h);
257
258	switch (ctx->num_sprite_warping_points) {
259	case 0:
260	s->sprite_offset[0][0] =
261	s->sprite_offset[0][1] =
262	s->sprite_offset[1][0] =
263	s->sprite_offset[1][1] = 0;
264	s->sprite_delta[0][0] = a;
265	s->sprite_delta[0][1] =
266	s->sprite_delta[1][0] = 0;
267	s->sprite_delta[1][1] = a;
268	ctx->sprite_shift[0] =
269	ctx->sprite_shift[1] = 0;
270	break;
271	case 1: // GMC only
272	s->sprite_offset[0][0] = sprite_ref[0][0] - a * vop_ref[0][0];
273	s->sprite_offset[0][1] = sprite_ref[0][1] - a * vop_ref[0][1];
274	s->sprite_offset[1][0] = ((sprite_ref[0][0] >> 1) | (sprite_ref[0][0] & 1)) -
275	a * (vop_ref[0][0] / 2);
276	s->sprite_offset[1][1] = ((sprite_ref[0][1] >> 1) | (sprite_ref[0][1] & 1)) -
277	a * (vop_ref[0][1] / 2);
278	s->sprite_delta[0][0] = a;
279	s->sprite_delta[0][1] =
280	s->sprite_delta[1][0] = 0;
281	s->sprite_delta[1][1] = a;
282	ctx->sprite_shift[0] =
283	ctx->sprite_shift[1] = 0;
284	break;
285	case 2:
286	s->sprite_offset[0][0] = (sprite_ref[0][0] * (1 << alpha + rho)) +
287	(-r * sprite_ref[0][0] + virtual_ref[0][0]) *
288	(-vop_ref[0][0]) +
289	(r * sprite_ref[0][1] - virtual_ref[0][1]) *
290	(-vop_ref[0][1]) + (1 << (alpha + rho - 1));
291	s->sprite_offset[0][1] = (sprite_ref[0][1] * (1 << alpha + rho)) +
292	(-r * sprite_ref[0][1] + virtual_ref[0][1]) *
293	(-vop_ref[0][0]) +
294	(-r * sprite_ref[0][0] + virtual_ref[0][0]) *
295	(-vop_ref[0][1]) + (1 << (alpha + rho - 1));
296	s->sprite_offset[1][0] = ((-r * sprite_ref[0][0] + virtual_ref[0][0]) *
297	(-2 * vop_ref[0][0] + 1) +
298	(r * sprite_ref[0][1] - virtual_ref[0][1]) *
299	(-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
300	sprite_ref[0][0] - 16 * w2 + (1 << (alpha + rho + 1)));
301	s->sprite_offset[1][1] = ((-r * sprite_ref[0][1] + virtual_ref[0][1]) *
302	(-2 * vop_ref[0][0] + 1) +
303	(-r * sprite_ref[0][0] + virtual_ref[0][0]) *
304	(-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
305	sprite_ref[0][1] - 16 * w2 + (1 << (alpha + rho + 1)));
306	s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
307	s->sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
308	s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
309	s->sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
310
311	ctx->sprite_shift[0] = alpha + rho;
312	ctx->sprite_shift[1] = alpha + rho + 2;
313	break;
314	case 3:
315	min_ab = FFMIN(alpha, beta);
316	w3 = w2 >> min_ab;
317	h3 = h2 >> min_ab;
318	s->sprite_offset[0][0] = (sprite_ref[0][0] * (1<<(alpha + beta + rho - min_ab))) +
319	(-r * sprite_ref[0][0] + virtual_ref[0][0]) *
320	h3 * (-vop_ref[0][0]) +
321	(-r * sprite_ref[0][0] + virtual_ref[1][0]) *
322	w3 * (-vop_ref[0][1]) +
323	(1 << (alpha + beta + rho - min_ab - 1));
324	s->sprite_offset[0][1] = (sprite_ref[0][1] * (1 << (alpha + beta + rho - min_ab))) +
325	(-r * sprite_ref[0][1] + virtual_ref[0][1]) *
326	h3 * (-vop_ref[0][0]) +
327	(-r * sprite_ref[0][1] + virtual_ref[1][1]) *
328	w3 * (-vop_ref[0][1]) +
329	(1 << (alpha + beta + rho - min_ab - 1));
330	s->sprite_offset[1][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
331	h3 * (-2 * vop_ref[0][0] + 1) +
332	(-r * sprite_ref[0][0] + virtual_ref[1][0]) *
333	w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
334	r * sprite_ref[0][0] - 16 * w2 * h3 +
335	(1 << (alpha + beta + rho - min_ab + 1));
336	s->sprite_offset[1][1] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
337	h3 * (-2 * vop_ref[0][0] + 1) +
338	(-r * sprite_ref[0][1] + virtual_ref[1][1]) *
339	w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
340	r * sprite_ref[0][1] - 16 * w2 * h3 +
341	(1 << (alpha + beta + rho - min_ab + 1));
342	s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3;
343	s->sprite_delta[0][1] = (-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3;
344	s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3;
345	s->sprite_delta[1][1] = (-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3;
346
347	ctx->sprite_shift[0] = alpha + beta + rho - min_ab;
348	ctx->sprite_shift[1] = alpha + beta + rho - min_ab + 2;
349	break;
350	}
351	/* try to simplify the situation */
352	if (s->sprite_delta[0][0] == a << ctx->sprite_shift[0] &&
353	s->sprite_delta[0][1] == 0 &&
354	s->sprite_delta[1][0] == 0 &&
355	s->sprite_delta[1][1] == a << ctx->sprite_shift[0]) {
356	s->sprite_offset[0][0] >>= ctx->sprite_shift[0];
357	s->sprite_offset[0][1] >>= ctx->sprite_shift[0];
358	s->sprite_offset[1][0] >>= ctx->sprite_shift[1];
359	s->sprite_offset[1][1] >>= ctx->sprite_shift[1];
360	s->sprite_delta[0][0] = a;
361	s->sprite_delta[0][1] = 0;
362	s->sprite_delta[1][0] = 0;
363	s->sprite_delta[1][1] = a;
364	ctx->sprite_shift[0] = 0;
365	ctx->sprite_shift[1] = 0;
366	s->real_sprite_warping_points = 1;
367	} else {
368	int shift_y = 16 - ctx->sprite_shift[0];
369	int shift_c = 16 - ctx->sprite_shift[1];
370
371	if (shift_c < 0 || shift_y < 0 ||
372	FFABS(s->sprite_offset[0][0]) >= INT_MAX >> shift_y ||
373	FFABS(s->sprite_offset[1][0]) >= INT_MAX >> shift_c ||
374	FFABS(s->sprite_offset[0][1]) >= INT_MAX >> shift_y ||
375	FFABS(s->sprite_offset[1][1]) >= INT_MAX >> shift_c
376	) {
377	avpriv_request_sample(s->avctx, "Too large sprite shift or offset");
378	goto overflow;
379	}
380
381	for (i = 0; i < 2; i++) {
382	s->sprite_offset[0][i] *= 1 << shift_y;
383	s->sprite_offset[1][i] *= 1 << shift_c;
384	s->sprite_delta[0][i] *= 1 << shift_y;
385	s->sprite_delta[1][i] *= 1 << shift_y;
386	ctx->sprite_shift[i] = 16;
387
388	}
389	for (i = 0; i < 2; i++) {
390	int64_t sd[2] = {
391	s->sprite_delta[i][0] - a * (1LL<<16),
392	s->sprite_delta[i][1] - a * (1LL<<16)
393	};
394
395	if (llabs(s->sprite_offset[0][i] + s->sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
396	llabs(s->sprite_offset[0][i] + s->sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
397	llabs(s->sprite_offset[0][i] + s->sprite_delta[i][0] * (w+16LL) + s->sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
398	llabs(s->sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
399	llabs(s->sprite_delta[i][1] * (w+16LL)) >= INT_MAX ||
400	llabs(sd[0]) >= INT_MAX ||
401	llabs(sd[1]) >= INT_MAX ||
402	llabs(s->sprite_offset[0][i] + sd[0] * (w+16LL)) >= INT_MAX ||
403	llabs(s->sprite_offset[0][i] + sd[1] * (h+16LL)) >= INT_MAX ||
404	llabs(s->sprite_offset[0][i] + sd[0] * (w+16LL) + sd[1] * (h+16LL)) >= INT_MAX
405	) {
406	avpriv_request_sample(s->avctx, "Overflow on sprite points");
407	goto overflow;
408	}
409	}
410	s->real_sprite_warping_points = ctx->num_sprite_warping_points;
411	}
412
413	return 0;
414	overflow:
415	memset(s->sprite_offset, 0, sizeof(s->sprite_offset));
416	memset(s->sprite_delta, 0, sizeof(s->sprite_delta));
417	return AVERROR_PATCHWELCOME;
418	}
419
420	static int decode_new_pred(Mpeg4DecContext *ctx, GetBitContext *gb) {
421	MpegEncContext *s = &ctx->m;
422	int len = FFMIN(ctx->time_increment_bits + 3, 15);
423
424	get_bits(gb, len);
425	if (get_bits1(gb))
426	get_bits(gb, len);
427	check_marker(s->avctx, gb, "after new_pred");
428
429	return 0;
430	}
431
432	/**
433	* Decode the next video packet.
434	* @return <0 if something went wrong
435	*/
436	int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
437	{
438	MpegEncContext *s = &ctx->m;
439
440	int mb_num_bits = av_log2(s->mb_num - 1) + 1;
441	int header_extension = 0, mb_num, len;
442
443	/* is there enough space left for a video packet + header */
444	if (get_bits_count(&s->gb) > s->gb.size_in_bits - 20)
445	return -1;
446
447	for (len = 0; len < 32; len++)
448	if (get_bits1(&s->gb))
449	break;
450
451	if (len != ff_mpeg4_get_video_packet_prefix_length(s)) {
452	av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
453	return -1;
454	}
455
456	if (ctx->shape != RECT_SHAPE) {
457	header_extension = get_bits1(&s->gb);
458	// FIXME more stuff here
459	}
460
461	mb_num = get_bits(&s->gb, mb_num_bits);
462	if (mb_num >= s->mb_num) {
463	av_log(s->avctx, AV_LOG_ERROR,
464	"illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
465	return -1;
466	}
467
468	s->mb_x = mb_num % s->mb_width;
469	s->mb_y = mb_num / s->mb_width;
470
471	if (ctx->shape != BIN_ONLY_SHAPE) {
472	int qscale = get_bits(&s->gb, s->quant_precision);
473	if (qscale)
474	s->chroma_qscale = s->qscale = qscale;
475	}
476
477	if (ctx->shape == RECT_SHAPE)
478	header_extension = get_bits1(&s->gb);
479
480	if (header_extension) {
481	int time_incr = 0;
482
483	while (get_bits1(&s->gb) != 0)
484	time_incr++;
485
486	check_marker(s->avctx, &s->gb, "before time_increment in video packed header");
487	skip_bits(&s->gb, ctx->time_increment_bits); /* time_increment */
488	check_marker(s->avctx, &s->gb, "before vop_coding_type in video packed header");
489
490	skip_bits(&s->gb, 2); /* vop coding type */
491	// FIXME not rect stuff here
492
493	if (ctx->shape != BIN_ONLY_SHAPE) {
494	skip_bits(&s->gb, 3); /* intra dc vlc threshold */
495	// FIXME don't just ignore everything
496	if (s->pict_type == AV_PICTURE_TYPE_S &&
497	ctx->vol_sprite_usage == GMC_SPRITE) {
498	if (mpeg4_decode_sprite_trajectory(ctx, &s->gb) < 0)
499	return AVERROR_INVALIDDATA;
500	av_log(s->avctx, AV_LOG_ERROR, "untested\n");
501	}
502
503	// FIXME reduced res stuff here
504
505	if (s->pict_type != AV_PICTURE_TYPE_I) {
506	int f_code = get_bits(&s->gb, 3); /* fcode_for */
507	if (f_code == 0)
508	av_log(s->avctx, AV_LOG_ERROR,
509	"Error, video packet header damaged (f_code=0)\n");
510	}
511	if (s->pict_type == AV_PICTURE_TYPE_B) {
512	int b_code = get_bits(&s->gb, 3);
513	if (b_code == 0)
514	av_log(s->avctx, AV_LOG_ERROR,
515	"Error, video packet header damaged (b_code=0)\n");
516	}
517	}
518	}
519	if (ctx->new_pred)
520	decode_new_pred(ctx, &s->gb);
521
522	return 0;
523	}
524
525	/**
526	* Get the average motion vector for a GMC MB.
527	* @param n either 0 for the x component or 1 for y
528	* @return the average MV for a GMC MB
529	*/
530	static inline int get_amv(Mpeg4DecContext *ctx, int n)
531	{
532	MpegEncContext *s = &ctx->m;
533	int x, y, mb_v, sum, dx, dy, shift;
534	int len = 1 << (s->f_code + 4);
535	const int a = s->sprite_warping_accuracy;
536
537	if (s->workaround_bugs & FF_BUG_AMV)
538	len >>= s->quarter_sample;
539
540	if (s->real_sprite_warping_points == 1) {
541	if (ctx->divx_version == 500 && ctx->divx_build == 413)
542	sum = s->sprite_offset[0][n] / (1 << (a - s->quarter_sample));
543	else
544	sum = RSHIFT(s->sprite_offset[0][n] * (1 << s->quarter_sample), a);
545	} else {
546	dx = s->sprite_delta[n][0];
547	dy = s->sprite_delta[n][1];
548	shift = ctx->sprite_shift[0];
549	if (n)
550	dy -= 1 << (shift + a + 1);
551	else
552	dx -= 1 << (shift + a + 1);
553	mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16 + dy * s->mb_y * 16;
554
555	sum = 0;
556	for (y = 0; y < 16; y++) {
557	int v;
558
559	v = mb_v + dy * y;
560	// FIXME optimize
561	for (x = 0; x < 16; x++) {
562	sum += v >> shift;
563	v += dx;
564	}
565	}
566	sum = RSHIFT(sum, a + 8 - s->quarter_sample);
567	}
568
569	if (sum < -len)
570	sum = -len;
571	else if (sum >= len)
572	sum = len - 1;
573
574	return sum;
575	}
576
577	/**
578	* Decode the dc value.
579	* @param n block index (0-3 are luma, 4-5 are chroma)
580	* @param dir_ptr the prediction direction will be stored here
581	* @return the quantized dc
582	*/
583	static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
584	{
585	int level, code;
586
587	if (n < 4)
588	code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
589	else
590	code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
591
592	if (code < 0 || code > 9 /* && s->nbit < 9 */) {
593	av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
594	return -1;
595	}
596
597	if (code == 0) {
598	level = 0;
599	} else {
600	if (IS_3IV1) {
601	if (code == 1)
602	level = 2 * get_bits1(&s->gb) - 1;
603	else {
604	if (get_bits1(&s->gb))
605	level = get_bits(&s->gb, code - 1) + (1 << (code - 1));
606	else
607	level = -get_bits(&s->gb, code - 1) - (1 << (code - 1));
608	}
609	} else {
610	level = get_xbits(&s->gb, code);
611	}
612
613	if (code > 8) {
614	if (get_bits1(&s->gb) == 0) { /* marker */
615	if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)) {
616	av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
617	return -1;
618	}
619	}
620	}
621	}
622
623	return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
624	}
625
626	/**
627	* Decode first partition.
628	* @return number of MBs decoded or <0 if an error occurred
629	*/
630	static int mpeg4_decode_partition_a(Mpeg4DecContext *ctx)
631	{
632	MpegEncContext *s = &ctx->m;
633	int mb_num = 0;
634	static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
635
636	/* decode first partition */
637	s->first_slice_line = 1;
638	for (; s->mb_y < s->mb_height; s->mb_y++) {
639	ff_init_block_index(s);
640	for (; s->mb_x < s->mb_width; s->mb_x++) {
641	const int xy = s->mb_x + s->mb_y * s->mb_stride;
642	int cbpc;
643	int dir = 0;
644
645	mb_num++;
646	ff_update_block_index(s);
647	if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
648	s->first_slice_line = 0;
649
650	if (s->pict_type == AV_PICTURE_TYPE_I) {
651	int i;
652
653	do {
654	if (show_bits_long(&s->gb, 19) == DC_MARKER)
655	return mb_num - 1;
656
657	cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
658	if (cbpc < 0) {
659	av_log(s->avctx, AV_LOG_ERROR,
660	"mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
661	return -1;
662	}
663	} while (cbpc == 8);
664
665	s->cbp_table[xy] = cbpc & 3;
666	s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
667	s->mb_intra = 1;
668
669	if (cbpc & 4)
670	ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
671
672	s->current_picture.qscale_table[xy] = s->qscale;
673
674	s->mbintra_table[xy] = 1;
675	for (i = 0; i < 6; i++) {
676	int dc_pred_dir;
677	int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
678	if (dc < 0) {
679	av_log(s->avctx, AV_LOG_ERROR,
680	"DC corrupted at %d %d\n", s->mb_x, s->mb_y);
681	return -1;
682	}
683	dir <<= 1;
684	if (dc_pred_dir)
685	dir |= 1;
686	}
687	s->pred_dir_table[xy] = dir;
688	} else { /* P/S_TYPE */
689	int mx, my, pred_x, pred_y, bits;
690	int16_t *const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
691	const int stride = s->b8_stride * 2;
692
693	try_again:
694	bits = show_bits(&s->gb, 17);
695	if (bits == MOTION_MARKER)
696	return mb_num - 1;
697
698	skip_bits1(&s->gb);
699	if (bits & 0x10000) {
700	/* skip mb */
701	if (s->pict_type == AV_PICTURE_TYPE_S &&
702	ctx->vol_sprite_usage == GMC_SPRITE) {
703	s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
704	MB_TYPE_16x16 |
705	MB_TYPE_GMC |
706	MB_TYPE_L0;
707	mx = get_amv(ctx, 0);
708	my = get_amv(ctx, 1);
709	} else {
710	s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
711	MB_TYPE_16x16 |
712	MB_TYPE_L0;
713	mx = my = 0;
714	}
715	mot_val[0] =
716	mot_val[2] =
717	mot_val[0 + stride] =
718	mot_val[2 + stride] = mx;
719	mot_val[1] =
720	mot_val[3] =
721	mot_val[1 + stride] =
722	mot_val[3 + stride] = my;
723
724	if (s->mbintra_table[xy])
725	ff_clean_intra_table_entries(s);
726	continue;
727	}
728
729	cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
730	if (cbpc < 0) {
731	av_log(s->avctx, AV_LOG_ERROR,
732	"mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
733	return -1;
734	}
735	if (cbpc == 20)
736	goto try_again;
737
738	s->cbp_table[xy] = cbpc & (8 + 3); // 8 is dquant
739
740	s->mb_intra = ((cbpc & 4) != 0);
741
742	if (s->mb_intra) {
743	s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
744	s->mbintra_table[xy] = 1;
745	mot_val[0] =
746	mot_val[2] =
747	mot_val[0 + stride] =
748	mot_val[2 + stride] = 0;
749	mot_val[1] =
750	mot_val[3] =
751	mot_val[1 + stride] =
752	mot_val[3 + stride] = 0;
753	} else {
754	if (s->mbintra_table[xy])
755	ff_clean_intra_table_entries(s);
756
757	if (s->pict_type == AV_PICTURE_TYPE_S &&
758	ctx->vol_sprite_usage == GMC_SPRITE &&
759	(cbpc & 16) == 0)
760	s->mcsel = get_bits1(&s->gb);
761	else
762	s->mcsel = 0;
763
764	if ((cbpc & 16) == 0) {
765	/* 16x16 motion prediction */
766
767	ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
768	if (!s->mcsel) {
769	mx = ff_h263_decode_motion(s, pred_x, s->f_code);
770	if (mx >= 0xffff)
771	return -1;
772
773	my = ff_h263_decode_motion(s, pred_y, s->f_code);
774	if (my >= 0xffff)
775	return -1;
776	s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
777	MB_TYPE_L0;
778	} else {
779	mx = get_amv(ctx, 0);
780	my = get_amv(ctx, 1);
781	s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
782	MB_TYPE_GMC |
783	MB_TYPE_L0;
784	}
785
786	mot_val[0] =
787	mot_val[2] =
788	mot_val[0 + stride] =
789	mot_val[2 + stride] = mx;
790	mot_val[1] =
791	mot_val[3] =
792	mot_val[1 + stride] =
793	mot_val[3 + stride] = my;
794	} else {
795	int i;
796	s->current_picture.mb_type[xy] = MB_TYPE_8x8 |
797	MB_TYPE_L0;
798	for (i = 0; i < 4; i++) {
799	int16_t *mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
800	mx = ff_h263_decode_motion(s, pred_x, s->f_code);
801	if (mx >= 0xffff)
802	return -1;
803
804	my = ff_h263_decode_motion(s, pred_y, s->f_code);
805	if (my >= 0xffff)
806	return -1;
807	mot_val[0] = mx;
808	mot_val[1] = my;
809	}
810	}
811	}
812	}
813	}
814	s->mb_x = 0;
815	}
816
817	return mb_num;
818	}
819
820	/**
821	* decode second partition.
822	* @return <0 if an error occurred
823	*/
824	static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count)
825	{
826	int mb_num = 0;
827	static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
828
829	s->mb_x = s->resync_mb_x;
830	s->first_slice_line = 1;
831	for (s->mb_y = s->resync_mb_y; mb_num < mb_count; s->mb_y++) {
832	ff_init_block_index(s);
833	for (; mb_num < mb_count && s->mb_x < s->mb_width; s->mb_x++) {
834	const int xy = s->mb_x + s->mb_y * s->mb_stride;
835
836	mb_num++;
837	ff_update_block_index(s);
838	if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
839	s->first_slice_line = 0;
840
841	if (s->pict_type == AV_PICTURE_TYPE_I) {
842	int ac_pred = get_bits1(&s->gb);
843	int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
844	if (cbpy < 0) {
845	av_log(s->avctx, AV_LOG_ERROR,
846	"cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
847	return -1;
848	}
849
850	s->cbp_table[xy] |= cbpy << 2;
851	s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
852	} else { /* P || S_TYPE */
853	if (IS_INTRA(s->current_picture.mb_type[xy])) {
854	int i;
855	int dir = 0;
856	int ac_pred = get_bits1(&s->gb);
857	int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
858
859	if (cbpy < 0) {
860	av_log(s->avctx, AV_LOG_ERROR,
861	"I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
862	return -1;
863	}
864
865	if (s->cbp_table[xy] & 8)
866	ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
867	s->current_picture.qscale_table[xy] = s->qscale;
868
869	for (i = 0; i < 6; i++) {
870	int dc_pred_dir;
871	int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
872	if (dc < 0) {
873	av_log(s->avctx, AV_LOG_ERROR,
874	"DC corrupted at %d %d\n", s->mb_x, s->mb_y);
875	return -1;
876	}
877	dir <<= 1;
878	if (dc_pred_dir)
879	dir |= 1;
880	}
881	s->cbp_table[xy] &= 3; // remove dquant
882	s->cbp_table[xy] |= cbpy << 2;
883	s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
884	s->pred_dir_table[xy] = dir;
885	} else if (IS_SKIP(s->current_picture.mb_type[xy])) {
886	s->current_picture.qscale_table[xy] = s->qscale;
887	s->cbp_table[xy] = 0;
888	} else {
889	int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
890
891	if (cbpy < 0) {
892	av_log(s->avctx, AV_LOG_ERROR,
893	"P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
894	return -1;
895	}
896
897	if (s->cbp_table[xy] & 8)
898	ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
899	s->current_picture.qscale_table[xy] = s->qscale;
900
901	s->cbp_table[xy] &= 3; // remove dquant
902	s->cbp_table[xy] |= (cbpy ^ 0xf) << 2;
903	}
904	}
905	}
906	if (mb_num >= mb_count)
907	return 0;
908	s->mb_x = 0;
909	}
910	return 0;
911	}
912
913	/**
914	* Decode the first and second partition.
915	* @return <0 if error (and sets error type in the error_status_table)
916	*/
917	int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx)
918	{
919	MpegEncContext *s = &ctx->m;
920	int mb_num;
921	const int part_a_error = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_ERROR | ER_MV_ERROR) : ER_MV_ERROR;
922	const int part_a_end = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_END | ER_MV_END) : ER_MV_END;
923
924	mb_num = mpeg4_decode_partition_a(ctx);
925	if (mb_num <= 0) {
926	ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
927	s->mb_x, s->mb_y, part_a_error);
928	return -1;
929	}
930
931	if (s->resync_mb_x + s->resync_mb_y * s->mb_width + mb_num > s->mb_num) {
932	av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
933	ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
934	s->mb_x, s->mb_y, part_a_error);
935	return -1;
936	}
937
938	s->mb_num_left = mb_num;
939
940	if (s->pict_type == AV_PICTURE_TYPE_I) {
941	while (show_bits(&s->gb, 9) == 1)
942	skip_bits(&s->gb, 9);
943	if (get_bits_long(&s->gb, 19) != DC_MARKER) {
944	av_log(s->avctx, AV_LOG_ERROR,
945	"marker missing after first I partition at %d %d\n",
946	s->mb_x, s->mb_y);
947	return -1;
948	}
949	} else {
950	while (show_bits(&s->gb, 10) == 1)
951	skip_bits(&s->gb, 10);
952	if (get_bits(&s->gb, 17) != MOTION_MARKER) {
953	av_log(s->avctx, AV_LOG_ERROR,
954	"marker missing after first P partition at %d %d\n",
955	s->mb_x, s->mb_y);
956	return -1;
957	}
958	}
959	ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
960	s->mb_x - 1, s->mb_y, part_a_end);
961
962	if (mpeg4_decode_partition_b(s, mb_num) < 0) {
963	if (s->pict_type == AV_PICTURE_TYPE_P)
964	ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
965	s->mb_x, s->mb_y, ER_DC_ERROR);
966	return -1;
967	} else {
968	if (s->pict_type == AV_PICTURE_TYPE_P)
969	ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
970	s->mb_x - 1, s->mb_y, ER_DC_END);
971	}
972
973	return 0;
974	}
975
976	/**
977	* Decode a block.
978	* @return <0 if an error occurred
979	*/
980	static inline int mpeg4_decode_block(Mpeg4DecContext *ctx, int16_t *block,
981	int n, int coded, int intra, int rvlc)
982	{
983	MpegEncContext *s = &ctx->m;
984	int level, i, last, run, qmul, qadd;
985	int av_uninit(dc_pred_dir);
986	RLTable *rl;
987	RL_VLC_ELEM *rl_vlc;
988	const uint8_t *scan_table;
989
990	// Note intra & rvlc should be optimized away if this is inlined
991
992	if (intra) {
993	if (ctx->use_intra_dc_vlc) {
994	/* DC coef */
995	if (s->partitioned_frame) {
996	level = s->dc_val[0][s->block_index[n]];
997	if (n < 4)
998	level = FASTDIV((level + (s->y_dc_scale >> 1)), s->y_dc_scale);
999	else
1000	level = FASTDIV((level + (s->c_dc_scale >> 1)), s->c_dc_scale);
1001	dc_pred_dir = (s->pred_dir_table[s->mb_x + s->mb_y * s->mb_stride] << n) & 32;
1002	} else {
1003	level = mpeg4_decode_dc(s, n, &dc_pred_dir);
1004	if (level < 0)
1005	return -1;
1006	}
1007	block[0] = level;
1008	i = 0;
1009	} else {
1010	i = -1;
1011	ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
1012	}
1013	if (!coded)
1014	goto not_coded;
1015
1016	if (rvlc) {
1017	rl = &ff_rvlc_rl_intra;
1018	rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
1019	} else {
1020	rl = &ff_mpeg4_rl_intra;
1021	rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
1022	}
1023	if (s->ac_pred) {
1024	if (dc_pred_dir == 0)
1025	scan_table = s->intra_v_scantable.permutated; /* left */
1026	else
1027	scan_table = s->intra_h_scantable.permutated; /* top */
1028	} else {
1029	scan_table = s->intra_scantable.permutated;
1030	}
1031	qmul = 1;
1032	qadd = 0;
1033	} else {
1034	i = -1;
1035	if (!coded) {
1036	s->block_last_index[n] = i;
1037	return 0;
1038	}
1039	if (rvlc)
1040	rl = &ff_rvlc_rl_inter;
1041	else
1042	rl = &ff_h263_rl_inter;
1043
1044	scan_table = s->intra_scantable.permutated;
1045
1046	if (s->mpeg_quant) {
1047	qmul = 1;
1048	qadd = 0;
1049	if (rvlc)
1050	rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
1051	else
1052	rl_vlc = ff_h263_rl_inter.rl_vlc[0];
1053	} else {
1054	qmul = s->qscale << 1;
1055	qadd = (s->qscale - 1) | 1;
1056	if (rvlc)
1057	rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
1058	else
1059	rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
1060	}
1061	}
1062	{
1063	OPEN_READER(re, &s->gb);
1064	for (;;) {
1065	UPDATE_CACHE(re, &s->gb);
1066	GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
1067	if (level == 0) {
1068	/* escape */
1069	if (rvlc) {
1070	if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1071	av_log(s->avctx, AV_LOG_ERROR,
1072	"1. marker bit missing in rvlc esc\n");
1073	return -1;
1074	}
1075	SKIP_CACHE(re, &s->gb, 1);
1076
1077	last = SHOW_UBITS(re, &s->gb, 1);
1078	SKIP_CACHE(re, &s->gb, 1);
1079	run = SHOW_UBITS(re, &s->gb, 6);
1080	SKIP_COUNTER(re, &s->gb, 1 + 1 + 6);
1081	UPDATE_CACHE(re, &s->gb);
1082
1083	if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1084	av_log(s->avctx, AV_LOG_ERROR,
1085	"2. marker bit missing in rvlc esc\n");
1086	return -1;
1087	}
1088	SKIP_CACHE(re, &s->gb, 1);
1089
1090	level = SHOW_UBITS(re, &s->gb, 11);
1091	SKIP_CACHE(re, &s->gb, 11);
1092
1093	if (SHOW_UBITS(re, &s->gb, 5) != 0x10) {
1094	av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
1095	return -1;
1096	}
1097	SKIP_CACHE(re, &s->gb, 5);
1098
1099	level = level * qmul + qadd;
1100	level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1101	SKIP_COUNTER(re, &s->gb, 1 + 11 + 5 + 1);
1102
1103	i += run + 1;
1104	if (last)
1105	i += 192;
1106	} else {
1107	int cache;
1108	cache = GET_CACHE(re, &s->gb);
1109
1110	if (IS_3IV1)
1111	cache ^= 0xC0000000;
1112
1113	if (cache & 0x80000000) {
1114	if (cache & 0x40000000) {
1115	/* third escape */
1116	SKIP_CACHE(re, &s->gb, 2);
1117	last = SHOW_UBITS(re, &s->gb, 1);
1118	SKIP_CACHE(re, &s->gb, 1);
1119	run = SHOW_UBITS(re, &s->gb, 6);
1120	SKIP_COUNTER(re, &s->gb, 2 + 1 + 6);
1121	UPDATE_CACHE(re, &s->gb);
1122
1123	if (IS_3IV1) {
1124	level = SHOW_SBITS(re, &s->gb, 12);
1125	LAST_SKIP_BITS(re, &s->gb, 12);
1126	} else {
1127	if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1128	av_log(s->avctx, AV_LOG_ERROR,
1129	"1. marker bit missing in 3. esc\n");
1130	if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR))
1131	return -1;
1132	}
1133	SKIP_CACHE(re, &s->gb, 1);
1134
1135	level = SHOW_SBITS(re, &s->gb, 12);
1136	SKIP_CACHE(re, &s->gb, 12);
1137
1138	if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1139	av_log(s->avctx, AV_LOG_ERROR,
1140	"2. marker bit missing in 3. esc\n");
1141	if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR))
1142	return -1;
1143	}
1144
1145	SKIP_COUNTER(re, &s->gb, 1 + 12 + 1);
1146	}
1147
1148	#if 0
1149	if (s->error_recognition >= FF_ER_COMPLIANT) {
1150	const int abs_level= FFABS(level);
1151	if (abs_level<=MAX_LEVEL && run<=MAX_RUN) {
1152	const int run1= run - rl->max_run[last][abs_level] - 1;
1153	if (abs_level <= rl->max_level[last][run]) {
1154	av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
1155	return -1;
1156	}
1157	if (s->error_recognition > FF_ER_COMPLIANT) {
1158	if (abs_level <= rl->max_level[last][run]*2) {
1159	av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1160	return -1;
1161	}
1162	if (run1 >= 0 && abs_level <= rl->max_level[last][run1]) {
1163	av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1164	return -1;
1165	}
1166	}
1167	}
1168	}
1169	#endif
1170	if (level > 0)
1171	level = level * qmul + qadd;
1172	else
1173	level = level * qmul - qadd;
1174
1175	if ((unsigned)(level + 2048) > 4095) {
1176	if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_AGGRESSIVE)) {
1177	if (level > 2560 || level < -2560) {
1178	av_log(s->avctx, AV_LOG_ERROR,
1179	"|level| overflow in 3. esc, qp=%d\n",
1180	s->qscale);
1181	return -1;
1182	}
1183	}
1184	level = level < 0 ? -2048 : 2047;
1185	}
1186
1187	i += run + 1;
1188	if (last)
1189	i += 192;
1190	} else {
1191	/* second escape */
1192	SKIP_BITS(re, &s->gb, 2);
1193	GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1194	i += run + rl->max_run[run >> 7][level / qmul] + 1; // FIXME opt indexing
1195	level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1196	LAST_SKIP_BITS(re, &s->gb, 1);
1197	}
1198	} else {
1199	/* first escape */
1200	SKIP_BITS(re, &s->gb, 1);
1201	GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1202	i += run;
1203	level = level + rl->max_level[run >> 7][(run - 1) & 63] * qmul; // FIXME opt indexing
1204	level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1205	LAST_SKIP_BITS(re, &s->gb, 1);
1206	}
1207	}
1208	} else {
1209	i += run;
1210	level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1211	LAST_SKIP_BITS(re, &s->gb, 1);
1212	}
1213	ff_tlog(s->avctx, "dct[%d][%d] = %- 4d end?:%d\n", scan_table[i&63]&7, scan_table[i&63] >> 3, level, i>62);
1214	if (i > 62) {
1215	i -= 192;
1216	if (i & (~63)) {
1217	av_log(s->avctx, AV_LOG_ERROR,
1218	"ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1219	return -1;
1220	}
1221
1222	block[scan_table[i]] = level;
1223	break;
1224	}
1225
1226	block[scan_table[i]] = level;
1227	}
1228	CLOSE_READER(re, &s->gb);
1229	}
1230
1231	not_coded:
1232	if (intra) {
1233	if (!ctx->use_intra_dc_vlc) {
1234	block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1235
1236	i -= i >> 31; // if (i == -1) i = 0;
1237	}
1238
1239	ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1240	if (s->ac_pred)
1241	i = 63; // FIXME not optimal
1242	}
1243	s->block_last_index[n] = i;
1244	return 0;
1245	}
1246
1247	/**
1248	* decode partition C of one MB.
1249	* @return <0 if an error occurred
1250	*/
1251	static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1252	{
1253	Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1254	int cbp, mb_type;
1255	const int xy = s->mb_x + s->mb_y * s->mb_stride;
1256
1257	mb_type = s->current_picture.mb_type[xy];
1258	cbp = s->cbp_table[xy];
1259
1260	ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1261
1262	if (s->current_picture.qscale_table[xy] != s->qscale)
1263	ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1264
1265	if (s->pict_type == AV_PICTURE_TYPE_P ||
1266	s->pict_type == AV_PICTURE_TYPE_S) {
1267	int i;
1268	for (i = 0; i < 4; i++) {
1269	s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1270	s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1271	}
1272	s->mb_intra = IS_INTRA(mb_type);
1273
1274	if (IS_SKIP(mb_type)) {
1275	/* skip mb */
1276	for (i = 0; i < 6; i++)
1277	s->block_last_index[i] = -1;
1278	s->mv_dir = MV_DIR_FORWARD;
1279	s->mv_type = MV_TYPE_16X16;
1280	if (s->pict_type == AV_PICTURE_TYPE_S
1281	&& ctx->vol_sprite_usage == GMC_SPRITE) {
1282	s->mcsel = 1;
1283	s->mb_skipped = 0;
1284	} else {
1285	s->mcsel = 0;
1286	s->mb_skipped = 1;
1287	}
1288	} else if (s->mb_intra) {
1289	s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1290	} else if (!s->mb_intra) {
1291	// s->mcsel = 0; // FIXME do we need to init that?
1292
1293	s->mv_dir = MV_DIR_FORWARD;
1294	if (IS_8X8(mb_type)) {
1295	s->mv_type = MV_TYPE_8X8;
1296	} else {
1297	s->mv_type = MV_TYPE_16X16;
1298	}
1299	}
1300	} else { /* I-Frame */
1301	s->mb_intra = 1;
1302	s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1303	}
1304
1305	if (!IS_SKIP(mb_type)) {
1306	int i;
1307	s->bdsp.clear_blocks(s->block[0]);
1308	/* decode each block */
1309	for (i = 0; i < 6; i++) {
1310	if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, s->mb_intra, ctx->rvlc) < 0) {
1311	av_log(s->avctx, AV_LOG_ERROR,
1312	"texture corrupted at %d %d %d\n",
1313	s->mb_x, s->mb_y, s->mb_intra);
1314	return -1;
1315	}
1316	cbp += cbp;
1317	}
1318	}
1319
1320	/* per-MB end of slice check */
1321	if (--s->mb_num_left <= 0) {
1322	if (mpeg4_is_resync(ctx))
1323	return SLICE_END;
1324	else
1325	return SLICE_NOEND;
1326	} else {
1327	if (mpeg4_is_resync(ctx)) {
1328	const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1329	if (s->cbp_table[xy + delta])
1330	return SLICE_END;
1331	}
1332	return SLICE_OK;
1333	}
1334	}
1335
1336	static int mpeg4_decode_mb(MpegEncContext *s, int16_t block[6][64])
1337	{
1338	Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1339	int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1340	int16_t *mot_val;
1341	static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
1342	const int xy = s->mb_x + s->mb_y * s->mb_stride;
1343
1344	av_assert2(s->h263_pred);
1345
1346	if (s->pict_type == AV_PICTURE_TYPE_P ||
1347	s->pict_type == AV_PICTURE_TYPE_S) {
1348	do {
1349	if (get_bits1(&s->gb)) {
1350	/* skip mb */
1351	s->mb_intra = 0;
1352	for (i = 0; i < 6; i++)
1353	s->block_last_index[i] = -1;
1354	s->mv_dir = MV_DIR_FORWARD;
1355	s->mv_type = MV_TYPE_16X16;
1356	if (s->pict_type == AV_PICTURE_TYPE_S &&
1357	ctx->vol_sprite_usage == GMC_SPRITE) {
1358	s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1359	MB_TYPE_GMC |
1360	MB_TYPE_16x16 |
1361	MB_TYPE_L0;
1362	s->mcsel = 1;
1363	s->mv[0][0][0] = get_amv(ctx, 0);
1364	s->mv[0][0][1] = get_amv(ctx, 1);
1365	s->mb_skipped = 0;
1366	} else {
1367	s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1368	MB_TYPE_16x16 |
1369	MB_TYPE_L0;
1370	s->mcsel = 0;
1371	s->mv[0][0][0] = 0;
1372	s->mv[0][0][1] = 0;
1373	s->mb_skipped = 1;
1374	}
1375	goto end;
1376	}
1377	cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1378	if (cbpc < 0) {
1379	av_log(s->avctx, AV_LOG_ERROR,
1380	"mcbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1381	return -1;
1382	}
1383	} while (cbpc == 20);
1384
1385	s->bdsp.clear_blocks(s->block[0]);
1386	dquant = cbpc & 8;
1387	s->mb_intra = ((cbpc & 4) != 0);
1388	if (s->mb_intra)
1389	goto intra;
1390
1391	if (s->pict_type == AV_PICTURE_TYPE_S &&
1392	ctx->vol_sprite_usage == GMC_SPRITE && (cbpc & 16) == 0)
1393	s->mcsel = get_bits1(&s->gb);
1394	else
1395	s->mcsel = 0;
1396	cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1397	if (cbpy < 0) {
1398	av_log(s->avctx, AV_LOG_ERROR,
1399	"P cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1400	return AVERROR_INVALIDDATA;
1401	}
1402
1403	cbp = (cbpc & 3) | (cbpy << 2);
1404	if (dquant)
1405	ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1406	if ((!s->progressive_sequence) &&
1407	(cbp || (s->workaround_bugs & FF_BUG_XVID_ILACE)))
1408	s->interlaced_dct = get_bits1(&s->gb);
1409
1410	s->mv_dir = MV_DIR_FORWARD;
1411	if ((cbpc & 16) == 0) {
1412	if (s->mcsel) {
1413	s->current_picture.mb_type[xy] = MB_TYPE_GMC |
1414	MB_TYPE_16x16 |
1415	MB_TYPE_L0;
1416	/* 16x16 global motion prediction */
1417	s->mv_type = MV_TYPE_16X16;
1418	mx = get_amv(ctx, 0);
1419	my = get_amv(ctx, 1);
1420	s->mv[0][0][0] = mx;
1421	s->mv[0][0][1] = my;
1422	} else if ((!s->progressive_sequence) && get_bits1(&s->gb)) {
1423	s->current_picture.mb_type[xy] = MB_TYPE_16x8 |
1424	MB_TYPE_L0 |
1425	MB_TYPE_INTERLACED;
1426	/* 16x8 field motion prediction */
1427	s->mv_type = MV_TYPE_FIELD;
1428
1429	s->field_select[0][0] = get_bits1(&s->gb);
1430	s->field_select[0][1] = get_bits1(&s->gb);
1431
1432	ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1433
1434	for (i = 0; i < 2; i++) {
1435	mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1436	if (mx >= 0xffff)
1437	return -1;
1438
1439	my = ff_h263_decode_motion(s, pred_y / 2, s->f_code);
1440	if (my >= 0xffff)
1441	return -1;
1442
1443	s->mv[0][i][0] = mx;
1444	s->mv[0][i][1] = my;
1445	}
1446	} else {
1447	s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1448	/* 16x16 motion prediction */
1449	s->mv_type = MV_TYPE_16X16;
1450	ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1451	mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1452
1453	if (mx >= 0xffff)
1454	return -1;
1455
1456	my = ff_h263_decode_motion(s, pred_y, s->f_code);
1457
1458	if (my >= 0xffff)
1459	return -1;
1460	s->mv[0][0][0] = mx;
1461	s->mv[0][0][1] = my;
1462	}
1463	} else {
1464	s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1465	s->mv_type = MV_TYPE_8X8;
1466	for (i = 0; i < 4; i++) {
1467	mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1468	mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1469	if (mx >= 0xffff)
1470	return -1;
1471
1472	my = ff_h263_decode_motion(s, pred_y, s->f_code);
1473	if (my >= 0xffff)
1474	return -1;
1475	s->mv[0][i][0] = mx;
1476	s->mv[0][i][1] = my;
1477	mot_val[0] = mx;
1478	mot_val[1] = my;
1479	}
1480	}
1481	} else if (s->pict_type == AV_PICTURE_TYPE_B) {
1482	int modb1; // first bit of modb
1483	int modb2; // second bit of modb
1484	int mb_type;
1485
1486	s->mb_intra = 0; // B-frames never contain intra blocks
1487	s->mcsel = 0; // ... true gmc blocks
1488
1489	if (s->mb_x == 0) {
1490	for (i = 0; i < 2; i++) {
1491	s->last_mv[i][0][0] =
1492	s->last_mv[i][0][1] =
1493	s->last_mv[i][1][0] =
1494	s->last_mv[i][1][1] = 0;
1495	}
1496
1497	ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1498	}
1499
1500	/* if we skipped it in the future P-frame than skip it now too */
1501	s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
1502
1503	if (s->mb_skipped) {
1504	/* skip mb */
1505	for (i = 0; i < 6; i++)
1506	s->block_last_index[i] = -1;
1507
1508	s->mv_dir = MV_DIR_FORWARD;
1509	s->mv_type = MV_TYPE_16X16;
1510	s->mv[0][0][0] =
1511	s->mv[0][0][1] =
1512	s->mv[1][0][0] =
1513	s->mv[1][0][1] = 0;
1514	s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1515	MB_TYPE_16x16 |
1516	MB_TYPE_L0;
1517	goto end;
1518	}
1519
1520	modb1 = get_bits1(&s->gb);
1521	if (modb1) {
1522	// like MB_TYPE_B_DIRECT but no vectors coded
1523	mb_type = MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1;
1524	cbp = 0;
1525	} else {
1526	modb2 = get_bits1(&s->gb);
1527	mb_type = get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1528	if (mb_type < 0) {
1529	av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1530	return -1;
1531	}
1532	mb_type = mb_type_b_map[mb_type];
1533	if (modb2) {
1534	cbp = 0;
1535	} else {
1536	s->bdsp.clear_blocks(s->block[0]);
1537	cbp = get_bits(&s->gb, 6);
1538	}
1539
1540	if ((!IS_DIRECT(mb_type)) && cbp) {
1541	if (get_bits1(&s->gb))
1542	ff_set_qscale(s, s->qscale + get_bits1(&s->gb) * 4 - 2);
1543	}
1544
1545	if (!s->progressive_sequence) {
1546	if (cbp)
1547	s->interlaced_dct = get_bits1(&s->gb);
1548
1549	if (!IS_DIRECT(mb_type) && get_bits1(&s->gb)) {
1550	mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1551	mb_type &= ~MB_TYPE_16x16;
1552
1553	if (USES_LIST(mb_type, 0)) {
1554	s->field_select[0][0] = get_bits1(&s->gb);
1555	s->field_select[0][1] = get_bits1(&s->gb);
1556	}
1557	if (USES_LIST(mb_type, 1)) {
1558	s->field_select[1][0] = get_bits1(&s->gb);
1559	s->field_select[1][1] = get_bits1(&s->gb);
1560	}
1561	}
1562	}
1563
1564	s->mv_dir = 0;
1565	if ((mb_type & (MB_TYPE_DIRECT2 | MB_TYPE_INTERLACED)) == 0) {
1566	s->mv_type = MV_TYPE_16X16;
1567
1568	if (USES_LIST(mb_type, 0)) {
1569	s->mv_dir = MV_DIR_FORWARD;
1570
1571	mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1572	my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1573	s->last_mv[0][1][0] =
1574	s->last_mv[0][0][0] =
1575	s->mv[0][0][0] = mx;
1576	s->last_mv[0][1][1] =
1577	s->last_mv[0][0][1] =
1578	s->mv[0][0][1] = my;
1579	}
1580
1581	if (USES_LIST(mb_type, 1)) {
1582	s->mv_dir |= MV_DIR_BACKWARD;
1583
1584	mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1585	my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1586	s->last_mv[1][1][0] =
1587	s->last_mv[1][0][0] =
1588	s->mv[1][0][0] = mx;
1589	s->last_mv[1][1][1] =
1590	s->last_mv[1][0][1] =
1591	s->mv[1][0][1] = my;
1592	}
1593	} else if (!IS_DIRECT(mb_type)) {
1594	s->mv_type = MV_TYPE_FIELD;
1595
1596	if (USES_LIST(mb_type, 0)) {
1597	s->mv_dir = MV_DIR_FORWARD;
1598
1599	for (i = 0; i < 2; i++) {
1600	mx = ff_h263_decode_motion(s, s->last_mv[0][i][0], s->f_code);
1601	my = ff_h263_decode_motion(s, s->last_mv[0][i][1] / 2, s->f_code);
1602	s->last_mv[0][i][0] =
1603	s->mv[0][i][0] = mx;
1604	s->last_mv[0][i][1] = (s->mv[0][i][1] = my) * 2;
1605	}
1606	}
1607
1608	if (USES_LIST(mb_type, 1)) {
1609	s->mv_dir |= MV_DIR_BACKWARD;
1610
1611	for (i = 0; i < 2; i++) {
1612	mx = ff_h263_decode_motion(s, s->last_mv[1][i][0], s->b_code);
1613	my = ff_h263_decode_motion(s, s->last_mv[1][i][1] / 2, s->b_code);
1614	s->last_mv[1][i][0] =
1615	s->mv[1][i][0] = mx;
1616	s->last_mv[1][i][1] = (s->mv[1][i][1] = my) * 2;
1617	}
1618	}
1619	}
1620	}
1621
1622	if (IS_DIRECT(mb_type)) {
1623	if (IS_SKIP(mb_type)) {
1624	mx =
1625	my = 0;
1626	} else {
1627	mx = ff_h263_decode_motion(s, 0, 1);
1628	my = ff_h263_decode_motion(s, 0, 1);
1629	}
1630
1631	s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1632	mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1633	}
1634	s->current_picture.mb_type[xy] = mb_type;
1635	} else { /* I-Frame */
1636	do {
1637	cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1638	if (cbpc < 0) {
1639	av_log(s->avctx, AV_LOG_ERROR,
1640	"I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1641	return -1;
1642	}
1643	} while (cbpc == 8);
1644
1645	dquant = cbpc & 4;
1646	s->mb_intra = 1;
1647
1648	intra:
1649	s->ac_pred = get_bits1(&s->gb);
1650	if (s->ac_pred)
1651	s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1652	else
1653	s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1654
1655	cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1656	if (cbpy < 0) {
1657	av_log(s->avctx, AV_LOG_ERROR,
1658	"I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1659	return -1;
1660	}
1661	cbp = (cbpc & 3) | (cbpy << 2);
1662
1663	ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1664
1665	if (dquant)
1666	ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1667
1668	if (!s->progressive_sequence)
1669	s->interlaced_dct = get_bits1(&s->gb);
1670
1671	s->bdsp.clear_blocks(s->block[0]);
1672	/* decode each block */
1673	for (i = 0; i < 6; i++) {
1674	if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 1, 0) < 0)
1675	return -1;
1676	cbp += cbp;
1677	}
1678	goto end;
1679	}
1680
1681	/* decode each block */
1682	for (i = 0; i < 6; i++) {
1683	if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 0, 0) < 0)
1684	return -1;
1685	cbp += cbp;
1686	}
1687
1688	end:
1689	/* per-MB end of slice check */
1690	if (s->codec_id == AV_CODEC_ID_MPEG4) {
1691	int next = mpeg4_is_resync(ctx);
1692	if (next) {
1693	if (s->mb_x + s->mb_y*s->mb_width + 1 > next && (s->avctx->err_recognition & AV_EF_AGGRESSIVE)) {
1694	return -1;
1695	} else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1696	return SLICE_END;
1697
1698	if (s->pict_type == AV_PICTURE_TYPE_B) {
1699	const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1700	ff_thread_await_progress(&s->next_picture_ptr->tf,
1701	(s->mb_x + delta >= s->mb_width)
1702	? FFMIN(s->mb_y + 1, s->mb_height - 1)
1703	: s->mb_y, 0);
1704	if (s->next_picture.mbskip_table[xy + delta])
1705	return SLICE_OK;
1706	}
1707
1708	return SLICE_END;
1709	}
1710	}
1711
1712	return SLICE_OK;
1713	}
1714
1715	static int mpeg4_decode_gop_header(MpegEncContext *s, GetBitContext *gb)
1716	{
1717	int hours, minutes, seconds;
1718
1719	if (!show_bits(gb, 23)) {
1720	av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
1721	return -1;
1722	}
1723
1724	hours = get_bits(gb, 5);
1725	minutes = get_bits(gb, 6);
1726	check_marker(s->avctx, gb, "in gop_header");
1727	seconds = get_bits(gb, 6);
1728
1729	s->time_base = seconds + 60*(minutes + 60*hours);
1730
1731	skip_bits1(gb);
1732	skip_bits1(gb);
1733
1734	return 0;
1735	}
1736
1737	static int mpeg4_decode_profile_level(MpegEncContext *s, GetBitContext *gb)
1738	{
1739
1740	s->avctx->profile = get_bits(gb, 4);
1741	s->avctx->level = get_bits(gb, 4);
1742
1743	// for Simple profile, level 0
1744	if (s->avctx->profile == 0 && s->avctx->level == 8) {
1745	s->avctx->level = 0;
1746	}
1747
1748	return 0;
1749	}
1750
1751	static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
1752	{
1753	MpegEncContext *s = &ctx->m;
1754	int width, height, vo_ver_id;
1755
1756	/* vol header */
1757	skip_bits(gb, 1); /* random access */
1758	s->vo_type = get_bits(gb, 8);
1759	if (get_bits1(gb) != 0) { /* is_ol_id */
1760	vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1761	skip_bits(gb, 3); /* vo_priority */
1762	} else {
1763	vo_ver_id = 1;
1764	}
1765	s->aspect_ratio_info = get_bits(gb, 4);
1766	if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1767	s->avctx->sample_aspect_ratio.num = get_bits(gb, 8); // par_width
1768	s->avctx->sample_aspect_ratio.den = get_bits(gb, 8); // par_height
1769	} else {
1770	s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[s->aspect_ratio_info];
1771	}
1772
1773	if ((ctx->vol_control_parameters = get_bits1(gb))) { /* vol control parameter */
1774	int chroma_format = get_bits(gb, 2);
1775	if (chroma_format != CHROMA_420)
1776	av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1777
1778	s->low_delay = get_bits1(gb);
1779	if (get_bits1(gb)) { /* vbv parameters */
1780	get_bits(gb, 15); /* first_half_bitrate */
1781	check_marker(s->avctx, gb, "after first_half_bitrate");
1782	get_bits(gb, 15); /* latter_half_bitrate */
1783	check_marker(s->avctx, gb, "after latter_half_bitrate");
1784	get_bits(gb, 15); /* first_half_vbv_buffer_size */
1785	check_marker(s->avctx, gb, "after first_half_vbv_buffer_size");
1786	get_bits(gb, 3); /* latter_half_vbv_buffer_size */
1787	get_bits(gb, 11); /* first_half_vbv_occupancy */
1788	check_marker(s->avctx, gb, "after first_half_vbv_occupancy");
1789	get_bits(gb, 15); /* latter_half_vbv_occupancy */
1790	check_marker(s->avctx, gb, "after latter_half_vbv_occupancy");
1791	}
1792	} else {
1793	/* is setting low delay flag only once the smartest thing to do?
1794	* low delay detection will not be overridden. */
1795	if (s->picture_number == 0) {
1796	switch(s->vo_type) {
1797	case SIMPLE_VO_TYPE:
1798	case ADV_SIMPLE_VO_TYPE:
1799	s->low_delay = 1;
1800	break;
1801	default:
1802	s->low_delay = 0;
1803	}
1804	}
1805	}
1806
1807	ctx->shape = get_bits(gb, 2); /* vol shape */
1808	if (ctx->shape != RECT_SHAPE)
1809	av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1810	if (ctx->shape == GRAY_SHAPE && vo_ver_id != 1) {
1811	av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1812	skip_bits(gb, 4); /* video_object_layer_shape_extension */
1813	}
1814
1815	check_marker(s->avctx, gb, "before time_increment_resolution");
1816
1817	s->avctx->framerate.num = get_bits(gb, 16);
1818	if (!s->avctx->framerate.num) {
1819	av_log(s->avctx, AV_LOG_ERROR, "framerate==0\n");
1820	return AVERROR_INVALIDDATA;
1821	}
1822
1823	ctx->time_increment_bits = av_log2(s->avctx->framerate.num - 1) + 1;
1824	if (ctx->time_increment_bits < 1)
1825	ctx->time_increment_bits = 1;
1826
1827	check_marker(s->avctx, gb, "before fixed_vop_rate");
1828
1829	if (get_bits1(gb) != 0) /* fixed_vop_rate */
1830	s->avctx->framerate.den = get_bits(gb, ctx->time_increment_bits);
1831	else
1832	s->avctx->framerate.den = 1;
1833
1834	s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
1835
1836	ctx->t_frame = 0;
1837
1838	if (ctx->shape != BIN_ONLY_SHAPE) {
1839	if (ctx->shape == RECT_SHAPE) {
1840	check_marker(s->avctx, gb, "before width");
1841	width = get_bits(gb, 13);
1842	check_marker(s->avctx, gb, "before height");
1843	height = get_bits(gb, 13);
1844	check_marker(s->avctx, gb, "after height");
1845	if (width && height && /* they should be non zero but who knows */
1846	!(s->width && s->codec_tag == AV_RL32("MP4S"))) {
1847	if (s->width && s->height &&
1848	(s->width != width || s->height != height))
1849	s->context_reinit = 1;
1850	s->width = width;
1851	s->height = height;
1852	}
1853	}
1854
1855	s->progressive_sequence =
1856	s->progressive_frame = get_bits1(gb) ^ 1;
1857	s->interlaced_dct = 0;
1858	if (!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1859	av_log(s->avctx, AV_LOG_INFO, /* OBMC Disable */
1860	"MPEG-4 OBMC not supported (very likely buggy encoder)\n");
1861	if (vo_ver_id == 1)
1862	ctx->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1863	else
1864	ctx->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1865
1866	if (ctx->vol_sprite_usage == STATIC_SPRITE)
1867	av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1868	if (ctx->vol_sprite_usage == STATIC_SPRITE ||
1869	ctx->vol_sprite_usage == GMC_SPRITE) {
1870	if (ctx->vol_sprite_usage == STATIC_SPRITE) {
1871	skip_bits(gb, 13); // sprite_width
1872	check_marker(s->avctx, gb, "after sprite_width");
1873	skip_bits(gb, 13); // sprite_height
1874	check_marker(s->avctx, gb, "after sprite_height");
1875	skip_bits(gb, 13); // sprite_left
1876	check_marker(s->avctx, gb, "after sprite_left");
1877	skip_bits(gb, 13); // sprite_top
1878	check_marker(s->avctx, gb, "after sprite_top");
1879	}
1880	ctx->num_sprite_warping_points = get_bits(gb, 6);
1881	if (ctx->num_sprite_warping_points > 3) {
1882	av_log(s->avctx, AV_LOG_ERROR,
1883	"%d sprite_warping_points\n",
1884	ctx->num_sprite_warping_points);
1885	ctx->num_sprite_warping_points = 0;
1886	return AVERROR_INVALIDDATA;
1887	}
1888	s->sprite_warping_accuracy = get_bits(gb, 2);
1889	ctx->sprite_brightness_change = get_bits1(gb);
1890	if (ctx->vol_sprite_usage == STATIC_SPRITE)
1891	skip_bits1(gb); // low_latency_sprite
1892	}
1893	// FIXME sadct disable bit if verid!=1 && shape not rect
1894
1895	if (get_bits1(gb) == 1) { /* not_8_bit */
1896	s->quant_precision = get_bits(gb, 4); /* quant_precision */
1897	if (get_bits(gb, 4) != 8) /* bits_per_pixel */
1898	av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n");
1899	if (s->quant_precision != 5)
1900	av_log(s->avctx, AV_LOG_ERROR,
1901	"quant precision %d\n", s->quant_precision);
1902	if (s->quant_precision<3 || s->quant_precision>9) {
1903	s->quant_precision = 5;
1904	}
1905	} else {
1906	s->quant_precision = 5;
1907	}
1908
1909	// FIXME a bunch of grayscale shape things
1910
1911	if ((s->mpeg_quant = get_bits1(gb))) { /* vol_quant_type */
1912	int i, v;
1913
1914	/* load default matrixes */
1915	for (i = 0; i < 64; i++) {
1916	int j = s->idsp.idct_permutation[i];
1917	v = ff_mpeg4_default_intra_matrix[i];
1918	s->intra_matrix[j] = v;
1919	s->chroma_intra_matrix[j] = v;
1920
1921	v = ff_mpeg4_default_non_intra_matrix[i];
1922	s->inter_matrix[j] = v;
1923	s->chroma_inter_matrix[j] = v;
1924	}
1925
1926	/* load custom intra matrix */
1927	if (get_bits1(gb)) {
1928	int last = 0;
1929	for (i = 0; i < 64; i++) {
1930	int j;
1931	if (get_bits_left(gb) < 8) {
1932	av_log(s->avctx, AV_LOG_ERROR, "insufficient data for custom matrix\n");
1933	return AVERROR_INVALIDDATA;
1934	}
1935	v = get_bits(gb, 8);
1936	if (v == 0)
1937	break;
1938
1939	last = v;
1940	j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1941	s->intra_matrix[j] = last;
1942	s->chroma_intra_matrix[j] = last;
1943	}
1944
1945	/* replicate last value */
1946	for (; i < 64; i++) {
1947	int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1948	s->intra_matrix[j] = last;
1949	s->chroma_intra_matrix[j] = last;
1950	}
1951	}
1952
1953	/* load custom non intra matrix */
1954	if (get_bits1(gb)) {
1955	int last = 0;
1956	for (i = 0; i < 64; i++) {
1957	int j;
1958	if (get_bits_left(gb) < 8) {
1959	av_log(s->avctx, AV_LOG_ERROR, "insufficient data for custom matrix\n");
1960	return AVERROR_INVALIDDATA;
1961	}
1962	v = get_bits(gb, 8);
1963	if (v == 0)
1964	break;
1965
1966	last = v;
1967	j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1968	s->inter_matrix[j] = v;
1969	s->chroma_inter_matrix[j] = v;
1970	}
1971
1972	/* replicate last value */
1973	for (; i < 64; i++) {
1974	int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1975	s->inter_matrix[j] = last;
1976	s->chroma_inter_matrix[j] = last;
1977	}
1978	}
1979
1980	// FIXME a bunch of grayscale shape things
1981	}
1982
1983	if (vo_ver_id != 1)
1984	s->quarter_sample = get_bits1(gb);
1985	else
1986	s->quarter_sample = 0;
1987
1988	if (get_bits_left(gb) < 4) {
1989	av_log(s->avctx, AV_LOG_ERROR, "VOL Header truncated\n");
1990	return AVERROR_INVALIDDATA;
1991	}
1992
1993	if (!get_bits1(gb)) {
1994	int pos = get_bits_count(gb);
1995	int estimation_method = get_bits(gb, 2);
1996	if (estimation_method < 2) {
1997	if (!get_bits1(gb)) {
1998	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* opaque */
1999	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* transparent */
2000	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* intra_cae */
2001	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* inter_cae */
2002	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* no_update */
2003	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* upsampling */
2004	}
2005	if (!get_bits1(gb)) {
2006	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* intra_blocks */
2007	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* inter_blocks */
2008	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* inter4v_blocks */
2009	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* not coded blocks */
2010	}
2011	if (!check_marker(s->avctx, gb, "in complexity estimation part 1")) {
2012	skip_bits_long(gb, pos - get_bits_count(gb));
2013	goto no_cplx_est;
2014	}
2015	if (!get_bits1(gb)) {
2016	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* dct_coeffs */
2017	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* dct_lines */
2018	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* vlc_syms */
2019	ctx->cplx_estimation_trash_i += 4 * get_bits1(gb); /* vlc_bits */
2020	}
2021	if (!get_bits1(gb)) {
2022	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* apm */
2023	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* npm */
2024	ctx->cplx_estimation_trash_b += 8 * get_bits1(gb); /* interpolate_mc_q */
2025	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* forwback_mc_q */
2026	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* halfpel2 */
2027	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* halfpel4 */
2028	}
2029	if (!check_marker(s->avctx, gb, "in complexity estimation part 2")) {
2030	skip_bits_long(gb, pos - get_bits_count(gb));
2031	goto no_cplx_est;
2032	}
2033	if (estimation_method == 1) {
2034	ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* sadct */
2035	ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* qpel */
2036	}
2037	} else
2038	av_log(s->avctx, AV_LOG_ERROR,
2039	"Invalid Complexity estimation method %d\n",
2040	estimation_method);
2041	} else {
2042
2043	no_cplx_est:
2044	ctx->cplx_estimation_trash_i =
2045	ctx->cplx_estimation_trash_p =
2046	ctx->cplx_estimation_trash_b = 0;
2047	}
2048
2049	ctx->resync_marker = !get_bits1(gb); /* resync_marker_disabled */
2050
2051	s->data_partitioning = get_bits1(gb);
2052	if (s->data_partitioning)
2053	ctx->rvlc = get_bits1(gb);
2054
2055	if (vo_ver_id != 1) {
2056	ctx->new_pred = get_bits1(gb);
2057	if (ctx->new_pred) {
2058	av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
2059	skip_bits(gb, 2); /* requested upstream message type */
2060	skip_bits1(gb); /* newpred segment type */
2061	}
2062	if (get_bits1(gb)) // reduced_res_vop
2063	av_log(s->avctx, AV_LOG_ERROR,
2064	"reduced resolution VOP not supported\n");
2065	} else {
2066	ctx->new_pred = 0;
2067	}
2068
2069	ctx->scalability = get_bits1(gb);
2070
2071	if (ctx->scalability) {
2072	GetBitContext bak = *gb;
2073	int h_sampling_factor_n;
2074	int h_sampling_factor_m;
2075	int v_sampling_factor_n;
2076	int v_sampling_factor_m;
2077
2078	skip_bits1(gb); // hierarchy_type
2079	skip_bits(gb, 4); /* ref_layer_id */
2080	skip_bits1(gb); /* ref_layer_sampling_dir */
2081	h_sampling_factor_n = get_bits(gb, 5);
2082	h_sampling_factor_m = get_bits(gb, 5);
2083	v_sampling_factor_n = get_bits(gb, 5);
2084	v_sampling_factor_m = get_bits(gb, 5);
2085	ctx->enhancement_type = get_bits1(gb);
2086
2087	if (h_sampling_factor_n == 0 || h_sampling_factor_m == 0 ||
2088	v_sampling_factor_n == 0 || v_sampling_factor_m == 0) {
2089	/* illegal scalability header (VERY broken encoder),
2090	* trying to workaround */
2091	ctx->scalability = 0;
2092	*gb = bak;
2093	} else
2094	av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
2095
2096	// bin shape stuff FIXME
2097	}
2098	}
2099
2100	if (s->avctx->debug&FF_DEBUG_PICT_INFO) {
2101	av_log(s->avctx, AV_LOG_DEBUG, "tb %d/%d, tincrbits:%d, qp_prec:%d, ps:%d, low_delay:%d %s%s%s%s\n",
2102	s->avctx->framerate.den, s->avctx->framerate.num,
2103	ctx->time_increment_bits,
2104	s->quant_precision,
2105	s->progressive_sequence,
2106	s->low_delay,
2107	ctx->scalability ? "scalability " :"" , s->quarter_sample ? "qpel " : "",
2108	s->data_partitioning ? "partition " : "", ctx->rvlc ? "rvlc " : ""
2109	);
2110	}
2111
2112	return 0;
2113	}
2114
2115	/**
2116	* Decode the user data stuff in the header.
2117	* Also initializes divx/xvid/lavc_version/build.
2118	*/
2119	static int decode_user_data(Mpeg4DecContext *ctx, GetBitContext *gb)
2120	{
2121	MpegEncContext *s = &ctx->m;
2122	char buf[256];
2123	int i;
2124	int e;
2125	int ver = 0, build = 0, ver2 = 0, ver3 = 0;
2126	char last;
2127
2128	for (i = 0; i < 255 && get_bits_count(gb) < gb->size_in_bits; i++) {
2129	if (show_bits(gb, 23) == 0)
2130	break;
2131	buf[i] = get_bits(gb, 8);
2132	}
2133	buf[i] = 0;
2134
2135	/* divx detection */
2136	e = sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
2137	if (e < 2)
2138	e = sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
2139	if (e >= 2) {
2140	ctx->divx_version = ver;
2141	ctx->divx_build = build;
2142	s->divx_packed = e == 3 && last == 'p';
2143	}
2144
2145	/* libavcodec detection */
2146	e = sscanf(buf, "FFmpe%*[^b]b%d", &build) + 3;
2147	if (e != 4)
2148	e = sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
2149	if (e != 4) {
2150	e = sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3) + 1;
2151	if (e > 1)
2152	build = (ver << 16) + (ver2 << 8) + ver3;
2153	}
2154	if (e != 4) {
2155	if (strcmp(buf, "ffmpeg") == 0)
2156	ctx->lavc_build = 4600;
2157	}
2158	if (e == 4)
2159	ctx->lavc_build = build;
2160
2161	/* Xvid detection */
2162	e = sscanf(buf, "XviD%d", &build);
2163	if (e == 1)
2164	ctx->xvid_build = build;
2165
2166	return 0;
2167	}
2168
2169	int ff_mpeg4_workaround_bugs(AVCodecContext *avctx)
2170	{
2171	Mpeg4DecContext *ctx = avctx->priv_data;
2172	MpegEncContext *s = &ctx->m;
2173
2174	if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1) {
2175	if (s->codec_tag == AV_RL32("XVID") ||
2176	s->codec_tag == AV_RL32("XVIX") ||
2177	s->codec_tag == AV_RL32("RMP4") ||
2178	s->codec_tag == AV_RL32("ZMP4") ||
2179	s->codec_tag == AV_RL32("SIPP"))
2180	ctx->xvid_build = 0;
2181	}
2182
2183	if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1)
2184	if (s->codec_tag == AV_RL32("DIVX") && s->vo_type == 0 &&
2185	ctx->vol_control_parameters == 0)
2186	ctx->divx_version = 400; // divx 4
2187
2188	if (ctx->xvid_build >= 0 && ctx->divx_version >= 0) {
2189	ctx->divx_version =
2190	ctx->divx_build = -1;
2191	}
2192
2193	if (s->workaround_bugs & FF_BUG_AUTODETECT) {
2194	if (s->codec_tag == AV_RL32("XVIX"))
2195	s->workaround_bugs |= FF_BUG_XVID_ILACE;
2196
2197	if (s->codec_tag == AV_RL32("UMP4"))
2198	s->workaround_bugs |= FF_BUG_UMP4;
2199
2200	if (ctx->divx_version >= 500 && ctx->divx_build < 1814)
2201	s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2202
2203	if (ctx->divx_version > 502 && ctx->divx_build < 1814)
2204	s->workaround_bugs |= FF_BUG_QPEL_CHROMA2;
2205
2206	if (ctx->xvid_build <= 3U)
2207	s->padding_bug_score = 256 * 256 * 256 * 64;
2208
2209	if (ctx->xvid_build <= 1U)
2210	s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2211
2212	if (ctx->xvid_build <= 12U)
2213	s->workaround_bugs |= FF_BUG_EDGE;
2214
2215	if (ctx->xvid_build <= 32U)
2216	s->workaround_bugs |= FF_BUG_DC_CLIP;
2217
2218	#define SET_QPEL_FUNC(postfix1, postfix2) \
2219	s->qdsp.put_ ## postfix1 = ff_put_ ## postfix2; \
2220	s->qdsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2; \
2221	s->qdsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
2222
2223	if (ctx->lavc_build < 4653U)
2224	s->workaround_bugs |= FF_BUG_STD_QPEL;
2225
2226	if (ctx->lavc_build < 4655U)
2227	s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2228
2229	if (ctx->lavc_build < 4670U)
2230	s->workaround_bugs |= FF_BUG_EDGE;
2231
2232	if (ctx->lavc_build <= 4712U)
2233	s->workaround_bugs |= FF_BUG_DC_CLIP;
2234
2235	if ((ctx->lavc_build&0xFF) >= 100) {
2236	if (ctx->lavc_build > 3621476 && ctx->lavc_build < 3752552 &&
2237	(ctx->lavc_build < 3752037 || ctx->lavc_build > 3752191) // 3.2.1+
2238	)
2239	s->workaround_bugs |= FF_BUG_IEDGE;
2240	}
2241
2242	if (ctx->divx_version >= 0)
2243	s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2244	if (ctx->divx_version == 501 && ctx->divx_build == 20020416)
2245	s->padding_bug_score = 256 * 256 * 256 * 64;
2246
2247	if (ctx->divx_version < 500U)
2248	s->workaround_bugs |= FF_BUG_EDGE;
2249
2250	if (ctx->divx_version >= 0)
2251	s->workaround_bugs |= FF_BUG_HPEL_CHROMA;
2252	}
2253
2254	if (s->workaround_bugs & FF_BUG_STD_QPEL) {
2255	SET_QPEL_FUNC(qpel_pixels_tab[0][5], qpel16_mc11_old_c)
2256	SET_QPEL_FUNC(qpel_pixels_tab[0][7], qpel16_mc31_old_c)
2257	SET_QPEL_FUNC(qpel_pixels_tab[0][9], qpel16_mc12_old_c)
2258	SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
2259	SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
2260	SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
2261
2262	SET_QPEL_FUNC(qpel_pixels_tab[1][5], qpel8_mc11_old_c)
2263	SET_QPEL_FUNC(qpel_pixels_tab[1][7], qpel8_mc31_old_c)
2264	SET_QPEL_FUNC(qpel_pixels_tab[1][9], qpel8_mc12_old_c)
2265	SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
2266	SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
2267	SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
2268	}
2269
2270	if (avctx->debug & FF_DEBUG_BUGS)
2271	av_log(s->avctx, AV_LOG_DEBUG,
2272	"bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
2273	s->workaround_bugs, ctx->lavc_build, ctx->xvid_build,
2274	ctx->divx_version, ctx->divx_build, s->divx_packed ? "p" : "");
2275
2276	if (CONFIG_MPEG4_DECODER && ctx->xvid_build >= 0 &&
2277	s->codec_id == AV_CODEC_ID_MPEG4 &&
2278	avctx->idct_algo == FF_IDCT_AUTO) {
2279	avctx->idct_algo = FF_IDCT_XVID;
2280	ff_mpv_idct_init(s);
2281	return 1;
2282	}
2283
2284	return 0;
2285	}
2286
2287	static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2288	{
2289	MpegEncContext *s = &ctx->m;
2290	int time_incr, time_increment;
2291	int64_t pts;
2292
2293	s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I; /* pict type: I = 0 , P = 1 */
2294	if (s->pict_type == AV_PICTURE_TYPE_B && s->low_delay &&
2295	ctx->vol_control_parameters == 0 && !(s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)) {
2296	av_log(s->avctx, AV_LOG_ERROR, "low_delay flag set incorrectly, clearing it\n");
2297	s->low_delay = 0;
2298	}
2299
2300	s->partitioned_frame = s->data_partitioning && s->pict_type != AV_PICTURE_TYPE_B;
2301	if (s->partitioned_frame)
2302	s->decode_mb = mpeg4_decode_partitioned_mb;
2303	else
2304	s->decode_mb = mpeg4_decode_mb;
2305
2306	time_incr = 0;
2307	while (get_bits1(gb) != 0)
2308	time_incr++;
2309
2310	check_marker(s->avctx, gb, "before time_increment");
2311
2312	if (ctx->time_increment_bits == 0 ||
2313	!(show_bits(gb, ctx->time_increment_bits + 1) & 1)) {
2314	av_log(s->avctx, AV_LOG_WARNING,
2315	"time_increment_bits %d is invalid in relation to the current bitstream, this is likely caused by a missing VOL header\n", ctx->time_increment_bits);
2316
2317	for (ctx->time_increment_bits = 1;
2318	ctx->time_increment_bits < 16;
2319	ctx->time_increment_bits++) {
2320	if (s->pict_type == AV_PICTURE_TYPE_P ||
2321	(s->pict_type == AV_PICTURE_TYPE_S &&
2322	ctx->vol_sprite_usage == GMC_SPRITE)) {
2323	if ((show_bits(gb, ctx->time_increment_bits + 6) & 0x37) == 0x30)
2324	break;
2325	} else if ((show_bits(gb, ctx->time_increment_bits + 5) & 0x1F) == 0x18)
2326	break;
2327	}
2328
2329	av_log(s->avctx, AV_LOG_WARNING,
2330	"time_increment_bits set to %d bits, based on bitstream analysis\n", ctx->time_increment_bits);
2331	if (s->avctx->framerate.num && 4*s->avctx->framerate.num < 1<<ctx->time_increment_bits) {
2332	s->avctx->framerate.num = 1<<ctx->time_increment_bits;
2333	s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
2334	}
2335	}
2336
2337	if (IS_3IV1)
2338	time_increment = get_bits1(gb); // FIXME investigate further
2339	else
2340	time_increment = get_bits(gb, ctx->time_increment_bits);
2341
2342	if (s->pict_type != AV_PICTURE_TYPE_B) {
2343	s->last_time_base = s->time_base;
2344	s->time_base += time_incr;
2345	s->time = s->time_base * s->avctx->framerate.num + time_increment;
2346	if (s->workaround_bugs & FF_BUG_UMP4) {
2347	if (s->time < s->last_non_b_time) {
2348	/* header is not mpeg-4-compatible, broken encoder,
2349	* trying to workaround */
2350	s->time_base++;
2351	s->time += s->avctx->framerate.num;
2352	}
2353	}
2354	s->pp_time = s->time - s->last_non_b_time;
2355	s->last_non_b_time = s->time;
2356	} else {
2357	s->time = (s->last_time_base + time_incr) * s->avctx->framerate.num + time_increment;
2358	s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
2359	if (s->pp_time <= s->pb_time ||
2360	s->pp_time <= s->pp_time - s->pb_time ||
2361	s->pp_time <= 0) {
2362	/* messed up order, maybe after seeking? skipping current B-frame */
2363	return FRAME_SKIPPED;
2364	}
2365	ff_mpeg4_init_direct_mv(s);
2366
2367	if (ctx->t_frame == 0)
2368	ctx->t_frame = s->pb_time;
2369	if (ctx->t_frame == 0)
2370	ctx->t_frame = 1; // 1/0 protection
2371	s->pp_field_time = (ROUNDED_DIV(s->last_non_b_time, ctx->t_frame) -
2372	ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2373	s->pb_field_time = (ROUNDED_DIV(s->time, ctx->t_frame) -
2374	ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2375	if (s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1) {
2376	s->pb_field_time = 2;
2377	s->pp_field_time = 4;
2378	if (!s->progressive_sequence)
2379	return FRAME_SKIPPED;
2380	}
2381	}
2382
2383	if (s->avctx->framerate.den)
2384	pts = ROUNDED_DIV(s->time, s->avctx->framerate.den);
2385	else
2386	pts = AV_NOPTS_VALUE;
2387	ff_dlog(s->avctx, "MPEG4 PTS: %"PRId64"\n", pts);
2388
2389	check_marker(s->avctx, gb, "before vop_coded");
2390
2391	/* vop coded */
2392	if (get_bits1(gb) != 1) {
2393	if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2394	av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
2395	return FRAME_SKIPPED;
2396	}
2397	if (ctx->new_pred)
2398	decode_new_pred(ctx, gb);
2399
2400	if (ctx->shape != BIN_ONLY_SHAPE &&
2401	(s->pict_type == AV_PICTURE_TYPE_P ||
2402	(s->pict_type == AV_PICTURE_TYPE_S &&
2403	ctx->vol_sprite_usage == GMC_SPRITE))) {
2404	/* rounding type for motion estimation */
2405	s->no_rounding = get_bits1(gb);
2406	} else {
2407	s->no_rounding = 0;
2408	}
2409	// FIXME reduced res stuff
2410
2411	if (ctx->shape != RECT_SHAPE) {
2412	if (ctx->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2413	skip_bits(gb, 13); /* width */
2414	check_marker(s->avctx, gb, "after width");
2415	skip_bits(gb, 13); /* height */
2416	check_marker(s->avctx, gb, "after height");
2417	skip_bits(gb, 13); /* hor_spat_ref */
2418	check_marker(s->avctx, gb, "after hor_spat_ref");
2419	skip_bits(gb, 13); /* ver_spat_ref */
2420	}
2421	skip_bits1(gb); /* change_CR_disable */
2422
2423	if (get_bits1(gb) != 0)
2424	skip_bits(gb, 8); /* constant_alpha_value */
2425	}
2426
2427	// FIXME complexity estimation stuff
2428
2429	if (ctx->shape != BIN_ONLY_SHAPE) {
2430	skip_bits_long(gb, ctx->cplx_estimation_trash_i);
2431	if (s->pict_type != AV_PICTURE_TYPE_I)
2432	skip_bits_long(gb, ctx->cplx_estimation_trash_p);
2433	if (s->pict_type == AV_PICTURE_TYPE_B)
2434	skip_bits_long(gb, ctx->cplx_estimation_trash_b);
2435
2436	if (get_bits_left(gb) < 3) {
2437	av_log(s->avctx, AV_LOG_ERROR, "Header truncated\n");
2438	return AVERROR_INVALIDDATA;
2439	}
2440	ctx->intra_dc_threshold = ff_mpeg4_dc_threshold[get_bits(gb, 3)];
2441	if (!s->progressive_sequence) {
2442	s->top_field_first = get_bits1(gb);
2443	s->alternate_scan = get_bits1(gb);
2444	} else
2445	s->alternate_scan = 0;
2446	}
2447
2448	if (s->alternate_scan) {
2449	ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
2450	ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
2451	ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2452	ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2453	} else {
2454	ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
2455	ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
2456	ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2457	ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2458	}
2459
2460	if (s->pict_type == AV_PICTURE_TYPE_S &&
2461	(ctx->vol_sprite_usage == STATIC_SPRITE ||
2462	ctx->vol_sprite_usage == GMC_SPRITE)) {
2463	if (mpeg4_decode_sprite_trajectory(ctx, gb) < 0)
2464	return AVERROR_INVALIDDATA;
2465	if (ctx->sprite_brightness_change)
2466	av_log(s->avctx, AV_LOG_ERROR,
2467	"sprite_brightness_change not supported\n");
2468	if (ctx->vol_sprite_usage == STATIC_SPRITE)
2469	av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2470	}
2471
2472	if (ctx->shape != BIN_ONLY_SHAPE) {
2473	s->chroma_qscale = s->qscale = get_bits(gb, s->quant_precision);
2474	if (s->qscale == 0) {
2475	av_log(s->avctx, AV_LOG_ERROR,
2476	"Error, header damaged or not MPEG-4 header (qscale=0)\n");
2477	return AVERROR_INVALIDDATA; // makes no sense to continue, as there is nothing left from the image then
2478	}
2479
2480	if (s->pict_type != AV_PICTURE_TYPE_I) {
2481	s->f_code = get_bits(gb, 3); /* fcode_for */
2482	if (s->f_code == 0) {
2483	av_log(s->avctx, AV_LOG_ERROR,
2484	"Error, header damaged or not MPEG-4 header (f_code=0)\n");
2485	s->f_code = 1;
2486	return AVERROR_INVALIDDATA; // makes no sense to continue, as there is nothing left from the image then
2487	}
2488	} else
2489	s->f_code = 1;
2490
2491	if (s->pict_type == AV_PICTURE_TYPE_B) {
2492	s->b_code = get_bits(gb, 3);
2493	if (s->b_code == 0) {
2494	av_log(s->avctx, AV_LOG_ERROR,
2495	"Error, header damaged or not MPEG4 header (b_code=0)\n");
2496	s->b_code=1;
2497	return AVERROR_INVALIDDATA; // makes no sense to continue, as the MV decoding will break very quickly
2498	}
2499	} else
2500	s->b_code = 1;
2501
2502	if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2503	av_log(s->avctx, AV_LOG_DEBUG,
2504	"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 time:%"PRId64" tincr:%d\n",
2505	s->qscale, s->f_code, s->b_code,
2506	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")),
2507	gb->size_in_bits,s->progressive_sequence, s->alternate_scan,
2508	s->top_field_first, s->quarter_sample ? "q" : "h",
2509	s->data_partitioning, ctx->resync_marker,
2510	ctx->num_sprite_warping_points, s->sprite_warping_accuracy,
2511	1 - s->no_rounding, s->vo_type,
2512	ctx->vol_control_parameters ? " VOLC" : " ", ctx->intra_dc_threshold,
2513	ctx->cplx_estimation_trash_i, ctx->cplx_estimation_trash_p,
2514	ctx->cplx_estimation_trash_b,
2515	s->time,
2516	time_increment
2517	);
2518	}
2519
2520	if (!ctx->scalability) {
2521	if (ctx->shape != RECT_SHAPE && s->pict_type != AV_PICTURE_TYPE_I)
2522	skip_bits1(gb); // vop shape coding type
2523	} else {
2524	if (ctx->enhancement_type) {
2525	int load_backward_shape = get_bits1(gb);
2526	if (load_backward_shape)
2527	av_log(s->avctx, AV_LOG_ERROR,
2528	"load backward shape isn't supported\n");
2529	}
2530	skip_bits(gb, 2); // ref_select_code
2531	}
2532	}
2533	/* detect buggy encoders which don't set the low_delay flag
2534	* (divx4/xvid/opendivx). Note we cannot detect divx5 without B-frames
2535	* easily (although it's buggy too) */
2536	if (s->vo_type == 0 && ctx->vol_control_parameters == 0 &&
2537	ctx->divx_version == -1 && s->picture_number == 0) {
2538	av_log(s->avctx, AV_LOG_WARNING,
2539	"looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2540	s->low_delay = 1;
2541	}
2542
2543	s->picture_number++; // better than pic number==0 always ;)
2544
2545	// FIXME add short header support
2546	s->y_dc_scale_table = ff_mpeg4_y_dc_scale_table;
2547	s->c_dc_scale_table = ff_mpeg4_c_dc_scale_table;
2548
2549	if (s->workaround_bugs & FF_BUG_EDGE) {
2550	s->h_edge_pos = s->width;
2551	s->v_edge_pos = s->height;
2552	}
2553	return 0;
2554	}
2555
2556	/**
2557	* Decode MPEG-4 headers.
2558	* @return <0 if no VOP found (or a damaged one)
2559	* FRAME_SKIPPED if a not coded VOP is found
2560	* 0 if a VOP is found
2561	*/
2562	int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2563	{
2564	MpegEncContext *s = &ctx->m;
2565	unsigned startcode, v;
2566	int ret;
2567
2568	/* search next start code */
2569	align_get_bits(gb);
2570
2571	if (s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630) {
2572	skip_bits(gb, 24);
2573	if (get_bits(gb, 8) == 0xF0)
2574	goto end;
2575	}
2576
2577	startcode = 0xff;
2578	for (;;) {
2579	if (get_bits_count(gb) >= gb->size_in_bits) {
2580	if (gb->size_in_bits == 8 &&
2581	(ctx->divx_version >= 0 || ctx->xvid_build >= 0) || s->codec_tag == AV_RL32("QMP4")) {
2582	av_log(s->avctx, AV_LOG_VERBOSE, "frame skip %d\n", gb->size_in_bits);
2583	return FRAME_SKIPPED; // divx bug
2584	} else
2585	return -1; // end of stream
2586	}
2587
2588	/* use the bits after the test */
2589	v = get_bits(gb, 8);
2590	startcode = ((startcode << 8) | v) & 0xffffffff;
2591
2592	if ((startcode & 0xFFFFFF00) != 0x100)
2593	continue; // no startcode
2594
2595	if (s->avctx->debug & FF_DEBUG_STARTCODE) {
2596	av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2597	if (startcode <= 0x11F)
2598	av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2599	else if (startcode <= 0x12F)
2600	av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2601	else if (startcode <= 0x13F)
2602	av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2603	else if (startcode <= 0x15F)
2604	av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2605	else if (startcode <= 0x1AF)
2606	av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2607	else if (startcode == 0x1B0)
2608	av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2609	else if (startcode == 0x1B1)
2610	av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2611	else if (startcode == 0x1B2)
2612	av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2613	else if (startcode == 0x1B3)
2614	av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2615	else if (startcode == 0x1B4)
2616	av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2617	else if (startcode == 0x1B5)
2618	av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2619	else if (startcode == 0x1B6)
2620	av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2621	else if (startcode == 0x1B7)
2622	av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2623	else if (startcode == 0x1B8)
2624	av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2625	else if (startcode == 0x1B9)
2626	av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2627	else if (startcode == 0x1BA)
2628	av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2629	else if (startcode == 0x1BB)
2630	av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2631	else if (startcode == 0x1BC)
2632	av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2633	else if (startcode == 0x1BD)
2634	av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2635	else if (startcode == 0x1BE)
2636	av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2637	else if (startcode == 0x1BF)
2638	av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2639	else if (startcode == 0x1C0)
2640	av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2641	else if (startcode == 0x1C1)
2642	av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2643	else if (startcode == 0x1C2)
2644	av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2645	else if (startcode == 0x1C3)
2646	av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2647	else if (startcode <= 0x1C5)
2648	av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2649	else if (startcode <= 0x1FF)
2650	av_log(s->avctx, AV_LOG_DEBUG, "System start");
2651	av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2652	}
2653
2654	if (startcode >= 0x120 && startcode <= 0x12F) {
2655	if ((ret = decode_vol_header(ctx, gb)) < 0)
2656	return ret;
2657	} else if (startcode == USER_DATA_STARTCODE) {
2658	decode_user_data(ctx, gb);
2659	} else if (startcode == GOP_STARTCODE) {
2660	mpeg4_decode_gop_header(s, gb);
2661	} else if (startcode == VOS_STARTCODE) {
2662	mpeg4_decode_profile_level(s, gb);
2663	} else if (startcode == VOP_STARTCODE) {
2664	break;
2665	}
2666
2667	align_get_bits(gb);
2668	startcode = 0xff;
2669	}
2670
2671	end:
2672	if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2673	s->low_delay = 1;
2674	s->avctx->has_b_frames = !s->low_delay;
2675
2676	return decode_vop_header(ctx, gb);
2677	}
2678
2679	av_cold void ff_mpeg4videodec_static_init(void) {
2680	static int done = 0;
2681
2682	if (!done) {
2683	ff_rl_init(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2684	ff_rl_init(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2685	ff_rl_init(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2686	INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2687	INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
2688	INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
2689	INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2690	&ff_mpeg4_DCtab_lum[0][1], 2, 1,
2691	&ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2692	INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2693	&ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2694	&ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2695	INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2696	&ff_sprite_trajectory_tab[0][1], 4, 2,
2697	&ff_sprite_trajectory_tab[0][0], 4, 2, 128);
2698	INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2699	&ff_mb_type_b_tab[0][1], 2, 1,
2700	&ff_mb_type_b_tab[0][0], 2, 1, 16);
2701	done = 1;
2702	}
2703	}
2704
2705	int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
2706	{
2707	Mpeg4DecContext *ctx = avctx->priv_data;
2708	MpegEncContext *s = &ctx->m;
2709
2710	/* divx 5.01+ bitstream reorder stuff */
2711	/* Since this clobbers the input buffer and hwaccel codecs still need the
2712	* data during hwaccel->end_frame we should not do this any earlier */
2713	if (s->divx_packed) {
2714	int current_pos = s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb) >> 3);
2715	int startcode_found = 0;
2716
2717	if (buf_size - current_pos > 7) {
2718
2719	int i;
2720	for (i = current_pos; i < buf_size - 4; i++)
2721
2722	if (buf[i] == 0 &&
2723	buf[i + 1] == 0 &&
2724	buf[i + 2] == 1 &&
2725	buf[i + 3] == 0xB6) {
2726	startcode_found = !(buf[i + 4] & 0x40);
2727	break;
2728	}
2729	}
2730
2731	if (startcode_found) {
2732	if (!ctx->showed_packed_warning) {
2733	av_log(s->avctx, AV_LOG_INFO, "Video uses a non-standard and "
2734	"wasteful way to store B-frames ('packed B-frames'). "
2735	"Consider using the mpeg4_unpack_bframes bitstream filter without encoding but stream copy to fix it.\n");
2736	ctx->showed_packed_warning = 1;
2737	}
2738	av_fast_padded_malloc(&s->bitstream_buffer,
2739	&s->allocated_bitstream_buffer_size,
2740	buf_size - current_pos);
2741	if (!s->bitstream_buffer) {
2742	s->bitstream_buffer_size = 0;
2743	return AVERROR(ENOMEM);
2744	}
2745	memcpy(s->bitstream_buffer, buf + current_pos,
2746	buf_size - current_pos);
2747	s->bitstream_buffer_size = buf_size - current_pos;
2748	}
2749	}
2750
2751	return 0;
2752	}
2753
2754	#if HAVE_THREADS
2755	static int mpeg4_update_thread_context(AVCodecContext *dst,
2756	const AVCodecContext *src)
2757	{
2758	Mpeg4DecContext *s = dst->priv_data;
2759	const Mpeg4DecContext *s1 = src->priv_data;
2760	int init = s->m.context_initialized;
2761
2762	int ret = ff_mpeg_update_thread_context(dst, src);
2763
2764	if (ret < 0)
2765	return ret;
2766
2767	memcpy(((uint8_t*)s) + sizeof(MpegEncContext), ((uint8_t*)s1) + sizeof(MpegEncContext), sizeof(Mpeg4DecContext) - sizeof(MpegEncContext));
2768
2769	if (CONFIG_MPEG4_DECODER && !init && s1->xvid_build >= 0)
2770	ff_xvid_idct_init(&s->m.idsp, dst);
2771
2772	return 0;
2773	}
2774	#endif
2775
2776	static av_cold int decode_init(AVCodecContext *avctx)
2777	{
2778	Mpeg4DecContext *ctx = avctx->priv_data;
2779	MpegEncContext *s = &ctx->m;
2780	int ret;
2781
2782	ctx->divx_version =
2783	ctx->divx_build =
2784	ctx->xvid_build =
2785	ctx->lavc_build = -1;
2786
2787	if ((ret = ff_h263_decode_init(avctx)) < 0)
2788	return ret;
2789
2790	ff_mpeg4videodec_static_init();
2791
2792	s->h263_pred = 1;
2793	s->low_delay = 0; /* default, might be overridden in the vol header during header parsing */
2794	s->decode_mb = mpeg4_decode_mb;
2795	ctx->time_increment_bits = 4; /* default value for broken headers */
2796
2797	avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2798	avctx->internal->allocate_progress = 1;
2799
2800	return 0;
2801	}
2802
2803	static const AVOption mpeg4_options[] = {
2804	{"quarter_sample", "1/4 subpel MC", offsetof(MpegEncContext, quarter_sample), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, 0},
2805	{"divx_packed", "divx style packed b frames", offsetof(MpegEncContext, divx_packed), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, 0},
2806	{NULL}
2807	};
2808
2809	static const AVClass mpeg4_class = {
2810	"MPEG4 Video Decoder",
2811	av_default_item_name,
2812	mpeg4_options,
2813	LIBAVUTIL_VERSION_INT,
2814	};
2815
2816	AVCodec ff_mpeg4_decoder = {
2817	.name = "mpeg4",
2818	.long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2819	.type = AVMEDIA_TYPE_VIDEO,
2820	.id = AV_CODEC_ID_MPEG4,
2821	.priv_data_size = sizeof(Mpeg4DecContext),
2822	.init = decode_init,
2823	.close = ff_h263_decode_end,
2824	.decode = ff_h263_decode_frame,
2825	.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2826	AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2827	AV_CODEC_CAP_FRAME_THREADS,
2828	.caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2829	.flush = ff_mpeg_flush,
2830	.max_lowres = 3,
2831	.pix_fmts = ff_h263_hwaccel_pixfmt_list_420,
2832	.profiles = NULL_IF_CONFIG_SMALL(ff_mpeg4_video_profiles),
2833	.update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg4_update_thread_context),
2834	.priv_class = &mpeg4_class,
2835	};
2836
2837
2838	#if CONFIG_MPEG4_VDPAU_DECODER && FF_API_VDPAU
2839	static const AVClass mpeg4_vdpau_class = {
2840	"MPEG4 Video VDPAU Decoder",
2841	av_default_item_name,
2842	mpeg4_options,
2843	LIBAVUTIL_VERSION_INT,
2844	};
2845
2846	AVCodec ff_mpeg4_vdpau_decoder = {
2847	.name = "mpeg4_vdpau",
2848	.long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2849	.type = AVMEDIA_TYPE_VIDEO,
2850	.id = AV_CODEC_ID_MPEG4,
2851	.priv_data_size = sizeof(Mpeg4DecContext),
2852	.init = decode_init,
2853	.close = ff_h263_decode_end,
2854	.decode = ff_h263_decode_frame,
2855	.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2856	AV_CODEC_CAP_HWACCEL_VDPAU,
2857	.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_VDPAU_MPEG4,
2858	AV_PIX_FMT_NONE },
2859	.priv_class = &mpeg4_vdpau_class,
2860	};
2861	#endif
2862