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vp5.c
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1 /*
2  * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * VP5 compatible video decoder
24  */
25 
26 #include <stdlib.h>
27 #include <string.h>
28 
29 #include "avcodec.h"
30 #include "get_bits.h"
31 
32 #include "vp56.h"
33 #include "vp56data.h"
34 #include "vp5data.h"
35 
36 
37 static int vp5_parse_header(VP56Context *s, const uint8_t *buf, int buf_size)
38 {
39  VP56RangeCoder *c = &s->c;
40  int rows, cols;
41 
42  ff_vp56_init_range_decoder(&s->c, buf, buf_size);
43  s->frames[VP56_FRAME_CURRENT]->key_frame = !vp56_rac_get(c);
44  vp56_rac_get(c);
45  ff_vp56_init_dequant(s, vp56_rac_gets(c, 6));
46  if (s->frames[VP56_FRAME_CURRENT]->key_frame)
47  {
48  vp56_rac_gets(c, 8);
49  if(vp56_rac_gets(c, 5) > 5)
50  return AVERROR_INVALIDDATA;
51  vp56_rac_gets(c, 2);
52  if (vp56_rac_get(c)) {
53  av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
54  return AVERROR_PATCHWELCOME;
55  }
56  rows = vp56_rac_gets(c, 8); /* number of stored macroblock rows */
57  cols = vp56_rac_gets(c, 8); /* number of stored macroblock cols */
58  if (!rows || !cols) {
59  av_log(s->avctx, AV_LOG_ERROR, "Invalid size %dx%d\n",
60  cols << 4, rows << 4);
61  return AVERROR_INVALIDDATA;
62  }
63  vp56_rac_gets(c, 8); /* number of displayed macroblock rows */
64  vp56_rac_gets(c, 8); /* number of displayed macroblock cols */
65  vp56_rac_gets(c, 2);
66  if (!s->macroblocks || /* first frame */
67  16*cols != s->avctx->coded_width ||
68  16*rows != s->avctx->coded_height) {
69  avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
70  return VP56_SIZE_CHANGE;
71  }
72  } else if (!s->macroblocks)
73  return AVERROR_INVALIDDATA;
74  return 0;
75 }
76 
77 static void vp5_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
78 {
79  VP56RangeCoder *c = &s->c;
80  VP56Model *model = s->modelp;
81  int comp, di;
82 
83  for (comp=0; comp<2; comp++) {
84  int delta = 0;
85  if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
86  int sign = vp56_rac_get_prob(c, model->vector_sig[comp]);
87  di = vp56_rac_get_prob(c, model->vector_pdi[comp][0]);
88  di |= vp56_rac_get_prob(c, model->vector_pdi[comp][1]) << 1;
89  delta = vp56_rac_get_tree(c, ff_vp56_pva_tree,
90  model->vector_pdv[comp]);
91  delta = di | (delta << 2);
92  delta = (delta ^ -sign) + sign;
93  }
94  if (!comp)
95  vect->x = delta;
96  else
97  vect->y = delta;
98  }
99 }
100 
101 static void vp5_parse_vector_models(VP56Context *s)
102 {
103  VP56RangeCoder *c = &s->c;
104  VP56Model *model = s->modelp;
105  int comp, node;
106 
107  for (comp=0; comp<2; comp++) {
108  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
109  model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
110  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
111  model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
112  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
113  model->vector_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
114  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
115  model->vector_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
116  }
117 
118  for (comp=0; comp<2; comp++)
119  for (node=0; node<7; node++)
120  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
121  model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
122 }
123 
124 static int vp5_parse_coeff_models(VP56Context *s)
125 {
126  VP56RangeCoder *c = &s->c;
127  VP56Model *model = s->modelp;
128  uint8_t def_prob[11];
129  int node, cg, ctx;
130  int ct; /* code type */
131  int pt; /* plane type (0 for Y, 1 for U or V) */
132 
133  memset(def_prob, 0x80, sizeof(def_prob));
134 
135  for (pt=0; pt<2; pt++)
136  for (node=0; node<11; node++)
137  if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
138  def_prob[node] = vp56_rac_gets_nn(c, 7);
139  model->coeff_dccv[pt][node] = def_prob[node];
140  } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
141  model->coeff_dccv[pt][node] = def_prob[node];
142  }
143 
144  for (ct=0; ct<3; ct++)
145  for (pt=0; pt<2; pt++)
146  for (cg=0; cg<6; cg++)
147  for (node=0; node<11; node++)
148  if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
149  def_prob[node] = vp56_rac_gets_nn(c, 7);
150  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
151  } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
152  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
153  }
154 
155  /* coeff_dcct is a linear combination of coeff_dccv */
156  for (pt=0; pt<2; pt++)
157  for (ctx=0; ctx<36; ctx++)
158  for (node=0; node<5; node++)
159  model->coeff_dcct[pt][ctx][node] = av_clip(((model->coeff_dccv[pt][node] * vp5_dccv_lc[node][ctx][0] + 128) >> 8) + vp5_dccv_lc[node][ctx][1], 1, 254);
160 
161  /* coeff_acct is a linear combination of coeff_ract */
162  for (ct=0; ct<3; ct++)
163  for (pt=0; pt<2; pt++)
164  for (cg=0; cg<3; cg++)
165  for (ctx=0; ctx<6; ctx++)
166  for (node=0; node<5; node++)
167  model->coeff_acct[pt][ct][cg][ctx][node] = av_clip(((model->coeff_ract[pt][ct][cg][node] * vp5_ract_lc[ct][cg][node][ctx][0] + 128) >> 8) + vp5_ract_lc[ct][cg][node][ctx][1], 1, 254);
168  return 0;
169 }
170 
171 static void vp5_parse_coeff(VP56Context *s)
172 {
173  VP56RangeCoder *c = &s->c;
174  VP56Model *model = s->modelp;
175  uint8_t *permute = s->idct_scantable;
176  uint8_t *model1, *model2;
177  int coeff, sign, coeff_idx;
178  int b, i, cg, idx, ctx, ctx_last;
179  int pt = 0; /* plane type (0 for Y, 1 for U or V) */
180 
181  for (b=0; b<6; b++) {
182  int ct = 1; /* code type */
183 
184  if (b > 3) pt = 1;
185 
186  ctx = 6*s->coeff_ctx[ff_vp56_b6to4[b]][0]
187  + s->above_blocks[s->above_block_idx[b]].not_null_dc;
188  model1 = model->coeff_dccv[pt];
189  model2 = model->coeff_dcct[pt][ctx];
190 
191  coeff_idx = 0;
192  for (;;) {
193  if (vp56_rac_get_prob(c, model2[0])) {
194  if (vp56_rac_get_prob(c, model2[2])) {
195  if (vp56_rac_get_prob(c, model2[3])) {
196  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 4;
197  idx = vp56_rac_get_tree(c, ff_vp56_pc_tree, model1);
198  sign = vp56_rac_get(c);
199  coeff = ff_vp56_coeff_bias[idx+5];
200  for (i=ff_vp56_coeff_bit_length[idx]; i>=0; i--)
201  coeff += vp56_rac_get_prob(c, ff_vp56_coeff_parse_table[idx][i]) << i;
202  } else {
203  if (vp56_rac_get_prob(c, model2[4])) {
204  coeff = 3 + vp56_rac_get_prob(c, model1[5]);
205  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 3;
206  } else {
207  coeff = 2;
208  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 2;
209  }
210  sign = vp56_rac_get(c);
211  }
212  ct = 2;
213  } else {
214  ct = 1;
215  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 1;
216  sign = vp56_rac_get(c);
217  coeff = 1;
218  }
219  coeff = (coeff ^ -sign) + sign;
220  if (coeff_idx)
221  coeff *= s->dequant_ac;
222  s->block_coeff[b][permute[coeff_idx]] = coeff;
223  } else {
224  if (ct && !vp56_rac_get_prob(c, model2[1]))
225  break;
226  ct = 0;
227  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 0;
228  }
229  coeff_idx++;
230  if (coeff_idx >= 64)
231  break;
232 
233  cg = vp5_coeff_groups[coeff_idx];
234  ctx = s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx];
235  model1 = model->coeff_ract[pt][ct][cg];
236  model2 = cg > 2 ? model1 : model->coeff_acct[pt][ct][cg][ctx];
237  }
238 
239  ctx_last = FFMIN(s->coeff_ctx_last[ff_vp56_b6to4[b]], 24);
240  s->coeff_ctx_last[ff_vp56_b6to4[b]] = coeff_idx;
241  if (coeff_idx < ctx_last)
242  for (i=coeff_idx; i<=ctx_last; i++)
243  s->coeff_ctx[ff_vp56_b6to4[b]][i] = 5;
244  s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[ff_vp56_b6to4[b]][0];
245  }
246 }
247 
248 static void vp5_default_models_init(VP56Context *s)
249 {
250  VP56Model *model = s->modelp;
251  int i;
252 
253  for (i=0; i<2; i++) {
254  model->vector_sig[i] = 0x80;
255  model->vector_dct[i] = 0x80;
256  model->vector_pdi[i][0] = 0x55;
257  model->vector_pdi[i][1] = 0x80;
258  }
259  memcpy(model->mb_types_stats, ff_vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
260  memset(model->vector_pdv, 0x80, sizeof(model->vector_pdv));
261 }
262 
263 static av_cold int vp5_decode_init(AVCodecContext *avctx)
264 {
265  VP56Context *s = avctx->priv_data;
266  int ret;
267 
268  if ((ret = ff_vp56_init(avctx, 1, 0)) < 0)
269  return ret;
270  s->vp56_coord_div = vp5_coord_div;
271  s->parse_vector_adjustment = vp5_parse_vector_adjustment;
272  s->parse_coeff = vp5_parse_coeff;
273  s->default_models_init = vp5_default_models_init;
274  s->parse_vector_models = vp5_parse_vector_models;
275  s->parse_coeff_models = vp5_parse_coeff_models;
276  s->parse_header = vp5_parse_header;
277 
278  return 0;
279 }
280 
281 AVCodec ff_vp5_decoder = {
282  .name = "vp5",
283  .type = AVMEDIA_TYPE_VIDEO,
284  .id = AV_CODEC_ID_VP5,
285  .priv_data_size = sizeof(VP56Context),
286  .init = vp5_decode_init,
287  .close = ff_vp56_free,
288  .decode = ff_vp56_decode_frame,
289  .capabilities = CODEC_CAP_DR1,
290  .long_name = NULL_IF_CONFIG_SMALL("On2 VP5"),
291 };
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