FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vp5.c
Go to the documentation of this file.
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 "dsputil.h"
31 #include "get_bits.h"
32 
33 #include "vp56.h"
34 #include "vp56data.h"
35 #include "vp5data.h"
36 
37 
38 static int vp5_parse_header(VP56Context *s, const uint8_t *buf, int buf_size)
39 {
40  VP56RangeCoder *c = &s->c;
41  int rows, cols;
42 
43  ff_vp56_init_range_decoder(&s->c, buf, buf_size);
44  s->framep[VP56_FRAME_CURRENT]->key_frame = !vp56_rac_get(c);
45  vp56_rac_get(c);
46  ff_vp56_init_dequant(s, vp56_rac_gets(c, 6));
47  if (s->framep[VP56_FRAME_CURRENT]->key_frame)
48  {
49  vp56_rac_gets(c, 8);
50  if(vp56_rac_gets(c, 5) > 5)
51  return AVERROR_INVALIDDATA;
52  vp56_rac_gets(c, 2);
53  if (vp56_rac_get(c)) {
54  av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
55  return AVERROR_PATCHWELCOME;
56  }
57  rows = vp56_rac_gets(c, 8); /* number of stored macroblock rows */
58  cols = vp56_rac_gets(c, 8); /* number of stored macroblock cols */
59  if (!rows || !cols) {
60  av_log(s->avctx, AV_LOG_ERROR, "Invalid size %dx%d\n",
61  cols << 4, rows << 4);
62  return AVERROR_INVALIDDATA;
63  }
64  vp56_rac_gets(c, 8); /* number of displayed macroblock rows */
65  vp56_rac_gets(c, 8); /* number of displayed macroblock cols */
66  vp56_rac_gets(c, 2);
67  if (!s->macroblocks || /* first frame */
68  16*cols != s->avctx->coded_width ||
69  16*rows != s->avctx->coded_height) {
70  avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
71  return VP56_SIZE_CHANGE;
72  }
73  } else if (!s->macroblocks)
74  return AVERROR_INVALIDDATA;
75  return 0;
76 }
77 
78 static void vp5_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
79 {
80  VP56RangeCoder *c = &s->c;
81  VP56Model *model = s->modelp;
82  int comp, di;
83 
84  for (comp=0; comp<2; comp++) {
85  int delta = 0;
86  if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
87  int sign = vp56_rac_get_prob(c, model->vector_sig[comp]);
88  di = vp56_rac_get_prob(c, model->vector_pdi[comp][0]);
89  di |= vp56_rac_get_prob(c, model->vector_pdi[comp][1]) << 1;
90  delta = vp56_rac_get_tree(c, ff_vp56_pva_tree,
91  model->vector_pdv[comp]);
92  delta = di | (delta << 2);
93  delta = (delta ^ -sign) + sign;
94  }
95  if (!comp)
96  vect->x = delta;
97  else
98  vect->y = delta;
99  }
100 }
101 
102 static void vp5_parse_vector_models(VP56Context *s)
103 {
104  VP56RangeCoder *c = &s->c;
105  VP56Model *model = s->modelp;
106  int comp, node;
107 
108  for (comp=0; comp<2; comp++) {
109  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
110  model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
111  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
112  model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
113  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
114  model->vector_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
115  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
116  model->vector_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
117  }
118 
119  for (comp=0; comp<2; comp++)
120  for (node=0; node<7; node++)
121  if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
122  model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
123 }
124 
125 static int vp5_parse_coeff_models(VP56Context *s)
126 {
127  VP56RangeCoder *c = &s->c;
128  VP56Model *model = s->modelp;
129  uint8_t def_prob[11];
130  int node, cg, ctx;
131  int ct; /* code type */
132  int pt; /* plane type (0 for Y, 1 for U or V) */
133 
134  memset(def_prob, 0x80, sizeof(def_prob));
135 
136  for (pt=0; pt<2; pt++)
137  for (node=0; node<11; node++)
138  if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
139  def_prob[node] = vp56_rac_gets_nn(c, 7);
140  model->coeff_dccv[pt][node] = def_prob[node];
141  } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
142  model->coeff_dccv[pt][node] = def_prob[node];
143  }
144 
145  for (ct=0; ct<3; ct++)
146  for (pt=0; pt<2; pt++)
147  for (cg=0; cg<6; cg++)
148  for (node=0; node<11; node++)
149  if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
150  def_prob[node] = vp56_rac_gets_nn(c, 7);
151  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
152  } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
153  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
154  }
155 
156  /* coeff_dcct is a linear combination of coeff_dccv */
157  for (pt=0; pt<2; pt++)
158  for (ctx=0; ctx<36; ctx++)
159  for (node=0; node<5; node++)
160  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);
161 
162  /* coeff_acct is a linear combination of coeff_ract */
163  for (ct=0; ct<3; ct++)
164  for (pt=0; pt<2; pt++)
165  for (cg=0; cg<3; cg++)
166  for (ctx=0; ctx<6; ctx++)
167  for (node=0; node<5; node++)
168  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);
169  return 0;
170 }
171 
172 static void vp5_parse_coeff(VP56Context *s)
173 {
174  VP56RangeCoder *c = &s->c;
175  VP56Model *model = s->modelp;
176  uint8_t *permute = s->scantable.permutated;
177  uint8_t *model1, *model2;
178  int coeff, sign, coeff_idx;
179  int b, i, cg, idx, ctx, ctx_last;
180  int pt = 0; /* plane type (0 for Y, 1 for U or V) */
181 
182  for (b=0; b<6; b++) {
183  int ct = 1; /* code type */
184 
185  if (b > 3) pt = 1;
186 
187  ctx = 6*s->coeff_ctx[ff_vp56_b6to4[b]][0]
188  + s->above_blocks[s->above_block_idx[b]].not_null_dc;
189  model1 = model->coeff_dccv[pt];
190  model2 = model->coeff_dcct[pt][ctx];
191 
192  coeff_idx = 0;
193  for (;;) {
194  if (vp56_rac_get_prob(c, model2[0])) {
195  if (vp56_rac_get_prob(c, model2[2])) {
196  if (vp56_rac_get_prob(c, model2[3])) {
197  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 4;
198  idx = vp56_rac_get_tree(c, ff_vp56_pc_tree, model1);
199  sign = vp56_rac_get(c);
200  coeff = ff_vp56_coeff_bias[idx+5];
201  for (i=ff_vp56_coeff_bit_length[idx]; i>=0; i--)
202  coeff += vp56_rac_get_prob(c, ff_vp56_coeff_parse_table[idx][i]) << i;
203  } else {
204  if (vp56_rac_get_prob(c, model2[4])) {
205  coeff = 3 + vp56_rac_get_prob(c, model1[5]);
206  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 3;
207  } else {
208  coeff = 2;
209  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 2;
210  }
211  sign = vp56_rac_get(c);
212  }
213  ct = 2;
214  } else {
215  ct = 1;
216  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 1;
217  sign = vp56_rac_get(c);
218  coeff = 1;
219  }
220  coeff = (coeff ^ -sign) + sign;
221  if (coeff_idx)
222  coeff *= s->dequant_ac;
223  s->block_coeff[b][permute[coeff_idx]] = coeff;
224  } else {
225  if (ct && !vp56_rac_get_prob(c, model2[1]))
226  break;
227  ct = 0;
228  s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx] = 0;
229  }
230  coeff_idx++;
231  if (coeff_idx >= 64)
232  break;
233 
234  cg = vp5_coeff_groups[coeff_idx];
235  ctx = s->coeff_ctx[ff_vp56_b6to4[b]][coeff_idx];
236  model1 = model->coeff_ract[pt][ct][cg];
237  model2 = cg > 2 ? model1 : model->coeff_acct[pt][ct][cg][ctx];
238  }
239 
240  ctx_last = FFMIN(s->coeff_ctx_last[ff_vp56_b6to4[b]], 24);
241  s->coeff_ctx_last[ff_vp56_b6to4[b]] = coeff_idx;
242  if (coeff_idx < ctx_last)
243  for (i=coeff_idx; i<=ctx_last; i++)
244  s->coeff_ctx[ff_vp56_b6to4[b]][i] = 5;
245  s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[ff_vp56_b6to4[b]][0];
246  }
247 }
248 
249 static void vp5_default_models_init(VP56Context *s)
250 {
251  VP56Model *model = s->modelp;
252  int i;
253 
254  for (i=0; i<2; i++) {
255  model->vector_sig[i] = 0x80;
256  model->vector_dct[i] = 0x80;
257  model->vector_pdi[i][0] = 0x55;
258  model->vector_pdi[i][1] = 0x80;
259  }
260  memcpy(model->mb_types_stats, ff_vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
261  memset(model->vector_pdv, 0x80, sizeof(model->vector_pdv));
262 }
263 
264 static av_cold int vp5_decode_init(AVCodecContext *avctx)
265 {
266  VP56Context *s = avctx->priv_data;
267 
268  ff_vp56_init(avctx, 1, 0);
269  s->vp56_coord_div = vp5_coord_div;
270  s->parse_vector_adjustment = vp5_parse_vector_adjustment;
271  s->parse_coeff = vp5_parse_coeff;
272  s->default_models_init = vp5_default_models_init;
273  s->parse_vector_models = vp5_parse_vector_models;
274  s->parse_coeff_models = vp5_parse_coeff_models;
275  s->parse_header = vp5_parse_header;
276 
277  return 0;
278 }
279 
280 AVCodec ff_vp5_decoder = {
281  .name = "vp5",
282  .type = AVMEDIA_TYPE_VIDEO,
283  .id = AV_CODEC_ID_VP5,
284  .priv_data_size = sizeof(VP56Context),
285  .init = vp5_decode_init,
286  .close = ff_vp56_free,
287  .decode = ff_vp56_decode_frame,
288  .capabilities = CODEC_CAP_DR1,
289  .long_name = NULL_IF_CONFIG_SMALL("On2 VP5"),
290 };
Generated on Sat May 25 2013 03:58:42 for FFmpeg by   doxygen 1.8.2