libavcodec/vp5.c

   1 /**
   2  * @file vp5.c
   3  * VP5 compatible video decoder
   4  *
   5  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
   6  *
   7  * This file is part of FFmpeg.
   8  *
   9  * FFmpeg is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * FFmpeg is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with FFmpeg; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include "avcodec.h"
  28 #include "dsputil.h"
  29 #include "bitstream.h"
  30
  31 #include "vp56.h"
  32 #include "vp56data.h"
  33 #include "vp5data.h"
  34
  35
  36 static int vp5_parse_header(vp56_context_t *s, const uint8_t *buf, int buf_size,
  37                             int *golden_frame)
  38 {
  39     vp56_range_coder_t *c = &s->c;
  40     int rows, cols;
  41
  42     vp56_init_range_decoder(&s->c, buf, buf_size);
  43     s->framep[VP56_FRAME_CURRENT]->key_frame = !vp56_rac_get(c);
  44     vp56_rac_get(c);
  45     vp56_init_dequant(s, vp56_rac_gets(c, 6));
  46     if (s->framep[VP56_FRAME_CURRENT]->key_frame)
  47     {
  48         vp56_rac_gets(c, 8);
  49         if(vp56_rac_gets(c, 5) > 5)
  50             return 0;
  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 0;
  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         vp56_rac_gets(c, 8);  /* number of displayed macroblock rows */
  59         vp56_rac_gets(c, 8);  /* number of displayed macroblock cols */
  60         vp56_rac_gets(c, 2);
  61         if (16*cols != s->avctx->coded_width ||
  62             16*rows != s->avctx->coded_height) {
  63             avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
  64             return 2;
  65         }
  66     }
  67     return 1;
  68 }
  69
  70 /* Gives very similar result than the vp6 version except in a few cases */
  71 static int vp5_adjust(int v, int t)
  72 {
  73     int s2, s1 = v >> 31;
  74     v ^= s1;
  75     v -= s1;
  76     v *= v < 2*t;
  77     v -= t;
  78     s2 = v >> 31;
  79     v ^= s2;
  80     v -= s2;
  81     v = t - v;
  82     v += s1;
  83     v ^= s1;
  84     return v;
  85 }
  86
  87 static void vp5_parse_vector_adjustment(vp56_context_t *s, vp56_mv_t *vect)
  88 {
  89     vp56_range_coder_t *c = &s->c;
  90     vp56_model_t *model = s->modelp;
  91     int comp, di;
  92
  93     for (comp=0; comp<2; comp++) {
  94         int delta = 0;
  95         if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
  96             int sign = vp56_rac_get_prob(c, model->vector_sig[comp]);
  97             di  = vp56_rac_get_prob(c, model->vector_pdi[comp][0]);
  98             di |= vp56_rac_get_prob(c, model->vector_pdi[comp][1]) << 1;
  99             delta = vp56_rac_get_tree(c, vp56_pva_tree,
 100                                       model->vector_pdv[comp]);
 101             delta = di | (delta << 2);
 102             delta = (delta ^ -sign) + sign;
 103         }
 104         if (!comp)
 105             vect->x = delta;
 106         else
 107             vect->y = delta;
 108     }
 109 }
 110
 111 static void vp5_parse_vector_models(vp56_context_t *s)
 112 {
 113     vp56_range_coder_t *c = &s->c;
 114     vp56_model_t *model = s->modelp;
 115     int comp, node;
 116
 117     for (comp=0; comp<2; comp++) {
 118         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
 119             model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
 120         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
 121             model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
 122         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
 123             model->vector_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
 124         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
 125             model->vector_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
 126     }
 127
 128     for (comp=0; comp<2; comp++)
 129         for (node=0; node<7; node++)
 130             if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
 131                 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
 132 }
 133
 134 static void vp5_parse_coeff_models(vp56_context_t *s)
 135 {
 136     vp56_range_coder_t *c = &s->c;
 137     vp56_model_t *model = s->modelp;
 138     uint8_t def_prob[11];
 139     int node, cg, ctx;
 140     int ct;    /* code type */
 141     int pt;    /* plane type (0 for Y, 1 for U or V) */
 142
 143     memset(def_prob, 0x80, sizeof(def_prob));
 144
 145     for (pt=0; pt<2; pt++)
 146         for (node=0; node<11; node++)
 147             if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
 148                 def_prob[node] = vp56_rac_gets_nn(c, 7);
 149                 model->coeff_dccv[pt][node] = def_prob[node];
 150             } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
 151                 model->coeff_dccv[pt][node] = def_prob[node];
 152             }
 153
 154     for (ct=0; ct<3; ct++)
 155         for (pt=0; pt<2; pt++)
 156             for (cg=0; cg<6; cg++)
 157                 for (node=0; node<11; node++)
 158                     if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
 159                         def_prob[node] = vp56_rac_gets_nn(c, 7);
 160                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
 161                     } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
 162                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
 163                     }
 164
 165     /* coeff_dcct is a linear combination of coeff_dccv */
 166     for (pt=0; pt<2; pt++)
 167         for (ctx=0; ctx<36; ctx++)
 168             for (node=0; node<5; node++)
 169                 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);
 170
 171     /* coeff_acct is a linear combination of coeff_ract */
 172     for (ct=0; ct<3; ct++)
 173         for (pt=0; pt<2; pt++)
 174             for (cg=0; cg<3; cg++)
 175                 for (ctx=0; ctx<6; ctx++)
 176                     for (node=0; node<5; node++)
 177                         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);
 178 }
 179
 180 static void vp5_parse_coeff(vp56_context_t *s)
 181 {
 182     vp56_range_coder_t *c = &s->c;
 183     vp56_model_t *model = s->modelp;
 184     uint8_t *permute = s->scantable.permutated;
 185     uint8_t *model1, *model2;
 186     int coeff, sign, coeff_idx;
 187     int b, i, cg, idx, ctx, ctx_last;
 188     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
 189
 190     for (b=0; b<6; b++) {
 191         int ct = 1;    /* code type */
 192
 193         if (b > 3) pt = 1;
 194
 195         ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]
 196               + s->above_blocks[s->above_block_idx[b]].not_null_dc;
 197         model1 = model->coeff_dccv[pt];
 198         model2 = model->coeff_dcct[pt][ctx];
 199
 200         for (coeff_idx=0; coeff_idx<64; ) {
 201             if (vp56_rac_get_prob(c, model2[0])) {
 202                 if (vp56_rac_get_prob(c, model2[2])) {
 203                     if (vp56_rac_get_prob(c, model2[3])) {
 204                         s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;
 205                         idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
 206                         sign = vp56_rac_get(c);
 207                         coeff = vp56_coeff_bias[idx+5];
 208                         for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
 209                             coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
 210                     } else {
 211                         if (vp56_rac_get_prob(c, model2[4])) {
 212                             coeff = 3 + vp56_rac_get_prob(c, model1[5]);
 213                             s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;
 214                         } else {
 215                             coeff = 2;
 216                             s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;
 217                         }
 218                         sign = vp56_rac_get(c);
 219                     }
 220                     ct = 2;
 221                 } else {
 222                     ct = 1;
 223                     s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;
 224                     sign = vp56_rac_get(c);
 225                     coeff = 1;
 226                 }
 227                 coeff = (coeff ^ -sign) + sign;
 228                 if (coeff_idx)
 229                     coeff *= s->dequant_ac;
 230                 s->block_coeff[b][permute[coeff_idx]] = coeff;
 231             } else {
 232                 if (ct && !vp56_rac_get_prob(c, model2[1]))
 233                     break;
 234                 ct = 0;
 235                 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;
 236             }
 237
 238             cg = vp5_coeff_groups[++coeff_idx];
 239             ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];
 240             model1 = model->coeff_ract[pt][ct][cg];
 241             model2 = cg > 2 ? model1 : model->coeff_acct[pt][ct][cg][ctx];
 242         }
 243
 244         ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);
 245         s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;
 246         if (coeff_idx < ctx_last)
 247             for (i=coeff_idx; i<=ctx_last; i++)
 248                 s->coeff_ctx[vp56_b6to4[b]][i] = 5;
 249         s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];
 250     }
 251 }
 252
 253 static void vp5_default_models_init(vp56_context_t *s)
 254 {
 255     vp56_model_t *model = s->modelp;
 256     int i;
 257
 258     for (i=0; i<2; i++) {
 259         model->vector_sig[i] = 0x80;
 260         model->vector_dct[i] = 0x80;
 261         model->vector_pdi[i][0] = 0x55;
 262         model->vector_pdi[i][1] = 0x80;
 263     }
 264     memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
 265     memset(model->vector_pdv, 0x80, sizeof(model->vector_pdv));
 266 }
 267
 268 static av_cold int vp5_decode_init(AVCodecContext *avctx)
 269 {
 270     vp56_context_t *s = avctx->priv_data;
 271
 272     vp56_init(avctx, 1, 0);
 273     s->vp56_coord_div = vp5_coord_div;
 274     s->parse_vector_adjustment = vp5_parse_vector_adjustment;
 275     s->adjust = vp5_adjust;
 276     s->parse_coeff = vp5_parse_coeff;
 277     s->default_models_init = vp5_default_models_init;
 278     s->parse_vector_models = vp5_parse_vector_models;
 279     s->parse_coeff_models = vp5_parse_coeff_models;
 280     s->parse_header = vp5_parse_header;
 281
 282     return 0;
 283 }
 284
 285 AVCodec vp5_decoder = {
 286     "vp5",
 287     CODEC_TYPE_VIDEO,
 288     CODEC_ID_VP5,
 289     sizeof(vp56_context_t),
 290     vp5_decode_init,
 291     NULL,
 292     vp56_free,
 293     vp56_decode_frame,
 294     CODEC_CAP_DR1,
 295     .long_name = NULL_IF_CONFIG_SMALL("On2 VP5"),
 296 };