libavcodec/vp5.c

   1 /**
   2  * @file libavcodec/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 "get_bits.h"
  30
  31 #include "vp56.h"
  32 #include "vp56data.h"
  33 #include "vp5data.h"
  34
  35
  36 static int vp5_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
  37                             int *golden_frame)
  38 {
  39     VP56RangeCoder *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 (!s->macroblocks || /* first frame */
  62             16*cols != s->avctx->coded_width ||
  63             16*rows != s->avctx->coded_height) {
  64             avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
  65             return 2;
  66         }
  67     } else if (!s->macroblocks)
  68         return 0;
  69     return 1;
  70 }
  71
  72 /* Gives very similar result than the vp6 version except in a few cases */
  73 static int vp5_adjust(int v, int t)
  74 {
  75     int s2, s1 = v >> 31;
  76     v ^= s1;
  77     v -= s1;
  78     v *= v < 2*t;
  79     v -= t;
  80     s2 = v >> 31;
  81     v ^= s2;
  82     v -= s2;
  83     v = t - v;
  84     v += s1;
  85     v ^= s1;
  86     return v;
  87 }
  88
  89 static void vp5_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
  90 {
  91     VP56RangeCoder *c = &s->c;
  92     VP56Model *model = s->modelp;
  93     int comp, di;
  94
  95     for (comp=0; comp<2; comp++) {
  96         int delta = 0;
  97         if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
  98             int sign = vp56_rac_get_prob(c, model->vector_sig[comp]);
  99             di  = vp56_rac_get_prob(c, model->vector_pdi[comp][0]);
 100             di |= vp56_rac_get_prob(c, model->vector_pdi[comp][1]) << 1;
 101             delta = vp56_rac_get_tree(c, vp56_pva_tree,
 102                                       model->vector_pdv[comp]);
 103             delta = di | (delta << 2);
 104             delta = (delta ^ -sign) + sign;
 105         }
 106         if (!comp)
 107             vect->x = delta;
 108         else
 109             vect->y = delta;
 110     }
 111 }
 112
 113 static void vp5_parse_vector_models(VP56Context *s)
 114 {
 115     VP56RangeCoder *c = &s->c;
 116     VP56Model *model = s->modelp;
 117     int comp, node;
 118
 119     for (comp=0; comp<2; comp++) {
 120         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
 121             model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
 122         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
 123             model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
 124         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
 125             model->vector_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
 126         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
 127             model->vector_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
 128     }
 129
 130     for (comp=0; comp<2; comp++)
 131         for (node=0; node<7; node++)
 132             if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
 133                 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
 134 }
 135
 136 static void vp5_parse_coeff_models(VP56Context *s)
 137 {
 138     VP56RangeCoder *c = &s->c;
 139     VP56Model *model = s->modelp;
 140     uint8_t def_prob[11];
 141     int node, cg, ctx;
 142     int ct;    /* code type */
 143     int pt;    /* plane type (0 for Y, 1 for U or V) */
 144
 145     memset(def_prob, 0x80, sizeof(def_prob));
 146
 147     for (pt=0; pt<2; pt++)
 148         for (node=0; node<11; node++)
 149             if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
 150                 def_prob[node] = vp56_rac_gets_nn(c, 7);
 151                 model->coeff_dccv[pt][node] = def_prob[node];
 152             } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
 153                 model->coeff_dccv[pt][node] = def_prob[node];
 154             }
 155
 156     for (ct=0; ct<3; ct++)
 157         for (pt=0; pt<2; pt++)
 158             for (cg=0; cg<6; cg++)
 159                 for (node=0; node<11; node++)
 160                     if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
 161                         def_prob[node] = vp56_rac_gets_nn(c, 7);
 162                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
 163                     } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
 164                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
 165                     }
 166
 167     /* coeff_dcct is a linear combination of coeff_dccv */
 168     for (pt=0; pt<2; pt++)
 169         for (ctx=0; ctx<36; ctx++)
 170             for (node=0; node<5; node++)
 171                 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);
 172
 173     /* coeff_acct is a linear combination of coeff_ract */
 174     for (ct=0; ct<3; ct++)
 175         for (pt=0; pt<2; pt++)
 176             for (cg=0; cg<3; cg++)
 177                 for (ctx=0; ctx<6; ctx++)
 178                     for (node=0; node<5; node++)
 179                         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);
 180 }
 181
 182 static void vp5_parse_coeff(VP56Context *s)
 183 {
 184     VP56RangeCoder *c = &s->c;
 185     VP56Model *model = s->modelp;
 186     uint8_t *permute = s->scantable.permutated;
 187     uint8_t *model1, *model2;
 188     int coeff, sign, coeff_idx;
 189     int b, i, cg, idx, ctx, ctx_last;
 190     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
 191
 192     for (b=0; b<6; b++) {
 193         int ct = 1;    /* code type */
 194
 195         if (b > 3) pt = 1;
 196
 197         ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]
 198               + s->above_blocks[s->above_block_idx[b]].not_null_dc;
 199         model1 = model->coeff_dccv[pt];
 200         model2 = model->coeff_dcct[pt][ctx];
 201
 202         for (coeff_idx=0; coeff_idx<64; ) {
 203             if (vp56_rac_get_prob(c, model2[0])) {
 204                 if (vp56_rac_get_prob(c, model2[2])) {
 205                     if (vp56_rac_get_prob(c, model2[3])) {
 206                         s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;
 207                         idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
 208                         sign = vp56_rac_get(c);
 209                         coeff = vp56_coeff_bias[idx+5];
 210                         for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
 211                             coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
 212                     } else {
 213                         if (vp56_rac_get_prob(c, model2[4])) {
 214                             coeff = 3 + vp56_rac_get_prob(c, model1[5]);
 215                             s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;
 216                         } else {
 217                             coeff = 2;
 218                             s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;
 219                         }
 220                         sign = vp56_rac_get(c);
 221                     }
 222                     ct = 2;
 223                 } else {
 224                     ct = 1;
 225                     s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;
 226                     sign = vp56_rac_get(c);
 227                     coeff = 1;
 228                 }
 229                 coeff = (coeff ^ -sign) + sign;
 230                 if (coeff_idx)
 231                     coeff *= s->dequant_ac;
 232                 s->block_coeff[b][permute[coeff_idx]] = coeff;
 233             } else {
 234                 if (ct && !vp56_rac_get_prob(c, model2[1]))
 235                     break;
 236                 ct = 0;
 237                 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;
 238             }
 239
 240             cg = vp5_coeff_groups[++coeff_idx];
 241             ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];
 242             model1 = model->coeff_ract[pt][ct][cg];
 243             model2 = cg > 2 ? model1 : model->coeff_acct[pt][ct][cg][ctx];
 244         }
 245
 246         ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);
 247         s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;
 248         if (coeff_idx < ctx_last)
 249             for (i=coeff_idx; i<=ctx_last; i++)
 250                 s->coeff_ctx[vp56_b6to4[b]][i] = 5;
 251         s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];
 252     }
 253 }
 254
 255 static void vp5_default_models_init(VP56Context *s)
 256 {
 257     VP56Model *model = s->modelp;
 258     int i;
 259
 260     for (i=0; i<2; i++) {
 261         model->vector_sig[i] = 0x80;
 262         model->vector_dct[i] = 0x80;
 263         model->vector_pdi[i][0] = 0x55;
 264         model->vector_pdi[i][1] = 0x80;
 265     }
 266     memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
 267     memset(model->vector_pdv, 0x80, sizeof(model->vector_pdv));
 268 }
 269
 270 static av_cold int vp5_decode_init(AVCodecContext *avctx)
 271 {
 272     VP56Context *s = avctx->priv_data;
 273
 274     vp56_init(avctx, 1, 0);
 275     s->vp56_coord_div = vp5_coord_div;
 276     s->parse_vector_adjustment = vp5_parse_vector_adjustment;
 277     s->adjust = vp5_adjust;
 278     s->parse_coeff = vp5_parse_coeff;
 279     s->default_models_init = vp5_default_models_init;
 280     s->parse_vector_models = vp5_parse_vector_models;
 281     s->parse_coeff_models = vp5_parse_coeff_models;
 282     s->parse_header = vp5_parse_header;
 283
 284     return 0;
 285 }
 286
 287 AVCodec vp5_decoder = {
 288     "vp5",
 289     CODEC_TYPE_VIDEO,
 290     CODEC_ID_VP5,
 291     sizeof(VP56Context),
 292     vp5_decode_init,
 293     NULL,
 294     vp56_free,
 295     vp56_decode_frame,
 296     CODEC_CAP_DR1,
 297     .long_name = NULL_IF_CONFIG_SMALL("On2 VP5"),
 298 };