• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • File List
  • Globals

libavcodec/vp5.c

Go to the documentation of this file.
00001 /*
00002  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00026 #include <stdlib.h>
00027 #include <string.h>
00028 
00029 #include "avcodec.h"
00030 #include "dsputil.h"
00031 #include "get_bits.h"
00032 
00033 #include "vp56.h"
00034 #include "vp56data.h"
00035 #include "vp5data.h"
00036 
00037 
00038 static int vp5_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
00039                             int *golden_frame)
00040 {
00041     VP56RangeCoder *c = &s->c;
00042     int rows, cols;
00043 
00044     ff_vp56_init_range_decoder(&s->c, buf, buf_size);
00045     s->framep[VP56_FRAME_CURRENT]->key_frame = !vp56_rac_get(c);
00046     vp56_rac_get(c);
00047     ff_vp56_init_dequant(s, vp56_rac_gets(c, 6));
00048     if (s->framep[VP56_FRAME_CURRENT]->key_frame)
00049     {
00050         vp56_rac_gets(c, 8);
00051         if(vp56_rac_gets(c, 5) > 5)
00052             return 0;
00053         vp56_rac_gets(c, 2);
00054         if (vp56_rac_get(c)) {
00055             av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
00056             return 0;
00057         }
00058         rows = vp56_rac_gets(c, 8);  /* number of stored macroblock rows */
00059         cols = vp56_rac_gets(c, 8);  /* number of stored macroblock cols */
00060         if (!rows || !cols) {
00061             av_log(s->avctx, AV_LOG_ERROR, "Invalid size %dx%d\n",
00062                    cols << 4, rows << 4);
00063             return 0;
00064         }
00065         vp56_rac_gets(c, 8);  /* number of displayed macroblock rows */
00066         vp56_rac_gets(c, 8);  /* number of displayed macroblock cols */
00067         vp56_rac_gets(c, 2);
00068         if (!s->macroblocks || /* first frame */
00069             16*cols != s->avctx->coded_width ||
00070             16*rows != s->avctx->coded_height) {
00071             avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
00072             return 2;
00073         }
00074     } else if (!s->macroblocks)
00075         return 0;
00076     return 1;
00077 }
00078 
00079 static void vp5_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
00080 {
00081     VP56RangeCoder *c = &s->c;
00082     VP56Model *model = s->modelp;
00083     int comp, di;
00084 
00085     for (comp=0; comp<2; comp++) {
00086         int delta = 0;
00087         if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
00088             int sign = vp56_rac_get_prob(c, model->vector_sig[comp]);
00089             di  = vp56_rac_get_prob(c, model->vector_pdi[comp][0]);
00090             di |= vp56_rac_get_prob(c, model->vector_pdi[comp][1]) << 1;
00091             delta = vp56_rac_get_tree(c, vp56_pva_tree,
00092                                       model->vector_pdv[comp]);
00093             delta = di | (delta << 2);
00094             delta = (delta ^ -sign) + sign;
00095         }
00096         if (!comp)
00097             vect->x = delta;
00098         else
00099             vect->y = delta;
00100     }
00101 }
00102 
00103 static void vp5_parse_vector_models(VP56Context *s)
00104 {
00105     VP56RangeCoder *c = &s->c;
00106     VP56Model *model = s->modelp;
00107     int comp, node;
00108 
00109     for (comp=0; comp<2; comp++) {
00110         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
00111             model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
00112         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
00113             model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
00114         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
00115             model->vector_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
00116         if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
00117             model->vector_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
00118     }
00119 
00120     for (comp=0; comp<2; comp++)
00121         for (node=0; node<7; node++)
00122             if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
00123                 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
00124 }
00125 
00126 static int vp5_parse_coeff_models(VP56Context *s)
00127 {
00128     VP56RangeCoder *c = &s->c;
00129     VP56Model *model = s->modelp;
00130     uint8_t def_prob[11];
00131     int node, cg, ctx;
00132     int ct;    /* code type */
00133     int pt;    /* plane type (0 for Y, 1 for U or V) */
00134 
00135     memset(def_prob, 0x80, sizeof(def_prob));
00136 
00137     for (pt=0; pt<2; pt++)
00138         for (node=0; node<11; node++)
00139             if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
00140                 def_prob[node] = vp56_rac_gets_nn(c, 7);
00141                 model->coeff_dccv[pt][node] = def_prob[node];
00142             } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
00143                 model->coeff_dccv[pt][node] = def_prob[node];
00144             }
00145 
00146     for (ct=0; ct<3; ct++)
00147         for (pt=0; pt<2; pt++)
00148             for (cg=0; cg<6; cg++)
00149                 for (node=0; node<11; node++)
00150                     if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
00151                         def_prob[node] = vp56_rac_gets_nn(c, 7);
00152                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
00153                     } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
00154                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
00155                     }
00156 
00157     /* coeff_dcct is a linear combination of coeff_dccv */
00158     for (pt=0; pt<2; pt++)
00159         for (ctx=0; ctx<36; ctx++)
00160             for (node=0; node<5; node++)
00161                 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);
00162 
00163     /* coeff_acct is a linear combination of coeff_ract */
00164     for (ct=0; ct<3; ct++)
00165         for (pt=0; pt<2; pt++)
00166             for (cg=0; cg<3; cg++)
00167                 for (ctx=0; ctx<6; ctx++)
00168                     for (node=0; node<5; node++)
00169                         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);
00170     return 0;
00171 }
00172 
00173 static void vp5_parse_coeff(VP56Context *s)
00174 {
00175     VP56RangeCoder *c = &s->c;
00176     VP56Model *model = s->modelp;
00177     uint8_t *permute = s->scantable.permutated;
00178     uint8_t *model1, *model2;
00179     int coeff, sign, coeff_idx;
00180     int b, i, cg, idx, ctx, ctx_last;
00181     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
00182 
00183     for (b=0; b<6; b++) {
00184         int ct = 1;    /* code type */
00185 
00186         if (b > 3) pt = 1;
00187 
00188         ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]
00189               + s->above_blocks[s->above_block_idx[b]].not_null_dc;
00190         model1 = model->coeff_dccv[pt];
00191         model2 = model->coeff_dcct[pt][ctx];
00192 
00193         coeff_idx = 0;
00194         for (;;) {
00195             if (vp56_rac_get_prob(c, model2[0])) {
00196                 if (vp56_rac_get_prob(c, model2[2])) {
00197                     if (vp56_rac_get_prob(c, model2[3])) {
00198                         s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;
00199                         idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
00200                         sign = vp56_rac_get(c);
00201                         coeff = vp56_coeff_bias[idx+5];
00202                         for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
00203                             coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
00204                     } else {
00205                         if (vp56_rac_get_prob(c, model2[4])) {
00206                             coeff = 3 + vp56_rac_get_prob(c, model1[5]);
00207                             s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;
00208                         } else {
00209                             coeff = 2;
00210                             s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;
00211                         }
00212                         sign = vp56_rac_get(c);
00213                     }
00214                     ct = 2;
00215                 } else {
00216                     ct = 1;
00217                     s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;
00218                     sign = vp56_rac_get(c);
00219                     coeff = 1;
00220                 }
00221                 coeff = (coeff ^ -sign) + sign;
00222                 if (coeff_idx)
00223                     coeff *= s->dequant_ac;
00224                 s->block_coeff[b][permute[coeff_idx]] = coeff;
00225             } else {
00226                 if (ct && !vp56_rac_get_prob(c, model2[1]))
00227                     break;
00228                 ct = 0;
00229                 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;
00230             }
00231             coeff_idx++;
00232             if (coeff_idx >= 64)
00233                 break;
00234 
00235             cg = vp5_coeff_groups[coeff_idx];
00236             ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];
00237             model1 = model->coeff_ract[pt][ct][cg];
00238             model2 = cg > 2 ? model1 : model->coeff_acct[pt][ct][cg][ctx];
00239         }
00240 
00241         ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);
00242         s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;
00243         if (coeff_idx < ctx_last)
00244             for (i=coeff_idx; i<=ctx_last; i++)
00245                 s->coeff_ctx[vp56_b6to4[b]][i] = 5;
00246         s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];
00247     }
00248 }
00249 
00250 static void vp5_default_models_init(VP56Context *s)
00251 {
00252     VP56Model *model = s->modelp;
00253     int i;
00254 
00255     for (i=0; i<2; i++) {
00256         model->vector_sig[i] = 0x80;
00257         model->vector_dct[i] = 0x80;
00258         model->vector_pdi[i][0] = 0x55;
00259         model->vector_pdi[i][1] = 0x80;
00260     }
00261     memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
00262     memset(model->vector_pdv, 0x80, sizeof(model->vector_pdv));
00263 }
00264 
00265 static av_cold int vp5_decode_init(AVCodecContext *avctx)
00266 {
00267     VP56Context *s = avctx->priv_data;
00268 
00269     ff_vp56_init(avctx, 1, 0);
00270     s->vp56_coord_div = vp5_coord_div;
00271     s->parse_vector_adjustment = vp5_parse_vector_adjustment;
00272     s->parse_coeff = vp5_parse_coeff;
00273     s->default_models_init = vp5_default_models_init;
00274     s->parse_vector_models = vp5_parse_vector_models;
00275     s->parse_coeff_models = vp5_parse_coeff_models;
00276     s->parse_header = vp5_parse_header;
00277 
00278     return 0;
00279 }
00280 
00281 AVCodec ff_vp5_decoder = {
00282     .name           = "vp5",
00283     .type           = AVMEDIA_TYPE_VIDEO,
00284     .id             = CODEC_ID_VP5,
00285     .priv_data_size = sizeof(VP56Context),
00286     .init           = vp5_decode_init,
00287     .close          = ff_vp56_free,
00288     .decode         = ff_vp56_decode_frame,
00289     .capabilities   = CODEC_CAP_DR1,
00290     .long_name = NULL_IF_CONFIG_SMALL("On2 VP5"),
00291 };
Generated on Fri Feb 1 2013 14:34:46 for FFmpeg by doxygen 1.7.1