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ffmpeg / libavcodec / vp5.c @ 704a2881

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/**
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 * @file vp5.c
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 * VP5 compatible video decoder
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 *
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 * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
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#include <stdlib.h>
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#include <string.h>
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#include "avcodec.h"
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#include "dsputil.h"
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#include "bitstream.h"
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#include "mpegvideo.h"
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#include "vp56.h"
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#include "vp56data.h"
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#include "vp5data.h"
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static int vp5_parse_header(vp56_context_t *s, uint8_t *buf, int buf_size,
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                            int *golden_frame)
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{
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    vp56_range_coder_t *c = &s->c;
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    int rows, cols;
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    vp56_init_range_decoder(&s->c, buf, buf_size);
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    s->framep[VP56_FRAME_CURRENT]->key_frame = !vp56_rac_get(c);
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    vp56_rac_get(c);
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    vp56_init_dequant(s, vp56_rac_gets(c, 6));
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    if (s->framep[VP56_FRAME_CURRENT]->key_frame)
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    {
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        vp56_rac_gets(c, 8);
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        if(vp56_rac_gets(c, 5) > 5)
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            return 0;
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        vp56_rac_gets(c, 2);
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        if (vp56_rac_get(c)) {
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            av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
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            return 0;
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        }
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        rows = vp56_rac_gets(c, 8);  /* number of stored macroblock rows */
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        cols = vp56_rac_gets(c, 8);  /* number of stored macroblock cols */
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        vp56_rac_gets(c, 8);  /* number of displayed macroblock rows */
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        vp56_rac_gets(c, 8);  /* number of displayed macroblock cols */
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        vp56_rac_gets(c, 2);
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        if (16*cols != s->avctx->coded_width ||
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            16*rows != s->avctx->coded_height) {
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            avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
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            return 2;
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        }
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    }
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    return 1;
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}
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/* Gives very similar result than the vp6 version except in a few cases */
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static int vp5_adjust(int v, int t)
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{
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    int s2, s1 = v >> 31;
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    v ^= s1;
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    v -= s1;
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    v *= v < 2*t;
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    v -= t;
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    s2 = v >> 31;
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    v ^= s2;
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    v -= s2;
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    v = t - v;
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    v += s1;
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    v ^= s1;
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    return v;
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}
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static void vp5_parse_vector_adjustment(vp56_context_t *s, vp56_mv_t *vect)
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{
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    vp56_range_coder_t *c = &s->c;
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    int comp, di;
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    for (comp=0; comp<2; comp++) {
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        int delta = 0;
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        if (vp56_rac_get_prob(c, s->vector_model_dct[comp])) {
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            int sign = vp56_rac_get_prob(c, s->vector_model_sig[comp]);
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            di  = vp56_rac_get_prob(c, s->vector_model_pdi[comp][0]);
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            di |= vp56_rac_get_prob(c, s->vector_model_pdi[comp][1]) << 1;
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            delta = vp56_rac_get_tree(c, vp56_pva_tree,
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                                      s->vector_model_pdv[comp]);
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            delta = di | (delta << 2);
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            delta = (delta ^ -sign) + sign;
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        }
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        if (!comp)
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            vect->x = delta;
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        else
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            vect->y = delta;
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    }
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}
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static void vp5_parse_vector_models(vp56_context_t *s)
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{
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    vp56_range_coder_t *c = &s->c;
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    int comp, node;
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    for (comp=0; comp<2; comp++) {
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        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
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            s->vector_model_dct[comp] = vp56_rac_gets_nn(c, 7);
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        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
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            s->vector_model_sig[comp] = vp56_rac_gets_nn(c, 7);
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        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
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            s->vector_model_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
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        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
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            s->vector_model_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
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    }
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    for (comp=0; comp<2; comp++)
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        for (node=0; node<7; node++)
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            if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
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                s->vector_model_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
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}
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static void vp5_parse_coeff_models(vp56_context_t *s)
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{
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    vp56_range_coder_t *c = &s->c;
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    uint8_t def_prob[11];
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    int node, cg, ctx;
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    int ct;    /* code type */
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    int pt;    /* plane type (0 for Y, 1 for U or V) */
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    memset(def_prob, 0x80, sizeof(def_prob));
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    for (pt=0; pt<2; pt++)
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        for (node=0; node<11; node++)
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            if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
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                def_prob[node] = vp56_rac_gets_nn(c, 7);
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                s->coeff_model_dccv[pt][node] = def_prob[node];
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            } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
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                s->coeff_model_dccv[pt][node] = def_prob[node];
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            }
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    for (ct=0; ct<3; ct++)
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        for (pt=0; pt<2; pt++)
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            for (cg=0; cg<6; cg++)
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                for (node=0; node<11; node++)
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                    if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
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                        def_prob[node] = vp56_rac_gets_nn(c, 7);
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                        s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
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                    } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
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                        s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
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                    }
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    /* coeff_model_dcct is a linear combination of coeff_model_dccv */
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    for (pt=0; pt<2; pt++)
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        for (ctx=0; ctx<36; ctx++)
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            for (node=0; node<5; node++)
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                s->coeff_model_dcct[pt][ctx][node] = av_clip(((s->coeff_model_dccv[pt][node] * vp5_dccv_lc[node][ctx][0] + 128) >> 8) + vp5_dccv_lc[node][ctx][1], 1, 254);
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    /* coeff_model_acct is a linear combination of coeff_model_ract */
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    for (ct=0; ct<3; ct++)
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        for (pt=0; pt<2; pt++)
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            for (cg=0; cg<3; cg++)
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                for (ctx=0; ctx<6; ctx++)
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                    for (node=0; node<5; node++)
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                        s->coeff_model_acct[pt][ct][cg][ctx][node] = av_clip(((s->coeff_model_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);
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}
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static void vp5_parse_coeff(vp56_context_t *s)
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{
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    vp56_range_coder_t *c = &s->c;
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    uint8_t *permute = s->scantable.permutated;
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    uint8_t *model, *model2;
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    int coeff, sign, coeff_idx;
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    int b, i, cg, idx, ctx, ctx_last;
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    int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
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    for (b=0; b<6; b++) {
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        int ct = 1;    /* code type */
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        if (b > 3) pt = 1;
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        ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]
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              + s->above_blocks[s->above_block_idx[b]].not_null_dc;
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        model = s->coeff_model_dccv[pt];
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        model2 = s->coeff_model_dcct[pt][ctx];
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        for (coeff_idx=0; coeff_idx<64; ) {
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            if (vp56_rac_get_prob(c, model2[0])) {
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                if (vp56_rac_get_prob(c, model2[2])) {
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                    if (vp56_rac_get_prob(c, model2[3])) {
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                        s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;
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                        idx = vp56_rac_get_tree(c, vp56_pc_tree, model);
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                        sign = vp56_rac_get(c);
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                        coeff = vp56_coeff_bias[idx];
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                        for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
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                            coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
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                    } else {
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                        if (vp56_rac_get_prob(c, model2[4])) {
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                            coeff = 3 + vp56_rac_get_prob(c, model[5]);
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                            s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;
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                        } else {
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                            coeff = 2;
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                            s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;
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                        }
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                        sign = vp56_rac_get(c);
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                    }
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                    ct = 2;
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                } else {
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                    ct = 1;
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                    s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;
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                    sign = vp56_rac_get(c);
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                    coeff = 1;
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                }
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                coeff = (coeff ^ -sign) + sign;
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                if (coeff_idx)
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                    coeff *= s->dequant_ac;
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                s->block_coeff[b][permute[coeff_idx]] = coeff;
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            } else {
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                if (ct && !vp56_rac_get_prob(c, model2[1]))
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                    break;
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                ct = 0;
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                s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;
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            }
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            cg = vp5_coeff_groups[++coeff_idx];
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            ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];
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            model = s->coeff_model_ract[pt][ct][cg];
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            model2 = cg > 2 ? model : s->coeff_model_acct[pt][ct][cg][ctx];
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        }
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        ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);
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        s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;
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        if (coeff_idx < ctx_last)
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            for (i=coeff_idx; i<=ctx_last; i++)
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                s->coeff_ctx[vp56_b6to4[b]][i] = 5;
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        s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];
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    }
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}
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static void vp5_default_models_init(vp56_context_t *s)
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{
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    int i;
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    for (i=0; i<2; i++) {
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        s->vector_model_sig[i] = 0x80;
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        s->vector_model_dct[i] = 0x80;
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        s->vector_model_pdi[i][0] = 0x55;
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        s->vector_model_pdi[i][1] = 0x80;
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    }
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    memcpy(s->mb_types_stats, vp56_def_mb_types_stats, sizeof(s->mb_types_stats));
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    memset(s->vector_model_pdv, 0x80, sizeof(s->vector_model_pdv));
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}
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static int vp5_decode_init(AVCodecContext *avctx)
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{
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    vp56_context_t *s = avctx->priv_data;
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    vp56_init(s, avctx, 1);
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    s->vp56_coord_div = vp5_coord_div;
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    s->parse_vector_adjustment = vp5_parse_vector_adjustment;
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    s->adjust = vp5_adjust;
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    s->parse_coeff = vp5_parse_coeff;
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    s->default_models_init = vp5_default_models_init;
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    s->parse_vector_models = vp5_parse_vector_models;
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    s->parse_coeff_models = vp5_parse_coeff_models;
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    s->parse_header = vp5_parse_header;
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    return 0;
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}
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AVCodec vp5_decoder = {
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    "vp5",
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    CODEC_TYPE_VIDEO,
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    CODEC_ID_VP5,
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    sizeof(vp56_context_t),
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    vp5_decode_init,
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    NULL,
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    vp56_free,
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    vp56_decode_frame,
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};