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/**
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 * @file vp6.c
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 * VP6 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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 *
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 * The VP6F decoder accept an optional 1 byte extradata. It is composed of:
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 *  - upper 4bits: difference between encoded width and visible width
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 *  - lower 4bits: difference between encoded height and visible height
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 */
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#include <stdlib.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 "vp6data.h"
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static int vp6_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 parse_filter_info;
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    int rows, cols;
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    int res = 1;
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    if (buf[0] & 1)
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        return 0;
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    s->frames[VP56_FRAME_CURRENT].key_frame = !(buf[0] & 0x80);
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    vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
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    if (s->frames[VP56_FRAME_CURRENT].key_frame) {
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        if ((buf[1] & 0xFE) != 0x46)  /* would be 0x36 for VP61 */
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            return 0;
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        if (buf[1] & 1) {
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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 = buf[2];  /* number of stored macroblock rows */
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        cols = buf[3];  /* number of stored macroblock cols */
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        /* buf[4] is number of displayed macroblock rows */
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        /* buf[5] is number of displayed macroblock cols */
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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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            if (s->avctx->extradata_size == 1) {
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                s->avctx->width  -= s->avctx->extradata[0] >> 4;
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                s->avctx->height -= s->avctx->extradata[0] & 0x0F;
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            }
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            res = 2;
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        }
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        vp56_init_range_decoder(c, buf+6, buf_size-6);
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        vp56_rac_gets(c, 2);
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        parse_filter_info = 1;
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    } else {
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        vp56_init_range_decoder(c, buf+1, buf_size-1);
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        *golden_frame = vp56_rac_get(c);
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        s->deblock_filtering = vp56_rac_get(c);
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        if (s->deblock_filtering)
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            vp56_rac_get(c);
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        parse_filter_info = vp56_rac_get(c);
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    }
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    if (parse_filter_info) {
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        if (vp56_rac_get(c)) {
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            s->filter_mode = 2;
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            s->sample_variance_threshold = vp56_rac_gets(c, 5);
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            s->max_vector_length = 2 << vp56_rac_gets(c, 3);
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        } else if (vp56_rac_get(c)) {
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            s->filter_mode = 1;
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        } else {
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            s->filter_mode = 0;
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        }
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        s->filter_selection = vp56_rac_gets(c, 4);
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    }
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    vp56_rac_get(c);
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    return res;
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}
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static void vp6_coeff_order_table_init(vp56_context_t *s)
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{
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    int i, pos, idx = 1;
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    s->coeff_index_to_pos[0] = 0;
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    for (i=0; i<16; i++)
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        for (pos=1; pos<64; pos++)
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            if (s->coeff_reorder[pos] == i)
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                s->coeff_index_to_pos[idx++] = pos;
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}
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static void vp6_default_models_init(vp56_context_t *s)
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{
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    s->vector_model_dct[0] = 0xA2;
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    s->vector_model_dct[1] = 0xA4;
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    s->vector_model_sig[0] = 0x80;
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    s->vector_model_sig[1] = 0x80;
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    memcpy(s->mb_types_stats, vp56_def_mb_types_stats, sizeof(s->mb_types_stats));
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    memcpy(s->vector_model_fdv, vp6_def_fdv_vector_model, sizeof(s->vector_model_fdv));
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    memcpy(s->vector_model_pdv, vp6_def_pdv_vector_model, sizeof(s->vector_model_pdv));
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    memcpy(s->coeff_model_runv, vp6_def_runv_coeff_model, sizeof(s->coeff_model_runv));
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    memcpy(s->coeff_reorder, vp6_def_coeff_reorder, sizeof(s->coeff_reorder));
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    vp6_coeff_order_table_init(s);
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}
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static void vp6_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, vp6_sig_dct_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, vp6_sig_dct_pct[comp][1]))
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            s->vector_model_sig[comp] = 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, vp6_pdv_pct[comp][node]))
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                s->vector_model_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
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    for (comp=0; comp<2; comp++)
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        for (node=0; node<8; node++)
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            if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))
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                s->vector_model_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
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}
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static void vp6_parse_coeff_models(vp56_context_t *s)
160
{
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    vp56_range_coder_t *c = &s->c;
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    int def_prob[11];
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    int node, cg, ctx, pos;
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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, vp6_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->frames[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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    if (vp56_rac_get(c)) {
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        for (pos=1; pos<64; pos++)
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            if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))
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                s->coeff_reorder[pos] = vp56_rac_gets(c, 4);
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        vp6_coeff_order_table_init(s);
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    }
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    for (cg=0; cg<2; cg++)
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        for (node=0; node<14; node++)
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            if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))
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                s->coeff_model_runv[cg][node] = vp56_rac_gets_nn(c, 7);
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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, vp6_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->frames[VP56_FRAME_CURRENT].key_frame) {
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                        s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
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                    }
200

    
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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<3; ctx++)
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            for (node=0; node<5; node++)
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                s->coeff_model_dcct[pt][ctx][node] = clip(((s->coeff_model_dccv[pt][node] * vp6_dccv_lc[ctx][node][0] + 128) >> 8) + vp6_dccv_lc[ctx][node][1], 1, 255);
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}
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static void vp6_parse_vector_adjustment(vp56_context_t *s, vp56_mv_t *vect)
209
{
210
    vp56_range_coder_t *c = &s->c;
211
    int comp;
212

    
213
    *vect = (vp56_mv_t) {0,0};
214
    if (s->vector_candidate_pos < 2)
215
        *vect = s->vector_candidate[0];
216

    
217
    for (comp=0; comp<2; comp++) {
218
        int i, delta = 0;
219

    
220
        if (vp56_rac_get_prob(c, s->vector_model_dct[comp])) {
221
            static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
222
            for (i=0; i<sizeof(prob_order); i++) {
223
                int j = prob_order[i];
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                delta |= vp56_rac_get_prob(c, s->vector_model_fdv[comp][j])<<j;
225
            }
226
            if (delta & 0xF0)
227
                delta |= vp56_rac_get_prob(c, s->vector_model_fdv[comp][3])<<3;
228
            else
229
                delta |= 8;
230
        } else {
231
            delta = vp56_rac_get_tree(c, vp56_pva_tree,
232
                                      s->vector_model_pdv[comp]);
233
        }
234

    
235
        if (delta && vp56_rac_get_prob(c, s->vector_model_sig[comp]))
236
            delta = -delta;
237

    
238
        if (!comp)
239
            vect->x += delta;
240
        else
241
            vect->y += delta;
242
    }
243
}
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245
static void vp6_parse_coeff(vp56_context_t *s)
246
{
247
    vp56_range_coder_t *c = &s->c;
248
    uint8_t *permute = s->scantable.permutated;
249
    uint8_t *model, *model2, *model3;
250
    int coeff, sign, coeff_idx;
251
    int b, i, cg, idx, ctx;
252
    int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
253

    
254
    for (b=0; b<6; b++) {
255
        int ct = 1;    /* code type */
256
        int run = 1;
257

    
258
        if (b > 3) pt = 1;
259

    
260
        ctx = s->left_block[vp56_b6to4[b]].not_null_dc
261
              + s->above_blocks[s->above_block_idx[b]].not_null_dc;
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        model = s->coeff_model_dccv[pt];
263
        model2 = s->coeff_model_dcct[pt][ctx];
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265
        for (coeff_idx=0; coeff_idx<64; ) {
266
            if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
267
                /* parse a coeff */
268
                if (coeff_idx == 0) {
269
                    s->left_block[vp56_b6to4[b]].not_null_dc = 1;
270
                    s->above_blocks[s->above_block_idx[b]].not_null_dc = 1;
271
                }
272

    
273
                if (vp56_rac_get_prob(c, model2[2])) {
274
                    if (vp56_rac_get_prob(c, model2[3])) {
275
                        idx = vp56_rac_get_tree(c, vp56_pc_tree, model);
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                        coeff = vp56_coeff_bias[idx];
277
                        for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
278
                            coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
279
                    } else {
280
                        if (vp56_rac_get_prob(c, model2[4]))
281
                            coeff = 3 + vp56_rac_get_prob(c, model[5]);
282
                        else
283
                            coeff = 2;
284
                    }
285
                    ct = 2;
286
                } else {
287
                    ct = 1;
288
                    coeff = 1;
289
                }
290
                sign = vp56_rac_get(c);
291
                coeff = (coeff ^ -sign) + sign;
292
                if (coeff_idx)
293
                    coeff *= s->dequant_ac;
294
                idx = s->coeff_index_to_pos[coeff_idx];
295
                s->block_coeff[b][permute[idx]] = coeff;
296
                run = 1;
297
            } else {
298
                /* parse a run */
299
                ct = 0;
300
                if (coeff_idx == 0) {
301
                    s->left_block[vp56_b6to4[b]].not_null_dc = 0;
302
                    s->above_blocks[s->above_block_idx[b]].not_null_dc = 0;
303
                } else {
304
                    if (!vp56_rac_get_prob(c, model2[1]))
305
                        break;
306

    
307
                    model3 = s->coeff_model_runv[coeff_idx >= 6];
308
                    run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
309
                    if (!run)
310
                        for (run=9, i=0; i<6; i++)
311
                            run += vp56_rac_get_prob(c, model3[i+8]) << i;
312
                }
313
            }
314

    
315
            cg = vp6_coeff_groups[coeff_idx+=run];
316
            model = model2 = s->coeff_model_ract[pt][ct][cg];
317
        }
318
    }
319
}
320

    
321
static int vp6_adjust(int v, int t)
322
{
323
    int V = v, s = v >> 31;
324
    V ^= s;
325
    V -= s;
326
    if (V-t-1 >= (unsigned)(t-1))
327
        return v;
328
    V = 2*t - V;
329
    V += s;
330
    V ^= s;
331
    return V;
332
}
333

    
334
static int vp6_block_variance(uint8_t *src, int stride)
335
{
336
    int sum = 0, square_sum = 0;
337
    int y, x;
338

    
339
    for (y=0; y<8; y+=2) {
340
        for (x=0; x<8; x+=2) {
341
            sum += src[x];
342
            square_sum += src[x]*src[x];
343
        }
344
        src += 2*stride;
345
    }
346
    return (16*square_sum - sum*sum) >> 8;
347
}
348

    
349
static void vp6_filter_hv2(vp56_context_t *s, uint8_t *dst, uint8_t *src,
350
                           int stride, int delta, int16_t weight)
351
{
352
    s->dsp.put_pixels_tab[1][0](dst, src, stride, 8);
353
    s->dsp.biweight_h264_pixels_tab[3](dst, src+delta, stride, 2,
354
                                       8-weight, weight, 0);
355
}
356

    
357
static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
358
                           int delta, const int16_t *weights)
359
{
360
    int x, y;
361

    
362
    for (y=0; y<8; y++) {
363
        for (x=0; x<8; x++) {
364
            dst[x] = clip_uint8((  src[x-delta  ] * weights[0]
365
                                 + src[x        ] * weights[1]
366
                                 + src[x+delta  ] * weights[2]
367
                                 + src[x+2*delta] * weights[3] + 64) >> 7);
368
        }
369
        src += stride;
370
        dst += stride;
371
    }
372
}
373

    
374
static void vp6_filter_diag2(vp56_context_t *s, uint8_t *dst, uint8_t *src,
375
                             int stride, int h_weight, int v_weight)
376
{
377
    uint8_t *tmp = s->edge_emu_buffer+16;
378
    int x, xmax;
379

    
380
    s->dsp.put_pixels_tab[1][0](tmp, src, stride, 8);
381
    s->dsp.biweight_h264_pixels_tab[3](tmp, src+1, stride, 2,
382
                                       8-h_weight, h_weight, 0);
383
    /* we need a 8x9 block to do vertical filter, so compute one more line */
384
    for (x=8*stride, xmax=x+8; x<xmax; x++)
385
        tmp[x] = (src[x]*(8-h_weight) + src[x+1]*h_weight + 4) >> 3;
386

    
387
    s->dsp.put_pixels_tab[1][0](dst, tmp, stride, 8);
388
    s->dsp.biweight_h264_pixels_tab[3](dst, tmp+stride, stride, 2,
389
                                       8-v_weight, v_weight, 0);
390
}
391

    
392
static void vp6_filter_diag4(uint8_t *dst, uint8_t *src, int stride,
393
                             const int16_t *h_weights,const int16_t *v_weights)
394
{
395
    int x, y;
396
    int tmp[8*11];
397
    int *t = tmp;
398

    
399
    src -= stride;
400

    
401
    for (y=0; y<11; y++) {
402
        for (x=0; x<8; x++) {
403
            t[x] = clip_uint8((  src[x-1] * h_weights[0]
404
                               + src[x  ] * h_weights[1]
405
                               + src[x+1] * h_weights[2]
406
                               + src[x+2] * h_weights[3] + 64) >> 7);
407
        }
408
        src += stride;
409
        t += 8;
410
    }
411

    
412
    t = tmp + 8;
413
    for (y=0; y<8; y++) {
414
        for (x=0; x<8; x++) {
415
            dst[x] = clip_uint8((  t[x-8 ] * v_weights[0]
416
                                 + t[x   ] * v_weights[1]
417
                                 + t[x+8 ] * v_weights[2]
418
                                 + t[x+16] * v_weights[3] + 64) >> 7);
419
        }
420
        dst += stride;
421
        t += 8;
422
    }
423
}
424

    
425
static void vp6_filter(vp56_context_t *s, uint8_t *dst, uint8_t *src,
426
                       int offset1, int offset2, int stride,
427
                       vp56_mv_t mv, int mask, int select, int luma)
428
{
429
    int filter4 = 0;
430
    int x8 = mv.x & mask;
431
    int y8 = mv.y & mask;
432

    
433
    if (luma) {
434
        x8 *= 2;
435
        y8 *= 2;
436
        filter4 = s->filter_mode;
437
        if (filter4 == 2) {
438
            if (s->max_vector_length &&
439
                (FFABS(mv.x) > s->max_vector_length ||
440
                 FFABS(mv.y) > s->max_vector_length)) {
441
                filter4 = 0;
442
            } else if (!s->sample_variance_threshold
443
                       || (vp6_block_variance(src+offset1, stride)
444
                           < s->sample_variance_threshold)) {
445
                filter4 = 0;
446
            }
447
        }
448
    }
449

    
450
    if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
451
        offset1 = offset2;
452
    }
453

    
454
    if (filter4) {
455
        if (!y8) {                      /* left or right combine */
456
            vp6_filter_hv4(dst, src+offset1, stride, 1,
457
                           vp6_block_copy_filter[select][x8]);
458
        } else if (!x8) {               /* above or below combine */
459
            vp6_filter_hv4(dst, src+offset1, stride, stride,
460
                           vp6_block_copy_filter[select][y8]);
461
        } else if ((mv.x^mv.y) >> 31) { /* lower-left or upper-right combine */
462
            vp6_filter_diag4(dst, src+offset1-1, stride,
463
                             vp6_block_copy_filter[select][x8],
464
                             vp6_block_copy_filter[select][y8]);
465
        } else {                        /* lower-right or upper-left combine */
466
            vp6_filter_diag4(dst, src+offset1, stride,
467
                             vp6_block_copy_filter[select][x8],
468
                             vp6_block_copy_filter[select][y8]);
469
        }
470
    } else {
471
        if (!y8) {                      /* left or right combine */
472
            vp6_filter_hv2(s, dst, src+offset1, stride, 1, x8);
473
        } else if (!x8) {               /* above or below combine */
474
            vp6_filter_hv2(s, dst, src+offset1, stride, stride, y8);
475
        } else if ((mv.x^mv.y) >> 31) { /* lower-left or upper-right combine */
476
            vp6_filter_diag2(s, dst, src+offset1-1, stride, x8, y8);
477
        } else {                        /* lower-right or upper-left combine */
478
            vp6_filter_diag2(s, dst, src+offset1, stride, x8, y8);
479
        }
480
    }
481
}
482

    
483
static int vp6_decode_init(AVCodecContext *avctx)
484
{
485
    vp56_context_t *s = avctx->priv_data;
486

    
487
    vp56_init(s, avctx, avctx->codec->id == CODEC_ID_VP6);
488
    s->vp56_coord_div = vp6_coord_div;
489
    s->parse_vector_adjustment = vp6_parse_vector_adjustment;
490
    s->adjust = vp6_adjust;
491
    s->filter = vp6_filter;
492
    s->parse_coeff = vp6_parse_coeff;
493
    s->default_models_init = vp6_default_models_init;
494
    s->parse_vector_models = vp6_parse_vector_models;
495
    s->parse_coeff_models = vp6_parse_coeff_models;
496
    s->parse_header = vp6_parse_header;
497

    
498
    return 0;
499
}
500

    
501
AVCodec vp6_decoder = {
502
    "vp6",
503
    CODEC_TYPE_VIDEO,
504
    CODEC_ID_VP6,
505
    sizeof(vp56_context_t),
506
    vp6_decode_init,
507
    NULL,
508
    vp56_free,
509
    vp56_decode_frame,
510
};
511

    
512
/* flash version, not flipped upside-down */
513
AVCodec vp6f_decoder = {
514
    "vp6f",
515
    CODEC_TYPE_VIDEO,
516
    CODEC_ID_VP6F,
517
    sizeof(vp56_context_t),
518
    vp6_decode_init,
519
    NULL,
520
    vp56_free,
521
    vp56_decode_frame,
522
};