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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 = 0;
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    int coeff_offset = 0;
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    int vrt_shift = 0;
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    int sub_version;
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    int rows, cols;
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    int res = 1;
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    int separated_coeff = buf[0] & 1;
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    s->framep[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->framep[VP56_FRAME_CURRENT]->key_frame) {
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        sub_version = buf[1] >> 3;
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        if (sub_version > 8)
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            return 0;
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        s->filter_header = buf[1] & 0x06;
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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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        if (separated_coeff || !s->filter_header) {
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            coeff_offset = AV_RB16(buf+2) - 2;
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            buf += 2;
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            buf_size -= 2;
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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 = s->filter_header;
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        if (sub_version < 8)
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            vrt_shift = 5;
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        s->sub_version = sub_version;
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    } else {
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        if (!s->sub_version)
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            return 0;
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        if (separated_coeff || !s->filter_header) {
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            coeff_offset = AV_RB16(buf+1) - 2;
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            buf += 2;
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            buf_size -= 2;
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        }
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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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        if (s->filter_header) {
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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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            if (s->sub_version > 7)
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                parse_filter_info = vp56_rac_get(c);
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        }
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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) << vrt_shift;
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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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        if (s->sub_version > 7)
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            s->filter_selection = vp56_rac_gets(c, 4);
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        else
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            s->filter_selection = 16;
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    }
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    vp56_rac_get(c);
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    if (coeff_offset) {
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        vp56_init_range_decoder(&s->cc, buf+coeff_offset,
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                                buf_size-coeff_offset);
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        s->ccp = &s->cc;
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    } else {
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        s->ccp = &s->c;
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    }
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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)
144
{
145
    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)
171
{
172
    vp56_range_coder_t *c = &s->c;
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    int comp, node;
174

    
175
    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)
194
{
195
    vp56_range_coder_t *c = &s->c;
196
    int def_prob[11];
197
    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) */
200

    
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    memset(def_prob, 0x80, sizeof(def_prob));
202

    
203
    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->framep[VP56_FRAME_CURRENT]->key_frame) {
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                s->coeff_model_dccv[pt][node] = def_prob[node];
210
            }
211

    
212
    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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    }
218

    
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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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224
    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++)
228
                    if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {
229
                        def_prob[node] = vp56_rac_gets_nn(c, 7);
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                        s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
231
                    } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
232
                        s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
233
                    }
234

    
235
    /* coeff_model_dcct is a linear combination of coeff_model_dccv */
236
    for (pt=0; pt<2; pt++)
237
        for (ctx=0; ctx<3; ctx++)
238
            for (node=0; node<5; node++)
239
                s->coeff_model_dcct[pt][ctx][node] = av_clip(((s->coeff_model_dccv[pt][node] * vp6_dccv_lc[ctx][node][0] + 128) >> 8) + vp6_dccv_lc[ctx][node][1], 1, 255);
240
}
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242
static void vp6_parse_vector_adjustment(vp56_context_t *s, vp56_mv_t *vect)
243
{
244
    vp56_range_coder_t *c = &s->c;
245
    int comp;
246

    
247
    *vect = (vp56_mv_t) {0,0};
248
    if (s->vector_candidate_pos < 2)
249
        *vect = s->vector_candidate[0];
250

    
251
    for (comp=0; comp<2; comp++) {
252
        int i, delta = 0;
253

    
254
        if (vp56_rac_get_prob(c, s->vector_model_dct[comp])) {
255
            static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
256
            for (i=0; i<sizeof(prob_order); i++) {
257
                int j = prob_order[i];
258
                delta |= vp56_rac_get_prob(c, s->vector_model_fdv[comp][j])<<j;
259
            }
260
            if (delta & 0xF0)
261
                delta |= vp56_rac_get_prob(c, s->vector_model_fdv[comp][3])<<3;
262
            else
263
                delta |= 8;
264
        } else {
265
            delta = vp56_rac_get_tree(c, vp56_pva_tree,
266
                                      s->vector_model_pdv[comp]);
267
        }
268

    
269
        if (delta && vp56_rac_get_prob(c, s->vector_model_sig[comp]))
270
            delta = -delta;
271

    
272
        if (!comp)
273
            vect->x += delta;
274
        else
275
            vect->y += delta;
276
    }
277
}
278

    
279
static void vp6_parse_coeff(vp56_context_t *s)
280
{
281
    vp56_range_coder_t *c = s->ccp;
282
    uint8_t *permute = s->scantable.permutated;
283
    uint8_t *model, *model2, *model3;
284
    int coeff, sign, coeff_idx;
285
    int b, i, cg, idx, ctx;
286
    int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
287

    
288
    for (b=0; b<6; b++) {
289
        int ct = 1;    /* code type */
290
        int run = 1;
291

    
292
        if (b > 3) pt = 1;
293

    
294
        ctx = s->left_block[vp56_b6to4[b]].not_null_dc
295
              + s->above_blocks[s->above_block_idx[b]].not_null_dc;
296
        model = s->coeff_model_dccv[pt];
297
        model2 = s->coeff_model_dcct[pt][ctx];
298

    
299
        for (coeff_idx=0; coeff_idx<64; ) {
300
            if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
301
                /* parse a coeff */
302
                if (coeff_idx == 0) {
303
                    s->left_block[vp56_b6to4[b]].not_null_dc = 1;
304
                    s->above_blocks[s->above_block_idx[b]].not_null_dc = 1;
305
                }
306

    
307
                if (vp56_rac_get_prob(c, model2[2])) {
308
                    if (vp56_rac_get_prob(c, model2[3])) {
309
                        idx = vp56_rac_get_tree(c, vp56_pc_tree, model);
310
                        coeff = vp56_coeff_bias[idx];
311
                        for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
312
                            coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
313
                    } else {
314
                        if (vp56_rac_get_prob(c, model2[4]))
315
                            coeff = 3 + vp56_rac_get_prob(c, model[5]);
316
                        else
317
                            coeff = 2;
318
                    }
319
                    ct = 2;
320
                } else {
321
                    ct = 1;
322
                    coeff = 1;
323
                }
324
                sign = vp56_rac_get(c);
325
                coeff = (coeff ^ -sign) + sign;
326
                if (coeff_idx)
327
                    coeff *= s->dequant_ac;
328
                idx = s->coeff_index_to_pos[coeff_idx];
329
                s->block_coeff[b][permute[idx]] = coeff;
330
                run = 1;
331
            } else {
332
                /* parse a run */
333
                ct = 0;
334
                if (coeff_idx == 0) {
335
                    s->left_block[vp56_b6to4[b]].not_null_dc = 0;
336
                    s->above_blocks[s->above_block_idx[b]].not_null_dc = 0;
337
                } else {
338
                    if (!vp56_rac_get_prob(c, model2[1]))
339
                        break;
340

    
341
                    model3 = s->coeff_model_runv[coeff_idx >= 6];
342
                    run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
343
                    if (!run)
344
                        for (run=9, i=0; i<6; i++)
345
                            run += vp56_rac_get_prob(c, model3[i+8]) << i;
346
                }
347
            }
348

    
349
            cg = vp6_coeff_groups[coeff_idx+=run];
350
            model = model2 = s->coeff_model_ract[pt][ct][cg];
351
        }
352
    }
353
}
354

    
355
static int vp6_adjust(int v, int t)
356
{
357
    int V = v, s = v >> 31;
358
    V ^= s;
359
    V -= s;
360
    if (V-t-1 >= (unsigned)(t-1))
361
        return v;
362
    V = 2*t - V;
363
    V += s;
364
    V ^= s;
365
    return V;
366
}
367

    
368
static int vp6_block_variance(uint8_t *src, int stride)
369
{
370
    int sum = 0, square_sum = 0;
371
    int y, x;
372

    
373
    for (y=0; y<8; y+=2) {
374
        for (x=0; x<8; x+=2) {
375
            sum += src[x];
376
            square_sum += src[x]*src[x];
377
        }
378
        src += 2*stride;
379
    }
380
    return (16*square_sum - sum*sum) >> 8;
381
}
382

    
383
static void vp6_filter_hv2(vp56_context_t *s, uint8_t *dst, uint8_t *src,
384
                           int stride, int delta, int16_t weight)
385
{
386
    s->dsp.put_pixels_tab[1][0](dst, src, stride, 8);
387
    s->dsp.biweight_h264_pixels_tab[3](dst, src+delta, stride, 2,
388
                                       8-weight, weight, 0);
389
}
390

    
391
static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
392
                           int delta, const int16_t *weights)
393
{
394
    int x, y;
395

    
396
    for (y=0; y<8; y++) {
397
        for (x=0; x<8; x++) {
398
            dst[x] = av_clip_uint8((  src[x-delta  ] * weights[0]
399
                                 + src[x        ] * weights[1]
400
                                 + src[x+delta  ] * weights[2]
401
                                 + src[x+2*delta] * weights[3] + 64) >> 7);
402
        }
403
        src += stride;
404
        dst += stride;
405
    }
406
}
407

    
408
static void vp6_filter_diag2(vp56_context_t *s, uint8_t *dst, uint8_t *src,
409
                             int stride, int h_weight, int v_weight)
410
{
411
    uint8_t *tmp = s->edge_emu_buffer+16;
412
    int x, xmax;
413

    
414
    s->dsp.put_pixels_tab[1][0](tmp, src, stride, 8);
415
    s->dsp.biweight_h264_pixels_tab[3](tmp, src+1, stride, 2,
416
                                       8-h_weight, h_weight, 0);
417
    /* we need a 8x9 block to do vertical filter, so compute one more line */
418
    for (x=8*stride, xmax=x+8; x<xmax; x++)
419
        tmp[x] = (src[x]*(8-h_weight) + src[x+1]*h_weight + 4) >> 3;
420

    
421
    s->dsp.put_pixels_tab[1][0](dst, tmp, stride, 8);
422
    s->dsp.biweight_h264_pixels_tab[3](dst, tmp+stride, stride, 2,
423
                                       8-v_weight, v_weight, 0);
424
}
425

    
426
static void vp6_filter_diag4(uint8_t *dst, uint8_t *src, int stride,
427
                             const int16_t *h_weights,const int16_t *v_weights)
428
{
429
    int x, y;
430
    int tmp[8*11];
431
    int *t = tmp;
432

    
433
    src -= stride;
434

    
435
    for (y=0; y<11; y++) {
436
        for (x=0; x<8; x++) {
437
            t[x] = av_clip_uint8((  src[x-1] * h_weights[0]
438
                               + src[x  ] * h_weights[1]
439
                               + src[x+1] * h_weights[2]
440
                               + src[x+2] * h_weights[3] + 64) >> 7);
441
        }
442
        src += stride;
443
        t += 8;
444
    }
445

    
446
    t = tmp + 8;
447
    for (y=0; y<8; y++) {
448
        for (x=0; x<8; x++) {
449
            dst[x] = av_clip_uint8((  t[x-8 ] * v_weights[0]
450
                                 + t[x   ] * v_weights[1]
451
                                 + t[x+8 ] * v_weights[2]
452
                                 + t[x+16] * v_weights[3] + 64) >> 7);
453
        }
454
        dst += stride;
455
        t += 8;
456
    }
457
}
458

    
459
static void vp6_filter(vp56_context_t *s, uint8_t *dst, uint8_t *src,
460
                       int offset1, int offset2, int stride,
461
                       vp56_mv_t mv, int mask, int select, int luma)
462
{
463
    int filter4 = 0;
464
    int x8 = mv.x & mask;
465
    int y8 = mv.y & mask;
466

    
467
    if (luma) {
468
        x8 *= 2;
469
        y8 *= 2;
470
        filter4 = s->filter_mode;
471
        if (filter4 == 2) {
472
            if (s->max_vector_length &&
473
                (FFABS(mv.x) > s->max_vector_length ||
474
                 FFABS(mv.y) > s->max_vector_length)) {
475
                filter4 = 0;
476
            } else if (s->sample_variance_threshold
477
                       && (vp6_block_variance(src+offset1, stride)
478
                           < s->sample_variance_threshold)) {
479
                filter4 = 0;
480
            }
481
        }
482
    }
483

    
484
    if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
485
        offset1 = offset2;
486
    }
487

    
488
    if (filter4) {
489
        if (!y8) {                      /* left or right combine */
490
            vp6_filter_hv4(dst, src+offset1, stride, 1,
491
                           vp6_block_copy_filter[select][x8]);
492
        } else if (!x8) {               /* above or below combine */
493
            vp6_filter_hv4(dst, src+offset1, stride, stride,
494
                           vp6_block_copy_filter[select][y8]);
495
        } else if ((mv.x^mv.y) >> 31) { /* lower-left or upper-right combine */
496
            vp6_filter_diag4(dst, src+offset1-1, stride,
497
                             vp6_block_copy_filter[select][x8],
498
                             vp6_block_copy_filter[select][y8]);
499
        } else {                        /* lower-right or upper-left combine */
500
            vp6_filter_diag4(dst, src+offset1, stride,
501
                             vp6_block_copy_filter[select][x8],
502
                             vp6_block_copy_filter[select][y8]);
503
        }
504
    } else {
505
        if (!y8) {                      /* left or right combine */
506
            vp6_filter_hv2(s, dst, src+offset1, stride, 1, x8);
507
        } else if (!x8) {               /* above or below combine */
508
            vp6_filter_hv2(s, dst, src+offset1, stride, stride, y8);
509
        } else if ((mv.x^mv.y) >> 31) { /* lower-left or upper-right combine */
510
            vp6_filter_diag2(s, dst, src+offset1-1, stride, x8, y8);
511
        } else {                        /* lower-right or upper-left combine */
512
            vp6_filter_diag2(s, dst, src+offset1, stride, x8, y8);
513
        }
514
    }
515
}
516

    
517
static int vp6_decode_init(AVCodecContext *avctx)
518
{
519
    vp56_context_t *s = avctx->priv_data;
520

    
521
    vp56_init(s, avctx, avctx->codec->id == CODEC_ID_VP6);
522
    s->vp56_coord_div = vp6_coord_div;
523
    s->parse_vector_adjustment = vp6_parse_vector_adjustment;
524
    s->adjust = vp6_adjust;
525
    s->filter = vp6_filter;
526
    s->parse_coeff = vp6_parse_coeff;
527
    s->default_models_init = vp6_default_models_init;
528
    s->parse_vector_models = vp6_parse_vector_models;
529
    s->parse_coeff_models = vp6_parse_coeff_models;
530
    s->parse_header = vp6_parse_header;
531

    
532
    return 0;
533
}
534

    
535
AVCodec vp6_decoder = {
536
    "vp6",
537
    CODEC_TYPE_VIDEO,
538
    CODEC_ID_VP6,
539
    sizeof(vp56_context_t),
540
    vp6_decode_init,
541
    NULL,
542
    vp56_free,
543
    vp56_decode_frame,
544
};
545

    
546
/* flash version, not flipped upside-down */
547
AVCodec vp6f_decoder = {
548
    "vp6f",
549
    CODEC_TYPE_VIDEO,
550
    CODEC_ID_VP6F,
551
    sizeof(vp56_context_t),
552
    vp6_decode_init,
553
    NULL,
554
    vp56_free,
555
    vp56_decode_frame,
556
};