PeerStreamer

/**

 * @file

 * VP5 compatible video decoder

 *

 * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include <stdlib.h>

#include <string.h>

#include "avcodec.h"

#include "dsputil.h"

#include "get_bits.h"

#include "vp56.h"

#include "vp56data.h"

#include "vp5data.h"

static int vp5_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,

                            int *golden_frame)

{

    VP56RangeCoder *c = &s->c;

    int rows, cols;

    ff_vp56_init_range_decoder(&s->c, buf, buf_size);

    s->framep[VP56_FRAME_CURRENT]->key_frame = !vp56_rac_get(c);

    vp56_rac_get(c);

    ff_vp56_init_dequant(s, vp56_rac_gets(c, 6));

    if (s->framep[VP56_FRAME_CURRENT]->key_frame)

    {

        vp56_rac_gets(c, 8);

        if(vp56_rac_gets(c, 5) > 5)

            return 0;

        vp56_rac_gets(c, 2);

        if (vp56_rac_get(c)) {

            av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");

            return 0;

        }

        rows = vp56_rac_gets(c, 8);  /* number of stored macroblock rows */

        cols = vp56_rac_gets(c, 8);  /* number of stored macroblock cols */

        vp56_rac_gets(c, 8);  /* number of displayed macroblock rows */

        vp56_rac_gets(c, 8);  /* number of displayed macroblock cols */

        vp56_rac_gets(c, 2);

        if (!s->macroblocks || /* first frame */

            16*cols != s->avctx->coded_width ||

            16*rows != s->avctx->coded_height) {

            avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);

            return 2;

        }

    } else if (!s->macroblocks)

        return 0;

    return 1;

}

static void vp5_parse_vector_adjustment(VP56Context *s, VP56mv *vect)

{

    VP56RangeCoder *c = &s->c;

    VP56Model *model = s->modelp;

    int comp, di;

    for (comp=0; comp<2; comp++) {

        int delta = 0;

        if (vp56_rac_get_prob(c, model->vector_dct[comp])) {

            int sign = vp56_rac_get_prob(c, model->vector_sig[comp]);

            di  = vp56_rac_get_prob(c, model->vector_pdi[comp][0]);

            di |= vp56_rac_get_prob(c, model->vector_pdi[comp][1]) << 1;

            delta = vp56_rac_get_tree(c, vp56_pva_tree,

                                      model->vector_pdv[comp]);

            delta = di | (delta << 2);

            delta = (delta ^ -sign) + sign;

        }

        if (!comp)

            vect->x = delta;

        else

            vect->y = delta;

    }

}

static void vp5_parse_vector_models(VP56Context *s)

{

    VP56RangeCoder *c = &s->c;

    VP56Model *model = s->modelp;

    int comp, node;

    for (comp=0; comp<2; comp++) {

        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))

            model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);

        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))

            model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);

        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))

            model->vector_pdi[comp][0] = vp56_rac_gets_nn(c, 7);

        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))

            model->vector_pdi[comp][1] = vp56_rac_gets_nn(c, 7);

    }

    for (comp=0; comp<2; comp++)

        for (node=0; node<7; node++)

            if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))

                model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);

}

static void vp5_parse_coeff_models(VP56Context *s)

{

    VP56RangeCoder *c = &s->c;

    VP56Model *model = s->modelp;

    uint8_t def_prob[11];

    int node, cg, ctx;

    int ct;    /* code type */

    int pt;    /* plane type (0 for Y, 1 for U or V) */

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

    for (pt=0; pt<2; pt++)

        for (node=0; node<11; node++)

            if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {

                def_prob[node] = vp56_rac_gets_nn(c, 7);

                model->coeff_dccv[pt][node] = def_prob[node];

            } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {

                model->coeff_dccv[pt][node] = def_prob[node];

            }

    for (ct=0; ct<3; ct++)

        for (pt=0; pt<2; pt++)

            for (cg=0; cg<6; cg++)

                for (node=0; node<11; node++)

                    if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {

                        def_prob[node] = vp56_rac_gets_nn(c, 7);

                        model->coeff_ract[pt][ct][cg][node] = def_prob[node];

                    } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {

                        model->coeff_ract[pt][ct][cg][node] = def_prob[node];

                    }

    /* coeff_dcct is a linear combination of coeff_dccv */

    for (pt=0; pt<2; pt++)

        for (ctx=0; ctx<36; ctx++)

            for (node=0; node<5; node++)

                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);

    /* coeff_acct is a linear combination of coeff_ract */

    for (ct=0; ct<3; ct++)

        for (pt=0; pt<2; pt++)

            for (cg=0; cg<3; cg++)

                for (ctx=0; ctx<6; ctx++)

                    for (node=0; node<5; node++)

                        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);

}

static void vp5_parse_coeff(VP56Context *s)

{

    VP56RangeCoder *c = &s->c;

    VP56Model *model = s->modelp;

    uint8_t *permute = s->scantable.permutated;

    uint8_t *model1, *model2;

    int coeff, sign, coeff_idx;

    int b, i, cg, idx, ctx, ctx_last;

    int pt = 0;    /* plane type (0 for Y, 1 for U or V) */

    for (b=0; b<6; b++) {

        int ct = 1;    /* code type */

        if (b > 3) pt = 1;

        ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]

              + s->above_blocks[s->above_block_idx[b]].not_null_dc;

        model1 = model->coeff_dccv[pt];

        model2 = model->coeff_dcct[pt][ctx];

        for (coeff_idx=0; coeff_idx<64; ) {

            if (vp56_rac_get_prob(c, model2[0])) {

                if (vp56_rac_get_prob(c, model2[2])) {

                    if (vp56_rac_get_prob(c, model2[3])) {

                        s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;

                        idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);

                        sign = vp56_rac_get(c);

                        coeff = vp56_coeff_bias[idx+5];

                        for (i=vp56_coeff_bit_length[idx]; i>=0; i--)

                            coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;

                    } else {

                        if (vp56_rac_get_prob(c, model2[4])) {

                            coeff = 3 + vp56_rac_get_prob(c, model1[5]);

                            s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;

                        } else {

                            coeff = 2;

                            s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;

                        }

                        sign = vp56_rac_get(c);

                    }

                    ct = 2;

                } else {

                    ct = 1;

                    s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;

                    sign = vp56_rac_get(c);

                    coeff = 1;

                }

                coeff = (coeff ^ -sign) + sign;

                if (coeff_idx)

                    coeff *= s->dequant_ac;

                s->block_coeff[b][permute[coeff_idx]] = coeff;

            } else {

                if (ct && !vp56_rac_get_prob(c, model2[1]))

                    break;

                ct = 0;

                s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;

            }

            cg = vp5_coeff_groups[++coeff_idx];

            ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];

            model1 = model->coeff_ract[pt][ct][cg];

            model2 = cg > 2 ? model1 : model->coeff_acct[pt][ct][cg][ctx];

        }

        ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);

        s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;

        if (coeff_idx < ctx_last)

            for (i=coeff_idx; i<=ctx_last; i++)

                s->coeff_ctx[vp56_b6to4[b]][i] = 5;

        s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];

    }

}

static void vp5_default_models_init(VP56Context *s)

{

    VP56Model *model = s->modelp;

    int i;

    for (i=0; i<2; i++) {

        model->vector_sig[i] = 0x80;

        model->vector_dct[i] = 0x80;

        model->vector_pdi[i][0] = 0x55;

        model->vector_pdi[i][1] = 0x80;

    }

    memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));

    memset(model->vector_pdv, 0x80, sizeof(model->vector_pdv));

}

static av_cold int vp5_decode_init(AVCodecContext *avctx)

{

    VP56Context *s = avctx->priv_data;

    ff_vp56_init(avctx, 1, 0);

    s->vp56_coord_div = vp5_coord_div;

    s->parse_vector_adjustment = vp5_parse_vector_adjustment;

    s->parse_coeff = vp5_parse_coeff;

    s->default_models_init = vp5_default_models_init;

    s->parse_vector_models = vp5_parse_vector_models;

    s->parse_coeff_models = vp5_parse_coeff_models;

    s->parse_header = vp5_parse_header;

    return 0;

}

AVCodec ff_vp5_decoder = {

    "vp5",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_VP5,

    sizeof(VP56Context),

    vp5_decode_init,

    NULL,

    ff_vp56_free,

    ff_vp56_decode_frame,

    CODEC_CAP_DR1,

    .long_name = NULL_IF_CONFIG_SMALL("On2 VP5"),

};