/*

 * 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 "avcodec.h"

#include "ffv1.h"

#include "parser_internal.h"

#include "rangecoder.h"

#include "libavutil/attributes.h"

typedef struct FFV1ParseContext {

    FFV1Context f;

    int got_first;

} FFV1ParseContext;

static int parse(AVCodecParserContext *s,

                 AVCodecContext *avctx,

                 const uint8_t **poutbuf, int *poutbuf_size,

                 const uint8_t *buf, int buf_size)

{

    FFV1ParseContext *p = s->priv_data;

    FFV1Context *f = &p->f;

    RangeCoder c;

    uint8_t keystate = 128;

    *poutbuf      = buf;

    *poutbuf_size = buf_size;

    if (!p->got_first) {

        int ret = ff_ffv1_common_init(avctx, f);

        p->got_first = 1;

        if (ret < 0)

            return buf_size;

        if (avctx->extradata_size > 0 && (ret = ff_ffv1_read_extra_header(f)) < 0)

            return buf_size;

    }

    ff_init_range_decoder(&c, buf, buf_size);

    ff_build_rac_states(&c, 0.05 * (1LL << 32), 256 - 8);

    f->avctx = avctx;

    s->key_frame = get_rac(&c, &keystate);

    s->pict_type = AV_PICTURE_TYPE_I;

    s->field_order = AV_FIELD_UNKNOWN;

    s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;

    if (s->key_frame) {

        uint8_t state[CONTEXT_SIZE];

        memset(state, 128, sizeof(state));

        ff_ffv1_parse_header(f, &c, state);

    }

    s->width  = f->width;

    s->height = f->height;

    s->format = f->pix_fmt;

    return buf_size;

}

static av_cold void ffv1_close(AVCodecParserContext *s)

{

    FFV1ParseContext *p = s->priv_data;

    p->f.avctx = NULL;

    ff_ffv1_close(&p->f);

}

const FFCodecParser ff_ffv1_parser = {

    PARSER_CODEC_LIST(AV_CODEC_ID_FFV1),

    .priv_data_size = sizeof(FFV1ParseContext),

    .parse          = parse,

    .close          = ffv1_close,

};