/*

 * DPX parser

 * Copyright (c) 2013 Paul B Mahol

 *

 * 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

 */

/**

 * @file

 * DPX parser

 */

#include "libavutil/bswap.h"

#include "libavutil/common.h"

#include "parser.h"

#include "parser_internal.h"

typedef struct DPXParseContext {

    ParseContext pc;

    uint32_t index;

    uint32_t fsize;

    uint32_t remaining_size;

    int is_be;

} DPXParseContext;

static int dpx_parse(AVCodecParserContext *s, AVCodecContext *avctx,

                     const uint8_t **poutbuf, int *poutbuf_size,

                     const uint8_t *buf, int buf_size)

{

    DPXParseContext *d = s->priv_data;

    uint32_t state = d->pc.state;

    int next = END_NOT_FOUND;

    int i = 0;

    s->pict_type = AV_PICTURE_TYPE_I;

    *poutbuf_size = 0;

    if (buf_size == 0)

        next = 0;

    if (!d->pc.frame_start_found) {

        for (; i < buf_size; i++) {

            state = (state << 8) | buf[i];

            if (state == MKBETAG('S','D','P','X') ||

                state == MKTAG('S','D','P','X')) {

                d->pc.frame_start_found = 1;

                d->is_be = state == MKBETAG('S','D','P','X');

                d->index = 0;

                break;

            }

        }

        d->pc.state = state;

    } else {

        if (d->remaining_size) {

            i = FFMIN(d->remaining_size, buf_size);

            d->remaining_size -= i;

            if (d->remaining_size)

                goto flush;

        }

    }

    for (; d->pc.frame_start_found && i < buf_size; i++) {

        d->pc.state = (d->pc.state << 8) | buf[i];

        d->index++;

        if (d->index == 17) {

            d->fsize = d->is_be ? d->pc.state : av_bswap32(d->pc.state);

            if (d->fsize <= 1664) {

                d->pc.frame_start_found = 0;

                goto flush;

            }

            if (d->fsize > buf_size - i + 19)

                d->remaining_size = d->fsize - buf_size + i - 19;

            else

                i += d->fsize - 19;

            break;

        } else if (d->index > 17) {

            if (d->pc.state == MKBETAG('S','D','P','X') ||

                d->pc.state == MKTAG('S','D','P','X')) {

                next = i - 3;

                break;

            }

        }

    }

flush:

    if (ff_combine_frame(&d->pc, next, &buf, &buf_size) < 0)

        return buf_size;

    d->pc.frame_start_found = 0;

    *poutbuf      = buf;

    *poutbuf_size = buf_size;

    return next;

}

const FFCodecParser ff_dpx_parser = {

    PARSER_CODEC_LIST(AV_CODEC_ID_DPX),

    .priv_data_size = sizeof(DPXParseContext),

    .parse          = dpx_parse,

    .close          = ff_parse_close,

};