/*

 * XWD parser

 * Copyright (c) 2022 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

 * XWD parser

 **/

#include "libavutil/intreadwrite.h"

#include "parser.h"

#include "parser_internal.h"

#include "xwd.h"

typedef struct XWDParseContext {

    ParseContext  pc;

    int           left;

    int           idx;

    uint8_t       hdr[XWD_HEADER_SIZE];

} XWDParseContext;

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

                     const uint8_t **poutbuf, int *poutbuf_size,

                     const uint8_t *buf, int buf_size)

{

    XWDParseContext *t = s->priv_data;

    ParseContext *pc   = &t->pc;

    int next           = END_NOT_FOUND;

    s->pict_type = AV_PICTURE_TYPE_NONE;

    *poutbuf      = NULL;

    *poutbuf_size = 0;

    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {

        next = buf_size;

    } else {

        for (int i = 0; i < buf_size; i++) {

            if (t->left > 0) {

                t->left--;

                if (t->left == 0) {

                    next = i;

                    break;

                }

                continue;

            }

            if (t->idx >= 100) {

                t->idx = 99;

                memmove(&t->hdr[0], &t->hdr[1], XWD_HEADER_SIZE-1);

            }

            t->hdr[t->idx++] = buf[i];

            if (t->idx >= 100 && AV_RB32(t->hdr + 4) == XWD_VERSION) {

                uint32_t header_size  = AV_RB32(t->hdr + 0);

                uint32_t height       = AV_RB32(t->hdr + 20);

                uint32_t lsize        = AV_RB32(t->hdr + 48);

                uint32_t ncolors      = AV_RB32(t->hdr + 76);

                uint32_t size         = header_size + ncolors * XWD_CMAP_SIZE + height * lsize;

                pc->frame_start_found = 1;

                t->left               = size - XWD_HEADER_SIZE + 1;

                t->idx                = 0;

                memset(t->hdr, 0, sizeof(t->hdr));

            }

        }

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

            return buf_size;

    }

    *poutbuf      = buf;

    *poutbuf_size = buf_size;

    s->pict_type = AV_PICTURE_TYPE_I;

    s->key_frame = 1;

    s->duration  = 1;

    return next;

}

const FFCodecParser ff_xwd_parser = {

    PARSER_CODEC_LIST(AV_CODEC_ID_XWD),

    .priv_data_size = sizeof(XWDParseContext),

    .parse          = xwd_parse,

    .close          = ff_parse_close,

};