/* * BMP parser * Copyright (c) 2012 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 * BMP parser */ #include "libavutil/bswap.h"#include "libavutil/common.h" #include "parser.h" typedef struct BMPParseContext {    ParseContext pc;    uint32_t fsize;    uint32_t remaining_size;} BMPParseContext; static int bmp_parse(AVCodecParserContext *s, AVCodecContext *avctx,                     const uint8_t **poutbuf, int *poutbuf_size,                     const uint8_t *buf, int buf_size){    BMPParseContext *bpc = s->priv_data;    uint64_t state = bpc->pc.state64;    int next = END_NOT_FOUND;    int i = 0;     *poutbuf_size = 0;    *poutbuf = NULL; restart:    if (bpc->pc.frame_start_found <= 2+4+4) {        for (; i < buf_size; i++) {            state = (state << 8) | buf[i];            if (bpc->pc.frame_start_found == 0) {                if ((state >> 48) == (('B' << 8) | 'M')) {                    bpc->fsize = av_bswap32(state >> 16);                    if (bpc->fsize > 17)                        bpc->pc.frame_start_found = 1;                }            } else if (bpc->pc.frame_start_found == 2+4+4) {//                 unsigned hsize = av_bswap32(state>>32);                unsigned ihsize = av_bswap32(state);                if (ihsize < 12 || ihsize > 200) {                    bpc->pc.frame_start_found = 0;                    continue;                }                bpc->pc.frame_start_found++;                bpc->remaining_size = bpc->fsize + i - 17;                 if (bpc->pc.index + i > 17) {                    next = i - 17;                    state = 0;                    break;                } else {                    bpc->pc.state64 = 0;                    goto restart;                }            } else if (bpc->pc.frame_start_found)                bpc->pc.frame_start_found++;        }        bpc->pc.state64 = state;    } else {        if (bpc->remaining_size) {            i = FFMIN(bpc->remaining_size, buf_size);            bpc->remaining_size -= i;            if (bpc->remaining_size)                goto flush;             bpc->pc.frame_start_found = 0;            goto restart;        }    } flush:    if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0)        return buf_size;     if (next != END_NOT_FOUND && next < 0)        bpc->pc.frame_start_found = FFMAX(bpc->pc.frame_start_found - i - 1, 0);    else        bpc->pc.frame_start_found = 0;     *poutbuf      = buf;    *poutbuf_size = buf_size;    return next;} const AVCodecParser ff_bmp_parser = {    .codec_ids      = { AV_CODEC_ID_BMP },    .priv_data_size = sizeof(BMPParseContext),    .parser_parse   = bmp_parse,    .parser_close   = ff_parse_close,};