yading@10: /*
yading@10:  * BMP parser
yading@10:  * Copyright (c) 2012 Paul B Mahol
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * BMP parser
yading@10:  */
yading@10: 
yading@10: #include "libavutil/bswap.h"
yading@10: #include "parser.h"
yading@10: 
yading@10: typedef struct BMPParseContext {
yading@10:     ParseContext pc;
yading@10:     uint32_t fsize;
yading@10:     uint32_t remaining_size;
yading@10: } BMPParseContext;
yading@10: 
yading@10: static int bmp_parse(AVCodecParserContext *s, AVCodecContext *avctx,
yading@10:                      const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                      const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     BMPParseContext *bpc = s->priv_data;
yading@10:     uint64_t state = bpc->pc.state64;
yading@10:     int next = END_NOT_FOUND;
yading@10:     int i = 0;
yading@10: 
yading@10:     s->pict_type = AV_PICTURE_TYPE_NONE;
yading@10: 
yading@10:     *poutbuf_size = 0;
yading@10:     if (buf_size == 0)
yading@10:         return 0;
yading@10: 
yading@10:     if (!bpc->pc.frame_start_found) {
yading@10:         for (; i < buf_size; i++) {
yading@10:             state = (state << 8) | buf[i];
yading@10:             if ((state >> 48) == (('B' << 8) | 'M')) {
yading@10:                 bpc->fsize = av_bswap32(state >> 16);
yading@10:                 bpc->pc.frame_start_found = 1;
yading@10:                 if (bpc->fsize > buf_size - i + 7)
yading@10:                     bpc->remaining_size = bpc->fsize - buf_size + i - 7;
yading@10:                 else
yading@10:                     next = bpc->fsize + i - 7;
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10:         bpc->pc.state64 = state;
yading@10:     } else {
yading@10:         if (bpc->remaining_size) {
yading@10:             i = FFMIN(bpc->remaining_size, buf_size);
yading@10:             bpc->remaining_size -= i;
yading@10:             if (bpc->remaining_size)
yading@10:                 goto flush;
yading@10:             next = i;
yading@10:         }
yading@10:     }
yading@10: 
yading@10: flush:
yading@10:     if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0)
yading@10:         return buf_size;
yading@10: 
yading@10:     bpc->pc.frame_start_found = 0;
yading@10: 
yading@10:     *poutbuf      = buf;
yading@10:     *poutbuf_size = buf_size;
yading@10:     return next;
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_bmp_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_BMP },
yading@10:     .priv_data_size = sizeof(BMPParseContext),
yading@10:     .parser_parse   = bmp_parse,
yading@10:     .parser_close   = ff_parse_close,
yading@10: };