diff options
Diffstat (limited to 'libavcodec/bmp_parser.c')
-rw-r--r-- | libavcodec/bmp_parser.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/libavcodec/bmp_parser.c b/libavcodec/bmp_parser.c new file mode 100644 index 0000000000..06ed367b38 --- /dev/null +++ b/libavcodec/bmp_parser.c @@ -0,0 +1,91 @@ +/* + * 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 "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; + + s->pict_type = AV_PICTURE_TYPE_NONE; + + *poutbuf_size = 0; + if (buf_size == 0) + return 0; + + if (!bpc->pc.frame_start_found) { + for (; i < buf_size; i++) { + state = (state << 8) | buf[i]; + if ((state >> 48) == (('B' << 8) | 'M')) { + bpc->fsize = av_bswap32(state >> 16); + bpc->pc.frame_start_found = 1; + if (bpc->fsize > buf_size - i + 7) + bpc->remaining_size = bpc->fsize - buf_size + i - 7; + else + next = bpc->fsize + i - 7; + break; + } + } + 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; + next = i; + } + } + +flush: + if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0) + return buf_size; + + bpc->pc.frame_start_found = 0; + + *poutbuf = buf; + *poutbuf_size = buf_size; + return next; +} + +AVCodecParser ff_bmp_parser = { + .codec_ids = { AV_CODEC_ID_BMP }, + .priv_data_size = sizeof(BMPParseContext), + .parser_parse = bmp_parse, + .parser_close = ff_parse_close, +}; |