1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-12 19:18:44 +02:00
FFmpeg/libavcodec/bmp_parser.c

113 lines
3.4 KiB
C
Raw Normal View History

/*
* 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;
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;
}
AVCodecParser ff_bmp_parser = {
Merge commit '36ef5369ee9b336febc2c270f8718cec4476cb85' * commit '36ef5369ee9b336febc2c270f8718cec4476cb85': Replace all CODEC_ID_* with AV_CODEC_ID_* lavc: add AV prefix to codec ids. Conflicts: doc/APIchanges doc/examples/decoding_encoding.c doc/examples/muxing.c ffmpeg.c ffprobe.c ffserver.c libavcodec/8svx.c libavcodec/avcodec.h libavcodec/dnxhd_parser.c libavcodec/dvdsubdec.c libavcodec/error_resilience.c libavcodec/h263dec.c libavcodec/libvorbisenc.c libavcodec/mjpeg_parser.c libavcodec/mjpegenc.c libavcodec/mpeg12.c libavcodec/mpeg4videodec.c libavcodec/mpegvideo.c libavcodec/mpegvideo_enc.c libavcodec/pcm.c libavcodec/r210dec.c libavcodec/utils.c libavcodec/v210dec.c libavcodec/version.h libavdevice/alsa-audio-dec.c libavdevice/bktr.c libavdevice/v4l2.c libavformat/asfdec.c libavformat/asfenc.c libavformat/avformat.h libavformat/avidec.c libavformat/caf.c libavformat/electronicarts.c libavformat/flacdec.c libavformat/flvdec.c libavformat/flvenc.c libavformat/framecrcenc.c libavformat/img2.c libavformat/img2dec.c libavformat/img2enc.c libavformat/ipmovie.c libavformat/isom.c libavformat/matroska.c libavformat/matroskadec.c libavformat/matroskaenc.c libavformat/mov.c libavformat/movenc.c libavformat/mp3dec.c libavformat/mpeg.c libavformat/mpegts.c libavformat/mxf.c libavformat/mxfdec.c libavformat/mxfenc.c libavformat/nsvdec.c libavformat/nut.c libavformat/oggenc.c libavformat/pmpdec.c libavformat/rawdec.c libavformat/rawenc.c libavformat/riff.c libavformat/sdp.c libavformat/utils.c libavformat/vocenc.c libavformat/wtv.c libavformat/xmv.c Merged-by: Michael Niedermayer <michaelni@gmx.at>
2012-08-07 23:45:46 +03:00
.codec_ids = { AV_CODEC_ID_BMP },
.priv_data_size = sizeof(BMPParseContext),
.parser_parse = bmp_parse,
.parser_close = ff_parse_close,
};