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/*
* Multipart JPEG format
* Copyright (c) 2015 Luca Barbato
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/avstring.h"
#include "avformat.h"
#include "internal.h"
static int get_line(AVIOContext *pb, char *line, int line_size)
{
int i = ff_get_line(pb, line, line_size);
if (i > 1 && line[i - 2] == '\r')
line[i - 2] = '\0';
if (pb->error)
return pb->error;
if (pb->eof_reached)
return AVERROR_EOF;
return 0;
}
static int split_tag_value(char **tag, char **value, char *line)
{
char *p = line;
while (*p != '\0' && *p != ':')
p++;
if (*p != ':')
return AVERROR_INVALIDDATA;
*p = '\0';
*tag = line;
p++;
while (av_isspace(*p))
p++;
*value = p;
return 0;
}
static int check_content_type(char *line)
{
char *tag, *value;
int ret = split_tag_value(&tag, &value, line);
if (ret < 0)
return ret;
if (av_strcasecmp(tag, "Content-type") ||
av_strcasecmp(value, "image/jpeg"))
return AVERROR_INVALIDDATA;
return 0;
}
static int mpjpeg_read_probe(AVProbeData *p)
{
AVIOContext *pb;
char line[128] = { 0 };
int ret = 0;
pb = avio_alloc_context(p->buf, p->buf_size, 0, NULL, NULL, NULL, NULL);
if (!pb)
return AVERROR(ENOMEM);
if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-')
return 0;
while (!pb->eof_reached) {
ret = get_line(pb, line, sizeof(line));
if (ret < 0)
break;
ret = check_content_type(line);
if (!ret) {
ret = AVPROBE_SCORE_MAX;
break;
}
}
av_free(pb);
return ret;
}
static int mpjpeg_read_header(AVFormatContext *s)
{
AVStream *st;
char boundary[70 + 2 + 1];
int64_t pos = avio_tell(s->pb);
int ret;
ret = get_line(s->pb, boundary, sizeof(boundary));
if (ret < 0)
return ret;
if (strncmp(boundary, "--", 2))
return AVERROR_INVALIDDATA;
st = avformat_new_stream(s, NULL);
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = AV_CODEC_ID_MJPEG;
avpriv_set_pts_info(st, 60, 1, 25);
avio_seek(s->pb, pos, SEEK_SET);
return 0;
}
static int parse_content_length(const char *value)
{
long int val = strtol(value, NULL, 10);
if (val == LONG_MIN || val == LONG_MAX)
return AVERROR(errno);
if (val > INT_MAX)
return AVERROR(ERANGE);
return val;
}
static int parse_multipart_header(AVFormatContext *s)
{
char line[128];
int found_content_type = 0;
int ret, size = -1;
ret = get_line(s->pb, line, sizeof(line));
if (ret < 0)
return ret;
if (strncmp(line, "--", 2))
return AVERROR_INVALIDDATA;
while (!s->pb->eof_reached) {
char *tag, *value;
ret = get_line(s->pb, line, sizeof(line));
if (ret < 0)
return ret;
if (line[0] == '\0')
break;
ret = split_tag_value(&tag, &value, line);
if (ret < 0)
return ret;
if (!av_strcasecmp(tag, "Content-type")) {
if (av_strcasecmp(value, "image/jpeg")) {
av_log(s, AV_LOG_ERROR,
"Unexpected %s : %s\n",
tag, value);
return AVERROR_INVALIDDATA;
} else
found_content_type = 1;
} else if (!av_strcasecmp(tag, "Content-Length")) {
size = parse_content_length(value);
if (size < 0)
return size;
}
}
if (!found_content_type || size < 0) {
return AVERROR_INVALIDDATA;
}
return size;
}
static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret;
int size = parse_multipart_header(s);
if (size < 0)
return size;
ret = av_get_packet(s->pb, pkt, size);
if (ret < 0)
return ret;
// trailing empty line
avio_skip(s->pb, 2);
return 0;
}
AVInputFormat ff_mpjpeg_demuxer = {
.name = "mpjpeg",
.long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"),
.mime_type = "multipart/x-mixed-replace",
.extensions = "mjpg",
.read_probe = mpjpeg_read_probe,
.read_header = mpjpeg_read_header,
.read_packet = mpjpeg_read_packet,
};
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