/*
* Multipart JPEG format
* Copyright (c) 2015 Luca Barbato
*
* 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
*/
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
#include "avformat.h"
#include "internal.h"
#include "avio_internal.h"
typedef struct MPJPEGDemuxContext {
const AVClass *class;
char *boundary;
char *searchstr;
int searchstr_len;
int strict_mime_boundary;
} MPJPEGDemuxContext;
static void trim_right(char *p)
{
char *end;
if (!p || !*p)
return;
end = p + strlen(p);
while (end > p && av_isspace(*(end-1)))
*(--end) = '\0';
}
static int get_line(AVIOContext *pb, char *line, int line_size)
{
ff_get_line(pb, line, line_size);
if (pb->error)
return pb->error;
if (pb->eof_reached)
return AVERROR_EOF;
trim_right(line);
return 0;
}
static int split_tag_value(char **tag, char **value, char *line)
{
char *p = line;
int foundData = 0;
*tag = NULL;
*value = NULL;
while (*p != '\0' && *p != ':') {
if (!av_isspace(*p)) {
foundData = 1;
}
p++;
}
if (*p != ':')
return foundData ? AVERROR_INVALIDDATA : 0;
*p = '\0';
*tag = line;
trim_right(*tag);
p++;
while (av_isspace(*p))
p++;
*value = p;
trim_right(*value);
return 0;
}
static int parse_multipart_header(AVIOContext *pb,
int* size,
const char* expected_boundary,
void *log_ctx);
static int mpjpeg_read_close(AVFormatContext *s)
{
MPJPEGDemuxContext *mpjpeg = s->priv_data;
av_freep(&mpjpeg->boundary);
av_freep(&mpjpeg->searchstr);
return 0;
}
static int mpjpeg_read_probe(AVProbeData *p)
{
AVIOContext *pb;
int ret = 0;
int size = 0;
if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-')
return 0;
pb = avio_alloc_context(p->buf, p->buf_size, 0, NULL, NULL, NULL, NULL);
if (!pb)
return 0;
ret = (parse_multipart_header(pb, &size, "--", NULL) >= 0) ? AVPROBE_SCORE_MAX : 0;
avio_context_free(&pb);
return ret;
}
static int mpjpeg_read_header(AVFormatContext *s)
{
AVStream *st;
char boundary[70 + 2 + 1] = {0};
int64_t pos = avio_tell(s->pb);
int ret;
do {
ret = get_line(s->pb, boundary, sizeof(boundary));
if (ret < 0)
return ret;
} while (!boundary[0]);
if (strncmp(boundary, "--", 2))
return AVERROR_INVALIDDATA;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->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(AVIOContext *pb,
int* size,
const char* expected_boundary,
void *log_ctx)
{
char line[128];
int found_content_type = 0;
int ret;
*size = -1;
// get the CRLF as empty string
ret = get_line(pb, line, sizeof(line));
if (ret < 0)
return ret;
/* some implementation do not provide the required
* initial CRLF (see rfc1341 7.2.1)
*/
while (!line[0]) {
ret = get_line(pb, line, sizeof(line));
if (ret < 0)
return ret;
}
if (!av_strstart(line, expected_boundary, NULL)) {
if (log_ctx)
av_log(log_ctx,
AV_LOG_ERROR,
"Expected boundary '%s' not found, instead found a line of %"SIZE_SPECIFIER" bytes\n",
expected_boundary,
strlen(line));
return AVERROR_INVALIDDATA;
}
while (!pb->eof_reached) {
char *tag, *value;
ret = get_line(pb, line, sizeof(line));
if (ret < 0) {
if (ret == AVERROR_EOF)
break;
return ret;
}
if (line[0] == '\0')
break;
ret = split_tag_value(&tag, &value, line);
if (ret < 0)
return ret;
if (value==NULL || tag==NULL)
break;
if (!av_strcasecmp(tag, "Content-type")) {
if (av_strcasecmp(value, "image/jpeg")) {
if (log_ctx)
av_log(log_ctx, 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 )
if (log_ctx)
av_log(log_ctx, AV_LOG_WARNING,
"Invalid Content-Length value : %s\n",
value);
}
}
return found_content_type ? 0 : AVERROR_INVALIDDATA;
}
static char* mpjpeg_get_boundary(AVIOContext* pb)
{
uint8_t *mime_type = NULL;
const char *start;
const char *end;
uint8_t *res = NULL;
int len;
/* get MIME type, and skip to the first parameter */
av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type);
start = mime_type;
while (start != NULL && *start != '\0') {
start = strchr(start, ';');
if (!start)
break;
start = start+1;
while (av_isspace(*start))
start++;
if (!av_stristart(start, "boundary=", &start)) {
end = strchr(start, ';');
if (end)
len = end - start - 1;
else
len = strlen(start);
/* some endpoints may enclose the boundary
in Content-Type in quotes */
if ( len>2 && *start == '"' && start[len-1] == '"' ) {
start++;
len -= 2;
}
res = av_strndup(start, len);
break;
}
}
av_freep(&mime_type);
return res;
}
static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int size;
int ret;
MPJPEGDemuxContext *mpjpeg = s->priv_data;
if (mpjpeg->boundary == NULL) {
uint8_t* boundary = NULL;
if (mpjpeg->strict_mime_boundary) {
boundary = mpjpeg_get_boundary(s->pb);
}
if (boundary != NULL) {
mpjpeg->boundary = boundary;
mpjpeg->searchstr = av_asprintf( "\r\n%s\r\n", boundary );
} else {
mpjpeg->boundary = av_strdup("--");
mpjpeg->searchstr = av_strdup("\r\n--");
}
if (!mpjpeg->boundary || !mpjpeg->searchstr) {
av_freep(&mpjpeg->boundary);
av_freep(&mpjpeg->searchstr);
return AVERROR(ENOMEM);
}
mpjpeg->searchstr_len = strlen(mpjpeg->searchstr);
}
ret = parse_multipart_header(s->pb, &size, mpjpeg->boundary, s);
if (ret < 0)
return ret;
if (size > 0) {
/* size has been provided to us in MIME header */
ret = av_get_packet(s->pb, pkt, size);
} else {
/* no size was given -- we read until the next boundary or end-of-file */
int remaining = 0, len;
const int read_chunk = 2048;
av_init_packet(pkt);
pkt->data = NULL;
pkt->size = 0;
pkt->pos = avio_tell(s->pb);
/* we may need to return as much as all we've read back to the buffer */
ffio_ensure_seekback(s->pb, read_chunk);
while ((ret = av_append_packet(s->pb, pkt, read_chunk - remaining)) >= 0) {
/* scan the new data */
char *start;
len = ret + remaining;
start = pkt->data + pkt->size - len;
do {
if (!memcmp(start, mpjpeg->searchstr, mpjpeg->searchstr_len)) {
// got the boundary! rewind the stream
avio_seek(s->pb, -len, SEEK_CUR);
pkt->size -= len;
return pkt->size;
}
len--;
start++;
} while (len >= mpjpeg->searchstr_len);
remaining = len;
}
/* error or EOF occurred */
if (ret == AVERROR_EOF) {
ret = pkt->size > 0 ? pkt->size : AVERROR_EOF;
} else {
av_packet_unref(pkt);
}
}
return ret;
}
#define OFFSET(x) offsetof(MPJPEGDemuxContext, x)
#define DEC AV_OPT_FLAG_DECODING_PARAM
const AVOption mpjpeg_options[] = {
{ "strict_mime_boundary", "require MIME boundaries match", OFFSET(strict_mime_boundary), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
{ NULL }
};
static const AVClass mpjpeg_demuxer_class = {
.class_name = "MPJPEG demuxer",
.item_name = av_default_item_name,
.option = mpjpeg_options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_mpjpeg_demuxer = {
.name = "mpjpeg",
.long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"),
.mime_type = "multipart/x-mixed-replace",
.extensions = "mjpg",
.priv_data_size = sizeof(MPJPEGDemuxContext),
.read_probe = mpjpeg_read_probe,
.read_header = mpjpeg_read_header,
.read_packet = mpjpeg_read_packet,
.read_close = mpjpeg_read_close,
.priv_class = &mpjpeg_demuxer_class,
.flags = AVFMT_NOTIMESTAMPS,
};