This addresses ticket 5023
From a2a0b9e0da14b6e82aa783535ec1878c8ffbede0 Mon Sep 17 00:00:00 2001
From: Alex Agranovsky <a...@sighthound.com>
Date: Tue, 24 Nov 2015 00:06:14 -0500
Subject: [PATCH 1/2] Allow mpjpeg demuxer to process MIME parts which do not
include Content-Length header.
Fixes ticket 5023
Signed-off-by: Alex Agranovsky <a...@sighthound.com>
---
libavformat/mpjpegdec.c | 176 ++++++++++++++++++++++++++++++++++++------------
1 file changed, 133 insertions(+), 43 deletions(-)
diff --git a/libavformat/mpjpegdec.c b/libavformat/mpjpegdec.c
index 2749a48..e494f1a 100644
--- a/libavformat/mpjpegdec.c
+++ b/libavformat/mpjpegdec.c
@@ -23,22 +23,16 @@
#include "avformat.h"
#include "internal.h"
+#include "avio_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;
-}
+/** Context for demuxing an MPJPEG stream. */
+typedef struct MPJPEGDemuxContext {
+ char* boundary;
+ char* searchstr;
+ int searchstr_len;
+} MPJPEGDemuxContext;
static void trim_right(char* p)
@@ -46,13 +40,32 @@ static void trim_right(char* p)
char *end;
if (!p || !*p)
return;
- end = p + strlen(p) - 1;
- while (end != p && av_isspace(*end)) {
+ int len = strlen(p);
+ if ( !len )
+ return;
+ end = p + len - 1;
+ while (end >= p && av_isspace(*end)) {
*end = '\0';
end--;
}
}
+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;
@@ -86,12 +99,24 @@ static int split_tag_value(char **tag, char **value, char
*line)
return 0;
}
-static int parse_multipart_header(AVIOContext *pb, void *log_ctx);
+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;
@@ -100,7 +125,7 @@ static int mpjpeg_read_probe(AVProbeData *p)
if (!pb)
return 0;
- ret = (parse_multipart_header(pb, NULL)>0)?AVPROBE_SCORE_MAX:0;
+ ret = ( parse_multipart_header(pb, &size, "--", NULL) > 0 ) ?
AVPROBE_SCORE_MAX : 0;
av_free(pb);
@@ -110,17 +135,19 @@ static int mpjpeg_read_probe(AVProbeData *p)
static int mpjpeg_read_header(AVFormatContext *s)
{
AVStream *st;
- char boundary[70 + 2 + 1];
+ 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]);
- ret = get_line(s->pb, boundary, sizeof(boundary));
- if (ret < 0)
- return ret;
-
- if (strncmp(boundary, "--", 2))
+ if (strncmp(boundary, "--", 2)) {
return AVERROR_INVALIDDATA;
+ }
st = avformat_new_stream(s, NULL);
if (!st)
@@ -147,28 +174,44 @@ static int parse_content_length(const char *value)
return val;
}
-static int parse_multipart_header(AVIOContext *pb, void *log_ctx)
+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;
+ int ret;
+
+ *size = -1;
// get the CRLF as empty string
ret = get_line(pb, line, sizeof(line));
- if (ret < 0)
+ if (ret < 0) {
return ret;
+ }
/* some implementation do not provide the required
* initial CRLF (see rfc1341 7.2.1)
*/
- if (!line[0]) {
+ while (!line[0]) {
ret = get_line(pb, line, sizeof(line));
- if (ret < 0)
+ if (ret < 0) {
return ret;
+ }
}
- if (strncmp(line, "--", 2))
+ if ( strncmp(line, expected_boundary, strlen(expected_boundary) ) ) {
+ if (log_ctx) {
+ av_log(log_ctx,
+ AV_LOG_ERROR,
+ "Expected boundary '%s' not found, instead found a line of %lu
bytes\n",
+ expected_boundary,
+ strlen(line) );
+ }
+
return AVERROR_INVALIDDATA;
+ }
while (!pb->eof_reached) {
char *tag, *value;
@@ -201,32 +244,77 @@ static int parse_multipart_header(AVIOContext *pb, void
*log_ctx)
} else
found_content_type = 1;
} else if (!av_strcasecmp(tag, "Content-Length")) {
- size = parse_content_length(value);
- if (size < 0)
- return size;
+ *size = parse_content_length(value);
}
}
- if (!found_content_type || size < 0) {
- return AVERROR_INVALIDDATA;
- }
-
- return size;
+ return (found_content_type) ? 0 : AVERROR_INVALIDDATA;
}
+
static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
{
- int ret;
- int size = parse_multipart_header(s->pb, s);
+ int size;
+ MPJPEGDemuxContext *mpjpeg = s->priv_data;
+ if ( mpjpeg->boundary == NULL ) {
+ mpjpeg->boundary = av_strdup("--");
+ mpjpeg->searchstr = av_strdup("\r\n--");
+ mpjpeg->searchstr_len = strlen( mpjpeg->searchstr );
+ }
+
+ int ret = parse_multipart_header(s->pb,
+ &size,
+ mpjpeg->boundary,
+ s);
- if (size < 0)
- return size;
- ret = av_get_packet(s->pb, pkt, size);
if (ret < 0)
return ret;
- return 0;
+ 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
*/
+
+ 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 );
+
+
+ int remaining = 0, len;
+
+ while ( ( ret = av_append_packet( s->pb, pkt, read_chunk - remaining )
) >= 0 ) {
+ /* scan the new data */
+ len = ret + remaining;
+ char* 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-2), SEEK_CUR );
+ pkt->size -= (len-2);
+ 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;
}
AVInputFormat ff_mpjpeg_demuxer = {
@@ -234,7 +322,9 @@ AVInputFormat ff_mpjpeg_demuxer = {
.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
};
--
2.4.9 (Apple Git-60)
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