It was possible for the old code to seek back before the most recently read
data if start of a new multipart was across read boundaries. Now we read some
small sections multiple times to avoid this, but that is OK.
Signed-off-by: Marton Balint <c...@passwd.hu>
---
libavformat/mpjpegdec.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/libavformat/mpjpegdec.c b/libavformat/mpjpegdec.c
index df2880412d..5fe00fd162 100644
--- a/libavformat/mpjpegdec.c
+++ b/libavformat/mpjpegdec.c
@@ -328,18 +328,18 @@ static int mpjpeg_read_packet(AVFormatContext *s,
AVPacket *pkt)
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;
+ int len;
const int read_chunk = 2048;
pkt->pos = avio_tell(s->pb);
- while ((ret = ffio_ensure_seekback(s->pb, read_chunk - remaining)) >=
0 && /* we may need to return as much as all we've read back to the buffer */
- (ret = av_append_packet(s->pb, pkt, read_chunk - remaining)) >=
0) {
+ while ((ret = ffio_ensure_seekback(s->pb, read_chunk)) >= 0 && /* we
may need to return as much as all we've read back to the buffer */
+ (ret = av_append_packet(s->pb, pkt, read_chunk)) >= 0) {
/* scan the new data */
char *start;
- len = ret + remaining;
+ len = ret;
start = pkt->data + pkt->size - len;
do {
if (!memcmp(start, mpjpeg->searchstr, mpjpeg->searchstr_len)) {
@@ -351,7 +351,8 @@ static int mpjpeg_read_packet(AVFormatContext *s, AVPacket
*pkt)
len--;
start++;
} while (len >= mpjpeg->searchstr_len);
- remaining = len;
+ avio_seek(s->pb, -len, SEEK_CUR);
+ pkt->size -= len;
}
/* error or EOF occurred */
--
2.26.2
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
