aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorZhao Zhili <zhilizhao@tencent.com>2022-09-25 12:28:40 +0800
committerZhao Zhili <zhilizhao@tencent.com>2022-10-08 22:56:20 +0800
commit0d17f5228f4d3854066ec1001f69c7d1714b0df9 (patch)
tree500477be72447bc1074bdd32aa3627d4023e2b56
parent2205ccd216bac64c08f2c3c7246dd19da745ef8d (diff)
downloadffmpeg-0d17f5228f4d3854066ec1001f69c7d1714b0df9.tar.gz
avformat/mp3dec: avoid seek back and forth
avio_seek() is called inside check(). Seeking to 'off' then seeking to 'off + i' is unefficient, and it can loop 64 * 1024 times in the worst case. When probe a malformed file over HTTP, it looks like stucked forvever. ffio_ensure_seekback() doesn't solve the issue when the stream is seekable but slow. Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
-rw-r--r--libavformat/mp3dec.c16
1 files changed, 7 insertions, 9 deletions
diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index 458d6dbd03..a9e494452d 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -408,18 +408,11 @@ static int mp3_read_header(AVFormatContext *s)
ffio_ensure_seekback(s->pb, i + 1024 + 4);
frame_size = check(s->pb, off + i, &header);
if (frame_size > 0) {
- ret = avio_seek(s->pb, off, SEEK_SET);
- if (ret < 0)
- return ret;
ffio_ensure_seekback(s->pb, i + 1024 + frame_size + 4);
ret = check(s->pb, off + i + frame_size, &header2);
if (ret >= 0 &&
(header & MP3_MASK) == (header2 & MP3_MASK))
{
- av_log(s, i > 0 ? AV_LOG_INFO : AV_LOG_VERBOSE, "Skipping %d bytes of junk at %"PRId64".\n", i, off);
- ret = avio_seek(s->pb, off + i, SEEK_SET);
- if (ret < 0)
- return ret;
break;
} else if (ret == CHECK_SEEK_FAILED) {
av_log(s, AV_LOG_ERROR, "Invalid frame size (%d): Could not seek to %"PRId64".\n", frame_size, off + i + frame_size);
@@ -429,10 +422,15 @@ static int mp3_read_header(AVFormatContext *s)
av_log(s, AV_LOG_ERROR, "Failed to read frame size: Could not seek to %"PRId64".\n", (int64_t) (i + 1024 + frame_size + 4));
return AVERROR(EINVAL);
}
+ }
+ if (i == 64 * 1024) {
ret = avio_seek(s->pb, off, SEEK_SET);
- if (ret < 0)
- return ret;
+ } else {
+ av_log(s, i > 0 ? AV_LOG_INFO : AV_LOG_VERBOSE, "Skipping %d bytes of junk at %"PRId64".\n", i, off);
+ ret = avio_seek(s->pb, off + i, SEEK_SET);
}
+ if (ret < 0)
+ return ret;
off = avio_tell(s->pb);
// the seek index is relative to the end of the xing vbr headers