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| author | Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com> | 2015-03-09 14:59:44 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2015-03-21 01:52:52 +0100 |
| commit | 93a0682b1d73f114720cd5c5bd69740546f78cdb (patch) | |
| tree | 05d01f47469fb00762177a432b2cd9c0392eed7c | |
| parent | 0e16c3843a3b2cd06b90898c04d85ed3d82266bb (diff) | |
| download | ffmpeg-93a0682b1d73f114720cd5c5bd69740546f78cdb.tar.gz | |
ffmdec: limit the backward seek to the last resync position
If resyncing leads to the same position as previously, it will again
lead to a resync attempt, resulting in an infinite loop.
Thus don't seek back beyond the last syncpoint.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 6b8263b03ab3d16d70525ae1893cb106be7852f1)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | libavformat/ffmdec.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/libavformat/ffmdec.c b/libavformat/ffmdec.c index ee34e73451..33bbde04b0 100644 --- a/libavformat/ffmdec.c +++ b/libavformat/ffmdec.c @@ -82,6 +82,7 @@ static int ffm_read_data(AVFormatContext *s, FFMContext *ffm = s->priv_data; AVIOContext *pb = s->pb; int len, fill_size, size1, frame_offset, id; + int64_t last_pos = -1; size1 = size; while (size > 0) { @@ -101,9 +102,11 @@ static int ffm_read_data(AVFormatContext *s, avio_seek(pb, tell, SEEK_SET); } id = avio_rb16(pb); /* PACKET_ID */ - if (id != PACKET_ID) + if (id != PACKET_ID) { if (ffm_resync(s, id) < 0) return -1; + last_pos = avio_tell(pb); + } fill_size = avio_rb16(pb); ffm->dts = avio_rb64(pb); frame_offset = avio_rb16(pb); @@ -117,7 +120,9 @@ static int ffm_read_data(AVFormatContext *s, if (!frame_offset) { /* This packet has no frame headers in it */ if (avio_tell(pb) >= ffm->packet_size * 3LL) { - avio_seek(pb, -ffm->packet_size * 2LL, SEEK_CUR); + int64_t seekback = FFMIN(ffm->packet_size * 2LL, avio_tell(pb) - last_pos); + seekback = FFMAX(seekback, 0); + avio_seek(pb, -seekback, SEEK_CUR); goto retry_read; } /* This is bad, we cannot find a valid frame header */ |