nutdec: fix infinite resync loops

nut->last_syncpoint_pos doesn't necessarily change between resync
attempts, so find_any_startcode can return the same startcode again.

Thus remember where the last resync happened and don't try to resync
before that.

This can't be done locally in nut_read_packet, because this wouldn't
prevent infinite resync loops, where after the resync a packet is
returned and while reading a following packet the resync happens again.

Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
(cherry picked from commit 37e679881d)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Andreas Cadhalpun 2015-05-20 00:06:05 +02:00 committed by Michael Niedermayer
parent 236452f83e
commit 936a5dd2c5
2 changed files with 5 additions and 1 deletions

View File

@ -102,6 +102,7 @@ typedef struct NUTContext {
unsigned int max_distance;
unsigned int time_base_count;
int64_t last_syncpoint_pos;
int64_t last_resync_pos;
int header_count;
AVRational *time_base;
struct AVTreeNode *syncpoints;

View File

@ -1129,7 +1129,8 @@ static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
default:
resync:
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
tmp = find_any_startcode(bc, nut->last_syncpoint_pos + 1);
tmp = find_any_startcode(bc, FFMAX(nut->last_syncpoint_pos, nut->last_resync_pos) + 1);
nut->last_resync_pos = avio_tell(bc);
if (tmp == 0)
return AVERROR_INVALIDDATA;
av_log(s, AV_LOG_DEBUG, "sync\n");
@ -1230,6 +1231,8 @@ static int read_seek(AVFormatContext *s, int stream_index,
for (i = 0; i < s->nb_streams; i++)
nut->stream[i].skip_until_key_frame = 1;
nut->last_resync_pos = 0;
return 0;
}