[FFmpeg-devel] question: why (pts < dts) is Invalid timestamps

[Maksym Veremeyenko]

Hi,

could somebody explain, what is wrong then packet has pts < dts:

1270             if(st->cur_pkt.pts != AV_NOPTS_VALUE &&
1271                st->cur_pkt.dts != AV_NOPTS_VALUE &&
1272                st->cur_pkt.pts < st->cur_pkt.dts){
1273                 av_log(s, AV_LOG_WARNING, "Invalid timestamps 
stream=%d, pts=%"PRId64", dts=%"PRId64", size=%d\n",
1274                     st->cur_pkt.stream_index,
1275                     st->cur_pkt.pts,
1276                     st->cur_pkt.dts,
1277                     st->cur_pkt.size);
1278 //                av_free_packet(&st->cur_pkt);
1279 //                return -1;
1280             }

i re-read some posts about dst/pts like:
http://ffmpeg-users.933282.n4.nabble.com/understanding-DTS-PTS-td940270.html
http://dranger.com/ffmpeg/tutorial05.html
but still have a questions.

 From the example:

PTS:    1 4 2 3
DTS:    1 2 3 4
Stream: I P B B

P and B frames has (pts < dts)

another real example is 
http://samples.mplayerhq.hu/mov/FCP/HDV_1080i50.mov that according to 
ctts atom:

     count=1, duration=2
     count=2, duration=-1
     count=1, duration=2
     count=2, duration=-1
     count=1, duration=2
     count=2, duration=-1
     count=1, duration=2
     [...]

PTS should be:

#  DTS  PTS
------------
0    0    2
1    1    0
2    2    1
3    3    5
4    4    3
5    5    4
6    6    8
7    7    6
8    8    7
9    9    11
[...]

that also has (pts < dts) from some samples, but current implementation 
in mov.c makes a DTS negative (even in index table):

#  DTS  PTS
------------
0   -1    2
1    0    0
2    1    1
3    2    5
4    3    3
5    4    4
6    5    8
7    6    6
8    7    7
9    8    11
[...]

to provide condition (pts >= dts)

and how seeking should works for this?

-- 
________________________________________
Maksym Veremeyenko