[Ffmpeg-devel] Bug in pts computation in compute_pkt_fields() ?

[Martin Wache]

Wolfram Gloger schrieb:
> Hi,
> 
>>> That is probably raw mpeg-ts, right?
>>>
>> No, it is already remuxed to pes.
> 
> Ok.
> 
>>>>    /* handle wrapping */
>>>>     if(st->cur_dts != AV_NOPTS_VALUE){
>>>>         if(pkt->pts != AV_NOPTS_VALUE)
>>>>             pkt->pts= lsb2full(pkt->pts, st->cur_dts, st->pts_wrap_bits);
>>>>         if(pkt->dts != AV_NOPTS_VALUE)
>>>>             pkt->dts= lsb2full(pkt->dts, st->cur_dts, st->pts_wrap_bits);
>>>>     }
>>>>
>>>> The result is negative pts value for the packet. So I guess this is a
>>>> bug in compute_pkt_fields(), or am I doing something wrong?
>>> Please check that st->pts_wrap_bits is set to 60 (and not 33) if the
>>> input stream is mpeg-ts.  A long time ago I had a similar problem
>>> which was caused by the transport stream not being detected correctly.
>>>
>> Hmm, you are right, st->pts_wrap_bits is 33 and it should be 60. If I
>> manually set it to 60 it works as it should. How did you fix that problem?
> 
> Sorry, I was wrong -- it seems pts_wrap_bits being 33 is correct.
> Can you print all the values
> 
> pkt->pts st->cur_dts st->pts_wrap_bits
>
Sure, each pair of lines is one call to compute_pkt_fields(), the first
line is at the start of compute_pkt_fields(), the second at the end:
st->cur_dts 8000000000000000 pkt->pts 8000000000000000 pkt->dts
8000000000000000 33
st->cur_dts 0 pkt->pts 0 pkt->dts 0

st->cur_dts 0 pkt->pts 8000000000000000 pkt->dts 8000000000000000 33
st->cur_dts 870 pkt->pts 0 pkt->dts 0

st->cur_dts 870 pkt->pts 113e0e706 pkt->dts 113e0e706 33
st->cur_dts ffffffff13e0ef76 pkt->pts ffffffff13e0e706 pkt->dts
ffffffff13e0e706

st->cur_dts ffffffff13e0ef76 pkt->pts 8000000000000000 pkt->dts
8000000000000000
 33
st->cur_dts ffffffff13e0f7e6 pkt->pts ffffffff13e0ef76 pkt->dts
ffffffff13e0ef76

st->cur_dts ffffffff13e0f7e6 pkt->pts 8000000000000000 pkt->dts
8000000000000000
 33
st->cur_dts ffffffff13e10056 pkt->pts ffffffff13e0f7e6 pkt->dts
ffffffff13e0f7e6

st->cur_dts ffffffff13e10056 pkt->pts 8000000000000000 pkt->dts
8000000000000000
 33
st->cur_dts ffffffff13e108c6 pkt->pts ffffffff13e10056 pkt->dts
ffffffff13e10056

st->cur_dts ffffffff13e108c6 pkt->pts 8000000000000000 pkt->dts
8000000000000000
 33
st->cur_dts ffffffff13e11136 pkt->pts ffffffff13e108c6 pkt->dts
ffffffff13e108c6


st->cur_dts ffffffff13e11136 pkt->pts 8000000000000000 pkt->dts
8000000000000000
 33
st->cur_dts ffffffff13e119a6 pkt->pts ffffffff13e11136 pkt->dts
ffffffff13e11136

st->cur_dts ffffffff13e119a6 pkt->pts 8000000000000000 pkt->dts
8000000000000000
 33
st->cur_dts ffffffff13e12216 pkt->pts ffffffff13e119a6 pkt->dts
ffffffff13e119a6

st->cur_dts ffffffff13e12216 pkt->pts 113e12216 pkt->dts 113e12216 33
st->cur_dts ffffffff13e12a86 pkt->pts ffffffff13e12216 pkt->dts
ffffffff13e12216

st->cur_dts ffffffff13e12a86 pkt->pts 8000000000000000 pkt->dts
8000000000000000
 33
st->cur_dts ffffffff13e132f6 pkt->pts ffffffff13e12a86 pkt->dts
ffffffff13e12a86

I hope this helps, but maybe Mans is right, I do send to pes streams to
ffmpeg, one video and one audio...

Bye,

Martin