[Libav-user] AVFrame pts and av_usleep funciton.

[Denis Gottardello]

Thanks for you reply.
So these lines of code:

int64_t pts= av_rescale(pAVFrame->pts, pAVCodecContextVideo->framerate.den, pAVCodecContextVideo->framerate.num);
printf("pts, %d\n", pts);

Should print the timestamp (as time_t) of each frame? Is the pts value calculated correctly?

In data lunedì 21 agosto 2023 11:15:06 CEST, Paul B Mahol ha scritto:
> On Mon, Aug 21, 2023 at 10:30 AM Denis Gottardello
> <info at denisgottardello.it>
> wrote:
> > In order to implement a sleep function and wait the right time to display
> > a frame I have written this code:
> > 
> > int framerate= pAVCodecContextVideo->framerate.num /
> > pAVCodecContextVideo->framerate.den;
> > 
> > if (previous!= 0) {
> > 
> >     av_usleep((pAVFrame->pts - previous) / framerate);
> > 
> > }
> > 
> > previous= pAVFrame->pts;
> > 
> > but the value passed to av_usleep() is wrong.
> > 
> > How have I to calculate it?
> 
> If you really want to do it that way you need to use floating point
> calculations, or use fixed point arithmetic (av_rescale*)
> to convert seconds to microseconds.
> 
> > Best regards.
> > 
> > 
> > --
> > 
> > +39.347.4070897
> > 
> > http://www.labcsp.com
> > 
> > http://www.denisgottardello.it
> > 
> > GMT+1
> > 
> > Skype: mrdebug
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-- 
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http://www.labcsp.com[1] 
http://www.denisgottardello.it[2] 
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--------
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[2] http://www.denisgottardello.it
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