[FFmpeg-devel] [PATCHv3] avfilter/vf_framerate: always request input if no output is provided in request_frame

Nicolas George george at nsup.org
Wed Apr 12 22:58:07 EEST 2017

Le tridi 23 germinal, an CCXXV, Marton Balint a écrit :
> Note that the above code which I moved returns 0 if ff_request_frame returns
> AVERROR_EOF. As far as I see, this can only happen a few times, not
> infinitely, so I am not sure if this is an error or not, so I kept is as it
> was before.

There are exactly three acceptable behaviours for request_frame() and
all the functions it calls:

* it pushes a frame and returns 0;

* it issues a ff_request_frame() on the input and returns 0;

* it returns EOF or an error.

If the "few times" correspond to frames pushed, then it is ok.
Otherwise, it is not. lavfi will not activate filters saying "hey, you
told me last time you had nothing to do, but just in case I am taking
news". A filter should never do nothing.


  Nicolas George
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