Deinterlace element and "fields=bottom" causes framerate to disappear (0/1)

[Graham Leggett]

On 10 Oct 2015, at 2:04 PM, Graham Leggett <minfrin at sharp.fm> wrote:

> I have the deinterlace element within a pipeline, and have noticed that when "fields=bottom” is added to the deinterlace element the framerate of the rest of the pipeline disappears and becomes 0/1.
> 
> Take the "fields=bottom” out again, and the framerate returns to 25/1.
> 
> Is this a bug or expected behaviour?

I have noticed that the same behaviour happens with a number of other combinations, it appears the libavdeinterlaceav, yadif and deinterlace all destroy the framerate, as does omxmpeg2videodec.

The avdec_mpeg2video element seems to preserve the framerate correctly, but I don’t understand the internals well enough yet to understand why a framerate might be destroyed by an element (hardcoded to 0/1).

Can anyone confirm where I should be looking for the problem?

Regards,
Graham
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