v4l2src and dynamic image/jpeg

[Matteo Valdina]

Hi,

It is probably a basic question but I didn't find a good answer.

I'm trying to write a Bin that it is something like:

v4l2src ! capsfilter! vaapijpegdec ! srcpad

I would like to add and remove jpeg decoder if my target resolution requires image/jpeg or x-raw.
For example, I have some camera that provides image/jpeg and other that provide I420.

How can I approach this problem?

Should I configure the caps filter with image/jpeg and I420 and use a probe query_downstream/upstream to dynamically link/remove the jpegdec?

There is a simpler approach for that?

Best

Matteo

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[Nicolas Dufresne-5]

Le samedi 19 août 2017 à 22:39 -0500, Matteo Valdina a écrit :

> Hi,
> It is probably a basic question but I didn't find a good answer.
>
> I'm trying to write a Bin that it is something like:
>
> v4l2src ! capsfilter! vaapijpegdec ! srcpad
>
> I would like to add and remove jpeg decoder if my target resolution
> requires image/jpeg or x-raw.
> For example, I have some camera that provides image/jpeg and other
> that provide I420.
>
> How can I approach this problem?
>
> Should I configure the caps filter with image/jpeg and I420 and use a
> probe query_downstream/upstream to dynamically link/remove the
> jpegdec?

You could use decodebin, it will passthrough on raw caps. Something
like this will set the preference to jpeg:

gst-launch-1.0 -v v4l2src device=/dev/video1 ! "image/jpeg;video/x-raw" ! decodebin ! glimagesink

>
> There is a simpler approach for that?
>
> Best
> Matteo
> --
> “There are two ways of constructing a software design: One way is to
> make it so simple that there are obviously no deficiencies, and the
> other way is to make it so complicated that there are no obvious
> deficiencies. The first method is far more difficult.”
> - Tony Hoare
> _______________________________________________
> gstreamer-devel mailing list
> [hidden email]
> https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

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