Wrong colors on Raspberry Pi 4

[Peter Maersk-Moller]

As far as I remember the last time i looked GStreamer uses byte-order
convention for defining color models. In byte-order RGBA refers to Red
being byte-0, Blue being byte-1, Green being byte-2 and Alpha being byte-3.
Raspberry Pi programming documentation uses Word-order for color models.
For this reason byteorder RGBA is defined in Raspberry Pi programming
documentation as ABGR8888. Byte-order BGRA is in Raspberry Pi documentation
defined as ARGB8888.

This difference/confusion can be an explanation for the colour change if
one of the modules get it wrong although it does not explain if the exact
same version produces one result in Rasp3 and another in Rasp4 .... unless
Rasp4 has a different definition for its colour model or one of the modules
compiles different code for Rasp4 compared to Rasp3. I believe the
graphical API changed somewhat for Rasp4 so code may be different.

Regards
Peter MM

On Fri, Nov 15, 2019 at 3:51 PM moritz.vieli <moritz.vieli at gmail.com> wrote:

> Hi all
>
> I have a simple pipe on a Raspberry Pi 4:
> gst-launch-1.0 -v videotestsrc ! videoconvert ! glimagesink
>
> The image is supposed to look like this:
> <http://gstreamer-devel.966125.n4.nabble.com/file/t378671/testsrc.png>
>
> However, all colors are wrong and it looks like this:
> <
> http://gstreamer-devel.966125.n4.nabble.com/file/t378671/testsrc_wrong.png>
>
>
> As you can see, the colors should be white, yellow, blue, green, etc. but
> are white, blue, yellow, green, etc. If I play a video, all colors are
> wrong
> as well and a blue sky with clouds has lots of yellow and green in.
>
> Omxplayer works well, I therefore think it's a Gstreamer-specific problem
> and not related to the Raspberry or the HDMI connection.
>
> Everything works well on a Raspberry Pi 3.
>
> Does anyone have an idea, where the problem could be?
>
> Thanks a lot for your feedback and best,
> Moritz
>
>
>
> --
> Sent from: http://gstreamer-devel.966125.n4.nabble.com/
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