[oe] Question about RDEPENDS and RRECOMMENDS

[Carlos Rafael Giani]

Hello,

I am updating the gstreamer1.0-plugins-imx recipe from meta-fsl-arm, and 
want to improve one aspect of it.
This recipe produces several packages. Among them are an audio and a 
video decoder plugin for GStreamer. In order to use the audio decoder at 
runtime, the "audioparsers" package from the gstreamer1.0-plugins-good 
recipe is required. Likewise, the video decoder needs video parsers from 
the gstreamer1.0-plugins-bad-videoparsersbad package.
It is possible to install gstreamer1.0-plugins-imx packages without 
these other packages. However, GStreamer will then be unable to 
automatically use these decoders.

So, it would make sense to establish some sort of dependency. But how 
exactly? I thought of something like this:

   RDEPENDS_gstreamer1.0-plugins-imx-imxaudio = 
"gstreamer1.0-plugins-good-audioparsers"
   RDEPENDS_gstreamer1.0-plugins-imx-imxvpu = 
"gstreamer1.0-plugins-bad-videoparsersbad"

but then I also need to add gstreamer1.0-plugins-good and 
gstreamer1.0-plugins-bad to the DEPENDS list, otherwise I get a warning 
like:

   QA Issue: gstreamer1.0-plugins-imx-imxaudio rdepends on 
gstreamer1.0-plugins-good-audioparsers, but it isn't a build dependency? 
[build-deps]

But if I add these recipes to the DEPENDS variable, then the RDEPENDS 
spec is pointless, isn't it?
Another option would be to use RRECOMMENDS instead of RDEPENDS, but I am 
not sure if this is such a good idea.

Any thoughts?