[mythtv] How are deinterlacers approved?

[Michael Haas]

Hello list,

I was looking through the code to find out why I was getting

> Failed to approve 'opengldoubleratefieldorder' deinterlacer

messages, but I couldn't find the reason. Let me add a quick
clarification first: I'm running trunk with r14455 backported from
mythtv-vid, that's why I have Mark Kendalls new deinterlacer.

Anyways, my understanding of the code tells me that said message is
printed if ApproveDeintFilter() is false. Digging further, I found
VideoOutput::ApproveDeintFilter (which returns false if the name of the
filter contains bobdeint, opengl or doublerate) and
VideoOutputXv::ApproveDeintFilter. Being a mere user and not a coder, I
don't fully understand VideoOutputXv::ApproveDeintFilter (what does "vos
>= XVideo" do?). However, it still doesn't seem to be an explanation for
the "Failed to approve" message.

I was wondering if approval failed because my refrsh rate was too low,
but that case seems to be handled in NuppelVideoPlayer.cpp and it's not
called, as far as I see.

Can anyone, maybe Daniel, enlighten me? Keep in mind I'm not a coder at
all, so it's easy for me to mis-interpet what I see in the source, but I
wanna know the reason

Thanks,

Michael