[GEM-dev] Fwd: another videoDV4L bug

[Ivica Ico Bukvic]

> > IMHO, if you get swapped red and blue, then it's possible that it's
> > actually U and V that are swapped, so you should replace this by a
> > fromYUYV() or prepend fromYUYV() using a swapUV() and check whether the
> > output looks better than swapRedBlue().
> >
> > This is because 0.75*U = B-Y whereas 0.40*V = R-Y, and those two
> > constants differ, so confusing U and V and then swapping reds and blues
> > will cause reds to appear brighter and blues to appear dimmer, than if
> > just U and V were swapped.
> >
> 
> yes, you are basically right.
> nevertheless, it is still unclear to me, how to detect correctly whether
> to use YUYV or YVYU

Either way, it appears to me that a message should be added to address
idiosyncrasies of various hardware solutions. This way a user should be able
to address this within PD rather than tinkering with the source, especially
given that PD is already a programming language in and of itself.

Best wishes,

Ico