RE: DSS2 Video Overlay Scaling Patch

Fischer Steven-P27614
2009-08-06T14:24:03Z

Tomi,

> -----Original Message-----
> From: Tomi Valkeinen [mailto:tomi.valkeinen@nokia.com]
> Sent: Thursday, August 06, 2009 8:38 AM
> To: Fischer Steven-P27614
> Cc: linux-omap@vger.kernel.org
> Subject: Re: DSS2 Video Overlay Scaling Patch
>
> Hi,
>
> ext Fischer Steven-P27614 wrote:
> > Tomi,
> >
> > I tried the patch you sent and after just a little testing
> I'm fairly
> > confident the change works just fine. Thanks.
> >
> > I couple of comments on the configure_overlay() function.
> Unless I'm
> > mis-understanding the code the overlay output rectangle is
> defined by
> > the local variable "x/y/outw/outh". I find it quite confusing that
> > there are separate "w" & "h" locals, since it makes it
> appear as if "x"
> > & "y" should be paired with "w" & "h" to make a rectangle. Further
> > more, I see "x" & "w" added together, which similarly makes them
> > appear to be part of the same rectangle. I would lightly suggest
> > changing the "x" & "y" locals to "outx" and "outy", just
> for clarity sake.
>
> I agree that it's confusing. Better naming making it clear
> what is used for input data and for output data would make it
> a bit clearer. Perhaps also use "inw" and "inh" to make it
> absolutely clear.
>

Yes, I would agree with that approach.

For now, I will use your patch as given and then wait for further
updates as they show up in your repo.

Thanks again,

Steve.

> >
> > Also, I wonder about the code that adds "x" & "w" or even "y" & "h".
> > Shouldn't that code be adding "x" & "outw" or "y" & "outh"? Again,
> > maybe I'm mis-understanding the code.
> >
>
> They are added only when w == outw, so it doesn't change the
> functionality. But you are again right, it's a bit confusing.
>
> I remember I was at some point trying to clean up this
> input/output confusion, but I think it wasn't too simple at
> some points. I'll have to look at it again at some point.
>
> Tomi
>
>
> > Steve.
> >
> > -----Original Message-----
> > From: Fischer Steven-P27614
> > Sent: Tuesday, August 04, 2009 5:22 PM
> > To: 'Tomi Valkeinen'
> > Cc: linux-omap@vger.kernel.org
> > Subject: RE: DSS2 Video Overlay Scaling Patch
> >
> > I'll try out your patch, hopefully tomorrow, and let you know.
> >
> > Thanks,
> >
> > Steve.
> >
> > -----Original Message-----
> > From: Tomi Valkeinen [mailto:tomi.valkeinen@nokia.com]
> > Sent: Tuesday, August 04, 2009 6:06 AM
> > To: Fischer Steven-P27614
> > Cc: linux-omap@vger.kernel.org
> > Subject: Re: DSS2 Video Overlay Scaling Patch
> >
> > Hi,
> >
> > ext Fischer Steven-P27614 wrote:
> >> Ugh, messed up morning, forgot the patch as well :(
> >>
> >> -----Original Message-----
> >> From: linux-omap-owner@vger.kernel.org
> >> [mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Fischer
> >> Steven-P27614
> >> Sent: Tuesday, July 07, 2009 8:05 AM
> >> To: linux-omap@vger.kernel.org
> >> Subject: RE: DSS2 Video Overlay Scaling Patch
> >>
> >> Sorry, missed the subject line.
> >>
> >> -----Original Message-----
> >> From: linux-omap-owner@vger.kernel.org
> >> [mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Fischer
> >> Steven-P27614
> >> Sent: Tuesday, July 07, 2009 7:54 AM
> >> To: linux-omap@vger.kernel.org
> >> Subject:
> >>
> >> All,
> >>
> >> The DSS2 code base seems to inadvertently prevent downscaling of
> >> video
> >
> >> overlay frames. Attached is my attempt at a patch to resolve this
> >> issue.
> >>
> >> As I gather from the code, there is an attempt to limit
> the overlay
> >> output frame size (x, y, outw, outh) to the managers
> updated window
> >> (mc->x, mc->y, mc->w, mc->h). The problem is that the input frame
> >> size (w & h) is being used to instead of the output frame
> size (outw,
> > outh).
> >> Due to this, when the input frame size is large than the
> output frame
> >> size, the input frame is being cropped, thus no downscaling occurs.
> >> My patch corrects this issue and also attempts to properly
> scale the
> >> input frame size if indeed the output frame is cropped.
> >>
> >> In my particular case, the output frame size is never
> cropped, so I
> >> have not explicitly tested these equations, but I believe they are
> >> mathematically correct.
> >>
> >> With this patch overlay downscaling is functional.
> >>
> >
> > It was indeed slightly broken. The code is there because we
> cannot use
> > partial update for scaled overlays, but we need to update the whole
> > overlay. Otherwise there could be visual errors on the screen.
> >
> > However, your patch didn't apply to my tree, and I think it can be
> > solved in slightly more clear way. If the overlay in question is
> > scaled, we don't even need to run that code. All we have to
> do is to
> > adjust x/y depending on the x/y of the update area.
> >
> > Here's a patch, can you check if it works for you?
> >
> > Tomi
> >
>
>