[mythtv] Feasability of using software scalers in mythtv videoout

Isaac Richards ijr at case.edu
Thu May 11 00:55:05 UTC 2006

On Wednesday 10 May 2006 6:45 pm, Bryan Mayland wrote:
> I'm considering the feasibility is of replacing XV's hardware scaling to
> zoom video playback with what could be higher quality software scalers.
> My mythtv is hooked to a display with a native resolution of 720p.  I've
> spent some time experimenting with various methods of getting my
> recorded SD video (from a Hauppauge PVR card) onto this screen with the
> best quality possible.  I've tried running a 720p modeline and letting
> XV scale up as well as running a 480p modeline and letting the
> television scale up.  Both these aren't all that fantastic.  Tonight I
> sat down and juked with using a software scaler to resize the video.
> Here are some results, taken with a digital camera of the television (I
> found this easier than doing a framegrab, I hope that's ok).
> XV Resize
> http://capnbry.net/~bmayland/fi/pvr150/resizetest1_xv.jpg
> http://capnbry.net/~bmayland/fi/pvr150/resizetest2_xv.jpg
> Software Resize (Lanczos)
> http://capnbry.net/~bmayland/fi/pvr150/resizetest1_lanc.jpg
> http://capnbry.net/~bmayland/fi/pvr150/resizetest2_lanc.jpg
> Ignore the jpeg artifacts, the pngs were a meg each, but note how much
> better picture quality you can get with the software scaler.
> So if this were implemented as an option, would it be something that
> would be accepted into svn?  Also, other than increased CPU usage, what
> other advantages and disadvantages are there?  I know there is already
> zoom and filter support in videoout, but this would take that one step
> further I think.

Sure, that'd be accepted.  What video card are you using for output, btw?


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