• Thanks: 33

Topic: Does SVP's downscaling override madVR's downscaling?

SVP has an option where it downscales 1080p content to fit the screen resolution to make processing easier.

Does that mean madVR's advanced downscaling algorithm isn't being used at all and we're only getting basic bilinear downscaling?

If that's the case, that would be another good reason to only increase frame rate after madVR is done.

  • MAG79
  • SVP developer
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Re: Does SVP's downscaling override madVR's downscaling?

Mystery
SVP performs downscaling before madVR. It uses Avisynth function BicubicResize([new width], [new height], b=0, c=0.75)
Downscale is performed before SVPFlow libraries work. It is needed to reduce CPU load.

  • Thanks: 33

Re: Does SVP's downscaling override madVR's downscaling?

Ok... in any way, I want my setup to work on both 768p display and 1080p display (where there would be no downscaling to reduce CPU load).

So in this case, I might be better off disabling the resize option so that madVR can do its job properly. And then see what quality difference I get.

One feature request for SVP: it builds profiles based on video types, but it would also be good if could make different profiles depending on the output type (768p or 1080p)

  • Thanks: 33

Re: Does SVP's downscaling override madVR's downscaling?

OK... after testing, my system cannot run SVP in 1080p + Catmull downscaling to 768p

So I just have to forget about Catmull downscaling.

Now that I'm looking at it, Catmull-Rom is too demanding for my computer in any cases. Without Anti-Ringing and without SVP, it has a rendering time of 16.8 which is slightly too high.

  • Thanks: 33

Re: Does SVP's downscaling override madVR's downscaling?

The videos that causes issues are generally 1080p 29.97fps.

One option is to create a new profile for those to make sure it uses a 2:1 ratio.

Or another option would be to disable SVP in this profile as 29.97 could be considered smooth enough and madVR would then do a better job.

For now I'll probably leave it to 2:1, and if I run into further issues with those videos, I might consider Plan B

  • Thanks: 33

Re: Does SVP's downscaling override madVR's downscaling?

mmm the "Decrease frame size" is actually doing one thing right: it is doing the resize BEFORE applying SVP which saves processing power and allows for higher quality processing.

You mentioned that ffdshow had options for applying rendering filters (madVR) before doing the other processing. If doing madVR resizing could be added to the Decrease Frame Size option list, that would be bad ass.

Re: Does SVP's downscaling override madVR's downscaling?

I really not sure madVR's HQ processing is really needed for downscaling. Plain old bicubic resize is just good enough for it.

8 Reply by Nintendo Maniac 64 (edited by Nintendo Maniac 64 30-01-2015 07:56:36)

Re: Does SVP's downscaling override madVR's downscaling?

MAG79 wrote:

MysteryIt uses Avisynth function BicubicResize([new width], [new height], b=0, c=0.75)

Is there a way to modify the value bolded?  As you may be aware, MPC-HC also gives the options for 0.60 and 1.00.

  • MAG79
  • SVP developer
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Re: Does SVP's downscaling override madVR's downscaling?

Nintendo Maniac 64
Yes. You can customize it yourself.
You can find it and change in generate.js. See this block there:

//downsize
    if(    mediaInfo.main.reswidth>mediaInfo.main.cbhwidth ||
        mediaInfo.main.resheight>mediaInfo.main.cbhheight)
        resizeString="BicubicResize("+mediaInfo.main.reswidth+", "+mediaInfo.main.resheight+", b=0, c=0.75)";