[mythtv] ffmpeg SWSCALE!

Bryan Mayland bmayland at leoninedev.com
Thu Aug 31 16:39:43 UTC 2006

Daniel Kristjansson wrote:
> Anyway, I wouldn't object to a good unsharp filter patch, even
> if I will personally never use it. The denoise3d filter has
> already been ported to mythtv. I would be interested in what
> kind of scaling the software scaler employs. If it's reasonable,
> I might implement the same filter in the hardware scaler. So
> they both look the same. This type of HW scaling would only be
> available on cards that supported the OpenGL 2.0 shading
> language, or the nVidia variant.
    In the experiments I was doing, I just plugged in some hard coded 
values into the videoout and filters system so the output was always a 
fixed size and a filter in the middle would resize (given a fixed size 
input as well) in software using a simple Lanczos 3-lobe windowed sinc 
scaler.  I was having a lot of problems getting the filter working 
though and had to backburner it as I got busy with other things in life. 

    Looking at the command line Richard Dale specified, -sws 9 is 
Lanczos (3 lobe default I believe) as well, although unless MythVideo 
adds -vf scale=... to the command line, -sws has no effect.

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