[MEncoder-users] 720p to 480i

[Rich Felker]

On Fri, Jan 25, 2008 at 07:19:26AM -0700, Loren Merritt wrote:
> On Fri, 25 Jan 2008, RC wrote:
> > On Thu, 24 Jan 2008 20:58:13 -0800 Kevin Bailey wrote:
> >
> >> I need to convert a raw video file from 720p to 480i.
> >
> > Use tinterlace, and scale in interlaced-mode to get the proper
> > dimentions.
> 
> Scale first in progressive mode, then tinterlace.
> 
> Vertical scaling of interlaced video (even with an interlace-aware scaler) 
> always looks bad, because interlaced video is aliased, and aliased content 
> can't be interpolated well. The only good way to vertically scale 
> interlaced video is to deinterlace it first. And since in this case you 
> start out with progressive content, you can skip the deinterlace step.

You could always band-limit it to 120 cycles before interlacing to
avoid aliasing.. :)

Rich