[MEncoder-users] Low res video playback in high res

[Reimar Döffinger]

On 23.03.2016, at 04:06, "Bill Crockett" <wsc4 at optusnet.com.au> wrote:
> 
>> Just wondering if it is possible to either re-encode or play back
>> a 1280x720 video in 1920x1080 resolution without losing sharpness, detail 
>> ...etc?
> 
> Sorry to have to say this, but it is impossible.  See for yourself:
> 
> mplayer -vf scale=1920:1080 your_video
> 
> It is like zooming in.  Quality goes out the window. 

There are better scaling windows (-sws) but if you consider that as quality going out the window probably nothing will make you happy...
Though if sharpness, detail, .. is the only concern you can use nearest-neighbour scaling.
It will not lose any, but it will likely look a bit strange and bad since every other line/column becomes twice as high/wide. Definitely no loss of sharpness or anything though.
As the scale factor is 1.5 it should be possible to do better by not just duplicating every other row/column but instead inserting the average.
But it will likely look more blurry even though it is not.