[FFmpeg-user] High Quality WEBM

Nicolas George george at nsup.org
Tue Dec 22 22:57:20 CET 2015

Le duodi 2 nivôse, an CCXXIV, jd1008 a écrit :
> So, would changing
> -vf 'scale=320:176,setdar=16/9,pad=320:180:0:2:000000'
> to
> -vf 'scale=1920:1080'
> be enough to get full HD resolution, or would that make the image lose
> clarity, definition and sharpness??

I am sure you realize we are not in Blade Runner, where you could ask the
computer to "enhance" an image and zoom to see a face in a tiny reflection
on a drinking glass. If someone's nose on the image is one pixel on the
320×176 version, it will become 6×6 pixels on the 1920×1080, but FFmpeg does
not know that it is a nose, nor what a nose should look like. It will just
take the color of the one pixel and fade it into the color of the
neighbouring pixels to avoid ugly staircase effects.

Unless you have a very good reason, upscaling a video before encoding it is
a bad idea.


  Nicolas George
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