[FFmpeg-user] scaling up without losing definition

[William Caulfield]

On Mon, Jul 17, 2017 at 11:10 PM, Cley Faye <cleyfaye at gmail.com> wrote:

> Le 18 juil. 2017 05:06, "JD" <jd1008 at gmail.com> a écrit :
>
> Can ffmpeg do that?
> Like from say 854x356 and transcode it to 1920x1080
> without losing high definition (i.e. no blurring as a
> result of transcoding to a larger display).
>
>
> Ffmpeg can do scaling using various algorithm, including the "simple"
> nearest neighbor that will upscale pixels nicely.
>
> There are two caveats on that however: first 1920x1080 is not a multiple of
> 854x356, meaning that you'll either have black bars, cropped parts, or
> imperfect scaling. Second, the actual video codec might mangle pixels
> because of compression, and cause blurriness and other artifacts.
>


Going back to my early Avisynth days, I recall that Bicubic or Lanczos was
recommended for scaling down and Bilinear was the recommendation for
scaling up. Not sure if that fits the current thinking.

https://ffmpeg.org/ffmpeg-scaler.html


> _______________________________________________
>


*William Caulfield *| *ContentBridge Systems*
Product Manager, Digital Media & Systems | www.contentbridge.tv