[FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?

[Natalia Molinero Mingorance]

what do you mean by " Why is the output size important if you use -preset
ultrafast?  "

El mar, 14 mar 2023 a las 13:48, Bouke / edit 'B (<bouke at editb.nl>)
escribió:

> On 14 Mar 2023, at 13:07, Phil Rhodes via ffmpeg-user <
> ffmpeg-user at ffmpeg.org> wrote:
> >
> > Also, it depends what you mean by 50% of the resolution. If your
> original video is 100x100 pixels and you reduce it to 50x50, then you have
> half the resolution, but you only have one quarter the pixels.
>
> But, the image will still have a tree, a house and a dog.
> From what I have understood, the resolution in terms of pixels does not
> compute to output file size (Unless you work uncompressed of course.)
>
> > P
> >    On Tuesday, 14 March 2023 at 09:37:36 GMT, Natalia Molinero
> Mingorance <eng.nataliamolinero at gmail.com <mailto:
> eng.nataliamolinero at gmail.com>> wrote:
> >
> > I'm using this command:
> >
> > -y -r -i $inVideoUri -movflags faststart -c:v libx265 -s
> > $videoResolution -c:a copy -preset ultrafast  $outPutUri
>
> ///
> > some headers or metadata added during the process but I would like to
> know
> > how to estimate the final video size.
>
> Why is the output size important if you use -preset ultrafast?
>
> Bouke
>
>
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> To unsubscribe, visit link above, or email
> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>