Resize MP4 video with ffmpeg and keeping aspect ratio?

[pxstein]

I want to resize a video to MP4 and H.264 codec.

I want to specify only the target width but let ffmpeg keep the existing aspect ration....and automatically calculate the appropriate height

Therefore I found two possible parameters:

.... -s 1440x1080 ....

or

... -vf scale=1680:-2 ....

Whats the difference between scale and -s parameter?

Can I use the "1680:-2" value with the -s parameter and vice versa:

.... -s 1680:-2

?

[ProWo]

https://trac.ffmpeg.org/wiki/Scaling