How To: best way to rescale

[cehoyos at ag.or.at (Carl Eugen Hoyos)]

Ken Bass <daytooner <at> gmail.com> writes:

> I need to rescale several videos. What is the best way to do that without
> recoding the entire video, but maintaining quality?
> 
> I have tried "ffmpeg -i <src.xxx> -s WxH src_new.xxx"

You should really tell ffmpeg:
Either the (video-) bitrate it should use: -b 1M
Or the quality (this is usually not the recommended method, if you don't just
want maximum quality): -qscale 2

It makes sense to also specify the audio bitrate: -ab 128k

Please read ffmpeg's man page for more information!

Concerning your home theater system: Are you sure that the problem is the
resolution (and not the container or codec type)? I find it surprising that the
system does not just down-scale the video to the maximum resolution. (Does it
show very small videos without upscaling them?)

Carl Eugen