How do I pick settings to optimally re-encode video for reduced file size?

[bootyhound1]

I want reduce the file size of my porn collection by 25 to 50%. I am okay with video quality comparable to youtube. I don't care much for the audio quality as long as I can hear it. Please help me with the following:




1) Should I keep the original video format or change it to x264?


2) Should I keep the original bitrate or change it? To what?


3) Should I keep the original resolution or change it? To what?


4) How do I change the audio bitrate and sample rate so I can hear it, but reduce quality?

[poisondeathray]

Filesize = bitrate * running time

So if you wanted 50% size, reduce the combined bitrate of audio & video by 50%