ffmpeg how do i know what audio rate to use?

Question

say i have something like this

ffmpeg -i video.avi -ar 22050 -ab 32 -f flv -s 320x240 video.flv 


-ar  (Audio sampling rate in Hz)
-ab  (Audio bit rate in kbit/s)

regarding the -ar and the -ab how do i know what rate to use? i got this ffmpeg command from a site somewhere and i was wondering how the person knew what values to put for the rates? do i have to understand audio in order to figure that out?

thanks

Answer 1

Probably 41000 for audio sampling rate and 128 for bit rate should be sufficient.

Check Wikipedia's sampling rate and audio bit rate articles for examples to see if those values are too high or too low for what you're trying to do.

Answer 2

I'm using -ar 22050 and -ab 48 for Avi and Mpeg video files. It works normally.