Making a 30 sec sample

Is it possible to make a 30 second sample of a file?
Let's say I input the start position in minutes and seconds and then have a script making a 30 second sample of the following 30 seconds of the mp3 file.

If a user upload blablabla.mp3
And then they input 1 minute 20 seconds

Then I would like the script to output blablabla_sample.mp3 with only the part between 1:20–1:50.

And I also tried to download the examples file that was mentioned in the file, but the link wasn't working.