Time stretching MP3 and other audio
Want to listen to that 8 hour audio book in 6 hours and not lose any details in the process?
I love Windows Media Player’s ability to speed up or slow down audio and video in real-time via its awesome Play Speed setting. This is commonly referred to as time stretching or changing tempo. If you listen to a lot of podcasts and audio books or watch a lot of instructional videos (like I do) this can save hours and hours in the long run.
The problem is that I like to listen to podcasts or audio books in the car, and I don’t have a fancy PC available to speed audio up in real-time. My Sansa e250 with Rockbox does lots of cool things, but alas it can’t speed up audio without the dreaded chipmunk effect.
I looked for a way to easily (and cheaply) time stretch my audio files, but mostly found a bunch of headaches. There are painful ways to do it with Audacity (open, apply filter, convert, save, etc.) and other audio editors. I think there’s a way to do it through WinAmp. There are also programs made to specifically convert audio like dbPoweramp, but I didn’t have much luck with that (and it’s not free).
My Solution
Here’s the best solution I’ve found so far (and I looked long and hard). It’s easy to setup and has worked super fantastically so far:
foobar2000 + SoundTouch DSP plug-in
1. Download and install foobar2000.
2. Download foo_dsp_soundtouch.dll from wherever you can find it (I got mine from here). This thing was a pain to find. You might also need the vc8 runtime files. They are included in the .NET runtime so might as well download and install that. Copy foo_dsp_soundtouch.dll to your foobar2000 components folder.
3. Drop an audio file (or a bunch of audio files) into foobar2000 (or use File -> Open). I’ll use an episode of the excellent Hanselminutes podcast as an example.
4. Choose a Convert option from the right-click context menu and set your encoding options (the ones in these pics work well for me).
5. Click OK and watch it churn out your sped up mp3(s).
Tips and Thoughts
I’ve been using 25% speed-up on audio books and informational podcasts and 12.5% on entertainment-related podcasts like Dawn and Drew. At 25% it’s easily listenable but you can really tell it’s sped up. At 12.5% you can really only tell if you listen to the original along side it. Also, I feel like I concentrate and pick up more (kind of a “flow” thing) when it is sped up.
Being able to drag and drop a bunch of files, right click once, and watch all the converted mp3s pop out is an amazing efficiency over some of the other methods I found.
So, let me know if you’ve found alternate solutions or can improve on this one (I haven’t tweaked many of the settings). And if you want to start looking forward to that hour-long drive to work in the morning, buy a cheap mp3 player and check some of these podcasts out.