Adjustable playback tempo with constant pitch

[phrvgi]

Started on: 2008-04-25
last update: 2008-04-25

Summary:

Adjust playback rate of a prerecorded TV program anywhere from half speed to double speed, with pitch-corrected audio. Very addicting feature once you try it. Open source code available.

Description:

Usually this feature is used to watch entire programs in about two-thirds the time, or skim it with audio in half the time. It is especially useful for programs with a lot of talking such as speeches and discussion panels, as well as documentaries. Even entertainment programs can be sped up a little, but you might not want to. Experience with this feature in MythTV has shown that just about any program can be sped up 15% to 20% without people noticing. It takes a few minutes of experience to get up to 50%, and then 70% faster and still comprehend everything people are saying. Slow speakers can still be understood at 100% faster.

MythTV (an open source PVR for Linux) has this feature and it works very well. However, the user interface for changing speeds is awkward: Press "A" and then use arrow keys to adjust speed in 5% increments. A better way to adjust would be to have dedicated buttons on the remote to speed up or slow down in 5% increments, so the feature is as easy to use as the volume control.

Once someone is used to this feature, it becomes a "must have" for any PVR to be considered. When deprived of it, watching any prerecorded program feels like a waste of time (not the watching part, but that it takes so long to get through it).

To see it in action just set up MythTV on a spare hard drive. I recommend googling "mythdora" or "mythbuntu" for easy, preconfigured setups. I would love to see this feature ported to a Windows-based PVR.