The poor developer's "Smart Speed"
AVAudioPlayer offers features for audio level metering:
/* metering */
open var isMeteringEnabled: Bool /* turns level metering on or off. default is off. */
open func updateMeters() /* call to refresh meter values */
open func peakPower(forChannel channelNumber: Int) -> Float /* returns peak power in decibels for a given channel */
open func averagePower(forChannel channelNumber: Int) -> Float /* returns average power in decibels for a given channel */And for adjusting playback, including:
open var rate: Float /* See enableRate. The playback rate for the sound. 1.0 is normal, 0.5 is half speed, 2.0 is double speed. */This code:
- turns metering on
- updates meters with a timer
- checks if there is currently silence playing using averagePower
- increases the playback rate 2x until the silence ends
I tested using episode 220 of ATP and Debug episode 49. In both cases the silences were noticeably reduced and, to my ear, sounded completely natural. I listened to the entire episode of Debug and it had shaved off a little over 3 minutes by the end.