With the latest iOS 12.2 beta, Apple has improved the quality of the audio messages sent in the Messages app. While previously audio messages sent in iMessage were recorded using AMR codec at 8000 Hz, they are now recorded using the Opus codec at 24000 Hz.
While audio files recorded using the AMR codec have an .amr extension at the end, the ones recorded using Opus have a .caf extension.
The change leads to a considerable improvement in audio quality, though this is also accompanied by an increase in the audio file size. Most users are unlikely to be bothered by this change as the Messages app automatically deletes all audio files a few minutes after they are sent. Plus, more users are going to value the improved audio quality more.
The Opus codec is already used by the likes of WhatsApp, Telegram, and in WebRTC for recording audio messages. So, it was Apple that has taken its time to make the switch here.
wow: on iOS 12.2 beta 5 finally voice messages on #iMessage seems to be fixed: they sound crystal clear now 😍
I’ve quickly analyzed the voice files (new codec!):
Previously: AMR Codec @ 8000 Hz Sample Rate
iOS 12.2 beta 5: Opus Codec @ 24000 Hz pic.twitter.com/OMxTLBmrj5
— frederik Riedel (@frederikRiedel) March 13, 2019
The difference in quality is pretty remarkable as audible from the media embedded in the tweet below.
Here's the direct comparison: what a difference! pic.twitter.com/8n2wQGZTJl
— frederik riedel (eating tacos) (@frederikRiedel) March 13, 2019
Improved audio messages quality is just one of the many changes that Apple is going to introduce with iOS 12.2. Other changes that are a part of iOS 12.2 include a new AirPlay system icon, new Animoji, HomeKit TV controls, and more.