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I know effectively nothing about these topics but I recall having that thought the other day. With Apple users FaceTime audio has far higher audio quality than
by nyarlathotep_ 2y ago
I know effectively nothing about these topics but I recall having that thought the other day.
With Apple users FaceTime audio has far higher audio quality than a "typical" phone call
Wondering what accounts for the difference. I assumed, if anything, audio compression would be more "aggressive" on web-service based calling than "traditional" calling.
- theandrewbailey 2y agoApple knows which devices Facetime will run on. Traditional calls need to run on old embedded infrastructure that barely has 2 bits to rub together.
- giantrobot 2y agoFaceTime's audio quality is both higher data rate and better audio codecs. FaceTime uses AAC audio and samples at close to the full audible audio band. It also uses a relatively high data rate compared to typical voice calls. LTE and 5G has the option of higher quality voice codecs (EVS) than older cellular networks when using VoLTE or VoNR. They support wider band sampling and higher data rates for better quality audio. Why most voice calls sound bad is inter-carrier compatibility still sucks. Typically calls will downgrade to AMR-WB or AMR-NB (8KHz and 4kHz sampling respectively). FaceTime calls, or any other pure IP voice services, don't need to downgrade codecs to interoperate. They might have to change encoded bitrates based on network conditions but never go with some lowest common denominator codec because another user is on a different network.
- nyarlathotep_ 2y agoAwesome, thanks for this. Where can I learn about these topics?