Re: [Linphone-users] - Linphone for music lessons

[Maciej Morycinski]

Dear Ms. Cortelli,

Your idea is wonderful, and maybe some company already created a product that would suit your needs exactly. It would certainly make sense to research that in professional music circles.

However, when it comes to using a SIP phone such as Linphone, it is probably the wrong tool for this particular job.

Issue #1 is with the codec. Despite your impression re Zoom, it is not possible at all to transfer sound across the Internet without using _some_ codec. Zoom certainly uses a default one.
If it is possible to select Opus Wide using Zoom, that might work for you. There are various codecs appropriate for different tasks, but most of them are unsuitable for music, as many are specifically
meant for speech only. Opus Wide is one of few exceptions.

This brings me to Issue #2: if the student is using a telephone, or Linphone, or anything that has a phone number assigned, then their telephone service provider could be only
allowing certain codecs. The codec that ends up being used is negotiated between your phone and your service provider, as well as between the student's phone, and their service provider,
and one of the codecs available on both ends is selected. So to make sure it works, both you and the student would have to have ONLY Opus Wide allowed in Linphone, and both service
providers would have to allow it on their system. Otherwise there would be translation, and sound quality would be lost.

Your student would need to have a high speed, low latency internet connection. If the connection is over a cellular network, then anything slower than LTE will not work properly,
due to high latency. If you use not only sound, but video as well, then the demands on the network throughput would be much higher than for sound only.

Bottom line is that I think using VOIP for music lessons MAY be possible using Zoom, but if Opus Wide is not available, a SIP system (Linphone + two service providers) will likely not work
to your satisfaction. It is still worth trying, but for business reasons, I would not see it as a commercially viable system.

If I had proper resources and a company, I would create custom software based on something like Network Audio System (NAS) but since I know nothing about it, I will leave it at that.

Maciej Morycinski
#204-5100 Capitol Dr
Burnaby, BC, Canada, V5B 4S7

+1-778-820-0182
morciej@gmail.com

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On 2020-12-16 2:28 p.m., Stéphanie Cortelli (mailing list) wrote:

> Hello,
>       
>       
>       I'm new to Linphone and would like to use it for music lessons,
>       where audio quality is very important.
>       
>       
>       [...]
>       
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