Good evening and thank you very much to all for the answers!
Now I start to understand better, I didn’t know that the SIP server also
affected the audio CODECS possibilities. I don't know if Linphone SIP
free account supports Opus Wide, I hope yes.
I have initially thought to Linphone or Jami, the possibility to choose
the bandwidth of Linphone is very nice, but now it seems me from your
answers that a WebRCT based situation such as Jitsi could perhaps be the
best for music, I also saw that there is a service, currently in beta,
based on Jitsi and optimized for music: https://sirius.video/ I'm
curious to try it out.
Searching on the web I also read about a use of Jamulus, which however
requires the server Jack, for the audio together with a software like
Jitsi or similar for the video.
I have to do some tests, at this point I should perhaps start from Jitsi
or maybe from Sirius, which is already optimized for music, before
thinking about software on SIP protocol.
Thank you again and best regards,
Stephanie
Il 17/12/20 03:13, Stuart Elvish - STU Telecom Inc ha scritto:
Good afternoon Maciej and Ms. Cortelli,
I can only provide very basic additional comments but this post caught
my attention.
I use Zoom several times a week to attend religious meetings (which
includes pre-recorded video and music as well as live speech) and
noticed that Zoom typically offers a decent but not outstanding audio
codec (I remember the number 24 but can't remember if that was KHz or
Kbps). The information is available in the statistics panel during a
screen share. If the audio is live then the clarity is scaled up/down
and you can run into some very serious issues which would result in a
sound that is not at all acceptable for music. The scaling is dynamic;
it is based on the person's internet connection, what equipment they
have etc, etc (and which way the wind is blowing). Other factors such
as the load on Zoom's servers (which has nothing to do with you or
your student) seem to also affect the quality but that is an anecdotal
observation. To summarise; Zoom is not reliable enough in my opinion.
During a meeting use the statistics information to see what quality
the audio is being transmitted at.
Also, Zoom uses noise gates (minimum thresholds for opening the audio
channel), background noise suppression algorithms and a few other
fancy tricks which are great for selective switching of videos and
preventing audio feedback but not so good for music.
Linphone has the advantage that it can use high bandwidth/high quality
codecs (forced codecs, you can control it to a certain extent) as well
as do the other things Zoom is capable of (primarily being able to
push video along with the audio). You can connect microphones to the
tablet/laptop/phone and achieve a nice audio feed through Linphone.
But, however hard you try, I am not sure you will achieve a result as
good as recording the audio with software local to the student. All
codecs have frequency limitations (equivalent of high and low pass
filters) and whilst this is not a problem for voice, it may be an
issue for musical instruments especially those producing higher
pitched notes. And some codecs look like they're wide band but it can
depend on the configuration/setup of the system and endpoints as to
whether or not you can use the full wideband capability. The easiest
way I found to show it is
https://developer.mozilla.org/en-US/docs/Web/Media/Formats/Audio_codecs#Opus
<https://developer.mozilla.org/en-US/docs/Web/Media/Formats/Audio_codecs#Opus>
Another suggestion I would make is to look at WebRTC. This requires
more infrastructure but if lockdown doesn't end any time soon it might
be a good way of achieving a better result. I am not sure if you are
teaching as part of a school, as part of a group etc but there may be
someone who can give you better advice on WebRTC and if it will work
well with your situation. WebRTC also allows someone to connect to the
meeting via a web browser and that likely makes picking up the
microphone feed much easier.
Kind regards
Stuart
On Thu, 17 Dec 2020 at 11:29, Maciej Morycinski <morc...@gmail.com
<mailto:morc...@gmail.com>> wrote:
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 <tel:+17788200182>
morc...@gmail.com <mailto:morc...@gmail.com>
------------------------------------------------------------------------
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.
[...]
_______________________________________________
Linphone-users mailing list
Linphone-users@nongnu.org <mailto:Linphone-users@nongnu.org>
https://lists.nongnu.org/mailman/listinfo/linphone-users
<https://lists.nongnu.org/mailman/listinfo/linphone-users>
_______________________________________________
Linphone-users mailing list
Linphone-users@nongnu.org <mailto:Linphone-users@nongnu.org>
https://lists.nongnu.org/mailman/listinfo/linphone-users
<https://lists.nongnu.org/mailman/listinfo/linphone-users>
_______________________________________________
Linphone-users mailing list
Linphone-users@nongnu.org
https://lists.nongnu.org/mailman/listinfo/linphone-users
_______________________________________________
Linphone-users mailing list
Linphone-users@nongnu.org
https://lists.nongnu.org/mailman/listinfo/linphone-users