Hi again!

after hours playing with our new toy, I seem to find audio quality quite poor in vMixCall. So far, I noticed that best bitrate for audio was around 64kbits (variable from 60 to 70ish and could be around 32kbps from a c920 thru webpage) and never produced a clear sound even when streaming an excellent source from vMix to vMix.

Maybe you guys did have better results... I'd like to hear from you on this point.

Based on my experience, I believe that audio is more important than video in a point to point transmission with remote guests. I did a lot of events with Skype calls and so far when the audio is good (even if the video is crappy) my customers are happy and we can cope with it sometimes only having audio on air with a simple picture of the guest. But if image is great and not audio, then there's no way to use the feed and usually my customers decide to shorten or cancel the guest appearance (and they're not happy).

So the request would be to increase audio bitrates a little, maybe up to 96 or 128kbps when the connection is really good but especially also when the bandwidth is limited and to give priority to audio over video, so that the sound is always as good as possible in any situation.

Thank you
Guillaume

Thanks for this technical feedback Martin...

I guess the only solution is to try to improve audio quality by processing with external equipments/softwares then. It's always very challenging because in general remote guests don't use professional mikes. The difference we had this morning with your DPA and guests laptop mikes was huge.

I don't think EC is an issue here as vMix does the mix minus. Besides I was disappointed by audio in a vMix to vMix situation where no browser is involved at all and no cheap microphone either : vMix 1 was capturing FullHD digital TV and sending it to vMix 2 thru vMixCall.

I could easily record both sides to compare but I fully agree and understand that vMixCall main interest is not here. I wished it could be used not only for remote guests but also for point to point transmissions where quality really matters.

Thanks for the explanation.

I'm very familiar with video conferencing quality and also VoiP/IPBX (I use Asterisk for nearly 15 years), so I'm not surprised by telephony audio codecs quality like G723, G729, GSM or uLaw/aLaw. I don't find Opus really better especially when used with cheap mikes. But I understand that AEC is a cause of quality reduction.

I was expecting/hoping that WebRTC integration into vMix would push audio quality to a broadcast level (or closer at least). And I really don't mind using more bandwidth to get a clearer sound 'cos I do hear a difference between a 64kbits or a 128kbps audio stream. I won't use vMixCall for chatting with my friends but to produce broadcast quality videos.

I understand the limitations. I'm a little disappointed that's all...

See below for some test results for Opus performance:

http://wiki.hydrogenaud....Opus#Bitrate_performance

Speech is "essentially transparent" around 32-40kbps.

The new, completely rewritten AEC for Chrome is known as AEC3 and planned for initial release in Chrome 58. This is purportedly not feature complete, but still better than the existing approach.

Because it's an entirely new AEC developers must stipulate its use in their apps. That is, they must enable AEC3 explicitly.

Yep! That's my point exactly. 1080p at 8/10Mbits with 128kbits audio would be perfect for this.

Agreed. I noticed today while having a guest on, sometimes their audio sounded a little crunchy/digital when they began to speak.

Is there a chance to put this request back on the list?

Besides streaming live I´m using vMix and especially vMixCall for 1:1 trainingsessions with students showing and listenning to recordings in my DAW (digital audio workstation). ATM vMixCall has a better sound quality than skype, teamspeak, and all the others, but it would be great to have the option to increase the bitrate to 192 or even better 256 kbit. This would also be great for my livestreaming-sessions on youtube.

So please, put it back on the list for your next update :-)