Slack Calls: Now with video • Hacker News Board

Re: Slack Calls: Now with video

#71

Post by calchris42 » Wed, Dec 14, 2016, 12:35 AM UTC

aluminussoma wrote: post #14

Has anyone else noticed how pristine the audio quality of a Slack call sounds? I wonder how they optimized it. My company's voip, and Lync, and Skype all fail to deliver the same kind of call quality. I've only noticed / admired better call quality when making a call within Cisco to another employee. I don't use video much but I hope they've done as good of a job as they did with audio.

Slack audio calling is using webRTC tech. On Chrome, you can check out statistics and configuration for how they set up the call by going to chrome://webrtc-internals

I checked, and it looks like they are using pretty standard webRTC settings. The audio is compressed with Opus codec. They look to be limiting the bitrate to 40 kbps. (I'm not sure, but I thought Chrome default limited the AVERAGE bitrate to 40 kbps, not the peak, so Slack might actually be imposing an even tighter limit here).

Opus does a pretty nice job and is full band. A lot of older VOIP tech used compression that severely limited the frequency response.

We've been working on a more conversational video conferencing service called Locus (inthelocus.com). There we do some processing on the audio stream to spatialize audio sources, and found audio quality improved up to bitrate of ~120 kbps. The compression difference was more noticeable when processing the stream vs. directly playing back.

Re: Slack Calls: Now with video

#72

Post by quicklyfrozen » Wed, Dec 14, 2016, 12:38 AM UTC

ts330 wrote: post #37

lovely. the sooner i can remove skype from my life the better. that said, why can't any of these phone systems deal with the use case of two people trying to call each other and then simply auto connect the two calls? why does one side have to drop the call and answer the other?

Because if you're calling someone you expect them to say hello. It's not that easy to explain to a user that the call they just placed was dropped and they're really now answering a call.

Re: Slack Calls: Now with video

#73

Post by fred_is_fred » Wed, Dec 14, 2016, 12:56 AM UTC

With video (again). Since they had it in 2014 and then yanked it out.

Re: Slack Calls: Now with video

#74

Post by taurath » Wed, Dec 14, 2016, 12:57 AM UTC

xeromal wrote: post #67

taurath wrote: post #66

Earlier quoted context omitted.

Their dropped packet handling is far far better than Skypes as well - in a dodgy wifi situation linq and skype are all but unusable while slack is crisp.

No hate towards you at all, but describing technical things as crisp drives me crazy. Can anyone enlighten me as to why that would bother my brain? Does a certain region use this or its usage widespread?

I'm not entirely certain - I use it to describe the opposite of "dull/distorted" sound, kind of a synonym of "fresh". I really have no idea where I picked it up, other than I grew up on the west coast.

Re: Slack Calls: Now with video

#75

Post by calchris42 » Wed, Dec 14, 2016, 1:02 AM UTC

joshmanders wrote: post #3

I hope screen sharing comes soon. They bought Screen Hero a while back, and said they were integrating it.

Slack calls are built on webRTC, and actually it isn't too bad adding screen sharing functionality with webRTC. I wrote a blog post on this recently. And actually, with the Screen Hero team on board, should be even way simpler for them.

https://medium.com/@chris_82106/implementing-webrtc-screen-s...

Re: Slack Calls: Now with video

#76

Post by Klathmon » Wed, Dec 14, 2016, 1:15 AM UTC

dbg31415 wrote: post #49

omouse wrote: post #39

bad enough that I can be reached after work via slack and get calls while I'm on a commute (which is never compensated for aside from general salary), it'll have video? also, this only works in Chrome and on mobile, which is really messed up considering that Firefox is also a bleeding edge browser.

Just set your Do Not Disturb hours... you won't get the calls. But I agree... more apps need to factor in if you are moving or not before placing calls or messages. I wish there was a way to say, "I only want music and maps when I drive..." on my phone and have it kill the connection and updates for everything else.

The new android-auto app for your phone can do exactly this.

It overlays a nice "car UI" that's much larger and easier to not only see but also hit while driving, and basically only has phone, maps, and music.

It hides all other notifications, it "silences" other sounds, and there's a setting to optionally run the app once you connect to a specific bluetooth device.

I'm pretty happy with it.

Re: Slack Calls: Now with video

#77

Post by brazzledazzle » Wed, Dec 14, 2016, 1:16 AM UTC

elliotlarson wrote: post #48

joshmanders wrote: post #3

I hope screen sharing comes soon. They bought Screen Hero a while back, and said they were integrating it.

Yeah, right?! I had the exact same thought when I saw this. Okay, video... that's cool. But, we've been waiting for the ScreenHero purchase to turn into Slack screen sharing for ages.

You probably already know but until they finish the integration you can sign up for a screenhero account from Slack. I'm not sure if you need a paid account or what tier you'd need but it's definitely available on ours.

Re: Slack Calls: Now with video

#78

Post by brazzledazzle » Wed, Dec 14, 2016, 1:20 AM UTC

jhgjklj wrote: post #57

joshmanders wrote: post #3

I hope screen sharing comes soon. They bought Screen Hero a while back, and said they were integrating it.

Exactly i came to comment the same thing. Lynx sucks. Takes a hell lot of time to reconnect. Can't believe the product is maintained by top developers.

I think you meant Lync and if so I agree wholeheartedly.

Re: Slack Calls: Now with video

#79

Post by Klathmon » Wed, Dec 14, 2016, 1:21 AM UTC

parent5446 wrote: post #68

Klathmon wrote: post #55

Earlier quoted context omitted.

This is the last thing we require before moving our team over from hangouts (which is the only thing we use even though we pay for the whole g-suite). Either a way to call-out, have external people call-in, or just allowing a connection of a 3rd party service (paid or otherwise) that lets us connect a phone line.

Why don't you just use normal Hangouts? G Suite isn't required.

We were using many of the gsuite features previously, and just over time moved off one by one.

Really we only have it now because it's nice to have support if needed, and having our work emails associated with the hangouts we do with people outside the company is nicer than everyone using their personal emails (with their personal profile pictures).

Re: Slack Calls: Now with video

#80

Post by nimchimpsky » Wed, Dec 14, 2016, 2:07 AM UTC

quicklyfrozen wrote: post #72

ts330 wrote: post #37

lovely. the sooner i can remove skype from my life the better. that said, why can't any of these phone systems deal with the use case of two people trying to call each other and then simply auto connect the two calls? why does one side have to drop the call and answer the other?

Because if you're calling someone you expect them to say hello. It's not that easy to explain to a user that the call they just placed was dropped and they're really now answering a call.

I doubt thats the actual reason.