# Nextcloud Talk
**Video- & audio-conferencing app for Nextcloud**
## Why is this so awesome?
* π¬ **Chat integration!** Nextcloud Talk comes with a simple text chat. Allowing you to share files from your Nextcloud and mentioning other participants.
* π₯ **Private, group, public and password protected calls!** Just invite somebody, a whole group or send a public link to invite to a call.
* π» **Screen sharing!** Share your screen with participants of your call. You just need to use Firefox version 52 (or newer), latest Edge or Chrome 49 (or newer) with this [Chrome extension](https://chrome.google.com/webstore/detail/screensharing-for-nextclo/kepnpjhambipllfmgmbapncekcmabkol).
* π **Integration with other Nextcloud apps** like Files, Contacts and Deck. More to come.
* π **Weβre not reinventing the wheel!** Based on the great [simpleWebRTC](https://simplewebrtc.com/) library.
And in the works for the [coming versions](https://github.com/nextcloud/spreed/milestones/):
* π [Federated calls](https://github.com/nextcloud/spreed/issues/21), to call people on other Nextclouds
If you have suggestions or problems, please [open an issue](https://github.com/nextcloud/spreed/issues) or contribute directly :)
### Supported Browsers
| Browser | Compatible |
|---|---|
| Firefox | βοΈ 52 or later |
| Chrome/Chromium | βοΈ 49 or later |
| Edge | β οΈ latest versions
π€ Speakers are not promoted
π· Name changes while a call is on-going are not reflected |
| Safari | β οΈ 12 or later
β No screensharing support
π₯ Viewing screens of others works |
## Installing for Production
Nextcloud Talk is really easy to install. You just need to enable the app from the [Nextcloud App Store](https://apps.nextcloud.com/apps/spreed) and everything will work out of the box.
There are some scenarios (users behind strict firewalls / symmetric NATs) where a TURN server is needed. That's a bit more tricky to install. You can [find instructions in our documentation](https://nextcloud-talk.readthedocs.io/en/latest/TURN/) and the team behind the Nextcloud VM has developed a script which takes care of everything for you ([vm-talk.sh](https://github.com/nextcloud/vm/blob/master/apps/talk.sh)). The script is tested on Ubuntu Server 18.04, but should work on 16.04 as well. Please keep in mind that it's developed for the VM specifically and any issues should be reported in that repo, not here.
Here's a short [video](https://youtu.be/KdTsWIy4eN0) on how it's done.
## Scalability
Talk works peer to peer, that is, each participant sends an end-to-end encrypted stream to each other participant and receives one stream per other participant. This grows bandwidth usage with the number of participants. As most users are on an asymetric local internet connection, the sending bandwidth often becomes the bottleneck. A typical Nextcloud Talk instance can handle a few dozen calls, but each call can have only 6-10 participants depending on the participants' bandwidth.
To limit bandwidth usage, participants can keep video disabled. Once a video stream is enabled it can currently not be disabled, even a muted or disabled video stream is being send out. This is due to the technical implementation details of WebRTC which is used by Talk. However, Talk remembers the state of audio and video. This means that disabling video, leaving the call and joining again will drop the bandwidth use to audio only (about 50 kbit/sec). This is about 1/20th of the bandwidth of video (1 mbit/sec), so when all participants are on a fast network, a call with 20 people without video could be doable.
Such a call does create a high load on the members' browsers and on the server as it handles signaling. This, for example, has consequences also for the devices that support calls. Mobile device browsers will sooner run out of compute capacity and cause issues to the call. While we continously work to optimize Talk for performance, there is still work to be done so it is not unlikely that the bottleneck will be there for the time being. We very much welcome help in optimization of calls!
### How to have the maximum number of participants in a call
To make sure a call can sustain the largest number of participants, make sure that:
* each participant has a fast upload and download
* each participant has a fast enough system (desktop/laptop browser, mobile device browsers will not do) or uses the Android/iOS app. Best use a desktop browser like Firefox or Chrome. The WebRTC implementation in other browsers is often sub-par.
* each participant has video disabled **from the start** - that means, if video is on when you start the call, disable it, exit the call and join again to ensure you are not sending 1 mbit/sec of blank screen
With this setup, 20 users is usually doable. Feedback on this is welcome!
### Scaling beyond 5-20 users in a call
Nextcloud offers a partner product, the Talk High Performance Back-end, which deals with this scalability issue by including a Selective Forwarding Unit (SFU). Each participant sends one stream to the SFU which distributes it under the participants. This typically scales to 30-50 or even more active participants. Further more, the HPB setup also allows calls with hundreds of passive participants. With this number of participants is only limited by the bandwidth of the SFU setup. This is ideal for one-to-many streaming like webinars or remote teaching lessons.
The HPB also takes care of signaling, decreasing the load of many calls on the Talk server and optional SIP integration so users can dial in to calls by phone.
If you need to use Talk in an enterprise environment, [contact our sales team](https://nextcloud.com/enterprise/buy/) for access to the high performance back-end. See our website for more details and [pricing](https://nextcloud.com/talk/#scalability).
## Development setup
1. Simply clone this repository into the `apps` folder of your Nextcloud development instance.
2. Run `make dev-setup` to install the dependencies;
3. Run `make build-js`
4. Then activate it through the apps management. :tada:
5. To build the docs locally, install mkdocs locally: `apt install mkdocs mkdocs-bootstrap`
We are also available on [our public Talk team conversation](https://cloud.nextcloud.com/call/c7fz9qpr), if you want to join the discussion.
### API documentation
The API documentation is available at https://nextcloud-talk.readthedocs.io/en/latest/
### Milestones and Branches
#### Branches
In the Talk app we have one branch per Nextcloud server version. stable* branches of the app should always work with the same branch of the Nextcloud server.
This is only off close to releases of the server, to allow easier finishing of features, so we don't have to backport them.
#### Milestones
* 5.0.0 - **Numeric** milestones are settled and waiting for their release or some final polishing
* π Next Minor (15) - The **next minor** milestone is for issues/PR that go into the next Dot-Release for the given Nextcloud version (in the example 15 - e.g. 5.0.1)
* π Next Major - The **next major** milestone is for issues/PR that go into the next feature release for the new Major Nextcloud version (as there are Minors for 15, this would be 16)
* π Following Major - The **following major** milestone is for issues/PR that should be worked towards/on but didn't make it into the next major due to timing constraints
* π Backlog - The **backlog** milestone is assigned to all remaining issues
You can always pick a task of any of the milestones and we will help you to get it into the assigned milestone or also an earlier one if time permits. It's just a matter of having an overview and better visibility what we think should be worked on, but it's not exclusive.
### Useful tricks for testing
* Disable camera until reboot: `sudo modprobe -r uvcvideo`
* Re-enable camera: `sudo modprobe uvcvideo`
* Send fake-stream (audio and video) in firefox:
1. Open `about:config`
2. Search for `fake`
3. Toggle `media.navigator.streams.fake` to **true**
## Contribution Guidelines
For more information please see the [guidelines for contributing](https://github.com/nextcloud/spreed/blob/master/.github/contributing.md) to this repository.