[HN Gopher] Show HN: Learn how WebRTC actually works. A book on ...
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Show HN: Learn how WebRTC actually works. A book on the protocols,
not just APIs
Author : Sean-Der
Score : 316 points
Date : 2020-08-30 15:43 UTC (7 hours ago)
(HTM) web link (webrtcforthecurious.com)
(TXT) w3m dump (webrtcforthecurious.com)
| Sean-Der wrote:
| Hey HN! This is a book I am working on to help de-mystify WebRTC.
| It is wonderful technology, but many find it hard to understand.
| Especially if you don't have a telephony background. Before this
| I worked on https://github.com/pion/webrtc and
| https://github.com/awslabs/amazon-kinesis-video-streams-webr...
|
| I wanted to share all my knowledge from working on these.
|
| ------
|
| Come learn about the WebRTC specification and how all the
| protocols work in depth, not just a tour of the APIs. The book is
| completely Open Source and available at
| https://github.com/webrtc-for-the-curious/webrtc-for-the-cur...
|
| Learn the full details of ICE, SCTP, DTLS, SRTP, and how they
| work together to make up the WebRTC stack.
|
| Hear how WebRTC implementers debug issues with the tools of the
| trade.
|
| Listen to interviews with the authors of foundational WebRTC
| tech! Hear the motivations and design details that pre-dated
| WebRTC by 20 years.
|
| Explore the cutting edge of what people are building with WebRTC.
| Learn about interesting use cases and how real-world applications
| get designed, tested and implemented in production.
|
| Written by developers who have written all of this from scratch.
| We learned it the hard way, now we want to share it with you!
|
| This book is vendor agnostic and multiple Open Source projects
| and companies are involved. We would love to have you involved!
|
| reply
| the-dude wrote:
| Hi Sean,
|
| I remember your username from earlier posts, IIRC also quality
| content about WebRTC or similar ( implementation? )
|
| I am not a writer, but did get some extended language
| education, and I suggest you get rid of most exclamation marks
| in your texts.
|
| It makes the reading ... boring might the wrong word ( not a
| native speaker ).
|
| Good luck and many thanks for your contributions.
| Sean-Der wrote:
| Thanks for the feedback. I agree.
|
| When talking to people I really want to emote. I am self
| conscious that people will think I am not interested/excited
| in the conversation. Through most of my life
| 'programming/tech' was something that I cared about. I never
| had any friends/family that cared though. When I became an
| adult and started working it felt like a re-birth of sorts :)
|
| I just don't ever want anyone else to feel like I am not
| interested/excited. I will try dropping the exclamation
| points, and I hope that my enthusiasm still comes through.
| the-dude wrote:
| Just to be clear : I am talking about the book, not your HN
| comment ( for example at
| https://webrtcforthecurious.com/docs/01-what-why-and-how/
| there are multiple examples )
| ficklepickle wrote:
| Wow, me too! And I also use lots of exclamation marks when
| I write! You explained it better than I could have. Glad
| I'm not the only one.
| lowercased wrote:
| My suggestion would be to throw in related illustrative
| real world anecdotes that drive a point home (personal
| experiences of real world impact of the tech or the
| architecture decisions, for example) instead of exclamation
| marks. That conveys the 'interested' part, and shows you
| can demonstrate real world connections to stuff that might
| otherwise be dry and academic. But it doesn't use
| exclamation marks! ;)
| jbaudanza wrote:
| This is great! I just spent the weekend researching WebRTC for a
| language learning project I'm working on. I have a few questions
| about SFUs. Maybe someone here can help.
|
| 1. SFUs seem to be the clear winner for multi-party calls. Do
| they provide any advantage for 1-on-1 calls over peer'd
| connections? It seems like using an SFU in this case would double
| the number of connections, and hence double the connection
| issues.
|
| 2. Do clients communicate with SFUs by establishing a normal
| RTCPeerConnection like they would with another peer? Or is there
| some other video sharing protocol for SFUs that I don't know
| about?
| kodablah wrote:
| 1. Not as much benefit for 1-on-1 except that you can guarantee
| connectivity without a STUN server, can get a bit more
| predictable network paths from client to server than client to
| client, and can abstract choosing the best simulcasted stream
| quality. It won't double the connection count, but it can make
| you upload unnecessary streams in the case of simulcast,
| because the client won't be the one determining which stream
| quality is best, it'll just send multiple.
|
| 2. Yup, SFU acts like another client. Some libs do one
| connection for up and one for down or other ways to handle
| stream multiplexing, but overall it's the same WebRTC peer
| connections.
| jbaudanza wrote:
| Thank you! This is very helpful! We are doing mostly 1-on-1
| calls, so I'm considering if peered connections would be
| better. They're certainly cheaper. I hadn't considering
| simulcasting multiple quality streams. That's something to
| think about.
|
| By "doubling connection count" I mean CLIENT <-> SFU <->
| CLIENT is twice as many as CLIENT <-> CLIENT.
| j1elo wrote:
| Some do peer to peer for 1:1, then upgrade to actually
| using the SFU for more participants. But that's a challenge
| on its own, so when more than 1:1 is expected, you might
| just prefer to use SFU from the start, and save the hassle
| for when to switch between those two models
| nottorp wrote:
| Any hints on getting the browser makers to enable us to _disable_
| it?
|
| I gave up on Chrome because it was preventing my mac from
| sleeping because "webRTC has active peer connections". Before de
| mistifying its inner workings, you may want to address why we'd
| want it and why it messes with power management.
| stjohnswarts wrote:
| You'll never get that. You'll just have to opt out of it. i
| think there is an extension or two to turn it off in chrome.
| Maybe that will fix your problem? Also I think there is just a
| bool to turn off in firefox as well.
| redmattred wrote:
| I would imagine contacting the browser makers could be a good
| start
| nottorp wrote:
| Google? I don't think I could get this topic to the top of HN
| and I don't know anyone high in the food chain at Google.
| So... that wouldn't work.
| ptsneves wrote:
| I made a live drone broadcasting platform called drohub at
| https://drohub.xyz based on webrtc. Webrtc is hard indeed even
| with the help of Janus gateway. Will definetly have a read, as I
| still consider myself a noob on it. Hope you get good feedback.
| PaulBGD_ wrote:
| Sean is amazing and has great expertise with webrtc, excited to
| read this :)
| frequentnapper wrote:
| Hi, thanks for this and making it freely available. just
| wondering why you chose the license to waive all attribution as
| well?
| Sean-Der wrote:
| I don't want to make the book (or my other projects) to be
| about me. Some developers use their Open Source projects to
| further their celebrity. Then no one else wants to contribute,
| why just help someones vanity project. The projects languish
| and die out.
|
| So I try not to put my name on things, and license liberally.
| My hope is that Pion and 'WebRTC for the Curious' will generate
| more of a community.
| j1elo wrote:
| Your stance is very nice and good intended, but I don't think
| being attributed your work should be a problem at all in
| forming a good community. IMHO the ingredients are not
| necessarily extreme humbleness and having the most liberal
| licensing, instead actually _good_ contents and just basic
| politeness / not thinking of oneself as a superior being,
| should be enough.
|
| Probably something like the GNU Free Documentation License
| [1] could have been also perfectly fine. It would also
| prevent some shark from waiting until the text is complete
| and polished and then take the work of authors and
| contributors and sell it while passing it as their own. And
| that's quite a nice feature in my book (pun intended)
|
| Whatever, I like the idea of making this the best possible
| resource for all things WebRTC :-)
|
| [1]:
| https://en.wikipedia.org/wiki/GNU_Free_Documentation_License
| nerdbaggy wrote:
| This is fantastic!!! Really well done.
| Sean-Der wrote:
| Thanks! Hopefully you learned something. If you have any ideas
| on how to make it better would love to hear :)
| atum47 wrote:
| I was fiddling with webrtc last week and I end up creating a very
| simplistic video chat. I was amazed on how easy it is to
| implement that kind of stuff. server (signaling) and client
| didn't took more than a few hundred lines of JS code.
|
| I was determined to make a real app out of it, but everything I
| could think of, there were already other people doing similar
| stuff.
|
| But its a nice piece of tech WebRTC, really impressed me.
|
| here's my video chat in action:
| https://www.youtube.com/watch?v=YbQsQqbt70g (no audio cause I was
| using it to capture me speaking for the video recording)
| kodablah wrote:
| I strongly suggest, for your next step up as a JS person, to
| take a peek at mediasoup.org. P2P has obvious scalability
| limitations. That lib not only makes server side forwarding
| easy (once you read example code), but it abstracts a lot of
| real-world needed WebRTC features such as simulcast and
| bandwidth estimation. You'll be making high quality Zoom-like
| pages in no time (beware though, the dev community ain't great
| for that lib because at least one of the authors comes off
| quite rude in the forums).
|
| Also I'd be remiss to not point out the OP's own pion Go libs
| which do similar on the server side.
| atum47 wrote:
| I'll check it out. thanks for the suggestion.
| ipnon wrote:
| I suspect we will see a deluge of video chat apps in the near
| future. They will be similar to the wave of chat apps that
| appeared around 2015. I hope that the technology will mature
| soon. The current state of video communication seems
| improvable.
| atum47 wrote:
| well, I thought about doing a video chat over some game play,
| so two friends could play a match of anything while having a
| video conversation, next day some one posted something
| similar here on HN.
|
| I then thought about drawing on top of the video stream so
| you can use as like one os those games where you have to
| guess what the other people is drawing or, to coach someone
| one to one and being able to "comment" on their screen as
| they speak, but again, I'm pretty sure every video chats does
| that. So I left the idea on the drawer for now.
|
| https://www.youtube.com/watch?v=yS3_CRr7tys (draw on the
| stream)
| fttx_ wrote:
| Any chance you can link the first one (video chat over
| gameplay)? I'm working on something similar. I've tried
| searching and didn't turn up all that much.
| fictorial wrote:
| For a client I created a telehealth system for mobile and desktop
| browsers atop Twilio Video and later OpenTok.
|
| As an experiment in cost savings, I dove into the details and
| made a raw WebRTC version which worked well for a small number of
| users in peer to peer mode.
|
| While I found plenty of device farms, none allowed use the device
| camera and mic.
|
| How would you test a raw WebRTC video chat system short of buying
| a bunch of devices every generation?
| spicyramen wrote:
| I started working with webrtc and compatibility across browsers
| was a problem not sure if now it's been standardized
| j1elo wrote:
| It still is, but webrtc-adapter [1] aims to provide shims
| wherever they are needed to transparently provide the same API
| across all supported browsers
|
| [1]: https://github.com/webrtchacks/adapter
| 5986043handy wrote:
| I remember working on a simple peer-peer chat using WebRTC [1]
| and it took me a long time to actually grok what the whole
| protocol was and how it worked, even with off-the-shelf libraries
| available. This would have saved me so much time!
|
| [1] https://github.com/cktang88/markdown-chat
| Sean-Der wrote:
| Thanks :)
|
| It is really empowering to build stuff quickly. When you hit
| that wall of abstraction it is so frustrating (especially when
| debugging).
|
| If there are any topics/ideas you have would love to hear! I
| want this to be a community owned resource.
| nmyk wrote:
| This is great! I recently built a similar thing because I
| wanted to learn more about WebRTC. Fun to see someone else's
| take.
|
| https://tmpch.at
| pfyy wrote:
| Great, this would have helped us a lot in the implementation of a
| remote control app we did with webrtc. In my opinion, the best
| available resource at the moment is https://hpbn.co/webrtc/.
| (Also about a lot of other protocols)
| linguinj wrote:
| I create this website using webRTC to play torrent videos
| https://popcorntime.tube/ on the browser
| axegon_ wrote:
| Hah! OK, now that is cool. Props!
| tumetab1 wrote:
| When you mention a protocol can clarify on what ISO/Stack it's?
|
| I have no idea if ICE is application protocols or connection and
| that really would me be understand the first chapter.
|
| Just add something like "ICE (at the same stack level as
| TCP/TLS/HTTP".
| Sean-Der wrote:
| Will do! ICE is layer 4(I think ?)
|
| ICE is used to establish connectivity over UDP, TCP, TLS or
| DTLS. With a preference in that order. It just keeps falling
| back to more expensive transports if the prior ones failed.
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(page generated 2020-08-30 23:00 UTC)