lhls-simple-live-platform

This readme shows how to build a very simple live streaming platform based on open source tools with a glass to glass latency around 2s.

To learn more about it see the presentation at syd\<video> on 2020/06/24:

Block diagram

Launch EC2
- Type:
  - t2.small (for transmuxing)
  - t2.xlarge (for transcoding from 720p to 720p and 480p)
- Security groups
  - Open Inbound TCP 1935 for everybody (RTMP)
  - - Open Inbound UDP 1935 for everybody (SRT)
  - Open Inbound 9094 for everybody (HTTP)
Update the machine sudo yum update -y
Install git: sudo yum install git -y
(optional) Install tmux: sudo yum install tmux -y
Install (compile) ffmpeg
- You can use this script or source code
Install DejaVu fonts (to do the overlay on transcoding): sudo yum install dejavu-sans-fonts -y

Install this repo

cd ~
git clone https://github.com/jordicenzano/lhls-simple-live-platform.git

Install GO, see instructions
From your home dir cd ~ install and compile go-ts-segmenter
```
go get github.com/jordicenzano/go-ts-segmenter
```
From your home dir cd ~ install and compile go-chunked-streaming-server
```
go get github.com/mjneil/go-chunked-streaming-server
```

Create a shell to the EC2 machine (tmux recommended), and start webserver in HTTPS
```
cd ~/go/bin/
./go-chunked-streaming-server
```
Create ANOTHER shell to the EC2 machine (tmux recommended), start RTMP server + segmenter with a multirendion transcoding configuration
```
cd ~/lhls-simple-live-platform/scripts/
./transcoding-multirendition-rtmp.sh live
```
Open your favorite RTMP client: OBS, Wirecast, Elemental, Wowza Clearcaster, ffmpeg, etc
- Configure the RTMP URL as: rtmp://[PUBLIC-IP-EC2]:1935/live/stream
- Recommended short GOP (1s) and (if possible) activate "zerolatency" video encoding mode
- Start streaming
Tested with following players: Safari, Quicktime and ffplay)
- Use this URL: http://[PUBLIC-IP-EC2]:9094/mrrtmp/playlist.m3u8
Example glass to glass latency with this set up: 2.01s

Create a shell to the EC2 machine (tmux recommended), and start webserver in HTTPS
```
cd ~/go/bin/
./go-chunked-streaming-server
```
Create ANOTHER shell to the EC2 machine (tmux recommended), start SRT server + segmenter with a multirendion transcoding configuration
```
cd ~/lhls-simple-live-platform/scripts/
./transcoding-multirendition-srt.sh live
```
Open your favorite SRT client: OBS, Wowza Clearcaster, ffmpeg, etc
- Configure the SRT URL as: srt://[PUBLIC-IP-EC2]:1935
- Recommended short GOP (1s) and (if possible) activate "zerolatency" video encoding mode
- Start streaming
Tested with following players: Safari, Quicktime and ffplay)
- Use this URL: http://[PUBLIC-IP-EC2]:9094/mrsrt/playlist.m3u8
Example glass to glass latency with this set up: 2.54s

This is JUST A PROOF OF CONCEPT / PROTOTYPE do not use it in production
- Example of known problem: If the encoder reconnect for any reason, the live stream finishes
There is a lot going on about how to do ABR when you are sending data at "media speed" and NOT at "cable speed". So for multirendtion and chunk transfer you should expect regular players going to the lower BW lane
go-chunked-streaming-server does not send max-age headers, so if you want to add a CDN on top of this prototype to scale this platform up you need to set up the expiration manually