SSH to the host OS

You can find the instance's public IP address in the list of instances (EC2 / Instances).

Ubuntu's default user is ubuntu, use the following command to SSH to your instance (to the host OS). On Linux and macOS, you'll first need to limit the key file permissions using the chmod command.

chmod 400 path/to/your-private-key.pem

ssh -i path/to/your-private-key.pem ubuntu@INSTANCE_IP

Update the OS

sudo apt update && sudo apt upgrade -y

docker-compose installation

We use the docker-compose tool for making it easier to launch our Docker container. Use the following command to install the docker-compose tool.

sudo curl -L https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose

Next, check that the docker-compose tool is successfully installed. The following command should return meaningful output.

docker-compose version

Configure cgroup settings

Edit the Configuration File /etc/docker/daemon.json and add or modify the cgroup-related settings:

{
  "default-cgroupns-mode": "host"
}

If your daemon.json file already contains the runtimes configuration for NVIDIA, you can simply add additional configuration for cgroup settings without overwriting the existing content.

{
    "runtimes": {
        "nvidia": {
            "args": [],
            "path": "nvidia-container-runtime"
        }
    },
    "default-cgroupns-mode": "host"
}

Save the file and restart the Docker daemon to apply the changes:

sudo systemctl restart docker

Disable mDNS on the host

The mDNS service mustn't be active in the host OS for NDI discovery to work. If present, this command removes it from the host OS:

sudo dpkg -l | grep "avahi-daemon"
sudo apt remove --purge avahi-daemon -y

Increase max UDP kernel buffer size

To receive and send streams with overall stream bitrate of 21mbps+, Live Transcoder needs to increase the UDP kernel buffer size. However, the default maximum size is too low so it needs to be increased.

SYSCTL_CONF="/etc/sysctl.d/10-udp-buffer-size.conf"
sudo sh -c "echo '#kernel send a receive windows buffer sizes' > $SYSCTL_CONF"
sudo sh -c "echo 'net.core.rmem_max=262144000' >> $SYSCTL_CONF"
sudo sh -c "echo 'net.core.wmem_max=262144000' >> $SYSCTL_CONF"
sudo sh -c "echo 'net.core.rmem_default=262144000' >> $SYSCTL_CONF"
sudo sh -c "echo 'net.core.wmem_default=262144000' >> $SYSCTL_CONF"
sudo sh -c "echo '' >> $SYSCTL_CONF"

Now load the updated config file.

sudo sysctl -p $SYSCTL_CONF

Increase txqueuelen for network interfaces

To stream out high-bitrate codecs (e.g., JPEG2000 or JPEG-XS), alsotxqueuelen parameter should be increased for the respective network interface(s). Below, we set the parameter for all available Ethernet network interfaces (by using KERNEL=="e*"):

sudo bash -c 'cat > /etc/udev/rules.d/80-txqueuelen.rules' << EOF
SUBSYSTEM=="net", ACTION=="add|change", KERNEL=="e*", ATTR{tx_queue_len}="10000"
EOF

To apply the changes immediately, run:

sudo udevadm control --reload-rules && sudo udevadm trigger