$ opam depext srt
# Detecting depexts using vars: arch=x86_64, os=linux, os-distribution=ubuntu, os-family=debian
# The following system packages are needed:
libsrt-dev
m4
pkg-config
The following command needs to be run through "sudo":
    apt-get install libsrt-dev m4 pkg-config
Allow ? [Y/n] y
Reading package lists... Done
Building dependency tree
Reading state information... Done
m4 is already the newest version (1.4.18-2).
pkg-config is already the newest version (0.29.1-0ubuntu3).
Suggested packages:
  libsrt-doc
The following NEW packages will be installed:
  libsrt-dev
0 upgraded, 1 newly installed, 0 to remove and 3 not upgraded.
Need to get 20.2 kB of archives.
After this operation, 88.1 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://europe-west1.gce.archive.ubuntu.com/ubuntu eoan/universe amd64 libsrt-dev amd64 1.3.2-1 [20.2 kB]
Fetched 20.2 kB in 0s (161 kB/s)
Selecting previously unselected package libsrt-dev:amd64.
(Reading database ... 122278 files and directories currently installed.)
Preparing to unpack .../libsrt-dev_1.3.2-1_amd64.deb ...
Unpacking libsrt-dev:amd64 (1.3.2-1) ...
Setting up libsrt-dev:amd64 (1.3.2-1) ...
# OS packages installation successful