Running Video by Zaweba from the command line

Clicking Export is fine for one project. For fifty, or for a job that should run overnight without anyone watching, a command line is better. Video by Zaweba can be run from a command prompt or a script, does its work and reports back in a form other programs can read.

The options

The program, ZawebaVideo.exe, accepts --commands, --run, --exec, --inspect, --probe and --export. Each one does a different job. --commands lists what the app can do. --run and --exec carry out commands or scripts. --inspect looks at a project. --probe looks at a media file. --export exports a project without opening the full window.

Results come back as JSON, a common structured text format, and the program finishes with exit codes that say whether it succeeded. Those two details are what make it practical to automate: a script can read the JSON for details and check the exit code to know whether to carry on or stop.

What people use it for

Batch exports are the obvious one. A script can work through a folder of projects and export each in turn, perhaps overnight, then report which succeeded.

Checking media is another. Using --probe on incoming files tells you about each one, which helps sort a large delivery before you start editing.

Inspecting projects suits anyone managing many of them, for example confirming which projects use a particular file before archiving it.

For the many people who never open a command prompt, none of this changes the app. It is simply there for those who want it.

The control channel

There is also a control channel over TCP on 127.0.0.1, the address that means this computer only. It lets another program on the same machine talk to a running copy of the app. It is off by default, so nothing listens unless you turn it on.

Leave it off unless you have a specific need for it. When you do use it, it stays local to the machine, since 127.0.0.1 is not reachable from other computers. Turn it off again when the job is done.

Using it well

Start by running --commands to see what is available, and try each option by hand on a test project before you build it into a script. Check exit codes in every script you write, so a failed export does not go unnoticed among a long list of successful ones.

Keep logs. Saving the JSON output of each run gives you a record of what happened and makes problems easier to trace.

If you want identical output from the same project every time, combine command line exports with the bit-exact export option. Together they suit automated builds that should only produce a changed file when something really changed.

Inside and outside the app

The command line sits alongside scripts, plug-ins and the command palette among Video by Zaweba's automation tools. The palette and scripts work inside the app; the command line works from outside it. For anyone producing video at volume, it turns repeated exporting into something a computer can do on its own while you get on with editing.