… for Codecs & Media

Tip #637: Compressor: Job Chaining

Larry Jordan – LarryJordan.com

Job chaining creates an intermediate master file, which saves time creating derivatives.

There is a hidden feature in Apple Compressor that can save time when creating multiple versions of the same master file. It’s called “Job Chaining” and here is how it works.

Every week, when I post my webinars, I add a watermark of my website URL into all the compressed versions. However, I never export the master file with a watermark, so that I always have a clean copy for archiving.

One of the versions I create is an HTTP Live Streaming (HLS) version of it for mobile devices. (See Tip #635). The problem is that HLS compression creates thousands of short ten-second movies from the master file. There’s no easy way to add watermarks to them.

So, I do this in two steps:

• First, create an intermediate master file – using ProRes 4444 – with a watermark.
• Then take the output of that process and “job chain” it as the source file for HLS compression. (see screen shot)

Specifically:

• Import your master file into Compressor
• Apply the setting to create the interim master – in my screen shot, this is called “Add Watermark Only.” All it does is burn a watermark into the intermediate master. Because I am working with ProRes 4444 there is no loss in audio or video quality.
• Control-click the compression setting and choose New Job with Selected Output.
• This creates a new line in Compressor to which I apply the HTTP Live Streaming settings.

This allows me to create one master file with the watermark, rather than re-create it over and over again.

I use this technique every week.