The encoding is taking a long time! Why? What can I do about it?

Unfortunately the encoding of images to JPEG2000 (the compression scheme used by DCPs) is computationally intensive. The library we use for the compression (openjpeg) is very good, but a little slow compared to some (expensive and closed-source) commercial libraries.

I am hopeful that over time the performance of openjpeg will be increased, either by me or by other developers that work on it. There is also some movement towards the acceleration of openjpeg by using the processing power of graphics cards.

In the mean time, there are a few things you can do to increase conversion speed:

• Make sure that the preference ‘threads to use for encoding on this host’ is set to the number of CPU cores in your machine.
• Use a faster machine: JPEG2000 encoding speed goes up pretty much linearly with passmark.
• Use one or more encoding servers (extra computers to share the workload) as described here.