Amazon Elastic Transcoder
Developer Guide (API Version 2012-09-25)

Working with Pipelines

Pipelines are queues that manage your transcoding jobs. When you create a job, you specify the pipeline to which you want to add the job. Elastic Transcoder starts processing the jobs in a pipeline in the order in which you added them.

One common configuration is to create two pipelines—one for standard-priority jobs, and one for high-priority jobs. Most jobs go into the standard-priority pipeline; you use the high-priority pipeline only when you need to transcode a file immediately.

If there are other jobs in a pipeline when you create a job, Elastic Transcoder starts processing the new job when resources are available. A pipeline can process more than one job simultaneously, and the time required to complete a job varies significantly based on the size of the file you're converting and the job specifications. As a result, jobs don't necessarily complete in the order in which you create them.

You can temporarily pause a pipeline so it stops processing jobs. This is useful if you want to cancel one or more jobs, which you can do only until Elastic Transcoder starts processing the jobs.