title: How do I know if Amazon Elastic Transcoder has completed transcoding
body: <p>Is there a way to have Amazon Elastic Transcoder inform a call back script that it has finished transcoding a specific video conversion?</p>
  
  <p>I'm working on this project that will let people upload videos, it has different steps and each step should start at successful completion of the previous step.</p>
  
  <p>I have been able to trigger the next step in every step but the last step is actually calling the AET and instructing it to go and take some videos from a S3 bucket, transcode them and store them in a different S3 bucket.</p>
  
  <p>So now I need to know if the AET has finished its task or not, I don't like regularly checking for the status with some kind of cron job, I much rather have the AET inform the system that it has finished its task.</p>