Is there a way to setup a transcoding pipeline on AWS such that it automatically transcodes any new files uploaded to a particular S3 bucket, and places them in another bucket?
I know there is a REST API, and that in theory the uploader could also issue a REST request to the transcoder after it has uploaded the file, but for a variety of reasons, this isn't really an option.
This can now be accomplished using AWS Lambda.
Lambda basically allows you to trigger/run scripts based off of events. You could easily create a Lambda script that runs as soon as a new file is uploaded to a designated s3 bucket. The script would then start a transcoding job for that newly uploaded video file.
This is literally one of the example use cases provided in the Lambda documentation.