rumblelabs/asset_sync — pull request #93 by statik (2012-08-03 20:47:00+00:00)
Title: Always provide mime_type when uploading, even for non-gzipped files

This fixes a bug I'm having where some video files are uploaded to s3/cloudfront and get a mime type of
application/mp4 rather than video/mp4. With this fix I am able to add this next line to my config/initializers/mime_types.rb file:
Mime::Type.register "video/mp4", :mp4, [], ['mp4']

and then I get the correct mime type showing up on the mp4 files in S3.