I also worry that since it is based on streams and heroku, that it doesn't re-write the meta data to the beginning of the video after encoding. This is a really important step as it cuts the time to first frame by 1/2.
Does your service automatically detect what type of video the users device can play and transcode the source from whatever format you uploaded it as into something that can be played?
Or does it simply upload the file from the server it is on to S3?
I can't see anywhere that you can specify transcoding to a different resolution or format?
And its any resolution to 480p.
But all these will be configurable via the URL in a future release.
I realize that the mp4 container can support a wide variety of codecs and you're probably transcoding to h264/mp4, but IMO it would help to use something else here (.wmv, .avi, etc) to drive home the use case.