Maximum size of video and modifying resolution resulting in multiple files

[MaruthiVSM]

I have three questions:

1. Will I able to get the modified versions of uploaded video with given resolutions and retain the original video? If I upload and modify it to 2 different resolutions, will I get three versions of video (original and 2 modified ones)?
2. What is the maximum size of video this library can accept for uploading and retrieval?
3. Is it possible to stream the uploaded videos using this library?
   Thanks in advance!