Is it possible to combine the great quality of Blu-rays with instant and reliable access? The answer is a cautious affirmative. According to the current U.S. laws, it is illegal to circumvent copy protection on DVDs and Blu-rays. Unfortunately, the instant / reliable access part is not possible without stripping the content protection. That said, it is difficult to imagine a situation where the fact that a consumer has stripped the DRM from a purchased disc is known to the outside world (as long as it is not being distributed in a public manner). Given this situation, it is highly unlikely that backing up your discs is going to earn you a visit from the FBI, but AnandTech is not a site for legal advice. So, if you decide to act on the tips below, note that you are on your own.
There are three different types of Blu-ray backups which don't involve re-encoding the audio and video tracks, and you should choose one of the formats that meets your requirements:
ISO: An ISO file is a disc image that retains almost all the contents of the disc in a sector-by-sector copy format. It also retains the file system of the disc. Most tools that back up to this format strip out the AACS folder.
Folder structure: This is similar to an ISO backup in the sense that all the contents of the disc are retained. However, the file system on the disc is not carried over. This means that some file system level tricks to save upon space (such as the 3D video SSIF folders in MVC encoded Blu-rays) can't be retained.
MKV: This is undoubtedly the most popular format for storing HD movies. In this backup mode, a playlist title is chosen (a collection of M2TS files on the disc in a particular sequence). The M2TS files are concatenated in the right order and the unnecessary audio and video tracks are taken out as dictated by the user. The tracks are then remuxed into an MKV container.