Updates and errata

Updates and errata

The technologies related to preservation keep changing, and errors in the book are bound to turn up, so this page will present corrections and updates as I find places where they’re needed.

Still image files

Here’s some updated information as of May 15, 2013, on the WebP format: Interest in it is starting to grow; in 2013, Facebook started offering some WebP images; Opera, Chrome, and Ice Cream Sandwich support it; the Firefox development team is reconsidering its previous opposition to it. The lossless specification is online.

Video files

Under “Summary of video container risks,” two bullet points got mashed together as one. They should be:

• WebM still isn’t well established as a container.
• MPEG-4 licensing is focused primarily on codecs, but if you save as an MP4 file, you’re getting a proprietary encoding.

The second bullet point isn’t as clear as it should be. What I was trying to say is that MP4 per se is a codec-agnostic container, but when you save a video as an MP4 file, the codec that’s used will most likely be proprietary.

VP8: Nokia is claiming patent rights on VP8 video compression and (as of this writing, May 2013) won’t license them; this is a preservation concern, since it limits implementations.