Unless you've been hiding in a cave for the last few years, you probably know about the free multimedia codecs with the fishy-sounding names from Xiph.org: Ogg Vorbis (for sound) and Ogg Theora (for video). You might be less familiar with other family and friends, including FLAC (lossless audio), Skeleton (metadata stream), and Kate (subtitles). However, together this collection of codecs can be used with the Ogg container format to provide all of the functionality of a DVD video file -- multiple soundtracks, full surround sound, high definition, and selectable subtitles. Having created the various streams for a prototype release of "Sintel" in my last few columns, I'm now going to integrate them into a single video file and test it with some players.
Ogg Vorbis and Ogg FLAC (the Ogg stream version of the Free Lossless Audio Codec) are popular free-licensed and patent-free codecs for handling sound. These are the formats I'll be using in a complex Ogg Theora video file that I am creating as part of my "Lib-Ray" experiment in creating an alternative format for distributing high definition video. In order to do this, I'll need to solve several technical challenges using the FLAC command line tools, Audacity, and VLC, which I'll demonstrate here.
One of the great advantages of using a free license for a work is that you can re-use a growing body of free-licensed source material to help you do it. But it can seem a little daunting to find the material that you both want and can legally use. Here's a little bit of my strategy, a few tips, and some sources, including Jamendo, which I found to be the most useful for finding music. I also touch upon some useful free software tools for listening and sorting tracks.
I found a useful sound effect in an online video from NASA which replaces an earlier temporary sound I used in a scene soundtrack for the Lunatics pilot, "No Children in Space." I'm going to extract the sound from the video (with VLC), cut out the sound I need, clean it up, and insert it into an existing sound mix (all with Audacity). This should give you some insight into using Audacity and a VLC on a real project.
There are not a lot of free software options for mastering DVDs. One of the more complete solutions is QDVDAuthor, although it still has a number of rough spots. It's a front-end to a collection of command-line free software tools that do each of the individual steps involved in going from a collection of digital video files, audio files, and images to a DVD with menus. As such, it's quite complicated, and not as stable as some software. Still, it is a rewarding experience if you stick with it. Here I'm going to walk through creating a DVD for a collection of animated videos by my new favorite free-culture artist, Nina Paley (partly because the CC By-SA 3.0 license eliminates any questions about copying the material here, and partly because they're pretty cool in themselves).
Last year, while running Ubuntu, I decided I wanted to watch a video, so I opened it up in the built-in Totem player. What happened next took me back to the dark era of codecs and computing. The XviD video I was watching became pixelated, the video became out of sync; within a few minutes it was unwatchable. I dual booted back into Windows XP, opened up by trusty MPUI and watched the video with the free software XviD codecs without any issues. The experience had left a bad taste in my mouth.