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.
One of the more interesting aspects of Ogg Video is that it allows an essentially unlimited number of subtitle tracks to be included. This is especially useful for free-culture videos, since they are generally released globally, and there are often contributed subtitles. In fact, for "Sintel", I was able to find 44 subtitle files. I will be including them all as Ogg Kate streams in my prototype "Lib-Ray" version of "Sintel", and in this column I will demonstrate the use of several command line utilities useful for this, especially the
kateenc tool for creating the streams.
GNU/Linux has never been short of audio and video players, but they live in a world of multiple codecs, chief culprit amongst them being MP3, AAC, WMA and (Adobe) Flash. I say "culprits" because they are not free and open codecs. They are encumbered by patents; most websites with embedded audio/video use them and most of the people who view them are also using other patented software: Windows. GNU/Linux is a good alternative and all distros come bundled with free and open multimedia alternatives too: Ogg. You would not be surprised that these players can handle Ogg but what if I told you that Mozilla's Firefox browser could not only handle this codec but could be used also to transcode videos to that format? Interested? Read on.
When I checked my feed reader at one point today I noticed that there was an interesting sounding article from the BBC available - “Tiny files set for a big future” was the heading. It did actually turn out to be a novel look at the importance of compression technologies when it comes to the availability of content on the web; then I read the last few paragraphs and it went horribly wrong: the BBC needs a wake up call (from us!).