We get a lot of E-mail from people, demanding support for OGM. Of course they come to us, it’s called ‘Ogg.’ We’re the ‘Ogg People.’ We don’t support OGM. We didn’t write it, and we don’t have the resources to help people with it…
Ogg Vs Ogm file format are the same, the main difference is the first header in each stream. OGM uses several standardised header formats, audio, video and text, in order to make identifying unknown codecs easier in directshow (and subsequently other frameworks). ie with those three headers you can use any audio or video format you choose without have to write custom header parsing routines for each codec in the demuxer.
In other words ogmtools provides the standard du jeur for encapsulating various common-in-avi codecs in an Ogg bitstream, like ‘divx’, ‘mp3’ and so on.
Google has created an opt-in beta program for anyone wanting to test YouTube with the HTML5 tag rather than using Flash. There are a few caveats however, with the number one being that it’s still all H.264 video. No Theora to speak of, yet, but it’s possibly a step in the right direction!