Thanks for raising the point about VP8 Hoikas, even if it was only in passing
- It's caused me to dig a bit deeper into the "legals" on this.
Pretty much everything on xiph.org (Ogg, Vorbis, Theora, etc.) seems to have been static for some time, and Theora hasn't had any new tickets raised in about 2 years. You could look at that as either: a) There's no-one using it, b) there's no-one bothering to do any new work or c) It's all really stable and there's no need to spend time on it.
Patents are not in themselves a problem provided that their use is properly licensed, which for our case mostly means that they're free from fees related to their use. So, looking a bit harder at libavcodec, despite being offered under GPL/LGPL licences from http://ffmpeg.org
it does seem to include numerous codecs for which the methods may
be subject to patents - FFmpeg claim not to know since they never used the patents to develop the codecs, and advise only that doing something for yourself is unlikely to be problematic but things could be different in a commercial environment. I see H.264 (MPEG-4) in there and I could readily see MPEG-LA getting twitchy over that (there are 59 pages of patents
involved). Google, however, seem to have made the necessary royalty-free grant of use of the patents
they acquired through On2 Technologies for VP8.
[digression] The VLC media player uses libavcodec but, as a French entity, VideoLan claim that software patents are not applicable in Europe under 2(c) of Article 52 of the European Patent Convention
: This seems tenuous at best as that only applies to the software code - where the underlying technology "solves a problem" (in this case the efficient streaming of AV data) then that is still patentable, so Article 52 only excludes some
of the relevant patents. There are comments around that "VideoLan could have their ass sued out of existence" which seem justifiable, but they don't seem to care.
Patent rights aside, the build issues that Hoikas reports are a significant concern. Most of the issues could probably be worked out in time but the question is whether it's worth the effort. I think Hoikas has already concluded that it probably isn't. Most of the Windows based C/C++ compilers I've seen don't fully comply with C99, so even getting something pre-compiled and ready to link would be a chore.
That leaves the issue of converting existing video data (or new video content) into the VP8 bitstream format, and it looks like there are several tools (many free) around for that. Ironically, you could use FFmpeg to convert Bink .bik files to VP8
although I'd expect (hope) that Cyan will have the pre-Bink source video files on hand somewhere anyway. If Chogon is not overly concerned about reformatting then that's good enough for me.
Google re-licensed VP8 under the Modified BSD licence (the "3-clause BSD license") which is compatible with GPLv3 (it was originally under the 4-clause BSD license which doesn't play well with GPL), so that's OK and doesn't cause any hiccups with the current CWE license. Removing Bink will leave a redundant additional permission in the CWE license but there's no need to re-license because of that (there are other redundant permissions there just now anyway, "just in case").