[theora-dev] Ogg MIME types scheme

Dan Miller
Thu, 13 Feb 2003 23:48:29 -0000

first,

My deepest apologies for another HTML posting.  Hopefully it will be the last.

>So, just to confirm, we will be able to take this footage and convert it
to Ogg Theora down the road right?  This is pretty important to us, to
be able to archive all this video patent-free without having to
transcode it down the road..
This is an important question. I cannot answer categorically since in the end it
is up to Xiph (Monty) to ensure that this remains the case. However my
understanding is as follows: the intention is to make Theora 1.0 'upwards
compatible' with VP3. What I mean by that is that a VP3 bitstream can be
_losslessly_ converted into a Theora stream (but not necessarily vice versa).
While some configuration bits and headers will change, the decompressed data
will be 100% identical to what you would get with the original file, and the
datarate will be almost exactly the same (a few K of global header, and perhaps
a few bytes per frame may be added).

Note however that the tool that does this conversion needs to be created by
someone. The documentation will make it possible, and I will make a personal
commitment to support anyone involved. I may even build the tool myself, but I
don't want to make a blanket commitment at this point as I have no idea what
my situation will be when the time is right to do it.  Also my experience is
more with AVI files; I assume this is a Quicktime thing.

However I think it's critical for us to confirm that this is technically
possible without superhuman effort. The way things stand right now, that's
definitely the case. The only thing that could change the situation would be
some major monkeying deep in the Theora/VP3 coder, and at this point that is not
anticipated prior to the first official release.

-dbm

        -----Original Message-----
        From: Arc [mailto:arc@indymedia.org]
        Sent: Fri 2/14/2003 1:47 AM
        To: theora-dev@xiph.org
        Cc:
        Subject: Re: [theora-dev] Ogg MIME types scheme



        On Fri, Feb 14, 2003 at 05:38:56PM +1100, Conrad Parker wrote:
	>
	> http://www.iana.org/assignments/media-types/application/
	>
	> scroll down to 'ogg'; it doesn't have an RFC number yet
	> (currently RFC-walleij-ogg-mediatype-08.txt) but it'll get
	> one soon (so I hear :)

        Awesome timing.

        For anyone that's interested, I'm going to spam this out here..
the
        IMC-NYC video team is going to be encoding all of the Feb 15th war
        protest footage in VP3, most of the audio is going to be archived in Ogg
        Vorbis, and there's going to be a live breaking news Quicktime/VP3
video
        stream accompanied by a Ogg Vorbis audio stream (same as video, but
        lower bitrate).  All this is being done in anticipation of being able to
        upgrade the archives to Ogg Theora down the road.. nyc.indymedia.org for
        URLs, if you're interested in what's happening in the streets of
NYC
        this weekend.

        So, just to confirm, we will be able to take this footage and convert it
        to Ogg Theora down the road right?  This is pretty important to us, to
        be able to archive all this video patent-free without having to
        transcode it down the road..

        --- >8 ----
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