[theora] oggcat or other ways to combine theora videos (with or without re-encoding)?

[Gregory Maxwell]

On Tue, Sep 15, 2009 at 11:21 AM,  <yorn at gmx.net> wrote:
> Hey all,
> Oh yes, I came around the problem before, but forgot about that.
> So this goes to the Theora guys:
> I encounted the following issue: The packet numbers for the theora headers created by the theora encoder are not numbered (all set to 0). This causes the strange output. Vorbis does create packet numbers for the header packets.
> Second thing is: The first packet number is set to "2", so the oggvt library expects a packet with number "3" and got a packet with number "2".
>
> Maybe someone could tell me if I am wrong and got some problems with my packet number reader or if this is true.

It's not clear to me what you're referring to by "packet number".

Ogg has two relevant framing constructs, the page and the packet. Ogg
packets are not explicit numbered.

If you're referring to the granule position, thats a page level
construct and the Vorbis specification states: "The granule position
of these first pages containing only headers is zero.".