[vorbis-dev] Confusion with page_segments / segment_table

[Monty]

On Wed, Nov 06, 2002 at 05:35:56PM +0100, Anders Thomsen wrote:
> As I understand it, the segment table consist of as many bytes as specified in page_segment, PLUS one trailing byte with a value between 0 and 254.

No.  The segment table is exactly as many bytes as are specified in
segment_table.  It can end with a byte of 255.

> I've looked at some files that has a Comment tag so large, that it
is spread over two pages.

Yes.  Overflow is more likely due to the setup (third) packet than the
comment packet, but it is certainly possible in the comment.

> Here, the first Page Header (not the first
Page Header in the entire file, but the one just before the comment
tag starts) has this extra trailing segment.

I don;t think you're seeing what you think you're seeing. 

> But the next Page Header (which is positioned in the middle of the comment tag) only has as many segments as specified in the Page Segments byte value. It does not have a trailing segment.
> 
> What am I missing here?

Look more closely at the structure.  Don't fall into the trap of
thinking that pages and packets are really all that closely related;
pages are just a synchronization structure.  They don't really
'contain' packets, just provide enough information to verify packets
and mark boundaries.

I expect what you're really seeing is third packet, which usually
begins on second page, being split between second and third page.

Monty
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