[mpeg2] Re: docs

[Kees Cook <kees@outflux.net>]

On Mon, Oct 01, 2001 at 02:11:10PM -0600, Warren Young wrote:
> I would be most impressed if you pulled that off.  :)  MPEG is not
> simple, even at the limited level you're talking about.

Heh.  Well, I meant write done the file format.

> If the GOP isn't closed, the final B frame depends on the I frame
> leading the next GOP.  If the encoder supports non-closed GOPs, you can
> often ask it to close some or all of the GOPs.  This either makes the B
> frame use forward prediction only (making it like a P frame) or makes
> the encoder replace the last B frame in the GOP with a P frame.  Failing
> that, you could probably keep the subsequent I frame, as you originally
> suggested.

Okay, cool.  I'll probably do the I-frame pair thing, then.  This is all 
just to trim down the size of MPEG2's from the kfir before I DivX them.

> Most people who are building MPEG software find a way to make some money
> at it, so spending a few hundred bucks on documents is no big thing. 
> It's really not much different from buying O'Reilly or FSF books, to
> help support the community.  Sure, these ISO standards are a _tad_ more
> expensive <grimmace> but they're also absolutely authoritative.  They
> took many person-years to hammer out, and the market for them is small. 
> I think the prices are justified.

Agreed.  If I was making money off this, I wouldn't hesitate to buy the 
ISO docs.  In fact, if I was writing an encoder or a decoder, I might just 
do it too, but I just thought it would be silly to pay that money to chop 
up existing files.  :)

-- 
Kees Cook                                            @outflux.net