similar to: granulepos start/end revisited

> No particular answers, but I can at least point out that the way > things were designed for CMML was to work with the existing Ogg > seeking algorithm. The idea is that a generic seeking routine can work > on any Ogg file, as long as it knows the granulepos->time mapping for > the logical bitstreams in the file. That's why all the > timestamp-related info is crammed into

> The advantage of storing this in the granulepos field itself, like > theora and CMML do, is that the seek code may already understand how > to handle the back pointer. Right now everything assumes the mapping > is from 'initialized decoder' + 'granulepos from page header' => > timestamp, or in the case of theora and CMML => 'timestamp' + 'last

Hi all, something which came up recently in relation to the design of Kate's granulepos was whether or not the granulepos of successive Ogg pages is allowed to be the same, ie. whether or not granulepos must be strictly increasing. As this question is more generally about Ogg granulepos, how about we answer it first and then get back to the discussion of Kate's granulepos ... Here is

Hi, I have a question about seeking. In fact, it's more or less a kind of rambling and thinking aloud, circling around a question. I've been wondering how to deal with seeking in a stream, and what to do when seeking in the middle of a set of active events (eg, when several bits of text are supposed to be shown, but you seek after the time when they are first shown, and before the time

Ups! Maybe it's time somebody corrected that statement then - the wiki seems the right place to put the correct algorithm, IMHO. Cheers, Silvia. On Feb 13, 2008 10:06 AM, Ralph Giles <ralph.giles@artifex.com> wrote: > > On 12-Feb-08, at 2:57 PM, Ralph Giles wrote: > > > http://wiki.xiph.org/index.php/GranulePosAndSeeking > > I'm not sure it's helpful to

I'm hoping this is a new proposal, and not a rehash of something that's already been discussed and shot down. Without logs of the recent IRC discussion there's no way for me to know without asking. When I suggested it in #theora earlier derf_ or AndrewBachmann said that it had already been discussed, so I'm under the belief that this is a new idea. <p>Ok so we've

> It is more complex, because the granulepos is available at the page > level. Ah. Good point, I always forget about the partial page problem :( I conveniently flush pages after each data packet in my case (due to unknown/arbitrary latency), so I tend to forget easily about those. > We've generally designed the seeking algorithm so it can be > implemented without looking inside

Monty, Thanks for writing up your thoughts on the mux design (ogg/doc/ogg-multiplex.html in cvs) Now that there's something to argue with, I'd like to comment. To recap, the documented proposal is that we make two categories of streams within the OggFile multiplexing library. Pages are sorted chronologically by the timestamp equivalent of their granulepos fields. Normal data like

David Flynn has proposed a new Ogg Dirac mapping. The draft is here: http://davidf.woaf.net/dirac-mapping-ogg.pdf This is a much bigger break from other codecs than my draft (at http://wiki.xiph.org/index.php/OggDirac). We talked a bit about it on IRC today. Below is my summary; hopefully David can correct anything I got wrong or misleading. Comments? There are two main differences

Hi, I'm hacking on and off on oggmerge (from ogg-tools). I've added support for Theora, Speex, and Kate, as well as a few other fixes and changes. Now, I've got an issue relating to the ordering of pages as done by oggmerge, and the way oggz-validate tests for presentation time ordering. oggmerge, when deciding what timestamp to assign to a page, uses the previous page's

After some more thought on this, I'm trying to work out whether the back link offset needs precision. Semantically, the only need we have for this is to be able to seek back to a point before the start of the earliest event still active at the time of the original seek. As far as I know, and please correct me if I'm wrong, nothing in Ogg mandates that this backlink actually resolves to a

On 2/7/08, ogg.k.ogg.k@googlemail.com <ogg.k.ogg.k@googlemail.com> wrote: > And this is the crux of the problem, as far as I understand how it works: > you'll have to do a first bisection to find the page that maps to that > granulepos, > then, and only then, you get to know the low bits of the actual granulepos, > and then you have to do another bisection to find it.

Hi, sorry, there is a bug in the CMML spec and wiki page ... I discussed this with Silvia earlier this week but haven't gotten around to correcting it yet. CMML granulepos is much like theora's; the previous granule is stored in the higher bits, and the delta since then is stored in the lower bits. The current timestamp is the sum of the two. This is the behavior of the implementations

On 12-Feb-08, at 2:54 PM, Silvia Pfeiffer wrote: > I've added Monty's email to the wiki at http://wiki.xiph.org/ > index.php/GranulePosAndSeeking , but I was unable to edit the wiki > entry page and add a "Granulepos and Seeking" link under the > "developer resources" section. Maybe somebody with more rights on > the wiki could add this. I'm

On 15-Feb-08, at 6:44 AM, ogg.k.ogg.k@googlemail.com wrote: > Well, it doesn't quite work because the second part of the gpos is > an offset, > rather than absolute, and the precision we shed on one, we need to > recover > on the other one, to keep the ability to timestamp events at the > correct > granularity. It would have worked if the second part was absolute

Hello, I recently added discontinuous stream support to libogg1. The patch is attached. I also wrote Writ codec for libogg1 (based on original code by Arc), and sample Writ encoder (SubRip to Writ converter) and decoder. Is anybody interested? WBR, Roman. -------------- next part -------------- Index: include/ogg/ogg.h =================================================================== ---

Hi, do you still think you need all this, if you are allowed to have equal granulepos on subsequent pages? Conrad. On 18/02/2008, ogg.k.ogg.k@googlemail.com <ogg.k.ogg.k@googlemail.com> wrote: > Hi, > > I've now got another way of encoding granule (oh, not *again*, I hear > you cry). I believe it's an improvement over the existing "generic" > method, so

2008/11/21 David Flynn <davidf+nntp at woaf.net>: > On 2008-11-21, Conrad Parker <conrad at metadecks.org> wrote: >> 2008/11/15 David Flynn <davidf+nntp at woaf.net>: >>> On 2008-11-14, Conrad Parker <conrad at metadecks.org> wrote: >>>> It seems oggz chop, merge and sort will need some attention to deal >>>> with the Dirac

2008/11/15 David Flynn <davidf+nntp at woaf.net>: > On 2008-11-14, Conrad Parker <conrad at metadecks.org> wrote: >> It seems oggz chop, merge and sort will need some attention to deal >> with the Dirac granulepos and dependency ordering, so let's leave them >> for the next release. > > ok. -- may be worth having them 'warn' if they are operating

On 11-Feb-08, at 2:46 AM, ogg.k.ogg.k@googlemail.com wrote: > For reference, my data packets start with start granule, end > granule, backlink > granule, all 64 bits, so picking the granule is just a simple > constant offset > lookup into the data packet, eg, you replace: > > backlink = granulepos<<32; > > by > > backlink =