similar to: Ogg: correspondence between playtime and file offset

Folks have noticed that the documentation is semi-silent about how to properly encode the granule position and interleave synchronization of keyframe-based video. The primary reasons for this: a) we at Xiph hadn't had to do it yet b) there are several easy possibilities, and the longer we had to think about it before mandating One True Spec, the better that spec would likely be. The

> 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

Hi, I am continuing to try to debug my ogg/theora decoder. The issue seems to be that not enough packets are being pulled from the bitstream, here is some sample output from my player with some debugging comments put in: (playback began at first frame, this is from the middle of the clip) get page at 1765027 got packet frame++, skip is 0 frame decoded page processed, kframe=414 : offs=442 get

Question: is it permissible to put more than one frame packet into a page? At 30 fps, Ogg page overhead is on the order of 8 - 10 kbits/sec. At low datarates, this is going to be unacceptable. If I shove a few frames into a page, how does this affect the granulepos stuff? ___ Dan Miller (++,) Founder, On2 Technologies <p>--- >8 ---- List archives: http://www.xiph.org/archives/

Hi all, I'm actually learning how to use ogg, theora and vorbis. My idea is to create a small program running, that is able to concatenate ogg video+audio files. However I have some small questions. Here I will start with the first one: I read the following for seeking in ogg for a theora key-frame: ---- snipp (http://www.xiph.org/ogg/doc/ogg-multiplex.html) ---- [...]The third point

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

Dear all I'm aware that there have been several discussions about the seeking issue and I'm sorry to bring this up again. To solve the problem with Inter-Frame garbage, a seek to the previous keyframe has to be made. The keyframe number should be extracted from the granulepos of the frame where we want to seek to. I hope I understood the theory - unfortunately a few questions have

Hi all, > One problem I see with your proposed implementation is that it does not > specify how audio and video would be synchronized, since there are no > absolute time stamps for the video frames. So it is difficult to account > for > audio latency on different systems, much like when you play an AVI file. > Ideally it would be wonderful to have timestamps that could be used

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

Hi, LLVM will look for the following environment variables to be set, and if not it will use /var/tmp: TMPDIR, TMP, TEMP, TEMPDIR You should be able to override its behaviour by setting one of those. Cheers, James On Thu, 24 Mar 2016 at 11:21 Ramakrishna Mallireddy via llvm-dev < llvm-dev at lists.llvm.org> wrote: > What are the various option we have in setting tmp dir. > >

I am trying to figure out how theora timestamps map to absolute time values. This information would be needed to seek by 1 sec, 5 secs etc. I understand the granulepos is interpreted as Absolute number of key frames so far | number of frames since last key frame. E.g. 1000|1, 1000|2, ... How does this map to absolute time in millisecs since the start, I can think of the following formula: Total

Hello, I'm just totally confused. In my theora streams encoded using ffmpeg2theora (but also when using my own encoder) I have packets with a granulepos of -1 so I can't identify the packet during a seeking operation correctly. I can also see those strange value when I just print the packet granulepos before sending it to the Theora decoder. I know why there are PAGES with granularpos of

What are the various option we have in setting tmp dir. I can't use the default var/tmp, and I am looking to pass the dir during compiler invocation as an arg. any help is great. Thanks Ramakrishna -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160324/263cba7a/attachment.html>

Hello, Thanks to people who responded to previous mail! Is there a way in which we can stop further sourcing of an R file? i.e., i am sourcing an R file and keep an equivalent of 'exit' in it and run the code till that point? Thanks again Regards Ramakrishna

Hi Devs, I am Kamlesh Kumar,CS undergraduate at NIT Manipur,India. I have been programming in C/C++ for more than 3 year. I have gone through various LLVM Core libraries and it's tool as well implemented it in my project .I am well aware of core concepts related to LLVM and it's code base, I have read three books available at Safari Online Books 1. LLVM - Essentials 2. LLVM - Cookbook 3.

> 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

Dear Admin, It seems that mails from our iit.ac.in domain are being marked as spam. It would be nice if something could be done about this. Best Regards Ramakrishna On Tue, Mar 24, 2015 at 1:12 AM, Aditya Kamath < adityakamath+llvmdev at gmail.com> wrote: > Hi all, > > (I received many emails that my posts were marked spam, so I am re-sending > this from another email address

I've developed an indexer which embeds a keyframe index track in Ogg files. It embeds the index in its own track, so that players that don't understand or don't want to use the index can just ignore it. Ogg needs this to make seeking over networks faster and more efficient. Currently we must do a bisection search when seeking, which usually takes aound 6 HTTP requests, give or

Hi all, I noticed the following Subversion commit today: r6719 | xiphmont | 2004-05-18 16:04:53 +1000 (Tue, 18 May 2004) | 11 lines Updated doc to reflect current proposal... Not as much a proposal at this point actually; this is the way I'm now implementing it. Although we're still in the 'RFC'/'look for horrible lossage' stage, this is close to being

OK... i've come across a problem trying to get the granule pos of the start of the page... it's not so crucial with single stream ogg files... but now that i have theora+vorbis in a file, i'm finding that when i seek to a position, i have no way to determine the relative offsets of the different streams at the new seek point and hence the av is out of sync. So given a page, is it