similar to: Keyframe seeking in Ogg and spec

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/

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

> 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 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

One of the issues I've consistently run into with the cortado player app is seek behavior, so I was curious to see how cortado handles video encoded with the latest ffmpeg2theora (0.26) and the new -seek-index option, so I tried converting an h.264 video: ffmpeg2theora tronlegacy-tsr1_480p.mov --seek-index This output the following advisory messages: > Allocated 372 bytes for theora

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

Oggz 0.9.8 Release ------------------ Oggz comprises liboggz and the command-line tools oggzinfo, oggzdump, oggzdiff, oggzmerge, oggzrip, oggz-chop, oggz-comment, oggz-scan, oggz-sort and oggz-validate. oggz-chop can be used to serve time ranges of Ogg media over HTTP by any web server that supports CGI. liboggz is a C library providing a simple programming interface for reading and writing Ogg

Oggz 0.9.8 Release ------------------ Oggz comprises liboggz and the command-line tools oggzinfo, oggzdump, oggzdiff, oggzmerge, oggzrip, oggz-chop, oggz-comment, oggz-scan, oggz-sort and oggz-validate. oggz-chop can be used to serve time ranges of Ogg media over HTTP by any web server that supports CGI. liboggz is a C library providing a simple programming interface for reading and writing Ogg

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

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

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

On 02/05/07, Elaine YueLien <et@ihear.com> wrote: > Hi, > > Several months ago, I asked a question about seeking without a metric. > You can find one answer in this beta release, demonstrated in the > example program multiThreadSeek. There is also an example demuxer, and a > rewriter. Hi Elaine, congratulations :-) that's a nicely designed API you've got there.

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

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

> 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

Is anyone working on liboggplay, and if so, is there any plan to support keyframe-based seeking? I found this, but seems to me that the feature ought to be part of liboggplay: http://pearce.org.nz/2009/05/video-seeking-improvements.html Is there a more appropriate list to post to regarding liboggplay? Shayne Wissler -------------- next part -------------- An HTML attachment was scrubbed...

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

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

Hi, When doing a live ogg+theora stream on our server we ran into the following problem: When a client connects we send out the theora header pages followed by the actual live stream pages. The problem is that the first ogg data page does not have the right page number (2), which causes libogg to not want to decode the first _packet_ of that page. Since that first packet happens to contain the