similar to: Decoding Theora: Number of frames?

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, I've been thinking about how a Theora encoder could be integrated into mencoder or transcode and I'm not sure whether I understand the A/V sync strategy of Theora/Vorbis correctly. When transcoding from some video format (ie MPEG2 or DivX), at least some images of the video stream will have time stamps, as well as the fragments of the audio stream. Or at least time stamps can be

2008/10/29 Romain Beauxis <toots at rastageeks.org>: > > I am currently implementing theora for our application. > In our model for generating ogg streams, we may want to stop > a stream while not providing a new YUV data buffer for encoding. > > Current API doesn't allow such thing, since the eos flag is set by the > packetout function only when the last_p parameter

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 guys, first of all, i'd like to ask if there any crossplatform software/service ( gui is also better, an online application like firefogg is great, or at least a command line tools for any platform) to combine theora videos, other than oggcat... i am doing some art projects that people should be able to remix featured theora videos and i find oggcat very usefull in theory but not in

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

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

> There are a usually lot more data packets than header packets, so > having an internal length there hurts your bitrate a lot more. Of > course, it may not be significant for an uncompressed text codec. If muxed with a video, it's insignificant (well, for my test cases). > With codecs using the 'count of decodable samples' rule to calculate > their granulepos, 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

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

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

I've been looking over Benjamin Schwartz's Skeleton A-mod proposal. I've been pretty busy with other projects over the past few months, so haven't had a chance to look at Ogg indexing until now... In general, I think Benjamin's ideas are sound, they're improvements, and I'm open to being convinced to take them in the next index version. We may as well get the index

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

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

Hello, > (1) Split the content into chain segments > (2) extract the first and last data packet from each segment, for all tracks > (3) recover / calculate the granulepos values for the first and last data packets (*) > (4) convert the granulepos values from the first and last data packets into time values > (5) take the largest difference between start and end time as the total

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/

On 10 May 2010 23:20, Chris Pearce <chris at pearce.org.nz> wrote: > The granulepos radix was something that Conrad and Ralph were talking about > at FOMS2010. I don't know how it's supposed to be used, or why we need it. > It was supposed to be needed for Dirac? Maybe Ralph or Conrad can remember? > If not, we should remove it. There's no point in adding a poorly

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

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

Hello list, Apologies are in order for the delay in getting 1.0 Final out, but the big word in the 1.0 release is STABILITY. The core team has found some last minute bugs that needed ironing out and they are being taken care of. In spite of this, we are close to see a proper release very soon and, as a stop-gap, all the latest developments have been collected into a new Release Candidate which