similar to: how to tell opus encoder to send generater a key frame?

I have almost finished integration of Theora into our videoconferencing program. Since a videoconferencing program is realtime, it is UDP-based and wraps the Theora stream in RTP (More on that later). The problem here is that most examples I could find, wraps the theora stream in ogg, and used over tcp or files. I send over UDP and clients need to be able to start in the middle of the stream.

Here is a fix that prevents the encoder from spending too many bits on keyframes. The main problem is that the old code computes the target keyframe bitrate incorrectly. This causes the code that computes the Q for the frame to think that it has tons of bits to spend. It selects a high Q value for the keyframe. Since so many bits were spend on the keyframe the the inter-frames have to use a much

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

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

I am going to improve theora codec with dynamically changing way. In this case we want to change compression parameters like video_q, sharpness when a keyframe is generated. When i set video quality parameter using cpi-> pb.info.quality in CommpressKeyFrame in encoder_toplevel it will not change dynamically. Can you please help me to do this. Wich function should i cange to achieve my

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...

Hi all, First of all a big thank you for your work. I would like to know what is (could be) the best (optimal in a psnr and/or subjectivity sense) maximum distance between keyframes or is theora using a good heuristic change scene detection mecanism? Does it really matter to theora as with mpeg4 part2/10? Thank you and keep up the good work -- Josh

Hello, Does anyone know the answer to this question below? (Note... they're calling the Theora codec "Ogg" below. I know technically it's not correct... but that's what some are calling it.) ---------- Forwarded message ---------- From: Enric <enric.media@gmail.com> Date: Aug 19, 2007 10:13 AM Subject: [show-in-a-box] Re: Ogg To: show-in-a-box@googlegroups.com A

Here is a patch that fixes distortions that appear during scenes with no motion. Tbe problem was that UpdateFrame() was not being called when a MotionScore of 0 was computed. Since UpdateFrame() was not called the buffer returned by theora_encode_packetout() would be the same buffer that was output for the last frame that had a non-zero MotionScore. This is obviously incorrect behavior. I've

> Right. This was, in fact, one of the roles of "chaining" where you'd > mark such changed components with a chain boundary, at which such > things are explicitly allowed to change. The drawbacks are the > overhead of resending all the setup data for configurable codecs like > vorbis and theora, and the semantic conflict between 'chain boundary > flags an edit

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

Monty, Derf and I were discussing some theora bitstream improvements. He was curious about the spare bits in the keyframe header. There's a keyframe type bit which is always DCT_KEY_FRAME aka '0' and two spare bits. You took out a lot of similar extra bits in the VP3 code. Do you remember anything about the motivation for leaving this one in? Given the constant, were there plans

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

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

I am using the directshow Theora encoder to compress a live video stream. A dump of the encoder settings is given below. The starred settings have been explicitly configured and the others are defaulted or derived values. These settings produce an even, dark (almost black) recorded result as does any recording with Keyframe Freq <= 32. Keyframe Freq >32 works perfectly. The incoming

Hello, i am member of red5 project. I am studying ways to integrate your codec into red5 and in a near future inside Flash Player. I want to figure some things about Theora codec. -> Is theora proper for live streams (i.e live transcondig webcam)? What is latency for encoding process? -> Is the format tolerant to lost frames? Thanks for the moment.

Hi all, I finally understand how lipopusenc is capable of producing chainable Opus files (in contrast to my program), and I managed to successfully implement the method [1]. Essentially, the last frame of a file is marked as a "keyframe" by disabling prediction for this frame in libopus. This encoded keyframe frame is then copied in verbatim to the next file, with the pre-skip set to

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/

> From: Jay Sprenkle [mailto:cupycake_jay@yahoo.com] > I thought > you had to back up to the previous complete frame, > then apply the differences in the following frames > to generate a new complete frame where the splice > was to happen. Are you going to handle editing to > arbitrary frames? I believe you have to do something > analogous in theora/ogg. yup. > ---

I'm new to the list so please excuse me if this has already been rehashed before. There seems to be something very odd about how the PP_INSTANCE::PrevFragments array is handled during keyframes. I'm not a video codec expert so I'm not entirely sure what the reason for keeping a history of blocks updated in the last few previous interframes and adding them to the blocks to be