similar to: Encoder keyframe frequency limited to >32

My apologies if this is considered somewhat off-topic but I presume that this information may be may also be of use to others using these filters. Is there someone with a better understanding of COM than I have who can tell me where I'm going wrong with the following C# interface definition? I can set and recover a quality setting using this interface but not the isUsingQualityMode flag. Not

I have an application written in c# which uses two instances of the theora encoder in a single filtergraph. Each one is followed by an ogg multiplexer for output to separate files. When I run the filtergraph the smaller video's buffer is intermittently written to the start of the larger video's buffer. I am using the latest filters from opencodecs_0.84.17338.exe and the smaller video is

Hi, I'am using the Xiph Theora Encoder directshow Filter in a csharp application. It works fine but I would like to modify the configuration, like the quality settings. I would like to know if there is a possibility to configure it programmatically without using the propertyPage dialog. Thanks a lot for your help Mathieu -------------- next part -------------- An HTML attachment was

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

(I think Timothy intended for this to go to the list; my apologies if it wasn't.) -------- Original Message -------- Subject: Re: [Theora-dev] Force keyframe creation Date: Sat, 06 Aug 2005 00:06:32 -0400 From: Timothy B. Terriberry <tterribe@vt.edu> To: David Barrett <dbarrett@quinthar.com> References: <42F4186C.1050605@quinthar.com> David Barrett wrote: > Is there any

Hi all, Attached is a trivial patch that speeds up encoding for key frame only streams. It skips the motion vector search which is not needed when there are never going to be any delta frames. It was made against thusnelda SVN revision 14589. Tested on Fedora 8 x64_64. -Phil -------------- next part -------------- A non-text attachment was scrubbed... Name:

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

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

Hello everybody ! I am working on a php class to enable, on the server-side, to extract useful data from Ogg theora videos. http://opensource.grisambre.net/ogg . I need to have it extract a thumbnail picture from a video (much like dailymotion or youtube). Right now, I am doing it using the ffmpeg-php extension (for picture extraction only), but the problem is that this module is available on

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

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

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

4) Subtract 1 from the keyframe, then repeat step 3). 5) Begin reading from the frame discovered in step 4. Drop any packets which are output on the first page. Count down until we reach the keyframe, dropping packets until then. 6) Continue counting down until we reach the target frame, we are now decoding each frame/packet. At the target frame produce the YUV output. Steps 4 and 5 are

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

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

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.

On Feb 11, 2008 9:27 PM, ogg.k.ogg.k@googlemail.com < ogg.k.ogg.k@googlemail.com> wrote: > > 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

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

<br> 4) Subtract 1 from the keyframe, then repeat step 3).<br> <br> 5) Begin reading from the frame discovered in step 4. Drop any packets<br> which are output on the first page. Count down until we reach the<br> keyframe, dropping packets until then.<br> <br> 6) Continue counting down until we reach the target frame, we are now<br> decoding each

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