I sent a little mail some time ago asking if there was going to be an ogg pic-format, and you replied that PNG, MNG and JNG is good enough (sorry for this late answer btw).. But, consider this: The ogg video-format (tarkin ? where do you get these names from anyway ? :) ) needs a way to compress its frames. Are you going to use MNG for that ? :) .. If you had an ogg pic format, that format could not only be used for normal pictures, but also for animations and movies! Both pictures, animations and "real" movies (should) have this in common: compress it to as good quality and small size as possible. Why not make all in one ? This format could also support some cool stuff that PNG doesn't, like layers. Actually, layers could simply be a special kind of animation, where all the frames are put on top of each other at once. Layered animations would then be animated animations :) . In animations, layers could even be shared for different frames! For movies this layer function could be used for fx. translation of text in the picture (normal subtitling should of course be text with timecodes). So, what do you think ? :) Gerry --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Gerry wrote:> I The ogg video-format (tarkin ? > where do you get these names from anyway ? :) )A few possibilities: 1) Grand Moff Tarkin - the nasty governor in Star Wars played by Peter Cushing. (I hope Lucasfilm Ltd. doesn't have trademark issues with this...) 2) St. Tarkin - Scottish Bishop in the 700's. Eric --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
> The ogg video-format [...]needs a way to compress its > frames. Are you going to use MNG for that ? :) ..No. The advantage of MNG is that it offers lossless compression if you want it. Tarkin will be a (very) lossy encoder specifically for video; the design requirements there are quite different and are best implemented as a separate format. MNG can be used as a high quality "source" format for video such as one needs for editing and effects work. Tarkin would be the final output format for electronic distribution. It was also my proposal that we use MNG for overlays on top of tarkin video, a la DVD subtitles. With text and other annotations the lossless nature and support of limited color palettes is a real win. And because of jng, there's support for lossy continuous-tone images as well. (think "pop-up-video") MNG was in fact designed for animation, and natively supports both layers and sprite animation. In that case it may back a good distribution format as well.> So, what do you think ? :)I think your enthusiasm is great, but you should do more homework before jumping in. :-) Cheers, -ralph ================================================================Internet service provided by telus.net http://www.telus.net/ --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Gerry wrote:> > I sent a little mail some time ago asking if there was going to be an ogg > pic-format, and you replied that PNG, MNG and JNG is good enough (sorry for > this late answer btw).. But, consider this: The ogg video-format (tarkin ? > where do you get these names from anyway ? :) ) needs a way to compress its > frames. Are you going to use MNG for that ? :) ..Well, have you ever tried saving a movie in MNG format? I doubt it'd compress very well compared to for example MPEG. I don't know the details of MNG, but if it's lossless like PNG then compression won't be good. And there's no need for it to be lossless since our brains only need a small amount of the information present in the stream. Thing is, if you store a bunch of images you're not exploiting inter-frame coherency, which is a real compression-killer.> If you had an ogg pic format, that format could not only be used for normal > pictures, but also for animations and movies! Both pictures, animations and > "real" movies (should) have this in common: compress it to as good quality > and small size as possible. Why not make all in one ? This format could also > support some cool stuff that PNG doesn't, like layers. Actually, layers > could simply be a special kind of animation, where all the frames are put on > top of each other at once. Layered animations would then be animated > animations :) . In animations, layers could even be shared for different > frames! For movies this layer function could be used for fx. translation of > text in the picture (normal subtitling should of course be text with > timecodes).Well, it's all the same really. A movie is a 3D block of information, so is a layered image. A layered movie is 4 dimensional. The difference is just a couple of flags to specify what is what, and possibly optimisations in the encoder. The currently available early experimental tarkin sources use an n-dimensional wavelet transform (currently 3D only, but the code is generic) and vector quantisation on the wavelet coefficients, which works well. I'm attempting to do cross and inter-frame fractal compression, using arbitrary triangles and edge detection and matching logic to speed up the process. So far it's not working, and I need to study so I don't have much time to hack. But I should be able to work on it again in a week or two, so I'll have another go at it then. Still, video coding is a very complex thing, and I have a feeling that existing theories and algorithms are nothing compared to what's possible.> So, what do you think ? :)I think that depending on the algorithms used to compress video it may still be useful to have a single image compression. On the other hand, if the images are all different then they will be detected by the encoder as all base-frames and encoded more or less independently anyway. Lourens --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
> I sent a little mail some time ago asking if there was going to be an ogg > pic-format, and you replied that PNG, MNG and JNG is good enough (sorry for > this late answer btw).. But, consider this: The ogg video-format (tarkin ? > where do you get these names from anyway ? :) ) needs a way to compress its > frames. Are you going to use MNG for that ? :) ..We need a lossless and a lossy compression format. One format generally doesn't do both well (Tarkin, for example, currently assumed a time dimesion in order to work properly).> If you had an ogg pic format, that format could not only be used for normal > pictures, but also for animations and movies! Both pictures, animations and > "real" movies (should) have this in common: compress it to as good quality > and small size as possible. Why not make all in one ? This format could also > support some cool stuff that PNG doesn't, like layers. Actually, layers > could simply be a special kind of animation, where all the frames are put on > top of each other at once. Layered animations would then be animated > animations :) . In animations, layers could even be shared for different > frames! For movies this layer function could be used for fx. translation of > text in the picture (normal subtitling should of course be text with > timecodes).This will be possible at very least at the Ogg level (specifying multiple video layers with alpha channel for overlay). Monty --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
At 6:41 PM +0100 1/26/01, Gerry wrote:>Both pictures, animations and >"real" movies (should) have this in common: compress it to as good quality >and small size as possible. Why not make all in one ?Except, of course, that they have very different perceptual and temporal characteristics. For instance, the Discrete Cosine Transform used in JPEG and MPEG can result in lots of visual noise in large single-color areas. Most animation consists of a large number of large single-color areas. Hence a compression scheme built around a DCT isn't the best for animation. Similarly, computer images will generally either be in an RGB or CMYK color space (depending on how they were generated/acquired and where they're eventually destined to be displayed). Video, on the other hand, is usually both captured and displayed in a luminance/chromanance format (often 4:2:2 Y'Cb'Cr'). These three color spaces have very different gamuts and perceptual behaviors. (For instance, with color printing -- CMYK, aka "process colors" or subtractive primaries -- you also have to worry about halftone patterns and dot gain.) -- Chris -- Chris Hanson <cmh@bDistributed.com> bDistributed.com: Making Business Distributed --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.