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Old 3rd April 2013, 04:48   #141  |  Link
Dark Shikari
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Quote:
Originally Posted by foxyshadis View Post
It's actually a reasonably fast range coder, and keeps separate state in both threads; most of the time seems to be spent in prediction, which is already SIMD'd to hell and back.
That seems kind of hard to believe -- median prediction only takes a few SIMD operations per 16 pixels, while even a highly optimized arithmetic coder like x264's takes a dozen or two cycles per output bit. Is something else odd going on here?
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Old 4th April 2013, 01:01   #142  |  Link
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Is anyone able to decode Lagarith with the 64 bit version of Avisynth?
I get FourCC error.

I can decode it if i use Lavfilterīs decoder for it though, but itīs a bit problematic.
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Old 3rd July 2013, 22:13   #143  |  Link
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A kind soul would add multithreaded colorspace rgb<->yuv conversion as well - a fairly straightforward optimization, which would make both encoding+decoding faster.
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Old 5th November 2013, 04:09   #144  |  Link
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Can anyone add YV24 support to Lagarith, please?
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Old 16th November 2013, 19:07   #145  |  Link
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I am experimenting with re-writing Lagarith to support high-bitdepth (10 bits/color channel or more). To do this though, I need to know what color formats would be the most useful, and sample videos in those formats. Hopefully, some people in this thread would be willing to provide such video. My criteria for test video is as follows:
  • Must be from a source that uses the full bitdepth (upsampled video will not properly test the compression).
  • Should not have lossy compression applied
  • Should not have been resized
  • Uncompressed AVI would be the desired format, since it guarantees that I will be able to access the video
  • Should be short to keep the file size reasonable (100 frames or so is plenty)
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Old 16th November 2013, 19:49   #146  |  Link
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Donīt have any sample videos, but can say state some color formats.

First YV24, even though itīs mostly unnecessary, it shouldnīt be to hard to implement while you are at it.
And then Rec.709, which is extremely useful but very rarely supported in a lossless codec.

Well thatīs probably about it now that i think about it, i hope that was something you wanted to know, or perhaps you wanted to know something about bitdepth and such, if so i provided the wrong information.

I hope you see this through, Lagarith is an underestimated codec, and whatīs it mostly is lacking is support and perhaps tweaks for encoding/decoding with newer CPU instructions.

EDIT:

Original 10bit videos will probably be quite hard to obtain, but itīs fairly simple to make one.

Take a video with much darkness and gradients. Fix it with Avisynth and work in 16bit.
Dither it to 10bit.

That way it wonīt be upsampled from 8bit for no reason, and there should be pretty useful information in the last 2 bit that should have impact on compression.

But of course a 10bit Broadcast tape would be preferred, but canīt see a way to obtain one if you donīt have some good contacts.

Last edited by zerowalker; 16th November 2013 at 22:10.
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Old 17th November 2013, 00:51   #147  |  Link
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The better reason to support YV24 (and YV16, YV411, and Y8) is because that rounds out all the colorspaces that AviSynth 2.6 supports.

And really, if Rec.709 support gets added, might as well future-proof it a bit and also add Rec.2020.
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Old 17th November 2013, 00:57   #148  |  Link
raffriff42
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ffmpeg can make nice high bit depth / deep color test videos...
EDIT test ramps seem to be generated with 8-bit math - sorry for not checking previously.
Try this thread: http://forum.doom9.org/showthread.php?t=158836

Last edited by raffriff42; 17th November 2013 at 18:34.
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Old 17th November 2013, 20:45   #149  |  Link
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I can use upsampled or generated high-bitdepth video for developing and testing for losslessness, but to really tune the compression algorithms and speed optimizations, I need real footage. The upsampled/generated video simply won't have the same statistical distribution for the synthesized bits, and that could skew the results. I don't need test video immediately either, just in the next couple of months.

Since this would be a re-write, I would like to simplify how color formats are handled so it is easier to support more of them. YV24 and YV8 would probably be added, and Lagarith can already support encoding YV16.

I don't think I will add an option for Rec.709 (or Rec.2020), since it is another option the user has to get right or they can introduce noticeable loss. I feel that is an option better left to the encoding or decoding program.
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Old 17th November 2013, 22:00   #150  |  Link
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OK try:EDIT

Last edited by raffriff42; 20th November 2013 at 09:53.
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Old 17th November 2013, 23:04   #151  |  Link
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Do you have any use for crummy-looking 10-bit footage? I can send you some VHS captures in v210, but I haven't figured out how to verify if the devices are actually filling those bits.
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Old 17th November 2013, 23:56   #152  |  Link
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Quote:
Originally Posted by SirLagsalot View Post
I need real footage.
Define "real". Every 10bit footage is artificially produced one way or another. If Ill take some video, apply to it 16bit color correction, dither it down to 10bit - would that be real enough for you?

Edit: actually sorry. something like that was already suggested by zerowalker. Only that "Broadcast tape" is not any different and just as "real" as the footage people here proposed.

Last edited by Keiyakusha; 17th November 2013 at 23:59.
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Old 18th November 2013, 01:40   #153  |  Link
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Howso? If color-correcting a 10-bit source was no different than starting from an 8-bit source, there would be no high-depth film scanners.
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Old 18th November 2013, 04:27   #154  |  Link
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Quote:
Originally Posted by ChiDragon View Post
Howso? If color-correcting a 10-bit source was no different than starting from an 8-bit source, there would be no high-depth film scanners.
If you answered to me, whatever you don't understand what I'm saying or I poorly explained it. By "If Ill take some video" I mean if I'll take 8-bit video. And after color correction, new color values will be created. Resulting footage is just as "real" as any other 10bit footage. And in fact may be even better, as most of the 10bit footage is created during production and not by scanners. Of course 3DCG rendered at 10+bits is an option too.

Last edited by Keiyakusha; 18th November 2013 at 04:36.
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Old 20th November 2013, 04:27   #155  |  Link
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Quote:
Originally Posted by Keiyakusha View Post
Define "real".
Either unprocessed source from a high-bitdepth camera, film scanner or similar capture source, or complex CG renderings done in high-bitdepth. Footage from an analog capture source is what I am most interested in, since I want to see how noisy such sources are. I figure if Lagarith can handle those types of footage well, it'll shouldn't have any trouble on upsampled video.

Quote:
Originally Posted by raffriff42
Links
Those look like they should be useful.

Quote:
Originally Posted by ChiDragon
Do you have any use for crummy-looking 10-bit footage? I can send you some VHS captures in v210, but I haven't figured out how to verify if the devices are actually filling those bits.
Sure, I can check if it is using the full bit-depth.
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Old 24th November 2013, 11:05   #156  |  Link
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Wait, are Broadcast Tapes 10bit upsampled?
Arenīt those originally in 10bit, but everything that actually shows to the World (Cinema, TV, DVD you name it) is 8bit, so the actual original (At least for broadcasts) are never actually seen?
It makes no sense if they just have 10bit tapes for the heck of it, if all material is actually 8bit, and when they are going to show it, they dither it down after it was upsampled once.


EDIT:

Not adding Rec.709 etc will actually be worse than not adding it.

As if you have RGB and save it to YV something, you will automatically convert it to Rec.601, so if thatīs wrong the only way to solve it is through Avisynth and Colormatrix conversion, which is a lot more advanced, and also not perfect.
I think you could add it as, "Expert", or something, cause Decoding will not solve this if itīs converted, as it will stay Rec.601 all the time.

Last edited by zerowalker; 24th November 2013 at 11:21.
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Old 24th November 2013, 20:08   #157  |  Link
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Quote:
Originally Posted by zerowalker View Post
Wait, are Broadcast Tapes 10bit upsampled?
Arenīt those originally in 10bit, but everything that actually shows to the World (Cinema, TV, DVD you name it) is 8bit, so the actual original (At least for broadcasts) are never actually seen?
It makes no sense if they just have 10bit tapes for the heck of it, if all material is actually 8bit, and when they are going to show it, they dither it down after it was upsampled once.
Storing in higher precision makes it possible to do overlays, color correction, etcetera without having to add more dither with every single filter. The same reason professional formats are all 4:2:2 even though all delivery formats are 4:2:0.
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Old 25th November 2013, 01:49   #158  |  Link
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I see, so 4:2:2 are also upsampled?
Though i am pretty sure that thing were broadcasted as 4:2:2 before Digital took over.
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Old 25th November 2013, 02:14   #159  |  Link
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zerowalker
You are doing too strong accent on the word "upsampled". For some reason I feel some kind of disappointment in your posts. It doesn't matters if it's upsampled or not. Also even though video often starts as 8bit, if some 16/32 bit processing applied to it (after which it is dithered to 10bit for archiving, delivery, whatever), you can no longer call it "upsampled". It became "real".

Quote:
Originally Posted by SirLagsalot View Post
I figure if Lagarith can handle those types of footage well, it'll shouldn't have any trouble on upsampled video.
If you're talking about upsampled video that was simply converted 8->16bit without any further modifications.... why would someone want to compress it with lagarith? I don't see the reason for that. I only happens when you was requested to deliver some footage in some "standard" format, which happened to be 10bit. In case of lagarith one would compress it before upsampling and upsample when needed. But I also don't think one would use 10bit lagarith for raw noisy captures. Not in professional world. And most likely more casual users won't do it either.
If you're talking about upsampled video that received some kind of processing on top of that, as I said above, I don't think you can call it "upsampled" anymore. This is exactly the kind of content for which you want to optimize the encoder. And not for some random noise... unless for lagarith it doesn't matter which content you have. But then there is even less reasons to optimize for something exotic

Last edited by Keiyakusha; 25th November 2013 at 02:34.
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Old 25th November 2013, 04:19   #160  |  Link
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Quote:
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why would someone want to compress it with lagarith?
For finding best x264 settings while not loosing time on repeating previoud work.
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