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Old 2nd February 2012, 22:03   #81  |  Link
sneaker_ger
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Originally Posted by QuantumRand View Post
Just out of curiosity, is there anything inherently bad about Target Average Bitrate encoding, other than it taking a long time?
No, two pass encoding is totally fine. Single pass ABR on the other hand has lower quality than CRF and two pass.

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Plus from what I've seen, turbo first-pass didn't have that huge of an effect on file size.
What else did you expect? ABR (both single and two pass) aims for a defined bitrate, so not having "that huge of an effect on file size" is totally meaningless in these modes.

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I've found that a 720p backup with an ABR around 5000kbps gives a pretty consistent ~2.2GB/hour.
Again: what else did you expect?
1h * 5000 kbit/s = 60s*60*5000kbit/s = 18,000,000 kbit ~= 2.2 GB

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And at 5000kbps, you can use the Normal preset and Turbo First-Pass and still get the same file size while still maintaining essentially transparent quality as you would with 16CRF. Turbo First-Pass, Normal preset takes like 25% longer than CRF16 on VerySlow but you get the same quality results. The file size is typically larger, but always consistent.
Frankly put, you're not making any sense. Don't use fast first pass if you only want to do only a single pass, use a faster preset instead.
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Old 2nd February 2012, 23:20   #82  |  Link
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how would this work (staring at libvpx docs):
-crf 21 -max-rate 5000 -preset variable-reencode-with-slower-preset-if-bitrate-limit-is-reached:else:lower-the-crf-and-tell-that-to-the-user ?
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Old 3rd February 2012, 01:51   #83  |  Link
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Frankly put, you're not making any sense. Don't use fast first pass if you only want to do only a single pass, use a faster preset instead.
I guess what I was getting at is that CRF mode seems to reduce the bitrate a little too much in some spots, exaggerating imperfections. This means you have to lower the CRF to points where the majority of the movie doesn't benefit, or you have to waste time experimenting with different CRF levels.

Assuming it actually does act this way, going the ABR route could avoid degraded quality in those situations, sacrificing some compression, but with a calculable result. But like I've said, I'm pretty new to the transcoding game, so I'm just making guesses.
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Old 3rd February 2012, 02:21   #84  |  Link
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This means you have to lower the CRF to points where the majority of the movie doesn't benefit, or you have to waste time experimenting with different CRF levels.

Assuming it actually does act this way, going the ABR route could avoid degraded quality in those situations, sacrificing some compression, but with a calculable result. But like I've said, I'm pretty new to the transcoding game, so I'm just making guesses.
This is an odd assumption, if some regions need a little more bitrate and lowering CRF "wastes" bits on regions that don't need it going ABR will make this even worse; it isn't as good at moving bits to where they are needed.

I think you want to play with psy settings and aq-strength instead of dropping crf.

Last edited by Asmodian; 3rd February 2012 at 02:25.
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Old 3rd February 2012, 03:03   #85  |  Link
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QuantumRand,
For the sake of full disclosure I discovered, due to participating in another thread, I'd been sending the wrong levels to the TV from my PC. I thought being a TV sending it TV levels would be correct, and the picture certainly looked fine to me, but after changing the levels and then adjusting the brightness to get it roughly back to where it was (I haven't tried to calibrate it properly yet) I had a look at the encodes I made of your samples again.
Most of the problems I could see before I can now no longer see because the dark areas are darker. Even the shot from above where the camera slowly turns and I said it appears to wobble..... the difference now between 1080p CRF 16 and 720p CRF 20 is fairly minimal. Not enough to really notice unless I compare the two. Even the scene of the sky where the blocking looked really obvious, well at 720p CRF 20 I can still see it if I look for it but during the process of watching a movie I'm not sure it's anything which would jump out at me.

shanndogg's samples are still a different matter. The darker areas now look pretty good but the banding in the lighter areas and the problem with dancing pixels is still something I can see fairly easily and still something which seems to get worse when encoding.
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Old 3rd February 2012, 05:18   #86  |  Link
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QuantumRand,
For the sake of full disclosure I discovered, due to participating in another thread, I'd been sending the wrong levels to the TV from my PC. I thought being a TV sending it TV levels would be correct, and the picture certainly looked fine to me, but after changing the levels and then adjusting the brightness to get it roughly back to where it was (I haven't tried to calibrate it properly yet) I had a look at the encodes I made of your samples again.
Most of the problems I could see before I can now no longer see because the dark areas are darker. Even the shot from above where the camera slowly turns and I said it appears to wobble..... the difference now between 1080p CRF 16 and 720p CRF 20 is fairly minimal. Not enough to really notice unless I compare the two. Even the scene of the sky where the blocking looked really obvious, well at 720p CRF 20 I can still see it if I look for it but during the process of watching a movie I'm not sure it's anything which would jump out at me.

shanndogg's samples are still a different matter. The darker areas now look pretty good but the banding in the lighter areas and the problem with dancing pixels is still something I can see fairly easily and still something which seems to get worse when encoding.
My issues with the banding were solved when I disabled the De-Noise feature in the Catalyst Control Center. CRF 17 did a good job compressing everything down, and the problem areas, while still visible, are certainly tolerable in a normal watching scenario. I'm happy with the result, especially since I don't think Thor is worth that much of my time, lol.

But like you said Shanndogg's issues are a different matter. The source itself has the banding issues. I think what he (she?) needs to do is focus on optimize the display settings, since the old TV didn't have the issue. I'd use the uncompressed sample as a guide for tuning in the settings to the best possible.

Maybe the TV's motion enhancement is screwing with things? Since I have my TV connected to my PC, I have all of the extra features turned off since the computer is capable of handling all of that better anyway.
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Old 3rd February 2012, 08:52   #87  |  Link
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I think what he (she?) needs to do is focus on optimize the display settings, since the old TV didn't have the issue. I'd use the uncompressed sample as a guide for tuning in the settings to the best possible.
A TV is not calibrated using uncompressed sources. It is calibrated using special patterns and methods to single out each element, then tune it accordingly.
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Maybe the TV's motion enhancement is screwing with things? Since I have my TV connected to my PC, I have all of the extra features turned off since the computer is capable of handling all of that better anyway.
The "extra features" are there for stupid people (sorry) that are more than happy to set them once and forget. With the notable exceptions of masochists and pros (who are anyway paid to do this, like it or not), nobody likes to fiddle the settings for each movie, show or whatever programme they watch. They also pay more for the TVs incorporating them, only to find out (if ) that the image is better without them activated.
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Old 3rd February 2012, 09:13   #88  |  Link
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But like you said Shanndogg's issues are a different matter. The source itself has the banding issues. I think what he (she?) needs to do is focus on optimize the display settings, since the old TV didn't have the issue. I'd use the uncompressed sample as a guide for tuning in the settings to the best possible.
I still don't think shanndogg's issues are related to calibration. I can see the banding on my PC monitor and I can see it on the TV both before and after changing the levels. It may be his old TV was hiding the problem somehow, or had some sort of built in deblocking or debanding which masked the problem. My TV has a digital noise filter and an mpeg noise filter and although I've not been able to determine exactly what they filter, one of them did reduce the blocking on a poor quality AVI I was using for testing. However when using the PC I have them turned off and they're set to "low" for the Bluray player.

And of course there's still the question as to why when converting his sample to uncompressed RGB, it makes the banding a lot worse. That doesn't make sense to me.
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Old 3rd February 2012, 09:38   #89  |  Link
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The "extra features" are there for stupid people (sorry) that are more than happy to set them once and forget. With the notable exceptions of masochists and pros (who are anyway paid to do this, like it or not), nobody likes to fiddle the settings for each movie, show or whatever programme they watch. They also pay more for the TVs incorporating them, only to find out (if ) that the image is better without them activated.
Just to clarify....
Is it the stupid people who pay more for a TV with extra features which they then happily set and forget while somehow still managing to discover the image looks better without them, or is it the non-stupid people paying paying more for TVs with "extra features" they're not going to use so they can be even less happy about fiddling with the settings for every movie?
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Old 3rd February 2012, 09:50   #90  |  Link
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The first category. It's the power of marketing.
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Old 3rd February 2012, 11:12   #91  |  Link
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Originally Posted by shanndogg View Post
7ekno - what profile do you use?
I use WDTV Lives and HTPCs, so not restrained to profile (yes, I have extensively tested my settings on a WDTV Live with level 5.1 and 5.0 profiles!) ...

Also note that I stated I degrained first before using those settings (so filesize is naturally reduced from degraining) ...

Personally I would use:
- Crop & Spline36 resize to 720p (or leave as 1080p)
- MCTemporalDenoise(settings="low", enhance=true)

Then encode with my previous settings (for 720p):
--crf 17 --tune film --preset veryslow --no-dct-decimate --aq-strength 1.15

Here is how I would have done the 720p versions:
http://www.teknosrealm.com/examples/001_720p.mkv
http://www.teknosrealm.com/examples/003_720p.mkv

7ek

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Old 3rd February 2012, 18:22   #92  |  Link
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The "extra features" are there for stupid people (sorry) that are more than happy to set them once and forget.
According to your tunnel vision, I'm in the category of "stupid people", too.

To keep it compact, here's a wall-of-text:

The strongest point, to me, indeed is the motion interpolation feature. I would not want to miss it from my TV anymore. Note that I do not, repeat: NOT like "soap opera" effects. But the problem is that it's not possible to really reproduce the so-called "film look" on any modern flatpanel display. Not without the help of additional "tools". Yes, film look is intended to show a kinda "rough" motion (and I like it.) But if you have e.g. a panning scene with a house front running through the frame, you are NOT supposed to see double- or, more likely, even triple- or quadrouple-contours on wall corners, windows,etc. But that's exactly what you get without motion interpolation. Necessarily, it can not be any other way. If each picture "stands" for 40 ms, but the eye is continuously moving as it is tracking any image feature, you necessarily get motion blur on the eye's retina. (And worse, it's even inverse motion blur, that is building up "backwards" during the integration time of one frame. But this gets a bit too far for this thread.) Is it so that self-conceived videophilists have "declared" such artifacts as being "the" film-look? To me, this simply is an optical artifact that should not be.... - Granted, I'm not sure how "all the various manufacturers" individually implement the feature. Anyhow, on my TV (Samsung) there is a rather fine-granulated control over the strength of the motion interpolation feature, and at low settings it does a mostly splendid job at reducing retina-motion-blur, while leaving the "rough" film look mostly intact.
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Old 3rd February 2012, 19:21   #93  |  Link
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[QUOTE=Didée;1555695]According to your tunnel vision, I'm in the category of "stupid people", too. /QUOTE]

Not at all, I like it too to have this kind of setting. But it should work correctly.

Unfortunately the one that decides what "improvements" are implemented and which not, is someone with the rot pencil, that listen more the marketing dept. than the engineering one. The customer['s opinion] doesn't count, if he doesn't buy, just lower a bit the prices and he will. Eventually. Because he has no real alternatives, or they cost way too much.
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Old 3rd February 2012, 20:24   #94  |  Link
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A film is NOT intended to show a rough motion. It was the limits of film reacting to light almost a century ago, and we haven't left it yet. If film was invented today, we would be going with hundreds of FPS and no one would say boo about the smooth motion looking too realistic. If you want your old movies to be choppy, then fine, but I don't think new movies should still suffer from it. They're new, and they should look new. By your logic, movie audio should just be mono so we know it's a movie, yet we strive to realism in the sound. But oh no!...once you get into specs on the picture, it's taboo to be new.
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Old 3rd February 2012, 20:43   #95  |  Link
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Unfortunately the one that decides what "improvements" are implemented and which not, is someone with the rot pencil, that listen more the marketing dept. than the engineering one. The customer['s opinion] doesn't count, if he doesn't buy, just lower a bit the prices and he will. Eventually. Because he has no real alternatives, or they cost way too much.
The nothing like following up a post of silly generalizations with another one even sillier.

Sure the marketing department can do it's job well, but have you heard of competition? Is a manufacturer going to ignore the engineering department when they announce they've found a way to do feature X better than everyone else if they think it'll help them sell more TVs? And yes of course new features are generally added to the more expensive models first, but it doesn't mean they can't trickle down to be included as standard on the average smart phone in a few years time.

I don't know who ramicio is arguing against. Who said film shouldn't be allowed to use higher frame rates?
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Old 3rd February 2012, 20:58   #96  |  Link
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Sure the marketing department can do it's job well, but have you heard of competition? Is a manufacturer going to ignore the engineering department when they announce they've found a way to do feature X better than everyone else if they think it'll help them sell more TVs? And yes of course new features are generally added to the more expensive models first, but it doesn't mean they can't trickle down to be included as standard on the average smart phone in a few years time.
There is no competition, my dear.

Or maybe who against whom? JVC versus Technics versus National versus Panasonic versus whatever-subsidiary-Matsushita-corp might have? Or maybe between the 101 companies Harman-Kardon fully owns?

Or maybe the 5 bigs in cellphone technology suddenly began to compete, ending a 20 years period of cartell-dealings?

There is definitively competition in electric toothbrushes industry, yes! But, no, wait, Philips sold everything except medical and lighting, no way... gosh, I almost found one ...
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Old 3rd February 2012, 21:02   #97  |  Link
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I don't know who ramicio is arguing against.
The "who" is not important. Important is the "against".
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Old 3rd February 2012, 21:13   #98  |  Link
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There is no competition, my dear.
No..... at least not for offering generalizations and confabulations
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Old 7th February 2012, 23:23   #99  |  Link
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QuantumRand,
For the sake of full disclosure I discovered, due to participating in another thread, I'd been sending the wrong levels to the TV from my PC.
After reading your post and the other thread about black levels, I went and reexamined all of my settings and found something interesting:

The Boxee Box which plays my MKVs was outputting RGB Low (16-235). On another site for the Panasonic VT30 series, it was indicated to have your Bluray player output YCbCr 4:2:2 (this is what I have my Bluray player set to). So I tried setting the Boxee Box to output YUV 4:2:2 (I assume it's the same as the Bluray player YCbCr?). Guess what? The original 720p file that looked really bad to me know looked way better... almost transparent and definitely acceptable. The 1080p's still looked better, but I could probably live with the 720p. Does this make sense?

Previously, I had the Bluray player and Boxee both outputting RGB low to the Sharp LCD and never had a problem. I remember I tried YCbCr on the bluray before with the Sharp, but it caused a weird flickering in the letterboxed portion of Blurays/DVDs.

Now, with the Panasonic, it looks like I need 4:2:2. I tried 4:4:4 but couldn't tell an immediate difference. With the difference so big between RGB and 4:2:2 on the Panasonic, I am wondering how the hell are you supposed to know what to use (RBG low/high, 4:2:2, 4:4:4) for which source/display?
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Old 8th February 2012, 00:13   #100  |  Link
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Now, with the Panasonic, it looks like I need 4:2:2. I tried 4:4:4 but couldn't tell an immediate difference. With the difference so big between RGB and 4:2:2 on the Panasonic, I am wondering how the hell are you supposed to know what to use (RBG low/high, 4:2:2, 4:4:4) for which source/display?
4:2:2 = low bandwidth 4:4:4. 4:4:4 is just better and doesn't change anything vs 4:2:2. Not that you can tell and your source content is almost surly 4:2:0 anyway but I wouldn't do much testing of 4:2:2 vs 4:4:4.

RGB low/high is one of those terrible names. Is RGB low = 16-235 or 0-255? I assume low = 16-235 because if you just switch back and forth between 16-235 and 0-255 using 16-235 looks darker.

EDIT: This is wrong! 0-255 looks darker (expanding 16-127 to 0 to 127 streaches more values into the "darker" range, 128-235 -> 128-255 does the same, makeing bright seens brighter but this is less noticable)

Anyway the YCbCr spaces (i.e. 4:4:4) allow your TV to do the conversion to RGB while if you set RGB out you need to pick the right one (16-235 for normal blurays etc.). How your TV does the convertion from YCbCr to RGB is up to it.

Last edited by Asmodian; 8th February 2012 at 21:33. Reason: fixed wrong statement, evil low/high limited/full confusion
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