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Old 22nd September 2015, 15:52   #41  |  Link
Music Fan
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Originally Posted by kolak View Post
Question is: can it be done in many ways or just 3:2:3:2:2 (I think this is what I have been told as 13 step cadence)?
You could maybe try to double one frame all 5 frames (and you will get 30p that you can interlace), but I'm not sure it will be better than what you propose, this could even be worse.
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Old 22nd September 2015, 16:15   #42  |  Link
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@kolak
You may want to check out this:
http://rationalqm.us/dgpulldown/dgpulldown.html

The 13 step cadence has been discussed somewhere along this thread:
http://forum.doom9.org/showthread.php?s=&threadid=88031

which finally lead to the development of the DGpulldown tool.
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Old 22nd September 2015, 16:16   #43  |  Link
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This unknown 13 step cadence is 2:2:3:2:3, so nothing fancy.
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Old 22nd September 2015, 16:18   #44  |  Link
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Originally Posted by Sharc View Post
@kolak
You may want to check out this:
http://rationalqm.us/dgpulldown/dgpulldown.html

The 13 step cadence has been discussed somewhere along this thread:
http://forum.doom9.org/showthread.php?s=&threadid=88031

which finally lead to the development of the DGpulldown tool.
Thanks, yes I figure it out.
My last question is about scene changes- can it create bad scene cuts?
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Old 22nd September 2015, 16:28   #45  |  Link
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Thanks, yes I figure it out.
My last question is about scene changes- can it create bad scene cuts?
In case of interlaced frames one field may be taken from scene A and the second field may come from scene B, I think
(If this is what you mean by bad scene cuts?)
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Old 22nd September 2015, 16:42   #46  |  Link
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Yes, this can cause problems when watched don TV with flashes on scene changes (or not). This is my remaining question.
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Old 22nd September 2015, 16:50   #47  |  Link
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Perhaps you can get more help when you post in Donald Graft's (DG...) forum:
http://rationalqm.us/board/index.php
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Old 22nd September 2015, 17:01   #48  |  Link
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Better my ass
Even 4k doesn't actually hit the limit of human vision of spatial resolution, and 1920x540??? You gotta be kidding me
And yet 24fps already looks kinda smooth to human eyes
There is a lot of strong opinion, and coarse language being voiced, but not a lot of factual information.

The collective wisdom of the engineers who designed both the original NTSC standard, and then the different set of engineers who designed our current set of international digital standards beats my knowledge of the subject, and also trumps everyone else in this forum. They understand the broad scope of all the engineering tradeoffs far better than anyone here.

As for 4K not hitting the limit of human visual resolution, that is a perfect example of the narrow filter being used to make such statements. It completely fails to take into account the most important element in any discussion of resolution, which of course is screen size. I spent a decade in the desktop publishing revolution, and in the print world, resolution is usually expressed in dots per inch or lines per inch, not in terms of total pixel count. When talking about video, DPI is seldom used, but for this discussion it is a more important measure than pixel count.

Why?

Well, as an obvious and irrefutable example, 4K video on a hand-held device will be indistinguishable from even 720p because the human eye cannot see the difference when all those dots are crammed together in a small space. This continues to be true even as you go to larger displays like small (13 "- 19") TV sets and computer displays. However, when you get to the lower end of current "big screen" TVs, let's say 55" diagonal size, you begin to see differences, but they are subtle. As you watch on displays larger than that, most people will begin to see the differences.

So, when the discussion is about 4K vs. 1920x1080 (interlaced or progressive), the spatial differences don't really become apparent or important, until you get to pretty big displays, and therefore 4K really is not important -- and never will be important -- unless the customer is watching on a really large display.

We've had this discussion over at the Sony forum, and the general consensus there is that, for display in the home, 4K is not going to be a big deal, but that it is a fantastic acquisition format, and that it is also a major innovation for theatrical projection. Having been to many 4K demonstrations, I completely agree: on small screens, it is not compelling, and in fact, no one tell the difference. We can debate at what screen size the difference becomes important, but I don't have any good, objective measure to offer to help define that. My general sense is that under ideal conditions, you can begin to see a difference at around 45" displays, but for most people (and that is key when talking about market size and commercial viability), the difference won't be important until you get to much larger displays.

Oh yes, seating distance from the display is also important.

Finally, the whole issue of interlacing comes up because the human brain really can tell a difference -- and it is not a subtle difference -- between 24 temporal events per second and 60 temporal events per second. As has already been mentioned, it is not as fun to watch sports at 24p or even 30p, as ESPN streams on the web. Therefore there is a lot of incentive to design a system that can transmit and display 60 temporal events per second, but at a price that most people can afford, and with technology that can actually be mass-produced.

I really do not understand the hostile tone in so many of these posts. We have some great choices in how we acquire our own video, and 60p 1920x1080 is easily available to everyone, so if you don't like some of the other standards, you don't ever have to deal with them. You can also easily get 4K camcorders. Use those and be happy.

Finally, the people here in this forum who seem to "hate" interlacing also claim to never watch TV. I am truly puzzled as to why they even care about something that they don't have to deal with.
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Old 22nd September 2015, 17:12   #49  |  Link
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No, I need 25p to 60i to be as smooth as possible.
As others have said, there is no "magic" pattern that is going to be better. If you want to reduce the problem, you can do what the "pros" have been doing for years, which is to change the playback speed of the original, without altering the frame at all, and then do your pulldown on that. This has been suggested in many other similar threads in this forum, but I don't think it has been mentioned here (I may have missed it). What you do is use assumefps(24) to change the playback speed, and then apply a standard 3:2 pulldown what results from that. You then adjust the audio speed, without changing pitch. I do that in Vegas, but others may know of a way to do it in AVISynth. Yes, the result will play a little slower, but that "artifact" may be more agreeable to you than the judder you get from pulldown needed to go from 25p.
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Old 22nd September 2015, 17:25   #50  |  Link
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What you do is use assumefps(24) to change the playback speed, and then apply a standard 3:2 pulldown what results from that. You then adjust the audio speed, without changing pitch. I do that in Vegas, but others may know of a way to do it in AVISynth.
If it's for an Ntsc dvd, one don't even need to create 3:2 pulldown ; feed the mpeg-2 encoder with 23.976 fps and encode in soft pulldown, the encoder will create the 3:2 pulldown flag (most of movies are encoded this way on Ntsc dvds).
To change audio speed and/or pitch, I use Hybrid (which uses Sox for audio changes) ;
http://forum.doom9.org/showthread.php?t=153035
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Old 22nd September 2015, 17:28   #51  |  Link
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If it's for an Ntsc dvd, one don't even need to create 3:2 pulldown ; feed the mpeg-2 encoder with 23.976 fps and encode in soft pulldown, the encoder will create the 3:2 pulldown flag (most of movies are encoded this way on Ntsc dvds).
To change audio speed and/or pitch, I use Hybrid (which uses Sox for audio changes) ;
http://forum.doom9.org/showthread.php?t=153035
Yes, that's what I meant to say. Thanks for the correction.
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Old 22nd September 2015, 17:30   #52  |  Link
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In case of interlaced frames one field may be taken from scene A and the second field may come from scene B, I think
(If this is what you mean by bad scene cuts?)
In this case, my idea to create 30p and simply encode it as interlaced (fake) is maybe not so bad because all the fields are kept, thus different frames won't be mixed.
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Old 22nd September 2015, 17:42   #53  |  Link
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Originally Posted by johnmeyer View Post
As others have said, there is no "magic" pattern that is going to be better. If you want to reduce the problem, you can do what the "pros" have been doing for years, which is to change the playback speed of the original, without altering the frame at all, and then do your pulldown on that. This has been suggested in many other similar threads in this forum, but I don't think it has been mentioned here (I may have missed it). What you do is use assumefps(24) to change the playback speed, and then apply a standard 3:2 pulldown what results from that. You then adjust the audio speed, without changing pitch. I do that in Vegas, but others may know of a way to do it in AVISynth. Yes, the result will play a little slower, but that "artifact" may be more agreeable to you than the judder you get from pulldown needed to go from 25p.
There are many case when you can't touch speed.

I'm not looking for "other" ideas (I know all of the possibilities), but strictly asking for pulldown method.
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Old 22nd September 2015, 17:48   #54  |  Link
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Finally, the whole issue of interlacing comes up because the human brain really can tell a difference -- and it is not a subtle difference -- between 24 temporal events per second and 60 temporal events per second. As has already been mentioned, it is not as fun to watch sports at 24p or even 30p, as ESPN streams on the web. Therefore there is a lot of incentive to design a system that can transmit and display 60 temporal events per second, but at a price that most people can afford, and with technology that can actually be mass-produced.
This is a very funny statement to make because it's a lot easier to just do away with interlacing and go with 60 frames per second, progressive. Sure, bandwidth is doubled, but only in terms of sample count. This is literally not a problem with lossy compression. I'm all ears if you can find a study proving me wrong.

Far as I can tell, feisty2 is the only person in this thread claiming that 24 fps is good enough. I think everyone else agrees that having 60 pictures per second allows for far more fluid motion than just 24 or 30.

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Finally, the people here in this forum who seem to "hate" interlacing also claim to never watch TV. I am truly puzzled as to why they even care about something that they don't have to deal with.
This is so far off base I don't even know how to reply to this, but lol, you tried.
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Old 22nd September 2015, 18:30   #55  |  Link
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There are many case when you can't touch speed.

I'm not looking for "other" ideas (I know all of the possibilities), but strictly asking for pulldown method.
I am glad you know of all the possibilities. I wish I could be that good.

Sorry for trying to help.

Last edited by johnmeyer; 22nd September 2015 at 18:45.
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Old 22nd September 2015, 18:43   #56  |  Link
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Far as I can tell, feisty2 is the only person in this thread claiming that 24 fps is good enough. I think everyone else agrees that having 60 pictures per second allows for far more fluid motion than just 24 or 30.
So do I. See my post earlier in this thread where I also agreed that 60p is always preferable to 60i: johnmeyer agrees that 60 is preferable to 24 or 30, and 60p trumps 60i

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Originally Posted by johnmeyer View Post
Finally, the people here in this forum who seem to "hate" interlacing also claim to never watch TV. I am truly puzzled as to why they even care about something that they don't have to deal with.
This is so far off base I don't even know how to reply to this, but lol, you tried.
This is a long thread, so perhaps you missed post #8: I hardly even watch TV, much less interlaced TV,.

So, actually, not off base at all. Also, if I wanted to spend the time, I could keep going and show you the posts where people imply that they don't watch "regular" TV very often.

Last edited by johnmeyer; 22nd September 2015 at 18:46.
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Old 22nd September 2015, 18:51   #57  |  Link
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Therefore there is a lot of incentive to design a system that can transmit and display 60 temporal events per second, but at a price that most people can afford, and with technology that can actually be mass-produced.
There was a lot of incentive. Digital video is perfectly capable of transmitting 60 temporal events per second without resorting to interlacing, which is only clinging to existence thanks to a self-perpetuating loop of legacy support. Look at the amount of computing power required to run QTGMC, then consider that your TV - if it's a good one - has to do something similar just to give you a nice picture.

Quote:
The collective wisdom of the engineers who designed both the original NTSC standard, and then the different set of engineers who designed our current set of international digital standards beats my knowledge of the subject, and also trumps everyone else in this forum. They understand the broad scope of all the engineering tradeoffs far better than anyone here.
Then it should interest you to know that: "The European Broadcasting Union has argued against interlaced video in production and broadcasting. They recommend 720p 50 fps (frames per second) for the current production format—and are working with the industry to introduce 1080p50 as a future-proof production standard.

"Broadcasters are still using interlacing so it must be a good thing" is really shaky logic. They seem to want rid of it just as much as everyone else.

Interlacing was a brilliant idea when it was conceived, but without it the entire broadcasting chain would be much more efficient.
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Old 22nd September 2015, 19:03   #58  |  Link
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There are many case when you can't touch speed.

I'm not looking for "other" ideas (I know all of the possibilities), but strictly asking for pulldown method.
In this case this plugin may also be out of your interest, so never mind I mention it. It seems to have some parameters to control scene changes and it claims maximum playback fluidity. I have no experience with this plugin, so I can't tell how it copes with the "soap opera" effect etc.
https://www.svp-team.com/wiki/Plugins:_SVPflow
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Old 22nd September 2015, 19:31   #59  |  Link
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This is a long thread, so perhaps you missed post #8: I hardly even watch TV, much less interlaced TV,.
Do you want an award in selective reading? I think you deserve it.
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Last edited by colours; 22nd September 2015 at 20:37. Reason: being nice is for suckers or something
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Old 22nd September 2015, 19:59   #60  |  Link
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Digital video is perfectly capable of transmitting 60 temporal events per second without resorting to interlacing, which is only clinging to existence thanks to a self-perpetuating loop of legacy support.
Yes, digital video can handle 60 temporal events per second. We have 60p, so that is not in dispute.

What IS in dispute is whether either broadcast TV or DBS (e.g., DirecTV), within the spectrum they are allocated, have the bandwidth to do that and still offer the same number of channels. I think we could all make the argument that 80% of the channels could be eliminated, but there are strong business reasons that push broadcasters in the other direction. So, even today, 1080i is being used in order to provide a "temporally pleasing" experience, without consuming too much bandwidth.

One other point that is obvious, but bears repeating, is that our current North American HD standard was finalized in 1993. That was the same year that the Intel Pentium processor was introduced, but almost all sales that year were 486 computers.

Think of the truly unbelievable increase in computing power in that time.

As this chart shows:

Instructions Per Second

the processing power these engineers had to work with was around 25 MIPS at 66 MHz.. In actuality, it was considerably less than that because consumer electronics have to sell for a low price, and the "horsepower" shown in these charts was out of that price range.

In 1996, the year before the DVD (an SD device) was introduced, the Pentium Pro got us to 541 MIPS at 200 MHz.

By the time the first consumer HD players arrived in stores (2004) Intel architecture chips were around 10,000 MIPS at 3 GHz.

Today, Intel i7 chips at over 100,000 MIPS at over 3 GHz.

The point is that many things that we can easily do today, were not even conceivable when these standards were developed.

So, "change the standards!!" you say.

Unfortunately, standards cannot be changed quickly. The best example of that is the changeover from SD to HD. In this country, that happened exactly seven years ago this month. Despite that time, and despite a mandate from Congress, we still have a sizeable number of channels broadcasting in SD (about 100 on my system).
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