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General Category => Off topic => Topic started by: mr_lou on 21:32, 06 June 16

Title: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 21:32, 06 June 16
I'm experimenting with CTM simulation in my video-editor.
Thinking about applying such a filter for all the Amstrad CPC videos in my project. (And also adding other filters for other videos).
Sadly I can't apply this filter using Java only, thus making it a user-choice. It has to be done in the video-editor, and therefore can't be a user-choice.

That's why I thought I better ask the community what they prefer.

Watching Amstrad CPC videos, would you prefer them with a CTM filter that definitely isn't 100% accurate, but nevertheless gives a semi-impression of a CTM, rather than the much too clean footage?

I wanted to upload to YouTube, but YouTube processing ruins the video, so instead you'll have to watch it from here: http://dewfall.dk/ctm-simulation.mp4 (http://dewfall.dk/ctm-simulation.mp4)
Spindizzy 1 minute gameplay where the CTM simulation comes in twice.

Thanks for your feedback.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: robcfg on 01:01, 07 June 16
I prefer raw pixels as many modern tvs will do a lot of postprocessing on the image, most probably showing a weird picture.


Also, I still watch movies on an crt tv. Retro all the way down, baby!
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: ||C|-|E|| on 01:08, 07 June 16
In this computer screen, emulation works very well for me  :)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 19:18, 07 June 16
Also, I still watch movies on an crt tv. Retro all the way down, baby!

Must admit we're using LCD TV's, but I'm also saving a 28" CRT for some nostalgic retro movie watching some day in the future. Like for example original Star Wars movies on VHS.  :)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 12:11, 08 June 16
I use a crt for most of my retro needs, it's the only way to watch laserdisc, so I prefer crt emulation.
If you haven't already you'll have to share your final method of simulating crt in your videos when you decide which way you're going to do it.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Gryzor on 12:28, 08 June 16
I do like a good (emphasis on good) CRT emulation myself...
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 12:29, 08 June 16
I do like a good (emphasis on good) CRT emulation myself...

And what do you think of this one?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Bryce on 12:31, 08 June 16
I have to say, I was never a fan of CTM emulation / scanlines etc. It's an artifact of the limitations of electronics back then. It's like buying a CD and wanting the scratch sounds of a vinyl record to be included.

Bryce.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 12:36, 08 June 16
But games were designed using those limitations.
When I remember playing Sonic on my Megadrive I don't remember Sonic being a blocky pixel mess because he wasn't thanks to those CRT limitations.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 12:38, 08 June 16
I have to say, I was never a fan of CTM emulation / scanlines etc. It's an artifact of the limitations of electronics back then. It's like buying a CD and wanting the scratch sounds of a vinyl record to be included.

Some CD's do have tracks with such vinyl noise "emulated", for the same reasons you would add a CTM filter.  ;)

For me it's about representing the games the way they were seen back in the day. But I have to admit I thought most people preferred avoiding CTM simulation.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Bryce on 12:41, 08 June 16
But games were designed using those limitations.
When I remember playing Sonic on my Megadrive I don't remember Sonic being a blocky pixel mess because he wasn't thanks to those CRT limitations.

Yes, but they weren't designed with those limitations in mind, it was just the best picture possible at the time.

Bryce.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 12:46, 08 June 16
There were designed to use the limitations.
Look at transparency effects on sega machines.
On emulators it's ugly vertical bars but on a real crt those vertical bars give a transparency effect.

There are lots of effects only possible thanks to crt limitations such as dithering which look ugly on LCD tv's etc.
Things that can't be replicated on LCD tv's and the closest you can get to them when watching old game footage on YouTube for instance is to drop the resolution to 360p.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 12:49, 08 June 16
But most CRT emulation effects are crap though.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 12:58, 08 June 16
But most CRT emulation effects are crap though.

You seem to be rather picky, and therefore exactly the right person to ask: What do you think about the CTM simulation I'm doing here?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 13:34, 08 June 16
You seem to be rather picky, and therefore exactly the right person to ask: What do you think about the CTM simulation I'm doing here?


Picky  ;D
I remember your other thread where you went through your different attempts at CRT emulation and thought you had something there.

I like it but it does wash out the colour and softens the edges a bit more than I'd like.
I'd like to see it on something with more colour.

Ok now I'm being picky.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 13:50, 08 June 16
Yes, the other attempt was made using pure Java coding, and was intended to be used on screenshots.
But I dropped that again because it takes too long to process, and takes up too much space if pre-processed.

So still images will be blocky pixels.

But I can pre-process videos.
It's rather straight forward: Apply a semi transparent PNG. Then add a glow filter. Then add some brightness. Basically the same I did using Java, only this time done in the video-editor.

I can reduce the glow filter to wash out the colours slightly less.

If you name a game I can create an example using that.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 14:11, 08 June 16
Which ever you have at hand.
It's more about seeing how it affects multiple colours.

Rastan?
No that's a joke.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: khaz on 14:13, 08 June 16
I do like a good (emphasis on good) CRT emulation myself...

How can't you love this:

(http://i.imgur.com/wLhwQLx.png)

Spoiler: show
Absolutely disgusting
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 14:13, 08 June 16
Bombjack then?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Gryzor on 14:16, 08 June 16
I have to say, I was never a fan of CTM emulation / scanlines etc. It's an artifact of the limitations of electronics back then. It's like buying a CD and wanting the scratch sounds of a vinyl record to be included.

Bryce.


Bad example, I think; we have all discussed how old games look horrible on modern screens, and that's not because of rose-tinted glasses. Just like DVD subtitles look so bad, so do games. It's not an external factor like vinyl filters etc...


And what do you think of this one?
   


Good, but I'm not selling my car just yet.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 14:50, 08 June 16
Here's Bomb Jack with Glow-blur=40 and Gamma=120

I'm stared myself blind looking at it, so I think everything looks wrong now.

http://www.dewfall.dk/Bombjack.mp4 (http://www.dewfall.dk/Bombjack.mp4)

Too little glow-blur? Too much?
Colours too washed out?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Gryzor on 15:00, 08 June 16
I think the amount is fine; it's the pattern that's not perfect...


If you hadn't mentioned colours I wouldn't have noticed them being washed out. They are, a bit, but who knows if that's because of the filter?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 15:32, 08 June 16
I think the amount is fine; it's the pattern that's not perfect...

If you hadn't mentioned colours I wouldn't have noticed them being washed out. They are, a bit, but who knows if that's because of the filter?

I can't produce a better pattern when being limited to 720p (and I am).
It's the closest thing I can get to the real thing, faking the placement of the RGB diodes (or whatever they're called).

Here's another rendering with glow-blur set to 60 and 80 and no gamma change from the original recording.
http://www.dewfall.dk/Bombjack-glowblur60.mp4 (http://www.dewfall.dk/Bombjack-glowblur60.mp4)
http://www.dewfall.dk/Bombjack-glowblur80.mp4 (http://www.dewfall.dk/Bombjack-glowblur80.mp4)

Applying the PNG file with semi transparent black lines obviously makes the whole picture a bit darker. Then adding the glow-filter (because diodes glow) brightens it back up. Some colour is changed in this process.

The question is, what do we prefer then? I'm thinking this project will represent the CPC in some way. How do we want to present it?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Carnivius on 15:38, 08 June 16
Yes, but they weren't designed with those limitations in mind, it was just the best picture possible at the time.

Actually the graphic artists had to take into consideration the effects a monitor screen would have on their sprites and other graphics when designing them.  Too much detail could result in a blurry mess.  But sometimes they used it to their advantage.  The concept of dithering was that the chessboard pattern of two colours would blur together on a monitor and give the impression of a new colour like the two had been mixed together.  Obviously on a sharp monitor or HD display that illusion is completely lost as you see the individual pixels of the original colours.

I'm absolutely fine with a cheap scanline effect and use them in my projects and whenever available in emulators and re-released versions of old games.  Having the pure raw imagee is juts a bit too pixelly even for my tastes particularly when viewing a very low resolution game on a very big HDTV and the scanline effect breaks it up nicely.  Doesn't work well in a video though as the video's variable size and compression tends to blur things too much and end up with a much too dark image.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: ||C|-|E|| on 16:00, 08 June 16
Anyway, colors and adjustments in an Amstrad CRT are not the same in all the screens  :) If you go through the service manual it tells you how to calibrate the monitor in a rather precise way but it is a manual process and the final result depends on how careful is the person doing the calibration, the screen itself and the instruments he has at hand. Not all the tubes and boards behave in the same way and, on top of that, after 30 years many of our screens have changed its response. On the other hand, my impression (but maybe is my impression) is that Amstrad had lots of different workers with different levels of skill and dedication. Sometimes you see boards that have been assembled with lots of care, sometimes you see something far for decent, although it works. For instance, the board of the tape deck in the 464 Plus I am upgrading had a corner chipped because it was cut in a really bad way. It is not important, but I repaired it with epoxy resin.

About CRTs themselves, I must admit that I like them a lot, but for the same reason I like tube amps. It is not that they are better by any means, is just that they bring some nice memories and for a computer like the Amstrad I prefer to have a setup that is as close as the original experience as possible, is just what I remember from my childhood days. But, to be honest, that is because I just plug the computer to enjoy some games and demos from time to time. If I had to code in a Amstrad color CRT or work in a serious way with it... well  :-\ That is why I enjoy a "good" CRT filter, it takes me to the past in a much better way than an unfiltered image  :D
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Gryzor on 16:23, 08 June 16
I honestly can't tell the difference between the last two vids! Maybe it's that I'm in a well-lit room, but I froze them both and was switching between them... couldn't tell them apart!
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: ||C|-|E|| on 16:30, 08 June 16
The second one is sharper!  :D

I will go for the first one, in my opinion it is closer to what you could see in a CRT (at least in the center, since the CRTs do not behave the same in all the areas of the screen...)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 17:01, 08 June 16
The difference is the amount of glow-blur.
Logically the 60 one should be sharper than the 80 one.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 12:47, 09 June 16
I can't produce a better pattern when being limited to 720p (and I am).
It's the closest thing I can get to the real thing, faking the placement of the RGB diodes (or whatever they're called).

Here's another rendering with glow-blur set to 60 and 80 and no gamma change from the original recording.
http://www.dewfall.dk/Bombjack-glowblur60.mp4 (http://www.dewfall.dk/Bombjack-glowblur60.mp4)
http://www.dewfall.dk/Bombjack-glowblur80.mp4 (http://www.dewfall.dk/Bombjack-glowblur80.mp4)

Applying the PNG file with semi transparent black lines obviously makes the whole picture a bit darker. Then adding the glow-filter (because diodes glow) brightens it back up. Some colour is changed in this process.

The question is, what do we prefer then? I'm thinking this project will represent the CPC in some way. How do we want to present it?



I really like the Blur 60 ine a lot. It keeps the colours bright and vivid as CPC colours should be and doesn't blur the image out too much.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 08:27, 10 June 16
I really like the Blur 60 ine a lot. It keeps the colours bright and vivid as CPC colours should be and doesn't blur the image out too much.

You don't think it's a bit too bright? I was thinking about lowering brightness a bit actually.
But yea, I do think this is the closest I can get to simulating a feeling of a CTM screen.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 09:10, 10 June 16
Didnt seem so on my tv.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 22:37, 10 June 16
I think the amount is fine; it's the pattern that's not perfect...

Here's another attempt.

Different pattern, bigger process.
Two problems: Because the resolution isn't high enough, I have to blur a bit more than I should in order to hide the wrong looks. And the colours are a bit dusty right now.

http://www.dewfall.dk/caves.mp4 (http://www.dewfall.dk/caves.mp4)

Have an idea for another pattern to try out too, but right now it's bedtime.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Gryzor on 14:18, 16 June 16
Hmmm I think I like this less - too fuzzy and the pattern doesn't look too right...?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: ||C|-|E|| on 16:54, 16 June 16
Here's another attempt.

Different pattern, bigger process.
Two problems: Because the resolution isn't high enough, I have to blur a bit more than I should in order to hide the wrong looks. And the colours are a bit dusty right now.

http://www.dewfall.dk/caves.mp4 (http://www.dewfall.dk/caves.mp4)

Have an idea for another pattern to try out too, but right now it's bedtime.

I like the previous ones more, to be honest  :) Maybe this changes from person to person, but when I stare at my CRT what I see more is the vertical pattern of the grid. Something like this:

(http://omega-glory.net/media/global/crt-pixel-layout.png)

However, I do not easily see horizontal patterns, like the scanlines that are emulated everywhere.
 
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: TFM on 18:51, 16 June 16
Last one is like the original monitor!  :)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Gryzor on 13:54, 17 June 16
Didn't we have some close ups posted somewhere?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Skunkfish on 17:13, 17 June 16
I like the previous ones more, to be honest  :) Maybe this changes from person to person, but when I stare at my CRT what I see more is the vertical pattern of the grid. Something like this:

(http://omega-glory.net/media/global/crt-pixel-layout.png)

However, I do not easily see horizontal patterns, like the scanlines that are emulated everywhere.

You're obviously sitting far too close to the screen, your eyes will go square!  :o
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 19:27, 17 June 16
Two tries more, again with a different approach.
http://www.dewfall.dk/spind2.mp4 (http://www.dewfall.dk/spind2.mp4)
http://www.dewfall.dk/spind3.mp4 (http://www.dewfall.dk/spind3.mp4)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: ||C|-|E|| on 20:20, 17 June 16
I like spind3.mp4 more :) The colors are brighter and they blend better together, in my opinion.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: TFM on 20:47, 17 June 16
Sorry, I don't see the difference!
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: robcfg on 22:13, 17 June 16
@mr_lou (http://www.cpcwiki.eu/forum/index.php?action=profile;u=96) , Have you tried taking a macro picture of the CPC screen?


That will surely show the true grid size of the screen so you can create the adequate filter.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 08:33, 18 June 16
@mr_lou (http://www.cpcwiki.eu/forum/index.php?action=profile;u=96) , Have you tried taking a macro picture of the CPC screen?


That will surely show the true grid size of the screen so you can create the adequate filter.

Yes I have. That's what I'm doing. But in order to create the best possible filter I will need even more than a 4k resolution.
I'm limited to 1280x720 pixels so I have to come up with some alternative within this limitation.

The grid on the CTM isn't that complex. It is vertical lines, each one shifted by a half in relation to each other. To reproduce this with 1280x720 pixels you can either filter out every 2nd pixel, or every 4th pixel. It really only comes down to which of those two you prefer. I'm leaning towards the 4th pixel one because my project is designed to run on a Blu-ray player, meaning the viewers will/should be sitting a good distances from the screen, and then get an impression of a CTM. It's not exactly the distance between LEDs that the CTM has, but from a distance it gives the impression of a monitor - if applying some blur too.

At least that's what I think. But that's why I'm posting here of course, to find out what everyone else thinks.

Don't you think the spind3.mp4 one could pass?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: ||C|-|E|| on 16:01, 18 June 16
I think that it could definitely pass, but it would be great if you could show us many different games to better evaluate. For example, I am very familiar with Dinamic arcades and seeing these will make easier to judge in my case  :)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: roudoudou on 16:18, 18 June 16
@mr_lou (http://www.cpcwiki.eu/forum/index.php?action=profile;u=96) , Have you tried taking a macro picture of the CPC screen?


That will surely show the true grid size of the screen so you can create the adequate filter.


Last time i saw a CPC screen macro view, i notice that the grid was kind of 7 physical pixels for 8 logical pixels, this is noticable in mode 2 where one single pixel is almost never on the grid, but slide a little more than a physical pixel




spind2 video is a little smooth, very nice and respect the main philosophy


When i see a real monitor, i think the main difference is when color change from one pixel to another, then the color isn't correct but a mix of neighboured colors


There is indeed more calculations if you want to do this


Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 09:32, 19 June 16
Another attempt, again using a different approach, and also a different pattern.
http://www.dewfall.dk/spind4.mp4 (http://www.dewfall.dk/spind4.mp4)

This one is very time consuming. What I'm doing is actually to scale the 720p video up to 4k resolution. Then applying an overlay with RGB-elements using multiply filter. Then adding some effects. This produces a 4k CTM simulation rather well I think. Looks cool. I think I will save these for a future 4k release of the project.  :)

But for the current project I'm limited to 720p, so I scale down this 4k video again and end up with the spind4.mp4 result.

I think this is the approach I'll end up using. I've already hired a FFmpeg expert to create a script for me that executes these steps.

The problem with the other attempts is that the actual CTM monitor will give a different pattern depending on which colour it's showing. Depending on which channels of the RGB-elements are lit up, it'll give a different pattern. Therefore any static pattern will never be satisfying.
By using 4k to apply the filter, and scale down to 720p again, we will get a varying pattern and looking close we won't recognize the CTM as such. But from a distance I think this is the best we can do with 720p.

Opinions?
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: roudoudou on 11:21, 19 June 16
still prefer the spind2 video!
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: ||C|-|E|| on 16:06, 24 June 16
Well... with the audio I must admit that I always want the cleanest possible output  :) however, I actually like how low resolution things look in CTM screens, more round and so on  :)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: Executioner on 03:37, 25 June 16
Last time i saw a CPC screen macro view, i notice that the grid was kind of 7 physical pixels for 8 logical pixels, this is noticable in mode 2 where one single pixel is almost never on the grid, but slide a little more than a physical pixel

I'm not sure it's even 7. Seems to be about 5 pixels on my macro images. This from Plustest:

(http://bitwise-systems.com/files/SYNC.JPG)
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: mr_lou on 07:52, 26 June 16
When I take a close look at my CTM monitor, the 8-pixel cursor seems to light up about 10½ RGB elements horizontally.

So that's what I'm trying to reproduce.

I've made so incredibly many experiments at this point now. I'll be using an approach that (obviously) doesn't give a 100% representation, but yet one that'll give an impression of a CTM monitor.
While it's not 100% like the CTM, flat colours aren't either. And then I prefer this "old look" rather than the flat colours.
Title: Re: Do you prefer CTM simulation in videos or not?
Post by: seanb on 03:40, 27 June 16
Seeing them all together on my TV I'm going to go for spind3 because the colours are brighter.
It misses some of the emulation effect compared to spind2 but not much and I like that one more than the rest.