Poll : Would KVR benefit from a video forum?

[vurt]

i only ask, because i refer you to handmade electronic music, using my old camera i used to take an out put from the yellow to audio in, and you'd get weird clicky stuff as cars drive past outside (my cam was on the window ledge)

obviously, there was some loss of information for it to convert full colour to click bzzzzt click click click bzzt bzzzzzt.
and it's all electrons i guess

Yeah, I mean at the end of the day if its an analogue output its just a voltage, and if that's a voltage that has something changing between 20- and 20-thousand times a second then, that's audio range.
going the other way is (afaik) a bit more complex because what's changing has to happen at fairly precise intervals to make 'sense' as a video signal.

but (also afaik) it used to be a bit easier. these days video displays arent analog, but the actual displays were proper CRTs you were literally sending the voltage direct (to erm, something something maybe magnets maybe deflecting photons coming maybe from the tube something something though maybe making this half-explanation up from stuff i half understand) so it -could- be a lot more forgiving of 'not proper' input.

ah yes, today's monitors probably wouldn't play well?

im not expecting a similar effect across the two, just, it surely must have some effect on the signal?
how different are the circuits in a video mixers fader channels for example?

is there any similarity anywhere?
not that it matters, ill be totally "itb" as the kids say for video

[whyterabbyt]

That’s probably true, but the circuitry itself should be similar to model.

Really sorry if Im just perpetually sounding negative here, but I wonder if that's true. Most of the hacked devices and toys, mixer schematics and things Ive been looking at rely quite heavily on ICs to do the specific and particular aspects of the work, and they seem a lot more involved (and proprietary) than the opamps and such you'd find in an analog synth, or even the CEM/SSM module-on-a-chip devices.

Not saying it cant be done, just not sure its that similar.

So for example, you cant just mix two video signals and expect them to work. The sync signal gets screwed up. (There is a way it works badly, but possibly badly enough that it cant be displayed properly unless you have a CRT)

So for a video mixer circuit like this:

https://gieskes.nl/visual-equipment/fil ... ic-600.jpg

that LM1881 chip is actually creating a new sync signal. I suspect there might be aspects of modelling these kinds of things which are outside the ballpark of someone familiar with modelling audio circuits.

Meanwhile, compared to how you would generate video fairly easily with shader code etc on a modern GPU, I honestly dont know if there would be many people doing 'video synth physical modelling'

File me under 'interested' if someone does though.

[whyterabbyt]

im not expecting a similar effect across the two, just, it surely must have some effect on the signal?
how different are the circuits in a video mixers fader channels for example?

is there any similarity anywhere?
not that it matters, ill be totally "itb" as the kids say for video

As per my response to guitarzan, you can do crude mixing with a simple pot (cf 'karl klomp dirty mixer') but the problem is that there's a precise sync signal as part an analogue video signal, and mixing crudely... well they almost certainly werent in time with each other, so you're also mixing two sync signals which arent, erm, in sync.
Again, CRTs will cope, because its just a voltage. VGA displays and anything digital probably wont.

so you need to superimpose a new, sane sync signal. That's what that LM1881 chip can do, its also what a proper video mixer should do in the form of having a Timebase Corrector circuit.

(full disclosure : I didnt even know half of this stuff before I started this thread, so if Im getting it wrong, someone please let me know)

[whyterabbyt]

The inability to crudely mix video signals well can be an interesting thing in and of itself, in terms of the artefacting, but as I say, it sometimes comes down to how you can display it and whether you have to fix sync somehow.

https://www.youtube.com/watch?v=iSRWvQf3u2c

https://www.youtube.com/watch?v=so7Mk16wGrA

[vurt]

i should say, im not expecting "put video in to delay, get delayed video image"

but, i shall give it up
was just wondering if it would have any effect.
i suppose the biggest clue should have been the price of things.
you don't seem to get as much for your money in the video realm, even in the digital world.

[whyterabbyt]

i should say, im not expecting "put video in to delay, get delayed video image"

Im pretty confident you wouldnt get delayed video trails (presumably as beloved by TOTP, circa 1983) -but- I am curious.

[vurt]

no, trails is unlikely.
but it must do something to an analogue signal? (staying purely analogue from start to finish).

taking a filter as an example, ignoring it's audio function, just as maths, it reduces signal flow. which in turn must have some function on any analogue signal?
what it would do to an image i don't know? may just act like a fader and fade to black...

[guitarzan]

That’s probably true, but the circuitry itself should be similar to model.

Really sorry if Im just perpetually sounding negative here, but I wonder if that's true. Most of the hacked devices and toys, mixer schematics and things Ive been looking at rely quite heavily on ICs to do the specific and particular aspects of the work, and they seem a lot more involved (and proprietary) than the opamps and such you'd find in an analog synth, or even the CEM/SSM module-on-a-chip devices.

Not saying it cant be done, just not sure its that similar.

So for example, you cant just mix two video signals and expect them to work. The sync signal gets screwed up. (There is a way it works badly, but possibly badly enough that it cant be displayed properly unless you have a CRT)

So for a video mixer circuit like this:

https://gieskes.nl/visual-equipment/fil ... ic-600.jpg

that LM1881 chip is actually creating a new sync signal. I suspect there might be aspects of modelling these kinds of things which are outside the ballpark of someone familiar with modelling audio circuits.

Meanwhile, compared to how you would generate video fairly easily with shader code etc on a modern GPU, I honestly dont know if there would be many people doing 'video synth physical modelling'

File me under 'interested' if someone does though.

No, you’re probably right — I think getting CRT emulation right would be the key thing for VA video synthesis and probably not trivial. Then you could be “not right” like CHA/V and still be good goofy picture-wise.

CHA/V is probably the way to go for budget analog. It’s certainly cheap enough, but then there’s the CRT, and the first thing he does in that posted video that involves audio is hook up a euro rack oscillator, then there’s the question of how to capture, etc. That’s why I thought a VA would be a good start. BUT…

Myself, I think I’m more drawn to the shader based stuff anyway — that Imaginando Visual Synth seems like the ultimate expanded Milkdrop/AVS environment I always wanted. I suppose the shader based synths are the modern digital video synths then?

[pekbro]

Here's kind of a lame effect you can do in Blender (and virtually every other decent 3D package)
use your visualization as the texture for a 3D object. Now it's not projected, it's actually looking
up the color values during each frame. Sry, I just happened to find this and upload it as it was
pretty small. Not to mention I was testing my brand new paid Vimeo account.

https://vimeo.com/581425894

[guitarzan]

Here's kind of a lame effect you can do in Blender (and virtually every other decent 3D package)
use your visualization as the texture for a 3D object. Now it's not projected, it's actually looking
up the color values during each frame.

I think it’s a pretty cool effect actually — thanks for posting that. I was hoping to find a way to tie in solid modeling somehow since that’s the only “visual” thing I have any real experience with, although in mechanical design (Solidworks since 1998).

[pekbro]

Here's kind of a lame effect you can do in Blender (and virtually every other decent 3D package)
use your visualization as the texture for a 3D object. Now it's not projected, it's actually looking
up the color values during each frame.

I think it’s a pretty cool effect actually — thanks for posting that. I was hoping to find a way to tie in solid modeling somehow since that’s the only “visual” thing I have any real experience with, although in mechanical design (Solidworks since 1998).

Thanks, and yeah, rudimentary is probably a better term. Solidworks is cool, I love solid modeling.
I haven't used Solidworks in years, definitely the way to go for mechanical stuff. If you have access
to that you should be able to come up with some super cool imagery. I look forward to seeing it.

[pekbro]

A 3 min Hypno OBS Studio test (video+audio), only VLC used to convert it to .mp4 VLC isn't overly
good at it either imo, it looks stylized but that's mostly quality loss. Not super fond of OBS either
tbh, and Vegas doesn't support NDI, at least the version I have. That's the problem I've found with
free video tools in the past, codec support is not very good IME. Going to take some experimenting
and possibly some different software.

Anyway its interesting to try and do stuff with CV control,

*SERIOUS EPILEPSY WARNING!*...

https://vimeo.com/581493995

[Biome_Digital]

Could be useful.

[whyterabbyt]

Well, my incredibly expensive video and broadcast quality <cough> capture setup works!

https://www.youtube.com/watch?v=tVVMrdg2zyE

PAL toy camera -> AV to HDM convertor -> HDMI to USB capture card.

[whyterabbyt]

Hmmm, it doesnt look as though the other USB video capture thing Ive got (PAL->USB convertor) want to work properly with Vegas. Vegas sees it as a camera device, but its not seeing the video feed.
Which is weird, because OBS works.

Anyway, these days it costs about a tenner more than the RCA->HDM->USB chain from the other test, and the results are, ooooh, much more crap erm, glitchy and artistic.

didnt capture the window properly in OBS, doesnt really matter.

https://www.youtube.com/watch?v=HgkZJppnA3k