VJing with an O2

[lewis]

Hi. I've got an SGI O2 (one of these (http://www.sgi.com/products/remarketed/o2/) bitches), and I'm playing with writing some software for it. I'm out of touch with where PC and Mac software has gotten to, but I'm guessing the lil' blue toaster can still do a few things toy computers can't, despite being eight years old and with all the CPU power of a pocket calculator.

So... is there software out there already to do live effects on video input? Things like inversion, colour adjustment, wrapping the video around 3D objects, motion blur, time delays, tiling, pixellation? Keying with video files from disk, or another live feed? Scratching with the live input? Grabbing bits of the video and squishing the image around? If so, what, and can it do it at the full PAL frame size? With how much latency? Is it actually useful?

Just playing around in the last couple of days I've done some of these things, and I should be able to do a pile more. Anyone else got any SGI machines, or experience in developing on them? O2s are pretty affordable on eBay now (coupla ?hundred). I'm wondering if such a piece of software would be useful to others (for free), or if PCs are fast enough to do all this now.

Any info apprecated.

[syzygy]

Originally posted by lewis

So... is there software out there already to do live effects on video input? Things like inversion, colour adjustment, wrapping the video around 3D objects, motion blur, time delays, tiling, pixellation? Keying with video files from disk, or another live feed? Scratching with the live input? Grabbing bits of the video and squishing the image around? If so, what, and can it do it at the full PAL frame size? With how much latency? Is it actually useful?



Yes; most VJ apps do realtime effects nowerdays. There is even an open API for writing effect plugins that allows VJ apps to be expanded with a common set of effects (see www.freeframe.org for more details)

going through your list of effects in order:

inversion,

I think all apps do this.

colour adjustment,

I've seen this in several apps

wrapping the video around 3D objects,

I think visualjockey does this

motion blur,

there is a freeframe effect that does this

time delays,

there are several freeframe effects that use delay effects

tiling,

there are several freeframe effects that use tiling effects

pixellation?

I've seen this in several VJ apps

Keying with video files from disk, or another live feed?

Do you mean using one video as an alpha channel for another? If so, I think visual jockey does this.

Most VJ apps provide a number of different ways to combine video streams.

Freeframe now provides for multi-input plugins, so future versions of VJ softwares will be able to support pluggable mixing modes :)

Scratching with the live input?

I'm actually working on a freeframe plugin to do just this ;)

Grabbing bits of the video and squishing the image around?

There are some freeframe plugins that do this kind of thing.


Performance wise, it is definitely possible to do these things (even to do more than one of them at the same time in a chain) using current PC technology. On our development laptop (which is by no means cutting edge) the plugins I have written take less than 10ms to process each frame of full PAL video that I throw at them. (can't be more precise than that - the freeframe test host only reports 0ms for them...)

Dan.

[many2]

Originally posted by lewis
So... is there software out there already to do live effects on video input? Things like inversion, colour adjustment, wrapping the video around 3D objects, motion blur, time delays, tiling, pixellation? Keying with video files from disk, or another live feed? Scratching with the live input? Grabbing bits of the video and squishing the image around? If so, what, and can it do it at the full PAL frame size? With how much latency? Is it actually useful?

I'm wondering if such a piece of software would be useful to others (for free), or if PCs are fast enough to do all this now.


visualJockey can do all of that (and much more) on a decent PC.
try the demo and see for yourself
http://www.visualjockey.com/

[vjrei]

An O2?

I had an O2 hat once. When I was studying Multimedia we all had our O2 in the lab. It was a good computer back in 1997-98.

I do not know why is such bad computer right now if back then it was such fast machine. I mean, the system bus and all the things were great, the interface was incredible and of course... it was meant for a network, not for an stand alone computer.

For VJing??? I assume it can do incredible things but I do not know how limitated is the hardware today. No firewire ports even.

[lowRes]

hi!

i don?t know if it still exists but u should try cluster, this is a video performance software for sgi built some years ago..
search for it on audiovisualizers (http://www.audiovisualizers.com/) toolshack!

r_x

[DrEskaton]

I used to work for an SGI reseller around when the O2 was current in 1996.

Sorry but that machine is outclassed by any mac or pc with a decent 3d card.

Pixelshox on my lowend G4 Tibook can wrap live video round a 3d object, vJo or Pilgrim can do the same on a pc. Any $99 card, eg a Geforce4MX is more powerful that that O2's graphics card.

It does have fast memory, I guess you might be able to do some tricks with hires textures that a pc can't do but pretty limited.

maybe a fun toy to hack on, but I don't think the performance would be anything special.

[lewis]

It does have fast memory, I guess you might be able to do some tricks with hires textures that a pc can't do but pretty limited.

Heh. The memory bandwidth is appalling, actually. Only 75 Mbytes/sec odd to the CPU. Buttloads to the graphics, yes, but that's not much use.

Thanks for everyone else's comments... what's the latency like for live video work with visualJockey et al?

[many2]

The key to avoid noticable latency in visualJockey (as in most applications made to apply effects to a live input) is to avoid the firewire input and go for a dedicated capture card. I happily recommend the Hauppauge PCI capture cards (model 401 with Svideo in is particularly interesting for the price) - they are really cheap (under 100$US) and they work quite well.

A NTSC feed (640x480 square pixel) through a PCI capture card with only some basic effects applied to it will play at 60 fps in visualJockey with a latency of around one or two frames.

[akira_k]

Don't let anyone discourage you on working on this machine if you want to. It probably is outclassed or "outpowered" by current PCs and Macs, but I think that if you can work with its limits and be creative about how to tackle them, you'll have a nice tool that will serve you good and might be unique. Todays people is used to have any hardware they might need without any other effort but economical. A bunch of decades before people had to work with what they had, which was limited, and they found workarounds to solve problems people thought impossible of tackling with that technology. This is still being done by a few that enjoy the lost art of "hardware milking"

Maybe (I'm not sure) trying to do what any VJ app out there does is not the right way to embark on development of a live visual tool for this machine. Try to be creative with what it does, find out what it is or was best for (talk to REAL users of these), and find out what you can do with it, I bet you can add it to your setup easily.

[lewis]

Hey, I won't be discouraged, I like programming and I'm bored of PCs :) The lowest latency I can get is three fields. There's no penalty for using proper non-square PAL pixels, either, which is nice.

I'll let y'all know if I write anything cool.

[syzygy]

I agree with akira_k - if you can get this beast to do some things that are different to what anything else does (or even if you can get it do do similar things in a different way), you'll be well set up.


Thinking about it, it seems that the big advantage is low latency - by the time a signal has gone through PC video input, processing and through the video output, I'd be very suprised if anything close to 3 field latency could be achieved on a PC with any sort of complex effects.

That being the case, maybe you should concentrate on things that can really make use of that low latency. The obvious one is audio reactivity or triggering effects to the beat. In these cases, poor latency can take the shine off otherwise impressive effects.

Also, with the hardware itself being reasonably cheap, maybe you might want to look at what can be achieved by using multiple O2 boxes together - perhaps linking them to synchronise their effects.

If you manage to build a system that can synchronise video streams and effects out of multiple O2 boxes, that's something we might be interested in - none of the PC VJ apps really specialise in doing multiple synchronised screen. (before sleepytom jumpos in, yes I know VJamm can do this, but I wouln't say it specialised in it)

Dan.

[murph]

I've heard of VJs that used O2s to render 3D projects, then VJ'd from tape, but never heard someone using it for live FX.

Give it a shot! (might be a fun box to have installed in a club, tho not necassarily to be lugging around to gigs)

[akira_k]

Yeah the low latency is a good point for lots of stuff, I would like to see it in an A/V setup. I really think the thing I desire the most out of my hardware, or the one I look for the most, is low latency.

[jaw]

i have one of these also wich i'm not using right now.. if you get something working and you feel like sharing info - please tell me :)

[lewis]

If you manage to build a system that can synchronise video streams and effects out of multiple O2 boxes, that's something we might be interested in

That's certainly possible - I'm told the RAF's Hawk training simulator runs on eight O2s working in synchrony.

[murph]

wow, after reading this thread, I saw a guy advertising O2's super cheap here.

I just picked one up, $30!

If anyone else wants one relatively close to MN, I can get you one for $30 plus shipping.

[akira_k]

30!!!!

Can yo ship to FL?

[lewis]

Wow! What spec are they? You could make a pretty hefty profit reselling those on eBay, if they're in working condition!

Just playing today, I got an NTSC video stream textured onto a plane and zoomed to 1600x1024 with less than 5% CPU usage... hooray.

[iKande]

hi there lewis. i've had an O2 for a bit over a year and i've been getting very interested in using it in my setup. i haven't found many programs out there but i'd be keen to start writing one. i need a bit i practice coding for it but if you'd like someone to collaborate with i'm be keen to push this to it's limits. i been considering an external raid array, maxing out the processor and ram for better video capture and storage but i'd need to use it for more than just that to justify the extra cash. i think it could be prefect as a video sampler with enough hard disk space. apparently majority of the 3d is done by the cpu so complex gl scenes would be better on a pc with a geforce. i've found seeking and a "scratching" with the mediaplayer cursor jog thing really fast and smooth so the video side of it should be great.

murph: that aren't that big or heavy. my pc is alot heavier and bulkier. i'd much prefer to take just the O2 to a club and back than my PC.

[DrEskaton]

guess my initial post was a bit negative.

thinking about it I reckon the O2 would be
perfect as a downstream wet effects box.

i.e. either put it after the mixer to do effects on
the total output or put it on a camera input that feeds into your mixer. a "live capture" buffer with scratch and loop facility would be cool.

basically a software version of a korg entrancer but hopefully with cooler higher resolution effects. The low latency would make it perfefct for this.

don't have an O2 at present but I'd be keen to pick one up and help beta test if you get something going.

[MJ]

there is a version of PD+GEM for irix

check this topic

http://www.vjforums.com/showthread.php?threadid=7971&highlight=irix

[iKande]

audio visualizers have a link to an irix5 compile of gem. pd works fine and both seem to come with full source so when i finishing downloading gcc i'll see if i can get it going on 6.5. who runs audio visualizers? anyone from here? i'll try and get them to update the toolshed. do got any sgis MJ?