"Glitch" looping effect - Is this possible, can anyone help?
by Richie Tovell
on
Jun 30, 2009 at 6:21:17 pm
I don't really know what you guys call this effect? In audio circles it's just called a glitch effect, dubbed "Glitch" after the form of music it's most commonly ascosiated with.
I'd like to create this effect in a professional video app, but I'm not sure if it can be done in AE, it's been pointed out to me that it would most likely require an expression linking two sliders to control the loop's start and end points over time, it's obvious to me that it would need someone very skilled in using expressions to creat it, if it can be done at all?
The clip bellow is an example, I've adjusted the start and end point's of the loop through various sections of a clip, I created the example using two apps, one a live video app the other an audio/midi app, the audio app sends midi yo the video app and controls the start and end points of the loop, but there are problems, midi and midi apps are very prone to latency problems and also jitter, this results (in this case) in frames dropping out or even freezing completly, hence my wish to find a pro app or plugin that can loop clips in this manner (including their audio if possible), AE is my main video app, it seems to be able to do most of what, however I'm at a loss as to what to do next exctly.
I'd really appreciate any help you guys might be able to give me, I'm really struggling to create this effect, presently I need to use three different app's and as you can see the resultss are far from perfect.
Re: "Glitch" looping effect - Is this possible, can anyone help? by Dan Ebberts on Jun 30, 2009 at 8:53:22 pm
Clearly a job for time remapping. It's hard to know what would be the best way to control this, but here's an idea. Drop this expression into the time remapping property. Wherever you want a glitch, put a layer marker with the frame number you want to skip to as the marker comment. A bunch of markers in a row (a few frames apart), each with the same frame number will cause a stutter, like in your example.
I'm sure there are better ways to automate it, but it's kind of fun to play around with.
n = 0;
if (marker.numKeys > 0){
n = marker.nearestKey(time).index;
if (marker.key(n).time > time){
n--;
}
}
if (n == 0){
value
}else{
t = time - marker.key(n).time;
f0 = parseInt(marker.key(n).comment,10);
if (isNaN(f0)){
value
}else{
framesToTime(f0) + t
}
}
Re: "Glitch" looping effect - Is this possible, can anyone help? by Dan Ebberts on Jun 30, 2009 at 9:16:10 pm
This is getting fun now. Here's an improved version. In this one, if you don't supply a frame number as the marker comment, the expression goes back in time until it finds a marker that has one. So you drop one marker with the frame you want glitch back to, then, for the rest of that glitch, you just drop blank markers wherever you want it to skip back. You can actually lay down a glitch pretty quickly using the "*" on the numeric keypad in combination with the Page Down key, to advance through the frames.
n = 0;
if (marker.numKeys > 0){
n = marker.nearestKey(time).index;
if (marker.key(n).time > time){
n--;
}
}
if (n == 0){
value
}else{
gotOne = false;
for (i = n; i >= 1; i--){
f0 = parseInt(marker.key(i).comment,10);
if (isNaN(f0)) continue;
gotOne = true;
break;
}
if (gotOne){
t = time - marker.key(n).time;
framesToTime(f0) + t
}else{
value
}
}
Re: "Glitch" looping effect - Is this possible, can anyone help? by Richie Tovell on Jul 1, 2009 at 12:08:46 am
Hi Dan, thanks for replying.
I've recorded whats happening in the two apps that I used, hopefully this will help explain the methods used better than me confusing everyone with my discription, you can hear and see there are problems with the midi this is why I want to work just in the one app, automating the composition would be preferable to the live controlling that I'm doing here.
Would it be possible to add two sliders in to your expression, that could then be keyframed? I'm not sure but I think that using markers is going to be too complicated, maybe I'm wrong, but anyway here's the vid, it should make things clearer.
Re: "Glitch" looping effect - Is this possible, can anyone help? by Richie Tovell on Jul 1, 2009 at 5:34:39 am
Thats a shame, thanks for trying though.
The problem I have is the apps I'm using take a lot of time to configure and are very tempramental, there's a lot of latency, they drop frames, there's jitter that needs to be tidied up and the app doesn't always render out footage propperly, also having to bounce footage between apps is far from ideal.
It probably looks more complex than it is, there's one clip and one loop with automated loop start and end points, simple really lol. seriously though I'm sure I couldn't put something like this together using expressions either, I know nothing about them but I think it's possible, AE has has assignable sliders and time remapping, I just have no idea how to configure them :(
Re: "Glitch" looping effect - Is this possible, can anyone help? by Kevin Camp on Jul 1, 2009 at 5:13:35 pm
this starts getting close, but i think there are still some issues, particularly as the loop duration increases over time... but here's the expression (it's basically dan ebberts's random jump cuts expression without the random part):
before pasting this into the time remapping expression field, add two sliders to the footage. the first slider will control the loop duration, the second will control the point at which the loop will start from (both values are in seconds).
Re: "Glitch" looping effect - Is this possible, can anyone help? by Kevin Camp on Jul 1, 2009 at 5:50:23 pm
actually, playing around with file with audio, this isn't working quite the way i though... the loop duration is effecting the playback speed if there is interpolation between keyframes (i.e. not hold keyframes). so it definitely needs more work, or may not be possible.
some sort of conditional statement that can evaluate the code only after the loop duration has been exceeded every time it loops... hmmm.
also, set the first slider to a value other than zero. the expression will fail if the value is zero (that can be fixed with a conditional, but there are bigger problems than that).
Re: "Glitch" looping effect - Is this possible, can anyone help? by Richie Tovell on Jul 1, 2009 at 6:05:53 pm
Thanks kevin.
It's really cool of you to help me out, it's way beyond me, I can still always import renders from the other apps (audio also) but any footage composed in these apps (when they work) is still effectivly "locked" to it's original state, ie it can not be adjusted whilst working on the comp in AE to any large extent, I'm really against bouncing footage around like this as well, it's a bit of a hang up I have I guess but no biggie.
If it isn't possible then I can still fall back on this way of working, but it would be really cool to find a way to do this in AE, I thought perhaps it might reqire a plugin, but I'm willing to give any expressions a shot if you have the time to work on them ;)
