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Glitch effect

Datamosh

Datamosh is a glitch video effect in FRCTL, the browser VJ studio. Measured motion vectors drag the held frame around, the way a broken codec does.

Runs live on video, images, a camera or generated art. Stack it with any other effect, and route LFOs, envelopes or any of ten audio bands to its controls so it moves with the music.

Try Datamosh free All effects

The untouched demo art: an eye inside a triangle over wavy teal, blue and peach lines — Source

The eye-in-triangle skewed and enlarged, its edges broken into small stepped blocks — Datamosh, default settings

What Datamosh does

Measures how each block of the live picture moved since the last frame, then applies those vectors to a held copy instead, the way a codec does after a lost keyframe. Moving subjects drag old pixels along in blocky slabs, and a still shows nothing. Drag scales the push, Hold how long the smear survives, Blocks the slab size, Bleed the colour split.

Using Datamosh

Where it works: Footage with real movement, such as a dancer, a camera pan or a crowd, which is why it suits a drop that should melt one shot into the next. On a still or a static logo it does nothing, so use Data Trails there.
With the music: Motion in the picture drives it, not the audio. Put B1 (kick) on Drag so each kick shoves the held frame further, and an LFO synced to the bar on Hold so the smear builds and clears once a bar.
Starting point: Drag at centre, Hold at three-quarters, Blocks at a quarter, Bleed at a quarter, Sense at centre, on footage with a clear pan.

Controls

Drag: How far the motion vectors push the held frame.
Hold: How long the frame smears before the source bleeds back in.
Blocks: Macroblock size, from coarse slabs to fine tearing.
Bleed: Color channel separation along the vectors.
Sense: How little texture counts as motion worth smearing.

Pairs well with Datamosh