Video Sources

Video sources let you play back clips as a source in your chain — loop them, trim them, blend them with anything else. This guide covers what files work, what to do when a file won’t play, and how to prepare clips for best results.

What works best

Lightbridge plays QuickTime (.mov) and MP4 files. On macOS it uses the system video decoder for H.264, HEVC and ProRes, and its own built-in decoder for HAP (in .mov files).

HAP, HAP Alpha, HAP Q, HAP Q Alpha and HAP R — the best choice for performing. HAP frames go straight to the graphics card, so many layers play smoothly at once, scrubbing and reverse stay responsive, and the computer’s video decoder isn’t involved. Files are larger than H.264. See Converting to HAP.
MP4 or MOV with H.264 — the safest everyday choice. Nearly every camera, phone, screen recorder and editor exports it. Fine for a few layers; heavy at 4K.
MP4 or MOV with HEVC / H.265 — good on Apple Silicon; heavy at 4K with many layers.
MOV with ProRes 422 or ProRes 4444 — high quality; ProRes 4444 can carry transparency.

What needs conversion

If a clip can’t be played, the video source’s panel usually says why — file not found, an unsupported format, or a damaged file — with a link back here. (A few unsupported files just stay black without a message; if a clip never appears, check its format against this list.) These need converting:

DXV — Resolume’s own codec. Convert to HAP (it plays the same way: straight to the graphics card).
WebM, MKV, AVI and Ogg files — convert to HAP, or to H.264 in an MP4.
DNxHD / DNxHR, CineForm, MPEG-2, XDCAM, uncompressed — editing and broadcast codecs. Convert to HAP, ProRes or H.264.
HAP Alpha-Only and HAP HDR — not supported yet. Re-export as HAP Alpha / HAP Q Alpha, or HAP Q / HAP R.
AV1 and VP9 — convert to HAP or H.264.

Converting to HAP

Two free tools do this well on a Mac:

Shutter Encoder — drag clips in, choose the HAP function, then HAP, HAP Alpha (keeps transparency) or HAP Q (higher quality, larger files). It can also read Resolume DXV files, so it converts DXV to HAP directly.
AVF Batch Exporter — from Vidvox, the makers of HAP. It offers every HAP flavour, including HAP Q Alpha, but only opens files your Mac can already play (H.264, HEVC, ProRes). For DXV, WebM and other formats, use Shutter Encoder.

Which HAP? HAP for most clips; HAP Alpha when the clip has transparency; HAP Q for gradients and fine detail where HAP shows blockiness; HAP Q Alpha for both.

Chunks: if the tool offers a “chunks” setting, use 4–8 (about the number of performance cores). Chunked files decode in parallel, which matters most at 4K. Single-chunk 4K files play, but each frame takes longer.

Size: HAP is large — roughly 1.5 GB per minute at 1080p30, about twice that for HAP Q, and four times that at 4K. Keep clips on a fast internal or USB-C SSD.

Converting to H.264

For a quick, small file (or a clip you’ll only use on one layer):

HandBrake — free. Pick the “Fast 1080p30” or “Fast 4K60” preset and click Start.
QuickTime Player — on a Mac, open the file and choose File > Export As > 1080p (or 4K).
Adobe Media Encoder / DaVinci Resolve — choose an H.264 preset, YUV 4:2:0 8-bit if offered.

File size and resolution

Lightbridge reads and decodes frames as they’re needed rather than loading whole clips into memory.

Resolution:

1080p (1920×1080) — smooth on any Mac, plenty sharp for most venues.
4K (3840×2160) — use HAP for more than a couple of layers.
Above 4K — convert or downscale before a show unless you have tested the exact file on the performance machine.

Frame rate: 24, 30 and 60fps clips all play at their own rate.

In / Out points

Every video source has In Point and Out Point sliders in the Playback group:

The readout shows seconds once the video has loaded (e.g. 12.34 s).
Drag to set the trim range — the video will loop (or bounce / play-once) within that range.
Both points respect the Play Mode: Loop, Bounce, or Once.

Transparency (alpha channel)

If you want to stack a video on top of other sources and have parts be see-through:

Export as HAP Alpha or HAP Q Alpha for many layers, or ProRes 4444 in a MOV for the highest quality.
Lightbridge composites video alpha as premultiplied alpha, matching the rest of the renderer.
Regular MP4/H.264 files do not carry transparency. The file has to use a codec and container that include an alpha channel.

Playback controls

Launch — the clip-launch action, at the top of the Motion group. Firing it jumps the playhead back to the in-point and starts playing — a clean clip relaunch. Bind it to a pad or key (drag it, or MIDI-learn) for live triggering; if the binding is beat-synced, the launch snaps to your global launch-quantization grid, so it always lands on the beat/bar.
Transport — play / pause.
Direction — forward / reverse.
Speed — 0× to 4× playback rate.
Play Mode — Loop (wrap back to in-point), Bounce (flip direction at out-point), Once (freeze on last frame).
Retrigger — a parameter that also jumps to the in-point on a rising edge. Launch is usually the better choice for live triggering — it fires through the impulse lane, so rapid presses never coalesce away.
Position — the playhead, as a normalized 0-1 value across the trim range (0 = in-point, 1 = out-point). Shown in seconds once metadata loads.

All of these are bindable to MIDI, modulation, or action buttons like any other parameter.

Transport bar

At the top of the Playback group, a compact transport strip puts the two most-used live actions in one place:

A play / pause button.
A scrub track showing the whole clip, with the trim window (In → Out) shaded, any cue points marked as ticks, and the playhead as a bright line. Click or drag anywhere in the track to scrub; the readout on the right shows the trim-relative position.

The detailed sliders below stay available for precise numeric entry and for binding to MIDI, modulation, or buttons. The scrub handle follows the Position parameter, so while a beat-sync or LFO is driving Position it marks the scrub anchor rather than the live decode playhead.

Position: time as a parameter

Position is where video sources become genuinely different from any other VJ tool. Instead of video time being locked to a playback clock, you can drive it with anything — an LFO, an audio band, a MIDI knob, a button macro.

Scrub with a sine LFO — the playhead rocks back and forth within your trim range. Cycle length sets the wobble speed.
Freeze on a single frame — set an LFO at 0Hz, or bind Position to a static MIDI value.
Jump-cut on the beat — use a beat-synced LFO with a stepped curve.
Audio-reactive stutter — bind a transient-detector band to Position.

When you add modulation to Position, the popup shows a 1× (X.Xs) button. Click it to set the LFO cycle length to exactly the length of your trim range — a saw LFO at that rate reproduces normal playback speed. Tune up/down from there for faster-than-life or ultra-slow drift.

Performance note

Position can be driven like any other parameter, but heavily modulated video still depends on codec, keyframe spacing, resolution, and the machine doing the decode. If you plan to scrub aggressively, test the clip in the show file and re-encode with a tighter keyframe interval if it stutters.

Troubleshooting

Nothing shows up after I drop the file in. The video source’s panel says why: the file wasn’t found (moved or on a disconnected drive), its format isn’t supported, or it looks damaged. For unsupported formats, see Converting to HAP.

Video plays but is very laggy. H.264 and HEVC get heavy at 4K and with several layers — Lightbridge shows a hint on heavy 4K clips. Convert them to HAP, or export at 1080p. Sparse keyframes also make scrubbing and reverse stutter on H.264/HEVC; HAP doesn’t have that problem. Check too that your Mac isn’t thermal-throttling.

Colors look wrong. Try the Color Space control in the Display group — it switches between sRGB and Rec.709 interpretation.

The file is huge. Use the CRF 20 setting in HandBrake (or the default “Fast 1080p30” preset). A 10-minute 1080p clip should land around 200-500 MB.