Skip to content

recording-sync.md

Latest commit

 

History

History
31 lines (20 loc) · 2.37 KB

recording-sync.md

File metadata and controls

31 lines (20 loc) · 2.37 KB
Raw

Filming Patternflow with synced sound

Goal: film the device (hands + LEDs) while the mapped Ableton sound is recorded cleanly, and end up with video and audio locked together in the edit — with as little ceremony as possible, so it actually happens every time.

The v1 workflow (no custom tools)

Principle: the camera records scratch audio of the same sound the room hears; Live records the clean version; the editor aligns them by waveform.

  1. Live set: keep a dedicated Record bus — one audio track whose input is Resampling, armed. Everything you hear goes to it.
  2. Play the speakers out loud (or at least a click/tone at the start) so the camera mic picks up something correlated with the clean audio.
  3. Roll camera → hit Live's global record → perform (turn knobs, switch patterns) → stop both.
  4. Export the Record bus clip as WAV, drop camera file + WAV into DaVinci Resolve → select both in the media pool → right-click → Auto Sync Audio → Based on Waveform. Resolve aligns them; mute the camera track.

That's the whole system. Premiere ("Synchronize → Audio") and Final Cut ("Synchronize Clips") do the same thing.

Make it foolproof

  • One take = one Live recording. Don't pause Live's transport mid-take; a single continuous WAV per camera file keeps sync trivial.
  • Clap once on camera before performing if the speaker level is low — a transient gives the waveform matcher (and you, as manual fallback) an anchor.
  • Name by take: pf-take03.wav next to pf-take03.mp4. Future-you will thank present-you.
  • Camera and Live sample clocks drift ~1 frame per several minutes at worst; for takes under ~10 minutes, ignore it.

v2 (planned): the device as its own clapperboard

The plan on the firmware roadmap (see osc-spec.md, planned addresses):

  1. A Slate button in the M4L bridge sends /patternflow/slate.
  2. The firmware flashes the full matrix white for one frame; simultaneously the bridge plays a short tone into the Record bus and starts Live's transport recording via the Live API.
  3. The video then contains a single white-flash frame and the audio a tone burst — an exact alignment pair. A small ffmpeg/python script (planned under tools/) finds both and muxes automatically.

Until then, Resolve's waveform sync covers 100% of the need with zero maintenance — which is the point of v1.