LTC timecode checker
An LTC timecode checker reads a Linear Timecode signal in a WAV file and tells you whether it is continuous and clean. LTC Check is a macOS LTC timecode checker built for exactly that.
What is LTC timecode?
LTC - Linear Timecode, sometimes called SMPTE LTC - is a timecode signal encoded as an audio waveform. It carries hours, minutes, seconds and frames, along with frame rate and drop-frame/non-drop-frame flags, and is commonly recorded onto a dedicated track in a WAV file alongside programme audio.
Because it's just audio, LTC can be routed, recorded, copied and played back through ordinary audio infrastructure - which is exactly why it's useful for synchronising playback systems, lighting, video and broadcast equipment. It's also why it can go wrong in ways that are easy to miss just by listening: a corrupted or discontinuous LTC file often sounds unremarkable.
What does an LTC checker actually check?
A proper LTC checker doesn't just confirm that a file "has timecode in it". It decodes the signal frame by frame and checks for:
- Frame rate (24fps, 25fps, 29.97fps, 30fps) and drop-frame mode
- Missing or skipped frames
- Duplicate frames
- Backward jumps or unexpected timecode restarts
- Unexpected forward jumps
- Sections where the signal drops out and can't be decoded at all
- Signal level and clipping on the LTC channel
This is the difference between an LTC checker and an LTC reader: a reader just displays the current timecode value, while a checker analyses the whole file and reports problems.
LTC Check: an LTC timecode checker for macOS
LTC Check is a small macOS application built specifically as an LTC validator. You drop in a WAV file, it decodes every frame, and it reports an overall status - valid, warning or error - along with the specific issues found and where they occur in the file.
It's designed for the people who depend on LTC being right: playback engineers, touring musicians, Resolume and QLab users, lighting programmers, theatre technicians and broadcast/video engineers checking a file before it goes into a live rig.
Files are analysed locally on your Mac - nothing is uploaded. See how LTC Check works for a full walkthrough of the checks it performs.
LTC checker vs LTC generator
LTC Check is not an LTC generator. If you need to create a timecode track from scratch, you need a generator. LTC Check exists for the step after that: verifying an LTC file - whether you generated it, received it from someone else, or exported it from a DAW - is actually continuous and clean before you rely on it in a show.
Related reading
- LTC dropout checker - what causes LTC dropouts and how to find them.
- SMPTE timecode checker - checking SMPTE timecode for broadcast and video workflows.