How LTC Check works

LTC Check reads an LTC/SMPTE timecode WAV file frame by frame and reports exactly what it finds - no upload, no interpretation required from you.

1. Open LTC Check and drop in a file

LTC Check runs as a native macOS application. You open the app and drop in a WAV file that contains an LTC (Linear Timecode) signal - typically a timecode track exported from a DAW, a playback rig, or supplied by a broadcast or touring partner.

2. LTC Check decodes every frame

LTC Check decodes the LTC signal frame by frame across the full length of the file, rather than sampling or spot-checking. For each frame it records the timecode value, the detected frame rate, and whether the frame decoded cleanly.

This lets it build a complete picture of the file's timecode, including:

Frame rate - 24fps, 25fps, 29.97fps or 30fps, detected from the signal.
Drop-frame / non-drop-frame mode - relevant to 29.97fps timecode used in NTSC-derived workflows.
Start and end timecode - the first and last decoded frame in the file.
Total frames decoded - used to cross-check against the file's duration.

3. LTC Check checks continuity

As it decodes, LTC Check compares each frame to the one before it and classifies anything unexpected:

Missing / skipped frames - a gap between consecutive frame numbers.
Duplicate frames - the same frame value repeated where the next frame was expected.
Backward jumps - timecode moving backwards, including a full restart.
Unexpected forward jumps - timecode advancing by more than one frame.
Frame rate changes - the detected rate changing partway through the file.
Decode dropouts - sections where the LTC signal could not be decoded at all.

Each issue is reported with its position in the file, the expected and actual timecode, and how many frames were affected - so you can find and fix the underlying problem rather than just knowing "something's wrong".

4. LTC Check checks the audio signal

Timecode problems are often signal problems. LTC Check also measures peak and RMS level, clipping, and leading/trailing silence on the channel carrying LTC, since low signal level, distortion or clipping are common causes of decode dropouts.

5. You get a report, not a black box

The result is a single validation report: an overall status (valid, warning or error), the decoded frame rate and time range, and a list of any issues found with enough detail to act on. See the full list of what LTC Check detects.

What LTC Check does not do

LTC Check does not generate or output LTC, and it does not modify your file. It is a read-only diagnostic tool. If you need to generate timecode, LTC Check is not the right tool - it exists specifically to check timecode you already have before you rely on it.