πŸ“€ LTC Generator Tool

Professional LTC Timecode Generator

πŸ“€ LTC Generator

00:00:00:00
Stopped 25.00 fps Free Run
10s
0.50

What LTC is

Linear Timecode is SMPTE timecode encoded as an audio signal. Each frame of video is represented by an 80-bit word, written using biphase mark encoding, so that the signal carries its own clock and can be read forwards, backwards and at varying speed. It sounds like a harsh buzz, and it has been the backbone of audio-video synchronisation since the 1970s precisely because any device with an audio input can read it.

This generator writes a WAV file containing a continuous LTC stream, starting from the timecode you choose, at the frame rate you choose, for as long as you need. No installation, no account: the file is built in your browser and downloaded straight to your machine.

How to jam-sync a camera or recorder

  1. Set the start timecode and the frame rate to match your production. If in doubt in Europe, that is 25 fps.
  2. Generate a file a few minutes longer than you think you need.
  3. Play it from a phone or laptop into the timecode input β€” or, on cameras without one, into an audio channel β€” at a healthy level.
  4. Put the camera or recorder into jam-sync mode and let it read at least ten seconds of clean code before you disconnect.
  5. Repeat on every device that has to agree.

Choosing the frame rate

Every device in the chain must be set to the same frame rate. A recorder set to 25 fps reading a 30 fps LTC stream will lock, and will be wrong.

Level, cabling and the mistakes that cost you a take

LTC is an audio signal and behaves like one. A few things worth knowing before you blame the code:

When a WAV file is not enough

A generated file is perfect for a shoot, a rehearsal, a bench test or a fault hunt. It has one limitation that no browser can fix: it starts from the number you typed, not from the real time, and it runs on the clock of the device playing it back. Over a long day that clock drifts.

A control room that has to stay correct all day, every day, does it the other way round: a hardware converter takes network time from an NTP or PTP reference and generates a continuous LTC stream that is right by construction, without anybody pressing play. That is what our NTP/LTC Converter does, and why it lives in a rack rather than in a browser tab.

Frequently asked questions

What is LTC timecode?

Linear Timecode is SMPTE timecode encoded as an audio waveform, using biphase mark encoding so that the signal carries its own clock. Any device with an audio input can read it, which is why it has been the standard method of synchronising audio and video since the 1970s.

What frame rate should I choose?

Match the production. 25 fps for European broadcast, 24 fps for cinema, 29.97 fps for NTSC, 23.976 fps for film finished in an NTSC pipeline. Every device in the chain must be set to the same rate.

What level should I record LTC at?

Around −12 dBFS. Too quiet and the reader misses transitions; too loud and clipping distorts the square wave beyond recognition.

Can I use an MP3 of the timecode?

No. Lossy compression destroys the sharp transitions that carry the data. Use the WAV file exactly as generated, with no processing anywhere in the chain.

How long should the file be?

Longer than the session. When the file ends, the reader holds the last valid frame and stops advancing, which is easy to miss until you check the rushes.

Is this LTC generator free?

Yes, with no registration. The WAV is generated in your browser and never leaves your machine.

Can I use the generated file instead of a hardware timecode generator?

For a shoot, a test or a rehearsal, yes. For continuous operation it is not equivalent: the file starts from a number you typed and runs on the playback device's clock, which drifts. A permanent installation uses a hardware converter locked to an NTP or PTP reference.