macOS · Broadcast BWF stamp
TCFrameLock app icon

TCFrameLock

Write the session timecode into the files. Then insert them using that timecode.

If you have multitrack recordings and an LTC track alongside them, TCFrameLock writes that timecode into every audio track as Broadcast Wave. In your movie editor, insert them onto the timeline using the timecode. They land on the right frame. The audio is copied, not re-encoded.

From session to timeline
TCFrameLock after a successful stamp: MIX and LTC files listed, decoded start 00:15:01:09, and a generated Broadcast WAV

What the app is for

You recorded several tracks, and one of them is Linear Timecode. You want those files on a movie timeline at the same place the camera was. TCFrameLock reads the LTC and writes that timecode into every audio track as Broadcast Wave. In the editor you insert them using that timecode so the new files land on the right frame.

Step 1

Drop the session

Your audio tracks plus the LTC. WAV or AIFF, or a whole folder. The app looks for the timecode track so you do not have to label it.

Step 2

It reads the LTC

That track is the clock that ran while you recorded. The app reads it and finds the timecode at the beginning of the session. Every audio track gets that same timecode.

Step 3

Insert using timecode

Each track comes back as a Broadcast WAV with that timecode already in the file. In the movie editor, insert them onto the timeline using that timecode. They land on the right frame.

From session to timeline

Drop the audio and the LTC that was recorded with it. These tabs walk through what the app does with those files, what you get back, and how the movie editor uses them.

Audio plus the LTC that ran with it

What you drop

This is a typical use. You have the tracks from the recorder, and one file is Linear Timecode recorded at the same time. Drop the files or the whole folder. The app looks for the LTC track so you do not have to label it.

Mix_L.wav 48 kHz · 24-bit
MIX
Mix_R.wav 48 kHz · 24-bit
MIX
Dialogue.wav 48 kHz · 24-bit
MIX
Session_LTC.wav LTC on channel 1
LTC

The LTC is the clock for the session

How they work together

That LTC file is not music. It is a clock that ran while you recorded. The app listens to it and reads the timecode off that track. The audio files get that same clock, so they stay together when you get to the editor.

01:00:00:03
01:00:00:04
01:00:00:05
01:00:00:06
01:00:00:07
01:00:00:08
01:00:00:09
01:00:00:10

Once it has a solid read of the LTC, every audio track can share that clock.

The beginning of the files, not a random hit in the middle

Where they belong

The first timecode the app hears might be a second into the recording. That is not where the files begin. It works back to the first sample so the timecode matches the actual beginning of the audio, which is what the movie editor needs.

00:59:59:10 beginning of the file
01:00:00:10 first LTC it locked onto

The timecode the movie editor will use

What gets written

Broadcast WAV files carry a timecode the editor can read. When you insert using timecode, that is what places the clip. Every audio track from the session gets the same one, taken from the LTC.

00HRS
:
59MIN
:
59SEC
:
10FRM

This is what the editor uses when you insert using timecode

New files, same audio, then the timeline

What you take to the editor

You get new Broadcast WAV files. The audio is the same. The LTC file is not rewritten. Bring those new files into your movie editor and insert them using the timecode. Each clip lands on the timeline at the right frame.

Same audio

Copied, not re-encoded. That is the recording you already have.

New Broadcast WAV

Each audio track comes back with the session timecode written in, so the editor can place it.

LTC left alone

It was only the clock. The app does not rewrite that file.

Insert using timecode

In the movie editor, that puts each clip on the timeline at the right frame.

1. Bring the session

Multitrack files plus the LTC that was recorded with them. Drop the files or a folder.

2. It reads the LTC

That track is the clock that ran with the recording. The app reads it and writes that same timecode onto every audio track.

3. It stamps every track

Each track gets a new Broadcast WAV with that timecode written in. Same audio. The LTC file is not rewritten.

4. Insert using timecode

Bring the new files into your movie editor. Insert them onto the timeline using the timecode in the file. They land on the right frame.

Specs

PlatformmacOS 14 or later, sandboxed native SwiftUI app
InputsWAV (RIFF) and AIFF / AIF, linear PCM
OutputsBroadcast WAV with bext; filename *_TC_HHmmss.wav
Frame rates23.976 NDF, 24, 25, 29.97 NDF, 29.97 DF, 30
Time ReferenceEBU Tech 3285, UInt64 little-endian at bext offset 338
OriginatorTCFrameLock, plus stamp date/time when creating a new bext
Not supportedRF64, compressed audio, files that would exceed the 4 GB RIFF limit
NetworkNone. Files never leave the Mac.

What you do with it

Sessions with an LTC track

Multitrack from the recorder, plus the Linear Timecode that was recorded with them. That is the whole job.

One clock for every audio track

The LTC is the clock. Every audio track comes back as a Broadcast WAV with that same timecode in the file.

Same audio

The sound is copied. You are not printing a new mix. The LTC file is only read, never rewritten.

Then the movie editor

In the movie editor, insert them using the timecode. Each clip lands on the timeline at the right frame.

On your Mac

No account, no upload. Files stay on the machine. Drop a session, get new files next to it or in a folder you choose.

WAV or AIFF

Drop files or a whole folder. The app looks for the LTC so you do not have to label it.

Buy TCFrameLock

One-time Mac license. Pay once, download, come back for updates.

License

$19.99 USD

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macOS 14 or later. One license per checkout email. After you pay, your download is on the next screen.

Get in touch

support@stackcommander.com

Questions about the app or a license.

Privacy

The app does not upload files or analytics. Processing is on your Mac. Checkout is handled by Paddle. Privacy policy.

Requirements

macOS 14 or later.

Common questions

What does TCFrameLock do?

If you have multitrack recordings and an LTC track recorded with them, TCFrameLock writes that timecode into every audio track as Broadcast Wave. In your movie editor, insert them onto the timeline using that timecode. They land on the right frame. The audio itself is not re-encoded.

What is a Broadcast WAV Time Reference?

In the EBU bext chunk, Time Reference is a 64-bit integer: PCM samples since midnight (00:00:00:00) at the file’s sample rate. NLEs use it to place sample 0 on a known SMPTE address. The app does not write a human-readable HH:MM:SS:FF string as the alignment value. It writes the sample count those systems expect.

Does it re-encode the audio?

No. A native WAV is stamped by injecting or updating bext and copying the data chunk. AIFF is converted to a working WAV first so the rest of the pipeline can run; the original AIFF is left alone.

Does it change the LTC file?

No. The LTC source is read only. Audio tracks are written as new timestamped WAV files. Existing files are never overwritten.

What if two files both look like LTC?

The session is marked ambiguous. You pick the LTC source in the UI, or right-click a file and assign it. If nothing locks, you can still type a timecode by hand.

Which frame rates are supported?

23.976 NDF, 24, 25, 29.97 NDF, 29.97 drop-frame, and 30. Changing the picker re-analyzes the files. A mismatch with the LTC signal is a warning, not a silent rewrite.

Is this a subscription?

No. It is a one-time license, not a subscription.