Practical Guide to Film and TV Timecode Sync: Tentacle Sync Bluetooth Wireless Multi-Camera Audio-Video Alignment Workflow

1. The post-production hell of multi-camera shooting: the collapse of manual alignment of audio and video

In large-scale interviews, concert multi-camera recording, wedding commercials or movie sets, it is usually equipped with the main position of camera A, the close-up position of camera B, the telephoto rocker of camera C, and a separate independent multi-track professional recorder (Sound Devices/Zoom):

1. Limitations of traditional clapperboard:

• Relying on the crisp sound of the clapper to close the picture; post-production editors need to manually search for the waveform jump peaks frame by frame in thousands of video clips and drag and align them;
• Faced with 500 independent lens clips, it takes two full days to manually align audio and video, which is extremely boring and prone to misalignment and dropped frames;

2. Free-drift clock oscillator (Oscillator Drift):

• The crystal oscillators in Sony cameras, Canon cameras and recorders have microsecond-level physical manufacturing tolerances;
• After recording for more than 20 minutes, the sound and picture of the two machines will spontaneously produce cumulative clock drift (Clock Drift) from a few frames to dozens of frames, causing the actor's lips to completely mismatch the sound.

2. The ultimate industrial solution: SMPTE absolute linear time code (Timecode)

The film and television industry standard SMPTE 12M time code gives every frame in the real world an absolutely unique physical ID card in the world:

1. Discrete data structure of time code (HH:MM:SS:FF):

• Hours, Minutes, Seconds, Frames;
• Whenever you press record, the 01:14:22:18 frame of machine A is absolutely strictly equal to the 01:14:22:18 frame of machine B and recorder in terms of physical reality time!

2. High-precision temperature-compensated crystal oscillator (TCXO - Temperature Compensated Crystal Oscillator):

• The professional timecode generator has a built-in TCXO constant-temperature crystal oscillator with extremely high accuracy. The cumulative error of the clock running continuously for 24 hours is less than half a frame (< 1/50 second)!

3. Practical operation of Tentacle Sync Bluetooth wireless timecode ecosystem

Currently, the most popular solution for independent documentaries and commercial teams around the world is the German Tentacle Sync E mkII micro timecode box:

1. Master Clock wireless transmission and mobile phone App matrix grouping:

• Open the Tentacle App on your phone and turn on Bluetooth;
• Designate one of the timecode boxes as the master clock generator (Master/Generator), and set a matching industrial frame rate (such as strictly 24.00 fps or 25.00 fps, the frame rates of all devices must be absolutely consistent!);
• Click "Wireless Sync All", and the mobile phone will synchronize the master clock's nanosecond-level high-precision timestamp into all sub-timecode boxes within 1 second via low-power Bluetooth.

2. Device-side physical connection and timecode injection:

• For professional movie projectors (with dedicated BNC / LEMO TC port, such as FX6/FX9/C300):
• Use the dedicated cable to plug the Tentacle into the TC IN interface of the machine;
• The timecode on the screen of the camera instantly becomes externally locked (EXT-LK) and is natively recorded into the video file metadata;
• For ordinary mirrorless cameras (without independent timecode port, such as A7M4, R6 II, GH6):
• Use the 3.5mm TRS elbow audio cable to plug the Tentacle directly into the MIC 3.5mm microphone input hole of the camera!
• Audio LTC / Linear Timecode black technology:
• Tentacle modulates high-frequency SMPTE digital timestamps into an audio signal (chirp) similar to the whirring of an old fax machine;
• The camera records it directly into the audio track of the video as ordinary left channel audio; the right channel retains the ambient reference sound of the built-in miniature microphone.

4. Post-production non-editing software with one-click fully automatic sound and picture alignment (Auto-Sync)

When the shooting is over and hundreds of messy materials are imported into the computer editing software:

1. DaVinci Resolve (DaVinci) second-level alignment practice:

• Native TC Alignment: Select all camera videos and multi-track WAV audio in the media pool, right-click to execute Auto-Sync Audio Based on Timecode (Auto-Sync Audio Based on Timecode), and all will be perfectly aligned and embedded in one second!
• Audio Timecode Parsing (Audio LTC):
• For mirrorless video recorded through the 3.5mm audio port, right-click and select Update Timecode from Audio Track;
• Resolve will automatically decode the modulated audio of the left channel, convert it into native metadata timecode, and automatically mute the harsh chirping noise!

2. Create Multicam Clip:

• Select all camera materials, right-click Create Multi-Cam Clip -> Angle Sync: Timecode;
• The software instantly creates a multi-camera monitor and presses the 1/2/3 keys on the keyboard to cut the camera in real time, just like a live broadcast station.

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