COntents:
Genlock is a technology used for synchronizing video equipment so that all devices operate in sync with the same timing. Genlock ensures that various devices, such as cameras, media servers, and video players, are synchronized with a common timing source, preventing issues like image tearing or stuttering.
How Genlock Works
Genlock transmits a clock signal (sync pulse) from one device to another, forcing them to operate at the same frame rate and synchronize their timing. This is particularly important in professional video production, where multiple cameras, video mixers, media servers, and other devices need to be precisely synchronized.
On different devices, you may encounter terms like Reference, Sync Reference, or External Sync.
It is important to know that the reference sync signal is an analog signal and will require an analog distribution amplifier if a larger number of channels is needed.
Genlock Applications
Cameras:
- Video Production: In multi-camera systems, such as in television studios or live broadcasts, Genlock is used to ensure that all cameras capture frames simultaneously. This is crucial to avoid delays or tearing when switching between cameras.
- Multi-Camera Shooting: When using multiple cameras to capture the same event, Genlock helps synchronize them so that each frame captured by each camera has the same timing.
Media Servers:
- Output Synchronization: Media servers using Genlock can synchronize their output video streams with an external sync source, such as a camera or another server. This is critical when using media servers for projection across multiple screens or for real-time video streaming.
- Cooperation Between Multiple Servers: When several media servers are used to output video to different screens, Genlock ensures that all servers output images in sync, avoiding mismatches or lags.
Blackburst / Tri-Level Sync
Blackburst and Tri-Level Sync are two different types of sync signals used for synchronizing video equipment in professional video systems.
Blackburst
What It Is:
Blackburst, also known as color burst or video sync pulse, is an analog video signal that carries a black frame with synchronization pulses and a color subcarrier. This signal is used to ensure that video devices are synchronized.
Usage:
Blackburst is primarily used in SD (Standard Definition, e.g., 480i) systems and sometimes in HD (High Definition) systems. It was the standard for synchronizing analog video equipment and is still used in some legacy systems.
Features:
Blackburst provides vertical and horizontal synchronization as well as color synchronization through the color subcarrier signal. This type of signal is simple and effective for basic synchronization in standard definition systems.
Tri-Level Sync
What It Is:
Tri-Level Sync is a synchronization signal that uses three voltage levels (positive, zero, and negative) to create a more precise and stable sync signal compared to Blackburst. It provides greater accuracy and reliability in synchronization.
Usage:
Tri-Level Sync is used in high-resolution systems like HD (1080p) and 4K, where more precise synchronization is required. It is the standard sync signal for digital video systems and high-resolution equipment.
Features:
Tri-Level Sync generates sync pulses at a higher frequency, making it the preferred choice for minimizing jitter and ensuring precise frame alignment in high-resolution video systems.
Genlock Generation
Special devices are used to generate Genlock, creating a synchronization signal that is transmitted to all connected devices.
Popular Devices:
AJA GEN10:
A sync generator supporting SD, HD, and 3G-SDI. It can be used to synchronize video equipment, including cameras and media servers.
Blackmagic Design Sync Generator:
A simple device for generating Genlock with SDI support. It generates stable clock signals and is used in professional studios for equipment synchronization.
Rosendahl Studiotechnik Nanosyncs HD:
A compact and powerful sync generator supporting HD and SD formats. It is used for precise synchronization of video equipment in studio environments.
