Distribute low-latency live feeds

On many film sets, different departments rely on live camera feeds. Directors, script supervisors, and other crew members often need to see the image with as little delay as possible.

Reeltime is designed with low-latency performance at its core and provides several mechanisms to distribute live video signals as fast and direct as possible.

When using a video I/O device for both input and output, Reeltime typically adds about 2–3 frames of latency when delivering a processed feed at the native frame rate of the incoming signal. The features below allow you to reduce latency much further depending on your setup.

For background information about latency in video pipelines, see:

Latency on film sets: how to achieve the fastest possible live feeds with Reeltime

Low-latency monitoring with unprocessed signals#

The following features bypass Reeltime’s processing pipeline and route the camera signal directly to an output. This results in the lowest possible latency, but the image is unprocessed.

Automations for instant video routing#

Reeltime’s Automation Manager allows you to automate video routing configurations based on specific events.

For example, you can create an automation that routes a direct camera signal to the director’s monitor whenever an input slot switches to playback. This ensures the director always receives a live feed with minimal latency even while other crew members review clips.

Because the signal bypasses Reeltime’s processing pipeline, latency is reduced to a minimum.

Automatic pass-through for AJA video I/O devices#

For compatible AJA video I/O devices, Reeltime provides automatic pass-through modes that allow direct signal routing between input and output.

This feature enables near-zero latency between the camera input and the monitor output by bypassing processing inside Reeltime.

When using multiple simultaneous pass-through signals on a single device, ensure that the camera signals are genlocked to guarantee stable operation.

Low-latency monitoring with processed signals#

In many workflows you still want to show processed images, for example with LUTs, overlays, or playback. Reeltime provides several options that maintain very low latency while allowing the signal to be processed.

Reduce latency by increasing the output frame rate of video I/O devices#

Recent versions of Reeltime allow the output format of supported video I/O devices to be configured independently from the input format.

This makes it possible to output signals at a higher frame rate than the camera input.

For example:

24 fps input → 60 fps output25 fps input → 50 fps output29.97 fps input → 59.94 fps output30 fps input → 60 fps output

Because frames are transmitted more frequently, the delay between camera input and monitor output is reduced.

In internal tests, increasing the output frame rate reduced latency from approximately 2–3 frames to only 1 additional frame compared to the direct camera feed.

Because Reeltime renders frames in real time, this configuration does not introduce additional processing delay.

Full-screen output via HDMI or Thunderbolt#

Reeltime can output video directly to monitors connected via HDMI, DisplayPort, or Thunderbolt.

When operated at 60 Hz, this method typically adds only 1–2 frames of delay compared to a direct camera-to-monitor connection.

The reduced latency is achieved because the display refresh rate is higher than the incoming camera frame rate, allowing frames to be presented more frequently.

Low-latency local streaming#

Reeltime Pro supports local streaming to its free companion app Reeltime Viewer (iOS and iPadOS).

The streaming system uses a custom protocol designed for reliable low-latency monitoring on set. Under stable network conditions the delay is typically about 1 frame compared to the direct live feed.

This allows crew members to monitor the camera signal on mobile devices while maintaining secure and stable connections over the local network.

Choosing the right configuration#

The best method for distributing low-latency feeds depends on your setup and the requirements of each viewer on set.