Dual sensors#
CineMate automatically detects each camera connected to the Raspberry Pi and spawns a separate cinepi-raw process per sensor. Cameras are synchronized with cam0 being the server and cam1 being the client.
HDMI preview#
With two sensors, both previews appear together on the on-camera HDMI monitor (HDMI-0), side-by-side, each with a white frame and a centre divider. The simple GUI columns keep their room on the left and right.
Switch which sensor(s) the monitor shows with the set preview command — the change is live, no restart:
| Command | Shows |
|---|---|
set preview both |
both side-by-side (default; cam0+cam1 is an alias) |
set preview cam0 |
cam0 full-screen |
set preview cam1 |
cam1 full-screen |
set preview pip_cam0 |
cam0 full-screen, cam1 as a corner inset (pip / pip0 alias) |
set preview pip_cam1 |
cam1 full-screen, cam0 as a corner inset (pip1 alias) |
set preview |
cycles both → cam0 → cam1 → pip_cam0 → pip_cam1 |
A single selected sensor fills the preview area just like a single-sensor setup. The default source is preview.default_hdmi_source in settings.json; the live value is the hdmi_preview_source Redis key.
Picture-in-picture#
The two pip_* modes show one sensor full-screen with the other shrunk into a corner. The inset geometry is set in settings.json under preview.pip:
| Key | Default | Meaning |
|---|---|---|
scale |
0.28 |
inset size as a fraction of the main pane |
corner |
lower_right |
lower_right, lower_left, upper_right, upper_left |
margin |
0.03 |
gap from the edge as a fraction of the pane |
If the secondary sensor hasn't produced a frame yet, pip falls back to cam0 full-screen so the monitor is never blank.
One monitor, both feeds. DRM master is exclusive per GPU, so the primary cinepi-raw process owns the display and composites both sensors; the secondary runs with --nopreview and hands its frame to the primary.
Recording#
Which sensor(s) record a take depends on the lock_dual_recording setting in settings.json and, when it is off, on the preview:
false — recording follows the preview. Note that if preview is changed while the Pi is recording, the recording has to be stopped and commenced again in order to start recording on the previewed sensor. Side-by-side records both.
true — force dual. Both sensors always record, whatever the preview shows.
Each sensor writes to its own clip folder (..._cam0 / ..._cam1).
When using the cam1 with the official Raspberry Pi CM carrier board, make sure to connect the JC GPIO pins as described here: https://www.raspberrypi.com/documentation/computers/compute-module.html#connect-two-cameras
You can override geometry, HDMI port, camera name, and FPS correction for each port independently in settings.json under camera.cam0 and camera.cam1. See settings.