uvc_cam UVC Camera streaming application

Captures frames from a V4L2 camera sensor and streams them to a USB host via the UVC (USB Video Class) gadget driver (/dev/uvc0).

The application queries the sensor’s native pixel format, resolution and frame rate via V4L2, then continuously captures frames and writes them to the UVC device node.

Dependencies

  • CONFIG_USBUVC=y – UVC gadget driver

  • CONFIG_VIDEO=y – Video subsystem

  • CONFIG_BOARDCTL_USBDEVCTRL=y – USB device control via boardctl

Configuration

  • CONFIG_EXAMPLES_UVC_CAM=y – Enable the UVC camera example

  • CONFIG_EXAMPLES_UVC_CAM_NFRAMES – Number of frames to stream (0 = infinite, default)

  • CONFIG_EXAMPLES_UVC_CAM_PRIORITY – Task priority (default 100)

  • CONFIG_EXAMPLES_UVC_CAM_STACKSIZE – Stack size (default 4096)

Supported Pixel Formats

  • YUYV (2 bytes per pixel)

  • RGB565 (2 bytes per pixel)

  • RGB24 (3 bytes per pixel)

Usage

uvc_cam [nframes] [video_dev] [uvc_dev]

  • nframes – Number of frames to capture (default from Kconfig, 0 = infinite)

  • video_dev – V4L2 camera device path (default /dev/video0)

  • uvc_dev – UVC gadget device path (default /dev/uvc0)

Examples

  • Stream indefinitely with defaults: uvc_cam

  • Stream 100 frames: uvc_cam 100

  • Use a different camera device: uvc_cam 0 /dev/video1

  • Specify both camera and UVC device: uvc_cam 0 /dev/video0 /dev/uvc1

Board Support

The lckfb-szpi-esp32s3 board provides a uvc configuration with camera and UVC gadget driver pre-enabled:

$ ./tools/configure.sh lckfb-szpi-esp32s3:uvc

This configuration enables the ESP32-S3 camera interface (GC0308 sensor), USB OTG and the UVC gadget driver. The uvc_cam example application is not enabled by default and must be turned on manually:

$ kconfig-tweak --enable CONFIG_EXAMPLES_UVC_CAM

Or via make menuconfig: Application Configuration ‣ Examples ‣ UVC Camera streaming example

After flashing, run the application manually from the NSH shell:

nsh> uvc_cam