Dual-Channel Video Capture (UVC)

Example source: examples/device/video_capture_2ch

A USB Video Class (UVC) device that exposes two independent video streaming functions on a single device.

What it does

  • Presents two UVC camera functions, both 128x96 at 10 fps.

  • Stream 0 sends YUY2 (uncompressed) color bars; stream 1 sends MJPEG color-bar frames.

  • Uses bulk streaming endpoints (CFG_TUD_VIDEO_STREAMING_BULK).

  • Adopts the frame interval requested by the host at stream commit, per stream.

  • Blinks the board LED to indicate USB state (not mounted / mounted / suspended).

USB Descriptors

Interface

Class driver

0–1

UVC video (control + streaming) — YUY2

2–3

UVC video (control + streaming) — MJPEG

Configuration

Notable tusb_config.h settings:

#define CFG_TUD_VIDEO                       2   // 2 video control interfaces
#define CFG_TUD_VIDEO_STREAMING            2   // 2 video streaming interfaces
#define CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE 256
#define CFG_TUD_VIDEO_STREAMING_BULK       1   // bulk streaming endpoints

Building

CMake:

mkdir build && cd build
cmake -DBOARD=raspberry_pi_pico ..
cmake --build .

Make:

make BOARD=raspberry_pi_pico all

Try it

Two webcam devices appear on the host. On Linux, list them with v4l2-ctl --list-devices and open each with ffplay /dev/videoN or a camera app — one shows YUY2 color bars, the other MJPEG color bars.