Video Capture (UVC)¶
Example source:
examples/device/video_capture
A USB Video Class (UVC) camera that streams generated color-bar frames.
What it does¶
Presents itself as a UVC camera and streams 128x96 video at 10 fps.
By default generates YUY2 (uncompressed) color-bar frames into a RAM frame buffer; build options select alternatives:
CFG_EXAMPLE_VIDEO_READONLYstreams fixed MJPEG images from flash (or YUY2 withCFG_EXAMPLE_VIDEO_DISABLE_MJPEG), andCFG_EXAMPLE_VIDEO_BUFFERLESSfills the payload on the fly.Uses an isochronous streaming endpoint by default (bulk if
CFG_TUD_VIDEO_STREAMING_BULKis set).Adopts the frame interval requested by the host at stream commit.
Blinks the board LED to indicate USB state (not mounted / mounted / suspended).
USB Descriptors¶
Interface |
Class driver |
|---|---|
0–1 |
UVC video (control + streaming) |
Configuration¶
Notable tusb_config.h settings:
#define CFG_TUD_VIDEO 1
#define CFG_TUD_VIDEO_STREAMING 1
#define CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE 256
#define CFG_TUD_VIDEO_STREAMING_BULK 0 // 0 = isochronous, 1 = bulk streaming
Building¶
CMake:
mkdir build && cd build
cmake -DBOARD=raspberry_pi_pico ..
cmake --build .
Make:
make BOARD=raspberry_pi_pico all
Try it¶
The device appears as a webcam. On Linux, find it with v4l2-ctl --list-devices and view it with ffplay /dev/videoN or any camera app. You should see scrolling color bars.