initial commit

third_party/tinyusb/examples/device/video_capture/README.md

@@ -0,0 +1,48 @@
+# Video Capture (UVC)
+
+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_READONLY` streams fixed MJPEG images from flash (or YUY2 with `CFG_EXAMPLE_VIDEO_DISABLE_MJPEG`), and `CFG_EXAMPLE_VIDEO_BUFFERLESS` fills the payload on the fly.
+- Uses an isochronous streaming endpoint by default (bulk if `CFG_TUD_VIDEO_STREAMING_BULK` is 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:
+
+```c
+#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:
+
+```bash
+mkdir build && cd build
+cmake -DBOARD=raspberry_pi_pico ..
+cmake --build .
+```
+
+Make:
+
+```bash
+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.