libuvc is a library that supports enumeration, control and streaming for USB Video Class (UVC) devices, such as consumer webcams.
Features
Roadmap
- Bulk-mode image capture
- One-shot image capture
- Improved support for standard settings
- Support for "extended" (vendor-defined) settings
Misc.
The
source code can be found at https://github.com/ktossell/libuvc. To build the library, install libusb 1.0+ and run:
$ git clone https:
$ cd libuvc
$ mkdir build
$ cd build
$ cmake -DCMAKE_BUILD_TYPE=Release ..
$ make && make install
Example
In this example, libuvc is used to acquire images in a 30 fps, 640x480 YUV stream from a UVC device such as a standard webcam.
#include "libuvc/libuvc.h"
#include <stdio.h>
if (!bgr) {
printf("unable to allocate bgr frame!");
return;
}
if (ret) {
return;
}
}
int main(int argc, char **argv) {
uvc_context_t *ctx;
uvc_device_t *dev;
uvc_device_handle_t *devh;
if (res < 0) {
return res;
}
puts("UVC initialized");
ctx, &dev,
0, 0, NULL);
if (res < 0) {
} else {
puts("Device found");
if (res < 0) {
} else {
puts("Device opened");
devh, &ctrl,
640, 480, 30
);
if (res < 0) {
} else {
if (res < 0) {
} else {
puts("Streaming...");
sleep(10);
puts("Done streaming.");
}
}
puts("Device closed");
}
uvc_unref_device(dev);
}
puts("UVC exited");
return 0;
}
void uvc_exit(uvc_context_t *ctx)
Closes the UVC context, shutting down any active cameras.
Definition: init.c:138
uvc_error_t uvc_init(uvc_context_t **pctx, struct libusb_context *usb_ctx)
Initializes the UVC context.
Definition: init.c:104
void uvc_print_stream_ctrl(uvc_stream_ctrl_t *ctrl, FILE *stream)
Print the values in a stream control block.
Definition: diag.c:106
uvc_frame_t * uvc_allocate_frame(size_t data_bytes)
Allocate a frame structure.
Definition: frame.c:64
uvc_error_t uvc_get_stream_ctrl_format_size(uvc_device_handle_t *devh, uvc_stream_ctrl_t *ctrl, enum uvc_frame_format cf, int width, int height, int fps)
Get a negotiated streaming control block for some common parameters.
Definition: stream.c:359
uvc_error_t uvc_start_streaming(uvc_device_handle_t *devh, uvc_stream_ctrl_t *ctrl, uvc_frame_callback_t *cb, void *user_ptr, uint8_t flags)
Begin streaming video from the camera into the callback function.
Definition: stream.c:686
void uvc_close(uvc_device_handle_t *devh)
Close a device.
Definition: device.c:1537
uint32_t height
Height of image in pixels.
Definition: libuvc.h:434
uvc_error_t uvc_set_ae_mode(uvc_device_handle_t *devh, uint8_t mode)
Sets camera's auto-exposure mode.
Definition: ctrl-gen.c:105
uint32_t width
Width of image in pixels.
Definition: libuvc.h:432
uvc_error_t uvc_any2bgr(uvc_frame_t *in, uvc_frame_t *out)
Convert a frame to BGR.
Definition: frame.c:438
void uvc_print_diag(uvc_device_handle_t *devh, FILE *stream)
Print camera capabilities and configuration.
Definition: diag.c:143
uvc_error_t uvc_open(uvc_device_t *dev, uvc_device_handle_t **devh)
Open a UVC device.
Definition: device.c:273
void uvc_perror(uvc_error_t err, const char *msg)
Print a message explaining an error in the UVC driver.
Definition: diag.c:73
enum uvc_error uvc_error_t
UVC error types, based on libusb errors.
An image frame received from the UVC device.
Definition: libuvc.h:426
void uvc_free_frame(uvc_frame_t *frame)
Free a frame structure.
Definition: frame.c:92
@ UVC_FRAME_FORMAT_YUYV
YUYV/YUV2/YUV422: YUV encoding with one luminance value per pixel and one UV (chrominance) pair for e...
Definition: libuvc.h:68
Streaming mode, includes all information needed to select stream.
Definition: libuvc.h:463
uvc_error_t uvc_find_device(uvc_context_t *ctx, uvc_device_t **dev, int vid, int pid, const char *sn)
Finds a camera identified by vendor, product and/or serial number.
Definition: device.c:128
void uvc_stop_streaming(uvc_device_handle_t *devh)
Stop streaming video.
Definition: stream.c:1203