Paparazzi UAS
v7.0_unstable
Paparazzi is a free software Unmanned Aircraft System.
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Capture images from a V4L2 device (Video for Linux 2) More...
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <malloc.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/videodev2.h>
#include <pthread.h>
#include "v4l2.h"
#include "virt2phys.h"
#include <sys/time.h>
#include "mcu_periph/sys_time.h"
Go to the source code of this file.
Macros | |
#define | CLEAR(x) memset(&(x), 0, sizeof (x)) |
Functions | |
static void * | v4l2_capture_thread (void *data) |
The main capturing thread This thread handles the queue and dequeue of buffers, to make sure only the latest image buffer is preserved for image processing. More... | |
bool | v4l2_init_subdev (char *subdev_name, uint8_t pad, uint16_t code, struct img_size_t size) |
Initialize a V4L2 subdevice. More... | |
struct v4l2_device * | v4l2_init (char *device_name, struct img_size_t size, struct crop_t crop, uint8_t buffers_cnt, uint32_t _pixelformat) |
Initialize a V4L2(Video for Linux 2) device. More... | |
void | v4l2_image_get (struct v4l2_device *dev, struct image_t *img) |
Get the latest image buffer and lock it (Thread safe, BLOCKING) This functions blocks until image access is granted. More... | |
bool | v4l2_image_get_nonblock (struct v4l2_device *dev, struct image_t *img) |
Get the latest image and lock it (Thread safe, NON BLOCKING) This function returns NULL if it can't get access to the current image. More... | |
void | v4l2_image_free (struct v4l2_device *dev, struct image_t *img) |
Free the image and enqueue the buffer (Thread safe) This must be done after processing the image, because else all buffers are locked. More... | |
bool | v4l2_start_capture (struct v4l2_device *dev) |
Start capturing images in streaming mode (Thread safe) More... | |
bool | v4l2_stop_capture (struct v4l2_device *dev) |
Stop capturing of the image stream (Thread safe) This function is blocking until capturing thread is closed. More... | |
void | v4l2_close (struct v4l2_device *dev) |
Close the V4L2 device (Thread safe) This needs to be preformed to clean up all the buffers and close the device. More... | |
Capture images from a V4L2 device (Video for Linux 2)
Definition in file v4l2.c.
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static |
The main capturing thread This thread handles the queue and dequeue of buffers, to make sure only the latest image buffer is preserved for image processing.
[in] | *data | The Video 4 Linux 2 device pointer |
Definition at line 57 of file v4l2.c.
References CLEAR, dev, get_sys_time_usec(), TRUE, and V4L2_IMG_NONE.
Referenced by v4l2_start_capture().
void v4l2_close | ( | struct v4l2_device * | dev | ) |
Close the V4L2 device (Thread safe) This needs to be preformed to clean up all the buffers and close the device.
Note that this also stops the capturing if it is still capturing.
[in] | *dev | The video for linux device to close(cleanup) |
Definition at line 537 of file v4l2.c.
References dev, and v4l2_stop_capture().
void v4l2_image_free | ( | struct v4l2_device * | dev, |
struct image_t * | img | ||
) |
Free the image and enqueue the buffer (Thread safe) This must be done after processing the image, because else all buffers are locked.
[in] | *dev | The video for linux device which the image is from |
[in] | *img | The image to free |
Definition at line 418 of file v4l2.c.
References image_t::buf_idx, CLEAR, and dev.
Referenced by video_thread_function().
void v4l2_image_get | ( | struct v4l2_device * | dev, |
struct image_t * | img | ||
) |
Get the latest image buffer and lock it (Thread safe, BLOCKING) This functions blocks until image access is granted.
This should not take that long, because it is only locked while enqueueing an image. Make sure you free the image after processing with v4l2_image_free()!
[in] | *dev | The V4L2 video device we want to get an image from |
[out] | *img | The image that we got from the video device |
Definition at line 344 of file v4l2.c.
References image_t::buf, image_t::buf_idx, image_t::buf_size, dev, image_t::h, IMAGE_YUV422, image_t::pprz_ts, image_t::ts, image_t::type, V4L2_IMG_NONE, and image_t::w.
Referenced by video_thread_function().
bool v4l2_image_get_nonblock | ( | struct v4l2_device * | dev, |
struct image_t * | img | ||
) |
Get the latest image and lock it (Thread safe, NON BLOCKING) This function returns NULL if it can't get access to the current image.
Make sure you free the image after processing with v4l2_image_free())!
[in] | *dev | The V4L2 video device we want to get an image from |
[out] | *img | The image that we got from the video device |
Definition at line 383 of file v4l2.c.
References image_t::buf, image_t::buf_idx, image_t::buf_size, dev, image_t::h, IMAGE_YUV422, image_t::pprz_ts, image_t::ts, image_t::type, V4L2_IMG_NONE, and image_t::w.
struct v4l2_device* v4l2_init | ( | char * | device_name, |
struct img_size_t | size, | ||
struct crop_t | crop, | ||
uint8_t | buffers_cnt, | ||
uint32_t | _pixelformat | ||
) |
Initialize a V4L2(Video for Linux 2) device.
Note that the device must be closed with v4l2_close(dev) at the end.
[in] | device_name | The video device name (like /dev/video1) |
[in] | width,height | The width and height of the images |
[in] | buffers_cnt | The amount of buffers used for mapping |
Definition at line 184 of file v4l2.c.
References v4l2_img_buf::buf, v4l2_device::buffers, check_contiguity(), CLEAR, dev, fd, img_size_t::h, crop_t::h, v4l2_img_buf::length, physmem::paddr, v4l2_img_buf::physp, physmem::size, img_size_t::w, crop_t::w, crop_t::x, and crop_t::y.
Referenced by initialize_camera().
bool v4l2_init_subdev | ( | char * | subdev_name, |
uint8_t | pad, | ||
uint16_t | code, | ||
struct img_size_t | size | ||
) |
Initialize a V4L2 subdevice.
[in] | *subdev_name | The subdevice name (like /dev/v4l-subdev0) |
[in] | pad,which | The way the subdevice should comminicate and be connected to the real device. |
[in] | code | The encoding the subdevice uses (like V4L2_MBUS_FMT_UYVY8_2X8, see the V4L2 manual for available encodings) |
[in] | width,height | The width and height of the images |
Definition at line 137 of file v4l2.c.
References CLEAR, fd, img_size_t::h, and img_size_t::w.
Referenced by initialize_camera().
bool v4l2_start_capture | ( | struct v4l2_device * | dev | ) |
Start capturing images in streaming mode (Thread safe)
[in] | *dev | The video for linux device to start capturing from |
Definition at line 439 of file v4l2.c.
References CLEAR, dev, v4l2_capture_thread(), and V4L2_IMG_NONE.
Referenced by video_thread_function().
bool v4l2_stop_capture | ( | struct v4l2_device * | dev | ) |
Stop capturing of the image stream (Thread safe) This function is blocking until capturing thread is closed.
[in] | *dev | The video for linux device to stop capturing |
Definition at line 502 of file v4l2.c.
References dev.
Referenced by stop_video_thread(), and v4l2_close().