usb_cam.cpp File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <malloc.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <asm/types.h>
#include <linux/videodev2.h>
#include <libavcodec/avcodec.h>
#include <libswscale/swscale.h>
#include <usb_cam/usb_cam.h>
#include <string>
#include <sstream>

Include dependency graph for usb_cam.cpp:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	buffer
Defines
#define	__STDC_CONSTANT_MACROS
#define	CLEAR(x)   memset (&(x), 0, sizeof (x))
Functions
static unsigned char	CLIPVALUE (int val)
static void	close_device (void)
static void	errno_exit (const char *s)
static void	init_device (int image_width, int image_height)
static int	init_mjpeg_decoder (int image_width, int image_height)
static void	init_mmap (void)
static void	init_read (unsigned int buffer_size)
static void	init_userp (unsigned int buffer_size)
static void	mjpeg2rgb (char *MJPEG, int len, char *RGB, int NumPixels)
static void	open_device (void)
static void	process_image (const void *src, int len, usb_cam_camera_image_t *dest)
static int	read_frame (usb_cam_camera_image_t *image)
static void	start_capturing (void)
static void	stop_capturing (void)
static void	uninit_device (void)
void	usb_cam_camera_grab_image (usb_cam_camera_image_t *image)
void	usb_cam_camera_shutdown (void)
usb_cam_camera_image_t *	usb_cam_camera_start (const char *dev, usb_cam_io_method io_method, usb_cam_pixel_format pixel_format, int image_width, int image_height)
void	uyvy2rgb (char *YUV, char *RGB, int NumPixels)
static int	xioctl (int fd, int request, void *arg)
static void	YUV2RGB (const unsigned char y, const unsigned char u, const unsigned char v, unsigned char *r, unsigned char *g, unsigned char *b)
static void	yuyv2rgb (char *YUV, char *RGB, int NumPixels)
Variables
static AVCodec *	avcodec = NULL
static AVCodecContext *	avcodec_context = NULL
static AVFrame *	avframe_camera = NULL
static int	avframe_camera_size = 0
static AVFrame *	avframe_rgb = NULL
static int	avframe_rgb_size = 0
struct buffer *	buffers = NULL
static char *	camera_dev
const int	clipping_table_offset = 128
static int	fd = -1
static usb_cam_io_method	io = IO_METHOD_MMAP
static unsigned int	n_buffers = 0
static unsigned int	pixelformat
const unsigned char	uchar_clipping_table []
struct SwsContext *	video_sws = NULL

---

Define Documentation

#define __STDC_CONSTANT_MACROS

Definition at line 36 of file usb_cam.cpp.

#define CLEAR

(

x

)

memset (&(x), 0, sizeof (x))

Definition at line 61 of file usb_cam.cpp.

---

Function Documentation

static unsigned char CLIPVALUE

(

int

val

)

[static]

Clip a value to the range 0<val<255. For speed this is done using an array, so can only cope with numbers in the range -128<val<383.

Definition at line 172 of file usb_cam.cpp.

static void close_device

(

void

)

[static]

Definition at line 775 of file usb_cam.cpp.

static void errno_exit

(

const char *

s

)

[static]

Definition at line 83 of file usb_cam.cpp.

static void init_device	(	int	image_width,
		int	image_height
	)			[static]

Definition at line 664 of file usb_cam.cpp.

static int init_mjpeg_decoder	(	int	image_width,
		int	image_height
	)			[static]

Definition at line 280 of file usb_cam.cpp.

static void init_mmap

(

void

)

[static]

Definition at line 571 of file usb_cam.cpp.

static void init_read

(

unsigned int

buffer_size

)

[static]

Definition at line 553 of file usb_cam.cpp.

static void init_userp

(

unsigned int

buffer_size

)

[static]

Definition at line 622 of file usb_cam.cpp.

static void mjpeg2rgb	(	char *	MJPEG,
		int	len,
		char *	RGB,
		int	NumPixels
	)			[static]

Definition at line 315 of file usb_cam.cpp.

static void open_device

(

void

)

[static]

Definition at line 783 of file usb_cam.cpp.

static void process_image	(	const void *	src,
		int	len,
		usb_cam_camera_image_t *	dest
	)			[static]

Definition at line 347 of file usb_cam.cpp.

static int read_frame

(

usb_cam_camera_image_t *

image

)

[static]

Definition at line 357 of file usb_cam.cpp.

static void start_capturing

(

void

)

[static]

Definition at line 473 of file usb_cam.cpp.

static void stop_capturing

(

void

)

[static]

Definition at line 453 of file usb_cam.cpp.

static void uninit_device

(

void

)

[static]

Definition at line 529 of file usb_cam.cpp.

void usb_cam_camera_grab_image

(

usb_cam_camera_image_t *

image

)

Definition at line 863 of file usb_cam.cpp.

void usb_cam_camera_shutdown

(

void

)

Definition at line 844 of file usb_cam.cpp.

usb_cam_camera_image_t* usb_cam_camera_start	(	const char *	dev,
		usb_cam_io_method	io_method,
		usb_cam_pixel_format	pixel_format,
		int	image_width,
		int	image_height
	)

Definition at line 805 of file usb_cam.cpp.

void uyvy2rgb	(	char *	YUV,
		char *	RGB,
		int	NumPixels
	)

Definition at line 236 of file usb_cam.cpp.

static int xioctl	(	int	fd,
		int	request,
		void *	arg
	)			[static]

Definition at line 90 of file usb_cam.cpp.

static void YUV2RGB	(	const unsigned char	y,
		const unsigned char	u,
		const unsigned char	v,
		unsigned char *	r,
		unsigned char *	g,
		unsigned char *	b
	)			[static]

Conversion from YUV to RGB. The normal conversion matrix is due to Julien (surname unknown):

[ R ] [ 1.0 0.0 1.403 ] [ Y ] [ G ] = [ 1.0 -0.344 -0.714 ] [ U ] [ B ] [ 1.0 1.770 0.0 ] [ V ]

and the firewire one is similar:

[ R ] [ 1.0 0.0 0.700 ] [ Y ] [ G ] = [ 1.0 -0.198 -0.291 ] [ U ] [ B ] [ 1.0 1.015 0.0 ] [ V ]

Corrected by BJT (coriander's transforms RGB->YUV and YUV->RGB do not get you back to the same RGB!) [ R ] [ 1.0 0.0 1.136 ] [ Y ] [ G ] = [ 1.0 -0.396 -0.578 ] [ U ] [ B ] [ 1.0 2.041 0.002 ] [ V ]

Definition at line 204 of file usb_cam.cpp.

static void yuyv2rgb	(	char *	YUV,
		char *	RGB,
		int	NumPixels
	)			[static]

Definition at line 258 of file usb_cam.cpp.

---

Variable Documentation

AVCodec* avcodec = NULL [static]

Definition at line 76 of file usb_cam.cpp.

AVCodecContext* avcodec_context = NULL [static]

Definition at line 77 of file usb_cam.cpp.

AVFrame* avframe_camera = NULL [static]

Definition at line 74 of file usb_cam.cpp.

int avframe_camera_size = 0 [static]

Definition at line 78 of file usb_cam.cpp.

AVFrame* avframe_rgb = NULL [static]

Definition at line 75 of file usb_cam.cpp.

int avframe_rgb_size = 0 [static]

Definition at line 79 of file usb_cam.cpp.

struct buffer* buffers = NULL

Definition at line 72 of file usb_cam.cpp.

char* camera_dev [static]

Definition at line 68 of file usb_cam.cpp.

const int clipping_table_offset = 128

Definition at line 166 of file usb_cam.cpp.

int fd = -1 [static]

Definition at line 71 of file usb_cam.cpp.

usb_cam_io_method io = IO_METHOD_MMAP [static]

Definition at line 70 of file usb_cam.cpp.

unsigned int n_buffers = 0 [static]

Definition at line 73 of file usb_cam.cpp.

unsigned int pixelformat [static]

Definition at line 69 of file usb_cam.cpp.

const unsigned char uchar_clipping_table[]

Definition at line 100 of file usb_cam.cpp.

struct SwsContext* video_sws = NULL

Definition at line 81 of file usb_cam.cpp.