usbvideo.h

一种linux下的看摄像头的画面的软件

	unsigned char ifaceAltInactive; /* Alt settings */
	unsigned long flags;		/* FLAGS_USBVIDEO_xxx */
	unsigned long paletteBits;	/* Which palettes we accept? */
	unsigned short defaultPalette;	/* What palette to use for read() */
	struct semaphore lock;
	int user;		/* user count for exclusive use */

	videosize_t videosize;	/* Current setting */
	videosize_t canvas;	/* This is the width,height of the V4L canvas */
	int max_frame_size;	/* Bytes in one video frame */

	int uvd_used;        	/* Is this structure in use? */
	int streaming;		/* Are we streaming Isochronous? */
	int grabbing;		/* Are we grabbing? */
	int settingsAdjusted;	/* Have we adjusted contrast etc.? */
	int last_error;		/* What calamity struck us? */

	char *fbuf;		/* Videodev buffer area */
	int fbuf_size;		/* Videodev buffer size */

	int curframe;
	int iso_packet_len;	/* Videomode-dependent, saves bus bandwidth */

	struct RingQueue dp;	/* Isoc data pump */
	struct usbvideo_frame frame[USBVIDEO_NUMFRAMES];
	struct usbvideo_sbuf sbuf[USBVIDEO_NUMSBUF];

	volatile int remove_pending;	/* If set then about to exit */

	struct video_picture vpic, vpic_old;	/* Picture settings */
	struct video_capability vcap;		/* Video capabilities */
	struct video_channel vchan;	/* May be used for tuner support */
	struct usbvideo_statistics stats;
	struct proc_dir_entry *procfs_vEntry;	/* /proc/video/MYDRIVER/video2 */
	char videoName[32];		/* Holds name like "video7" */
};

/*
 * usbvideo callbacks (virtual methods). They are set when usbvideo
 * services are registered. All of these default to NULL, except those
 * that default to usbvideo-provided methods.
 */
struct usbvideo_cb {
	void *(*probe)(struct usb_device *, unsigned int,const struct usb_device_id *);
	void (*userFree)(struct uvd *);
	void (*disconnect)(struct usb_device *, void *);
	int (*setupOnOpen)(struct uvd *);
	void (*videoStart)(struct uvd *);
	void (*videoStop)(struct uvd *);
	void (*processData)(struct uvd *, struct usbvideo_frame *);
	void (*postProcess)(struct uvd *, struct usbvideo_frame *);
	void (*adjustPicture)(struct uvd *);
	int (*getFPS)(struct uvd *);
	int (*overlayHook)(struct uvd *, struct usbvideo_frame *);
	int (*getFrame)(struct uvd *, int);
	int (*procfs_read)(char *page,char **start,off_t off,int count,int *eof,void *data);
	int (*procfs_write)(struct file *file,const char *buffer,unsigned long count,void *data);
	int (*startDataPump)(struct uvd *uvd);
	void (*stopDataPump)(struct uvd *uvd);
	int (*setVideoMode)(struct uvd *uvd, struct video_window *vw);
};

struct usbvideo {
	int num_cameras;		/* As allocated */
	struct usb_driver usbdrv;	/* Interface to the USB stack */
	char drvName[80];		/* Driver name */
	struct semaphore lock;		/* Mutex protecting camera structures */
	struct usbvideo_cb cb;		/* Table of callbacks (virtual methods) */
	struct video_device vdt;	/* Video device template */
	struct uvd *cam;			/* Array of camera structures */
	int uses_procfs;		/* Non-zero if we create /proc entries */
	struct proc_dir_entry *procfs_dEntry;	/* /proc/video/MYDRIVER */
	struct module *md_module;	/* Minidriver module */
};


/*
 * This macro retrieves callback address from the struct uvd object.
 * No validity checks are done here, so be sure to check the
 * callback beforehand with VALID_CALLBACK.
 */
#define	GET_CALLBACK(uvd,cbName) ((uvd)->handle->cb.cbName)

/*
 * This macro returns either callback pointer or NULL. This is safe
 * macro, meaning that most of components of data structures involved
 * may be NULL - this only results in NULL being returned. You may
 * wish to use this macro to make sure that the callback is callable.
 * However keep in mind that those checks take time.
 */
#define	VALID_CALLBACK(uvd,cbName) ((((uvd) != NULL) && \
		((uvd)->handle != NULL)) ? GET_CALLBACK(uvd,cbName) : NULL)

int  RingQueue_Dequeue(struct RingQueue *rq, unsigned char *dst, int len);
int  RingQueue_Enqueue(struct RingQueue *rq, const unsigned char *cdata, int n);
void RingQueue_WakeUpInterruptible(struct RingQueue *rq);
void RingQueue_Flush(struct RingQueue *rq);

static inline int RingQueue_GetLength(const struct RingQueue *rq)
{
	return (rq->wi - rq->ri + rq->length) & (rq->length-1);
}

static inline int RingQueue_GetFreeSpace(const struct RingQueue *rq)
{
	return rq->length - RingQueue_GetLength(rq);
}

void usbvideo_CollectRawData(struct uvd *uvd, struct usbvideo_frame *frame);
void usbvideo_DrawLine(
	struct usbvideo_frame *frame,
	int x1, int y1,
	int x2, int y2,
	unsigned char cr, unsigned char cg, unsigned char cb);
void usbvideo_HexDump(const unsigned char *data, int len);
void usbvideo_OverlayChar(struct uvd *uvd, struct usbvideo_frame *frame, int x, int y, int ch);
void usbvideo_OverlayString(struct uvd *uvd, struct usbvideo_frame *frame, int x, int y, const char *str);
void usbvideo_OverlayStats(struct uvd *uvd, struct usbvideo_frame *frame);
void usbvideo_ReportStatistics(const struct uvd *uvd);
void usbvideo_SayAndWait(const char *what);
void usbvideo_TestPattern(struct uvd *uvd, int fullframe, int pmode);
void usbvideo_VideosizeToString(char *buf, int bufLen, videosize_t vs);

/* Memory allocation routines */
unsigned long usbvideo_uvirt_to_kva(pgd_t *pgd, unsigned long adr);
unsigned long usbvideo_kvirt_to_pa(unsigned long adr);
void *usbvideo_rvmalloc(unsigned long size);
void usbvideo_rvfree(void *mem, unsigned long size);

int usbvideo_register(
	struct usbvideo **pCams,
	const int num_cams,
	const int num_extra,
	const char *driverName,
	const struct usbvideo_cb *cbTable,
	struct module *md,
	const struct usb_device_id *id_table);
struct uvd *usbvideo_AllocateDevice(struct usbvideo *cams);
int usbvideo_RegisterVideoDevice(struct uvd *uvd);
void usbvideo_Deregister(struct usbvideo **uvt);
void usbvideo_Disconnect(struct usb_device *dev, void *ptr);
void usbvideo_CameraRelease(struct uvd *uvd);

void usbvideo_v4l_close(struct video_device *dev);
int usbvideo_v4l_initialize(struct video_device *dev);
int usbvideo_v4l_ioctl(struct video_device *dev, unsigned int cmd, void *arg);
int usbvideo_v4l_mmap(struct video_device *dev, const char *adr, unsigned long size);
int usbvideo_v4l_open(struct video_device *dev, int flags);
long usbvideo_v4l_read(struct video_device *dev, char *buf,
			unsigned long count, int noblock);
long usbvideo_v4l_write(struct video_device *dev, const char *buf,
			unsigned long count, int noblock);

int usbvideo_GetFrame(struct uvd *uvd, int frameNum);
int usbvideo_NewFrame(struct uvd *uvd, int framenum);
int usbvideo_StartDataPump(struct uvd *uvd);
void usbvideo_StopDataPump(struct uvd *uvd);
void usbvideo_DeinterlaceFrame(struct uvd *uvd, struct usbvideo_frame *frame);
void usbvideo_SoftwareContrastAdjustment(struct uvd *uvd, struct usbvideo_frame *frame);

/*
 * This code performs bounds checking - use it when working with
 * new formats, or else you may get oopses all over the place.
 * If pixel falls out of bounds then it gets shoved back (as close
 * to place of offence as possible) and is painted bright red.
 *
 * There are two important concepts: frame width, height and
 * V4L canvas width, height. The former is the area requested by
 * the application -for this very frame-. The latter is the largest
 * possible frame that we can serve (we advertise that via V4L ioctl).
 * The frame data is expected to be formatted as lines of length
 * VIDEOSIZE_X(fr->request), total VIDEOSIZE_Y(frame->request) lines.
 */
static inline void RGB24_PUTPIXEL(
	struct usbvideo_frame *fr,
	int ix, int iy,
	unsigned char vr,
	unsigned char vg,
	unsigned char vb)
{
	register unsigned char *pf;
	int limiter = 0, mx, my;
	mx = ix;
	my = iy;
	if (mx < 0) {
		mx=0;
		limiter++;
	} else if (mx >= VIDEOSIZE_X((fr)->request)) {
		mx= VIDEOSIZE_X((fr)->request) - 1;
		limiter++;
	}
	if (my < 0) {
		my = 0;
		limiter++;
	} else if (my >= VIDEOSIZE_Y((fr)->request)) {
		my = VIDEOSIZE_Y((fr)->request) - 1;
		limiter++;
	}
	pf = (fr)->data + V4L_BYTES_PER_PIXEL*((iy)*VIDEOSIZE_X((fr)->request) + (ix));
	if (limiter) {
		*pf++ = 0;
		*pf++ = 0;
		*pf++ = 0xFF;
	} else {
		*pf++ = (vb);
		*pf++ = (vg);
		*pf++ = (vr);
	}
}

#endif /* usbvideo_h */