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meteor(4)

NAME

     meteor -- video capture driver interface

DESCRIPTION

     The meteor driver defined a video capture interface.  The meteor driver
     is no longer in the tree, but other devices support this interface so the
     interface portion is documented here.

   Meteor Capture Modes
     The meteor capture driver has three modes of capture operation.

     1.   Conventional read(2) interface.

	  This mode is the easiest and slowest to use.	This mode is great for
	  capturing a single field at little programming cost.

	  In this mode, the user opens the device, sets the capture mode and
	  size (see: METEORSETGEO ioctl(2) call), and uses the read(2) system
	  call to load the data into a buffer.

	  meteor_read.c; read 400x300 RGB24 into a viewable PPM file

	  #include <sys/fcntl.h>
	  #include <machine/ioctl_meteor.h>

	  extern int errno;
	  #define ROWS 300
	  #define COLS 400
	  #define SIZE (ROWS * COLS * 4)
	  main()
	  {
		  struct meteor_geomet geo;
		  char buf[SIZE],b[4],header[16],*p;
		  int i,o,c;

		  if ((i = open("/dev/meteor0", O_RDONLY)) < 0) {
			  printf("open failed: %d\n", errno);
			  exit(1);
		  }
		  /* set up the capture type and size */
		  geo.rows = ROWS;
		  geo.columns = COLS;
		  geo.frames = 1;
		  geo.oformat = METEOR_GEO_RGB24 ;

		  if (ioctl(i, METEORSETGEO, &geo) < 0) {
			  printf("ioctl failed: %d\n", errno);
			  exit(1);
		  }

		  c = METEOR_FMT_NTSC;

		  if (ioctl(i, METEORSFMT, &c) < 0) {
			  printf("ioctl failed: %d\n", errno);
			  exit(1);
		  }

			  printf("read failed %d %d %d\n", c, i, errno);
			  close(i);
			  exit(1);
		  }
		  close(i);

		  if ((o = open("rgb24.ppm", O_WRONLY | O_CREAT, 0644)) < 0) {
			  printf("ppm open failed: %d\n", errno);
			  exit(1);
		  }

		  /* make PPM header and save to file */
		  strcpy(&header[0], "P6 400 300 255 ");
		  header[2] = header[6]  = header[10] = header[14] = '\n';
		  write (o, &header[0], 15);
		  /* save the RGB data to PPM file */
		  for (p = &buf[0]; p < &buf[SIZE]; ) {
			  b[2] = *p++;		  /* blue */
			  b[1] = *p++;		  /* green */
			  b[0] = *p++;		  /* red */
			  *p++; 		  /* NULL byte */
			  write(o,&b[0], 3);	  /* not very efficient */
		  }
		  close(o);
		  exit(0);
	  }

     2.   Memory mapped single capture or unsynchronized continuous capture.

	  The single capture mode is designed for conferencing tools such as
	  nv.  These tools need to control the starting of the image capture
	  and also need several frames a second.  The continuous capture mode
	  is designed for applications that want free-running data.

	  In this mode, the user opens the device, sets the capture mode and
	  size (see: METEORSETGEO ioctl(2) call), mmap(2)s the frame buffer
	  memory into the user process space, and issues either the single-
	  capture or the continuous capture call (see: METEORCAPTUR ioctl(2)
	  call) to load the data into the memory mapped buffer.

	  As explained in the METEORCAPTUR ioctl(2) call, the single frame
	  capture ioctl(2) will block until the capture is complete, the con-
	  tinuous capture will return immediately.

	  meteor_mmap_single_continuous.c

	  #include <sys/types.h>
	  #include <sys/mman.h>
	  #include <sys/fcntl.h>
	  #include <machine/ioctl_meteor.h>

	  extern int errno;
	  #define ROWS 480
	  #define COLS 640
	  #define SIZE (ROWS * COLS * 2)
	  main()
	  {
		  struct meteor_geomet geo;

		  geo.rows = ROWS;
		  geo.columns = COLS;
		  geo.frames = 1;
		  geo.oformat = METEOR_GEO_RGB16 ;

		  if (ioctl(i, METEORSETGEO, &geo) < 0) {
			  printf("ioctl failed: %d\n", errno);
			  exit(1);
		  }

		  c = METEOR_FMT_NTSC;

		  if (ioctl(i, METEORSFMT, &c) < 0) {
			  printf("ioctl failed: %d\n", errno);
			  exit(1);
		  }

		  c = METEOR_INPUT_DEV0;

		  if (ioctl(i, METEORSINPUT, &c) < 0) {
			  printf("ioctl failed: %d\n", errno);
			  exit(1);
		  }

		  mmbuf=(char *)mmap((caddr_t)0, SIZE, PROT_READ,
			  MAP_SHARED, i, (off_t)0);

	  #ifdef SINGLE_MODE
		  /* single frame capture */
		  c = METEOR_CAP_SINGLE ;
		  ioctl(i, METEORCAPTUR, &c);	  /* wait for the frame */

		  /* directly access the frame buffer array data in mmbuf */
	  #else
		  /* continuous frame capture */
		  c = METEOR_CAP_CONTINOUS ;
		  ioctl(i, METEORCAPTUR, &c);	  /* returns immediately */

		  /* directly access the frame buffer array data in mmbuf */

		  c = METEOR_CAP_STOP_CONT ;
		  ioctl(i, METEORCAPTUR, &c);	  /* close will also stop capture */
	  #endif

		  close(i);
		  exit(0);
	  }

     3.   Memory mapped, multi-frame ring buffer synchronize capture.

	  This continuous capture mode is synchronized with the application
	  that processes up to 32 frames.  This gives the advantages of both
	  single and continuous capture modes.

	  The kernel notifies the application of a new data by raising an
	  application defined signal.  The driver also shares a structure with
	  the application that allows them to communicate which frame has been
	  or
		((number_rows * number_columns * pixel_depth + 4095)/4096) *
		4096

	  The shared structure is of type struct meteor_mem.  The two most
	  important fields are called active and num_active_buf.  active is a
	  bitmap of frames written by the kernel.  num_active_bufs is a count
	  of frames marked in the active field.  When a frame is read in by
	  the driver, the num_active_bufs count is tested, if this count is
	  below the threshold of number of active frames (value in
	  meteor_mem's hiwat variable), the bit representing frame number in
	  the buffer is stored in the active variable, the num_active_bufs is
	  incremented, the kernel then raises the specified signal to activate
	  the user application.  The user application's responsibility when
	  getting the signal is to check the active bitmap to determine the
	  lowest active frame, use the data as the application desires, clear
	  the bitmap entry for that frame, and decrement the num_active_bufs.
	  If the threshold of number of active frames (hiwat) has been
	  exceeded, no new frames or signal from the kernel will occur until
	  the num_active_bufs is less than or equal to lowat.

	  The driver loads the frames in a round-robin fashion.  It is
	  expected that the user removes them in the same order.  The driver
	  does not check to see if the frame is already active.

	  The frame_size and number of frames in the buffer are also provided
	  to the meteor_mem structure, but changing these fields in the appli-
	  cation will not change the operation of the driver.

	  In programming for this mode, the user opens the device, sets the
	  geometry, mmap(2)s the data/common control structure, then starts
	  the continuous capture mode.	A special signal catcher is required
	  to process the frames as they are read by the kernel.

	  When specifying the geometry (see: METEORSETGEO ioctl(2) call), it
	  is important that the number of frames is set greater than 1.

	  skeleton_capture_n.c

	  #include <sys/types.h>
	  #include <sys/mman.h>
	  #include <sys/fcntl.h>
	  #include <sys/signal.h>
	  #include <machine/ioctl_meteor.h>

	  int video;  /* made global if you wish to stop capture in signal handler */
	  caddr_t data_frames;
	  struct meteor_mem *common_mem;
	  extern int errno;

	  #define FRAME_MAX

	  void
	  usr2_catcher()
	  {
	  #ifdef SIGNAL_STOP
		  struct meteor_capframe capframe;	  /* for ioctl */
	  #endif
		  common_mem->num_active_bufs--;

		  /* process next frame on next interrupt */
		  sig_cnt = ((sig_cnt+1) % FRAME_MAX);

	  #ifdef SIGNAL_STOP
		  if (some_condition_requiring_stopping) {
			  capframe.command=METEOR_CAP_STOP_FRAMES;

			  if (ioctl(i, METEORCAPFRM, &capframe) < 0) {
				  printf("METEORCAPFRM failed %d\n", errno);
				  exit(1);
			  }
		  }
	  #endif
	  }

	  main()
	  {
		  struct meteor_geomet geo;
		  int height, width, depth, frames, size;
		  struct meteor_capframe capframe;

		  if ((i = open("/dev/meteor0", O_RDONLY)) < 0) {
			  printf("open failed\n");
			  exit(1);
		  }
		  printf("test %d %d\n", errno, i);

		  height = geo.rows = 120;
		  width= geo.columns = 320;
		  frames = geo.frames = FRAME_MAX;
		  depth = 2;	  /* 2 bytes per pixel for RGB*/

		  geo.oformat = METEOR_GEO_RGB16;

		  if (ioctl(i, METEORSETGEO, &geo) < 0) {
			  printf("METEORSETGEO failed %d\n", errno);
			  exit(1);
		  }

		  c = METEOR_FMT_NTSC;

		  if (ioctl(i, METEORSFMT, &c) < 0) {
			  printf("ioctl failed: %d\n", errno);
			  exit(1);
		  }

		  c = METEOR_INPUT_DEV0;

		  if (ioctl(i, METEORSINPUT, &c) < 0) {
			  printf("ioctl failed: %d\n", errno);
			  exit(1);
		  }

		  size = ((width*height*depth*frames+4095)/4096)*4096;
		  /* add one page after data for meteor_mem */
		  signal(SIGUSR2, usr2_catcher);  /* catch new frame message */

		  capframe.command=METEOR_CAP_N_FRAMES;
		  capframe.signal=SIGUSR2;
		  capframe.lowat=12;		  /* must be < hiwat */
		  capframe.hiwat=14;		  /* must be < FRAME_MAX */

						  /* start the sync capture */
		  if (ioctl(i, METEORCAPFRM, &capframe) < 0) {
			  printf("METEORCAPFRM failed %d\n", errno);
			  exit(1);
		  }

		  /* this is the background working area, or you can sleep */

		  /* to stop capture */
		  capframe.command=METEOR_CAP_STOP_FRAMES;

		  if (ioctl(i, METEORCAPFRM, &capframe) < 0) {
			  printf("METEORCAPFRM failed %d\n", errno);
			  exit(1);
		  }
	  }

   Meteor IOCTL Call and Parameters
     The meteor capture driver has ioctl(2) requests for capturing, reading
     card status, for setting and reading the geometry, and for setting and
     reading the attributes.

     IT IS VERY IMPORTANT TO CHECK FOR ERRORS ON THESE RETURNING IOCTLs.
     Errors indicate that something is very wrong with the ioctl(2) and the
     application should not attempt to proceed further with capturing.	The
     meteor capture driver still makes attempts to stop the next capture step
     if an error occurred in a previous step but was ignored by the applica-
     tion programmer.

     1.   ioctl(2) requests METEORSETGEO and METEORGETGEO

	  METEORSETGEO and METEORGETGEO are used to set and read the input
	  size, input device, and output format for frame capture.

	  These ioctl(2) routines use the meteor_geomet structure that has the
	  following entries:

	  rows	   number of rows (lines high) in output image

	  columns  number of pixels in a row (width) in output image

	  frames   number of frames in buffer.	Should be 1, unless using the
		   multi-framed synchronous capture mode (METEORCAPFRM) which
		   REQUIRES frames to be larger than 1.

		   Note: if rows, columns or frames is not changed, then the
		   existing values are used.  The system defaults is
		   640x480x1.

	  oformat  you may choose one of the following output format:
					  mat: u0 y0 v0 y1 u1 y2 v1 y3 ...)

		   METEOR_GEO_YUV_PLANER  (4-2-2 YUV 16 bits planer format:
					  rows * columns bytes of y rows *
					  column / 4 bytes of even u rows *
					  column / 4 bytes of even v rows *
					  column / 4 bytes of odd u rows *
					  column / 4 bytes of odd v)

	  The METEORSETGEO ioctl(2) will fail if more than one entry from a
	  category is selected.  It is highly recommended that a METEORSETGEO
	  is done before capturing data because you cannot guarantee the ini-
	  tial mode the card.

	  The METEORSETGEO will also attempt to reallocate a new contiguous
	  kernel buffer if the new geometry exceeds the old geometry.  On
	  other hand, if the new geometry will fit in the existing buffer, the
	  existing buffer is used.

	  If METEORSETGEO fails the ioctl(2) will return a value of -1 and the
	  external variable errno will be set to:

	  [EINVAL]	     invalid meteor_geomet structure pointer, rows,
			     columns, frames were invalid.

	  [ENOMEM]	     could not allocate the contiguous block.

     2.   ioctl(2) requests METEORSFMT and METEORGFMT

	  METEORSFMT and METEORGFMT are used to set and read the camera input
	  standard format.

	  Possible formats are:

	  METEOR_FMT_NTSC      NTSC (default mode)
	  METEOR_FMT_PAL       PAL
	  METEOR_FMT_SECAM     SECAM
	  METEOR_FMT_AUTOMODE  Autodetect.

     3.   ioctl(2) requests METEORSINPUT and METEORGINPUT

	  METEORSINPUT and METEORGINPUT are used to set and read the camera
	  input device.  Using the DB9 connector on the Meteor card, 4 input
	  devices can be connected and an input camera can be selected with
	  this ioctl(2).

	  Possible formats are:

	  METEOR_INPUT_DEV0	   (default if none specified)
	  METEOR_INPUT_DEV_RCA	   (same as METEOR_INPUT_DEV0)
	  METEOR_INPUT_DEV1
	  METEOR_INPUT_DEV2
	  METEOR_INPUT_DEV_SVIDEO  (same as METEOR_INPUT_DEV2)

     4.   ioctl(2) request METEORSTATUS

	  METEORSTATUS is used to read the status of the Meteor capture card
	  and returns the following information:
				   1 = odd field detected.

	  METEOR_STATUS_SVP	   VRAM Port state:
				   0 = inputs HFL and INCADDR inactive.
				   1 = inputs HFL and INCADDR active.

	  METEOR_STATUS_STTC	   0 = TV horizontal time constant (slow).
				   1 = VCR horizontal time constant (fast).

	  METEOR_STATUS_HCLK	   0 = Horizontal Phase Lock Loop locked.
				   1 = Horizontal Phase Lock Loop unlocked.

	  METEOR_STATUS_FIDT	   0 = 50 Hz Field detected.
				   1 = 60 Hz Field detected.

	  METEOR_STATUS_ALTD	   0 = no line alternating color burst
				       detected.
				   1 = line alternating color burst detected
				       (PAL/SECAM).

	  METEOR_STATUS_CODE	   0 = no color information detected.
				   1 = color information detected.

     5.   ioctl(2) request METEORCAPTUR

	  METEORCAPTUR is used to single frame capture or unsynchronized con-
	  tinuous capture.

	  The single frame capture ioctl(2) request will return only after a
	  frame has been captured and transfered to the frame buffer.

	  The unsynchronized continuous capture will return immediately and
	  data is directly deposited into the buffer when it is available.
	  Since this is unsynchronized, it is possible the data is being writ-
	  ten by the kernel while being read by the application.

	  These ioctl(2) routines use the following settings:

	  METEOR_CAP_SINGLE	capture one frame
	  METEOR_CAP_CONTINOUS	unsynchronized continuous capture
	  METEOR_CAP_STOP_CONT	stop the unsynchronized continuous capture

	  If METEORCAPTUR fails the ioctl(2) will return a value of -1 and the
	  external variable errno will be set to:

	  [EINVAL]	     invalid capture command value

	  [ENXIO]	     there is not internal buffer to hold the frame.
			     This indicates the previous set geometry ioctl(2)
			     failed.

	  [EIO] 	     card is already capturing.

     6.   ioctl(2) request METEORCAPFRM

	  METEORCAPFRM is used for synchronous capture of multiple frames.

	  This ioctl(2) routine uses the meteor_capture structure that has the
					   variables in the structure as
					   inputs

	  signal   signal to send to application when a new frame has been
		   captured.  This signal will only be raised if the captured
		   frame is saved.

	  lowat    see below

	  hiwat    see below

	  When a new frame is completed, the driver checks the current unread
	  frame count stored in shared variable (the shared variable is stored
	  in the meteor_mem structure) num_active_buf; if the count is larger
	  than hiwat, the driver will not store any new frames and will not
	  send capture signal to the user application until the num_active_buf
	  is lower than lowat.

	  If METEORCAPFRM fails the ioctl(2) will return a value of -1 and the
	  external variable errno will be set to:

	  [EINVAL]	     invalid meteor_geomet structure pointer or bad
			     command.

	  [ENXIO]	     there is not internal buffer to hold the frame.
			     This indicates the previous set geometry ioctl(2)
			     failed.

	  [EIO] 	     card is already capturing.

     7.   ioctl(2) requests METEORSCHCV and METEORGCHCV

	  METEORSCHCV and METEORGCHCV are used to set and get the chrominance
	  gain control and effects the UV output amplitude.

	  If METEORSCHCV or METEORGCHCV fails the ioctl(2) will return a value
	  of -1 and the external variable errno will be set to:

	  [EINVAL]	     invalid unsigned char pointer.

     8.   ioctl(2) requests METEORGHUE and METEORSHUE

	  METEORGHUE and METEORSHUE are used to get and set the hue.  The
	  signed character has legal values are from +127 which represent
	  +178.6 degrees to -128 which represents -180 degrees.

	  If METEORGHUE or METEORSHUE fails the ioctl(2) will return a value
	  of -1 and the external variable errno will be set to:

	  [EINVAL]	     invalid signed char pointer.

     9.   ioctl(2) requests METEORSCOUNT and METEORGCOUNT

	  METEORGCOUNT is used to get the count of frame errors, DMA errors
	  and count of the number of frames captured that have occurred since
	  the device was opened.  METEORSCOUNT can be used to reinitialize the
	  counters.


	  If METEORSCOUNT or METEORGCOUNT fails the ioctl(2) will return a
	  value of -1 and the external variable errno will be set to:

	  [EINVAL]	     invalid meteor_counts structure pointer.

BUGS

     The meteor driver no longer works at all.

AUTHORS

     Jim Lowe <james@miller.cs.uwm.edu>,
     Mark Tinguely <tinguely@plains.nodak.edu>

FreeBSD 5.4			August 15, 1995 		   FreeBSD 5.4

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