freebsd-dev/share/man/man4/meteor.4

.\"
.\" $FreeBSD$
.\"
.Dd August 15, 1995
.Dt METEOR 4
.Os
.Sh NAME
.Nm meteor
.Nd "video capture driver interface"
.Sh DESCRIPTION
The
.Nm
driver defined a video capture interface.
The
.Nm
driver is no longer in the tree, but other devices support this interface
so the interface portion is documented here.
.Ss Meteor Capture Modes
The
.Nm
capture driver has three modes of capture operation.
.Bl -enum
.It
Conventional
.Xr read 2
interface.
.Pp
This mode is the easiest and slowest to use.
This mode is great for
capturing a single field at little programming cost.
.Pp
In this mode, the user opens the device, sets the capture mode
and size (see:
.Dv METEORSETGEO
.Xr ioctl 2
call), and uses the
.Xr read 2
system
call to load the data into a buffer.
.Pp
.Pa meteor_read.c ;
read 400x300 RGB24 into a viewable PPM file
.Bd -literal
#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);
	}

	c = METEOR_INPUT_DEV0;

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

	if ((c=read(i, &buf[0], SIZE)) < SIZE) {
		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);
}
.Ed
.It
Memory mapped single capture or unsynchronized continuous capture.
.Pp
The single capture mode is designed for conferencing tools such as
.Nm 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.
.Pp
In this mode, the user opens the device, sets the capture mode
and size (see:
.Dv METEORSETGEO
.Xr ioctl 2
call),
.Xr mmap 2 Ns s
the frame buffer
memory into the user process space, and issues either the
single-capture or the continuous capture call (see:
.Dv METEORCAPTUR
.Xr ioctl 2
call) to load the data into the memory mapped buffer.
.Pp
As explained in the
.Dv METEORCAPTUR
.Xr ioctl 2
call, the single frame capture
.Xr ioctl 2
will block until the capture is complete, the continuous capture
will return immediately.
.Pp
.Pa meteor_mmap_single_continuous.c
.Bd -literal
#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;
	char buf[SIZE];
	char *mmbuf;
	int i,c;

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

        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);
}
.Ed
.It
Memory mapped, multi-frame ring buffer synchronize capture.
.Pp
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.
.Pp
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
written by the kernel and which frame has been read by the application.
.Pp
The shared structure starts on the first page after your data.
The
structure address can be found by calculation:
.Pp
.Dl "(number_rows * number_columns * pixel_depth + 4095) & 0xfffff000"
or
.Dl "((number_rows * number_columns * pixel_depth + 4095)/4096) * 4096"
.Pp
The shared structure is of type
.Va struct meteor_mem .
The two most
important fields are called
.Va active
and
.Va num_active_buf .
.Va active
is a bitmap of frames written by the kernel.
.Va num_active_bufs
is
a count of frames marked in the
.Va active
field.
When a frame is read
in by the driver, the
.Va num_active_bufs
count is tested, if this
count is below the threshold of number of active frames (value
in
.Va meteor_mem Ns 's
.Va hiwat
variable), the bit representing frame
number in the buffer is stored in the
.Va active
variable, the
.Va 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
.Va num_active_bufs .
If the threshold of number of active frames
.Pq Va hiwat
has been exceeded, no new frames or signal from the kernel will occur
until the
.Va num_active_bufs
is less than or equal to
.Va lowat .
.Pp
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.
.Pp
The
.Va frame_size
and number of frames in the buffer are also provided
to the
.Va meteor_mem
structure, but changing these fields in the
application will not change the operation of the driver.
.Pp
In programming for this mode, the user opens the device, sets the
geometry,
.Xr mmap 2 Ns 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.
.Pp
When specifying the geometry (see:
.Dv METEORSETGEO
.Xr ioctl 2
call),
it
is important that the number of frames is set greater than 1.
.Pp
.Pa skeleton_capture_n.c
.Bd -literal
#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
	char *frame;

	/* find frame */
	frame = (char *) (data_frames + sig_cnt * common_mem->frame_size) ;

	/* add frame processing here */
	/* deactivate frame */
	common_mem->active &= ~(1 << (sig_cnt % 16));
	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 */
	data_frames = mmap((caddr_t)0, size + 4096, PROT_READ | PROT_WRITE,
						MAP_SHARED, i, (off_t)0);

	if (data_frames == (caddr_t) MAP_FAILED) return (0);

	/* common_mem is located at page following data */
	common_mem = (struct meteor_mem *) (y + size);

	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);
	}
}
.Ed
.El
.Ss Meteor IOCTL Call and Parameters
The
.Nm
capture driver has
.Xr ioctl 2
requests for capturing, reading card
status, for setting and reading the geometry, and for setting and reading the
attributes.
.Pp
.Bf -symbolic
IT IS VERY IMPORTANT TO CHECK FOR ERRORS ON THESE RETURNING IOCTLs.
.Ef
Errors indicate that something is very wrong with the
.Xr ioctl 2
and the
application should not attempt to proceed further with capturing.
The
.Nm
capture driver still makes attempts to stop the next capture step if
an error occurred in a previous step but was ignored by the application
programmer.
.Bl -enum
.It
.Xr ioctl 2
requests
.Dv METEORSETGEO
and
.Dv METEORGETGEO
.Pp
.Dv METEORSETGEO
and
.Dv METEORGETGEO
are used to set and read the input
size, input device, and output format for frame capture.
.Pp
These
.Xr ioctl 2
routines use the
.Va meteor_geomet
structure that has the
following entries:
.Pp
.Bl -tag -width columns
.It Va rows
number of rows (lines high) in output image
.It Va columns
number of pixels in a row (width) in output image
.It Va frames
number of frames in buffer.
Should be 1, unless using
the multi-framed synchronous capture mode
.Pq Dv METEORCAPFRM
which REQUIRES frames to be larger than 1.
.Pp
Note: if
.Va rows , columns
or
.Va frames
is not changed, then
the existing values are used.
The system defaults
is 640x480x1.
.It Va oformat
you may choose one of the following output format:
.Bl -tag -width METEOR_GEO_YUV_PACKED
.It Dv METEOR_GEO_RGB16
(RGB 16 bits xrrrrrgg gggbbbbb default)
.It Dv METEOR_GEO_RGB24
(RGB 24 bits packed in 32 bits:
00000000 rrrrrrrr gggggggg bbbbbbbb)
.It Dv METEOR_GEO_YUV_PACKED
(4-2-2 YUV 16 bits packed byte format:
u0 y0 v0 y1 u1 y2 v1 y3 ...)
.It Dv 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)
.El
.El
.Pp
The
.Dv METEORSETGEO
.Xr ioctl 2
will fail if more than one entry from a category
is selected.
It is highly recommended that a
.Dv METEORSETGEO
is done
before capturing data because you cannot guarantee the initial mode
the card.
.Pp
The
.Dv 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.
.Pp
If
.Dv METEORSETGEO
fails the
.Xr ioctl 2
will return a value of -1 and the
external variable
.Va errno
will be set to:
.Bl -tag -width Er
.It Bq Er EINVAL
invalid
.Va meteor_geomet
structure pointer,
.Va rows , columns , frames
were invalid.
.It Bq Er ENOMEM
could not allocate the contiguous block.
.El
.It
.Xr ioctl 2
requests
.Dv METEORSFMT
and
.Dv METEORGFMT
.Pp
.Dv METEORSFMT
and
.Dv METEORGFMT
are used to set and read the camera input
standard format.
.Pp
Possible formats are:
.Pp
.Bl -tag -width METEOR_FMT_AUTOMODE -compact
.It Dv METEOR_FMT_NTSC
NTSC (default mode)
.It Dv METEOR_FMT_PAL
PAL
.It Dv METEOR_FMT_SECAM
SECAM
.It Dv METEOR_FMT_AUTOMODE
Autodetect.
.El
.It
.Xr ioctl 2
requests
.Dv METEORSINPUT
and
.Dv METEORGINPUT
.Pp
.Dv METEORSINPUT
and
.Dv METEORGINPUT
are used to set and read the camera
input device.
Using the DB9 connector on the
.Tn Meteor
card, 4 input
devices can be connected and an input camera can be selected with this
.Xr ioctl 2 .
.Pp
Possible formats are:
.Pp
.Bl -tag -width METEOR_INPUT_DEV_SVIDEO -compact
.It Dv METEOR_INPUT_DEV0
(default if none specified)
.It Dv METEOR_INPUT_DEV_RCA
(same as METEOR_INPUT_DEV0)
.It Dv METEOR_INPUT_DEV1
.It Dv METEOR_INPUT_DEV2
.It Dv METEOR_INPUT_DEV_SVIDEO
(same as METEOR_INPUT_DEV2)
.El
.It
.Xr ioctl 2
request
.Dv METEORSTATUS
.Pp
.Dv METEORSTATUS
is used to read the status of the
.Tn Meteor
capture card
and returns the following information:
.Bl -column "METEOR_STATUS_ID_MASK" ""
.It Dv METEOR_STATUS_ID_MASK "	4 bit ID of the SAA7196 scaler chip."
.Pp
.It Dv METEOR_STATUS_DIR "	0 =	scaler uses internal source."
.It "	1 =	scaler uses external data of expansion bus."
.Pp
.It Dv METEOR_STATUS_OEF "	0 =	even field detected."
.It "	1 =	odd field detected."
.Pp
.It Dv METEOR_STATUS_SVP "	VRAM Port state:"
.It "	0 =	inputs HFL and INCADDR inactive."
.It "	1 =	inputs HFL and INCADDR active."
.Pp
.It Dv METEOR_STATUS_STTC "	0 =	TV horizontal time constant (slow)."
.It "	1 =	VCR horizontal time constant (fast)."
.Pp
.It Dv METEOR_STATUS_HCLK "	0 =	Horizontal Phase Lock Loop locked."
.It "	1 =	Horizontal Phase Lock Loop unlocked."
.Pp
.It Dv METEOR_STATUS_FIDT "	0 =	50 Hz Field detected."
.It "	1 =	60 Hz Field detected."
.Pp
.It Dv METEOR_STATUS_ALTD "	0 =	no line alternating color burst detected."
.It "	1 =	line alternating color burst detected (PAL/SECAM)."
.Pp
.It Dv METEOR_STATUS_CODE "	0 =	no color information detected."
.It "	1 =	color information detected."
.El
.It
.Xr ioctl 2
request
.Dv METEORCAPTUR
.Pp
.Dv METEORCAPTUR
is used to single frame capture or unsynchronized
continuous capture.
.Pp
The single frame capture
.Xr ioctl 2
request will return only after a
frame has been captured and transfered to the frame buffer.
.Pp
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
written by the kernel while being read by the application.
.Pp
These
.Xr ioctl 2
routines use the following settings:
.Pp
.Bl -tag -width METEOR_CAP_CONTINOUS -compact
.It Dv METEOR_CAP_SINGLE
capture one frame
.It Dv METEOR_CAP_CONTINOUS
unsynchronized continuous capture
.It Dv METEOR_CAP_STOP_CONT
stop the unsynchronized continuous
capture
.El
.Pp
If
.Dv METEORCAPTUR
fails the
.Xr ioctl 2
will return a value of -1 and the
external variable
.Va errno
will be set to:
.Bl -tag -width Er
.It Bq Er EINVAL
invalid capture command value
.It Bq Er ENXIO
there is not internal buffer to hold the frame.
This indicates the previous set geometry
.Xr ioctl 2
failed.
.It Bq Er EIO
card is already capturing.
.El
.It
.Xr ioctl 2
request
.Dv METEORCAPFRM
.Pp
.Dv METEORCAPFRM
is used for synchronous capture of multiple frames.
.Pp
This
.Xr ioctl 2
routine uses the
.Va meteor_capture
structure that has the
following entries:
.Bl -tag -width command
.It Va command
possible values for
.Va command
are:
.Bl -tag -width METEOR_CAP_STOP_FRAMES
.It Dv METEOR_CAP_STOP_FRAMES
stop the capture; does not use the
other variable in structure.
.It Dv METEOR_CAP_N_FRAMES
start the capture using the other
variables in the structure as inputs
.El
.It Va 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.
.It Va lowat
see below
.It Va hiwat
see below
.El
.Pp
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
.Va meteor_mem
structure)
.Va num_active_buf ;
if the count is larger
than
.Va hiwat ,
the driver will not store any new frames and will not
send capture signal to the user application until the
.Va num_active_buf
is lower than
.Va lowat .
.Pp
If
.Dv METEORCAPFRM
fails the
.Xr ioctl 2
will return a value of -1 and the
external variable
.Va errno
will be set to:
.Bl -tag -width Er
.It Bq Er EINVAL
invalid meteor_geomet structure pointer or bad command.
.It Bq Er ENXIO
there is not internal buffer to hold the frame.
This indicates the previous set geometry
.Xr ioctl 2
failed.
.It Bq Er EIO
card is already capturing.
.El
.It
.Xr ioctl 2
requests
.Dv METEORSCHCV
and
.Dv METEORGCHCV
.Pp
.Dv METEORSCHCV
and
.Dv METEORGCHCV
are used to set and get the chrominance
gain control and effects the UV output amplitude.
.Pp
If
.Dv METEORSCHCV
or
.Dv METEORGCHCV
fails the
.Xr ioctl 2
will return a value
of -1 and the external variable
.Va errno
will be set to:
.Bl -tag -width Er
.It Bq Er EINVAL
invalid unsigned char pointer.
.El
.It
.Xr ioctl 2
requests
.Dv METEORGHUE
and
.Dv METEORSHUE
.Pp
.Dv METEORGHUE
and
.Dv 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.
.Pp
If
.Dv METEORGHUE
or
.Dv METEORSHUE
fails the
.Xr ioctl 2
will return a value of
-1 and the external variable
.Va errno
will be set to:
.Bl -tag -width Er
.It Bq Er EINVAL
invalid signed char pointer.
.El
.It
.Xr ioctl 2
requests
.Dv METEORSCOUNT
and
.Dv METEORGCOUNT
.Pp
.Dv 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.
.Dv METEORSCOUNT
can be used to reinitialize the
counters.
.Pp
This
.Xr ioctl 2
routines use the
.Va meteor_counts
structure that has the
following entries:
.Bl -tag -width frame_count
.It Va fifo_errors
number of FIFO errors since device was opened.
.It Va dma_errors
number of DMA errors since device was opened.
.It Va frame_count
number of frames captured since device was opened.
.El
.Pp
If
.Dv METEORSCOUNT
or
.Dv METEORGCOUNT
fails the
.Xr ioctl 2
will return a value
of -1 and the external variable
.Va errno
will be set to:
.Bl -tag -width Er
.It Bq Er EINVAL
invalid meteor_counts structure pointer.
.El
.El
.Sh BUGS
The
.Nm
driver no longer works at all.
.Sh AUTHORS
.An Jim Lowe Aq james@miller.cs.uwm.edu ,
.An Mark Tinguely Aq tinguely@plains.nodak.edu