meteor -- video capture driver
device meteor
The meteor driver provides support for a PCI video capture. It allows
the capture of 24 bit RGB, 16 bit RGB and 16 bit YUV output formats.
Meteor Driver Installation [Toc] [Back]
To use the Matrox Meteor card in your system, you need a computer that
supports the PCI (preferably the Type 2 or better) interface bus. It is
recommended that the system has more than 16 MB of RAM since this capture
card directly deposits the image to system RAM.
The files required for Matrox Meteor card are:
/sys/pci/meteor.c
/sys/i386/include/ioctl_meteor.h
For FreeBSD release versions 2.1 and earlier, the following patch files
are also required:
meteor/usr/sys/i386/i386/conf.patch
meteor/usr/sys/conf/files.patch
meteor/sys/i386/conf/LINT.patch
These files are available for anonymous FTP at:
ftp://joy.cs.ndsu.nodak.edu/pub/meteor.tgz
1. In the configuration file, add the line (as shown in
meteor/usr/sys/i386/conf/LINT.patch):
device meteor0
2. There is also a couple of optional parameters you may use:
options "METEOR_ALLOC_PAGES=xxx"
Specifies the number of contiguous pages to allocate when
successfully probed. The default number of pages allocated
by the kernel is 151. This means that there are (151*4096)
bytes available for use.
options METEOR_DEALLOC_PAGES
Deallocate all pages when closing the device. Note, the
chances of contiguously re-allocating new pages are very
small. The default behavior is to not deallocate pages.
options "METEOR_DEALLOC_ABOVE=xxx"
Deallocate all pages above the specified number. The
default action is to not deallocate above any pages.
3. Make and install the kernel.
4. Make the special file name:
# mknod /dev/meteor0 c <major> 0
The major number is determined by the placement of the device in
conf.c. The patch supplied with the driver will make the major number
67.
Meteor Capture Modes [Toc] [Back]
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);
}
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);
}
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 singlecapture
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 continuous
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;
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);
}
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
written by the kernel and which frame has been read by the application.
The shared structure starts on the first page after your data. The
structure address can be found by calculation:
(number_rows * number_columns * pixel_depth + 4095) &
0xfffff000
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 application
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
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);
}
}
Meteor IOCTL Call and Parameters [Toc] [Back]
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. [Toc] [Back]
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 application
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:
METEOR_GEO_RGB16 (RGB 16 bits xrrrrrgg gggbbbbb
default)
METEOR_GEO_RGB24 (RGB 24 bits packed in 32 bits:
00000000 rrrrrrrr gggggggg bbbbbbbb)
METEOR_GEO_YUV_PACKED (4-2-2 YUV 16 bits packed byte format:
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 initial
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:
METEOR_STATUS_ID_MASK 4 bit ID of the SAA7196 scaler chip.
METEOR_STATUS_DIR 0 = scaler uses internal source.
1 = scaler uses external data of expansion
bus.
METEOR_STATUS_OEF 0 = even field detected.
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 continuous
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 written
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
following entries:
command possible values for command are:
METEOR_CAP_STOP_FRAMES stop the capture; does not use the
other variable in structure.
METEOR_CAP_N_FRAMES start the capture using the other
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.
This ioctl(2) routines use the meteor_counts structure that has the
following entries:
fifo_errors number of FIFO errors since device was opened.
dma_errors number of DMA errors since device was opened.
frame_count number of frames captured since device was opened.
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.
1. IIC register is difficult to set. We got around that by adding a
long wait at each IIC register write.
2. We had difficulties getting the Meteor capture card to work on systems
that used NCR chipset SCSI cards. It is possible that the
Meteor and NCR SCSI could work together using the newer TRITON motherboards.
Jim Lowe <[email protected]>,
Mark Tinguely <[email protected]>
FreeBSD 5.2.1 August 15, 1995 FreeBSD 5.2.1 [ Back ] |
