163 lines
7.1 KiB
Plaintext
163 lines
7.1 KiB
Plaintext
Driver for Trust Computer Products Framegrabber, version 0.6.1
|
|
------ --- ----- -------- -------- ------------ ------- - - -
|
|
|
|
- ZORAN ------------------------------------------------------
|
|
Author: Pauline Middelink <middelin@polyware.nl>
|
|
Date: 18 September 1999
|
|
Version: 0.6.1
|
|
|
|
- Description ------------------------------------------------
|
|
|
|
Video4Linux compatible driver for an unknown brand framegrabber
|
|
(Sold in the Netherlands by TRUST Computer Products) and various
|
|
other zoran zr36120 based framegrabbers.
|
|
|
|
The card contains a ZR36120 Multimedia PCI Interface and a Philips
|
|
SAA7110 Onechip Frontend videodecoder. There is also an DSP of
|
|
which I have forgotten the number, since i will never get that thing
|
|
to work without specs from the vendor itself.
|
|
|
|
The SAA711x are capable of processing 6 different video inputs,
|
|
CVBS1..6 and Y1+C1, Y2+C2, Y3+C3. All in 50/60Hz, NTSC, PAL or
|
|
SECAM and delivering a YUV datastream. On my card the input
|
|
'CVBS-0' corresponds to channel CVBS2 and 'S-Video' to Y2+C2.
|
|
|
|
I have some reports of other cards working with the mentioned
|
|
chip sets. For a list of other working cards please have a look
|
|
at the cards named in the tvcards struct in the beginning of
|
|
zr36120.c
|
|
|
|
After some testing, I discovered that the carddesigner messed up
|
|
on the I2C interface. The Zoran chip includes 2 lines SDA and SCL
|
|
which (s)he connected reversely. So we have to clock on the SDA
|
|
and r/w data on the SCL pin. Life is fun... Each cardtype now has
|
|
a bit which signifies if you have a card with the same deficiency.
|
|
|
|
Oh, for the completeness of this story I must mention that my
|
|
card delivers the VSYNC pulse of the SAA chip to GIRQ1, not
|
|
GIRQ0 as some other cards have. This is also incorporated in
|
|
the driver be clearing/setting the 'useirq1' bit in the tvcard
|
|
description.
|
|
|
|
Another problems of continuous capturing data with a Zoran chip
|
|
is something nasty inside the chip. It effectively halves the
|
|
fps we ought to get... Here is the scenario: capturing frames
|
|
to memory is done in the so-called snapshot mode. In this mode
|
|
the Zoran stops after capturing a frame worth of data and wait
|
|
till the application set GRAB bit to indicate readiness for the
|
|
next frame. After detecting a set bit, the chip neatly waits
|
|
till the start of a frame, captures it and it goes back to off.
|
|
Smart ppl will notice the problem here. Its the waiting on the
|
|
_next_ frame each time we set the GRAB bit... Oh well, 12,5 fps
|
|
is still plenty fast for me.
|
|
-- update 28/7/1999 --
|
|
Don't believe a word I just said... Proof is the output
|
|
of `streamer -t 300 -r 25 -f avi15 -o /dev/null`
|
|
++--+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+- 25/25
|
|
+-s+-+-+-+-+-+-+-+-+-+-+-+-+-s+-+-+-+-+-+-+-+-+-+-+-
|
|
syncer: done
|
|
writer: done
|
|
(note the /dev/null is prudent here, my system is not able to
|
|
grab /and/ write 25 fps to a file... gifts welcome :) )
|
|
The technical reasoning follows: The zoran completed the last
|
|
frame, the VSYNC goes low, and GRAB is cleared. The interrupt
|
|
routine starts to work since its VSYNC driven, and again
|
|
activates the GRAB bit. A few ms later the VSYNC (re-)rises and
|
|
the zoran starts to work on a new and freshly broadcasted frame....
|
|
|
|
For pointers I used the specs of both chips. Below are the URLs:
|
|
http://www.zoran.com/ftp/download/devices/pci/ZR36120/36120data.pdf
|
|
http://www-us.semiconductor.philips.com/acrobat/datasheets/SAA_7110_A_1.pdf
|
|
Some alternatives for the Philips SAA 7110 datasheet are:
|
|
http://www.datasheetcatalog.com/datasheets_pdf/S/A/A/7/SAA7110.shtml
|
|
http://www.datasheetarchive.com/search.php?search=SAA7110&sType=part
|
|
|
|
The documentation has very little on absolute numbers or timings
|
|
needed for the various modes/resolutions, but there are other
|
|
programs you can borrow those from.
|
|
|
|
------ Install --------------------------------------------
|
|
Read the file called TODO. Note its long list of limitations.
|
|
|
|
Build a kernel with VIDEO4LINUX enabled. Activate the
|
|
BT848 driver; we need this because we have need for the
|
|
other modules (i2c and videodev) it enables.
|
|
|
|
To install this software, extract it into a suitable directory.
|
|
Examine the makefile and change anything you don't like. Type "make".
|
|
|
|
After making the modules check if you have the much needed
|
|
/dev/video devices. If not, execute the following 4 lines:
|
|
mknod /dev/video c 81 0
|
|
mknod /dev/video1 c 81 1
|
|
mknod /dev/video2 c 81 2
|
|
mknod /dev/video3 c 81 3
|
|
mknod /dev/video4 c 81 4
|
|
|
|
After making/checking the devices do:
|
|
modprobe i2c
|
|
modprobe videodev
|
|
modprobe saa7110 (optional)
|
|
modprobe saa7111 (optional)
|
|
modprobe tuner (optional)
|
|
insmod zoran cardtype=<n>
|
|
|
|
<n> is the cardtype of the card you have. The cardnumber can
|
|
be found in the source of zr36120. Look for tvcards. If your
|
|
card is not there, please try if any other card gives some
|
|
response, and mail me if you got a working tvcard addition.
|
|
|
|
PS. <TVCard editors behold!)
|
|
Don't forget to set video_input to the number of inputs
|
|
you defined in the video_mux part of the tvcard definition.
|
|
It's a common error to add a channel but not incrementing
|
|
video_input and getting angry with me/v4l/linux/linus :(
|
|
|
|
You are now ready to test the framegrabber with your favorite
|
|
video4linux compatible tool
|
|
|
|
------ Application ----------------------------------------
|
|
|
|
This device works with all Video4Linux compatible applications,
|
|
given the limitations in the TODO file.
|
|
|
|
------ API ------------------------------------------------
|
|
|
|
This uses the V4L interface as of kernel release 2.1.116, and in
|
|
fact has not been tested on any lower version. There are a couple
|
|
of minor differences due to the fact that the amount of data returned
|
|
with each frame varies, and no doubt there are discrepancies due to my
|
|
misunderstanding of the API. I intend to convert this driver to the
|
|
new V4L2 API when it has stabilized more.
|
|
|
|
------ Current state --------------------------------------
|
|
|
|
The driver is capable of overlaying a video image in screen, and
|
|
even capable of grabbing frames. It uses the BIGPHYSAREA patch
|
|
to allocate lots of large memory blocks when tis patch is
|
|
found in the kernel, but it doesn't need it.
|
|
The consequence is that, when loading the driver as a module,
|
|
the module may tell you it's out of memory, but 'free' says
|
|
otherwise. The reason is simple; the modules wants its memory
|
|
contiguous, not fragmented, and after a long uptime there
|
|
probably isn't a fragment of memory large enough...
|
|
|
|
The driver uses a double buffering scheme, which should really
|
|
be an n-way buffer, depending on the size of allocated framebuffer
|
|
and the requested grab-size/format.
|
|
This current version also fixes a dead-lock situation during irq
|
|
time, which really, really froze my system... :)
|
|
|
|
Good luck.
|
|
Pauline
|