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This is a driver for the CPiA PPC2 driven parallel connected

Camera. For example the Creative WebcamII is CPiA driven.

   ) [1]Peter Pregler, Linz 2000, published under the [2]GNU GPL

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USAGE:

General:

========

1) Make sure you have created the video devices (/dev/video*):

- if you have a recent MAKEDEV do a 'cd /dev;./MAKEDEV video'

- otherwise do a:

cd /dev

mknod video0 c 81 0

ln -s video0 video

2) Compile the kernel (see below for the list of options to use),

   configure your parport and reboot.

3) If all worked well you should get messages similar

   to the following (your versions may be different) on the console:

V4L-Driver for Vision CPiA based cameras v0.7.4

parport0: read2 timeout.

parport0: Multimedia device, VLSI Vision Ltd PPC2

Parallel port driver for Vision CPiA based camera

  CPIA Version: 1.20 (2.0)

  CPIA PnP-ID: 0553:0002:0100

  VP-Version: 1.0 0100

  1 camera(s) found

As modules:

===========

Make sure you have selected the following kernel options (you can

select all stuff as modules):

The cpia-stuff is in the section 'Character devices -> Video For Linux'.

CONFIG_PARPORT=m

CONFIG_PARPORT_PC=m

CONFIG_PARPORT_PC_FIFO=y

CONFIG_PARPORT_1284=y

CONFIG_VIDEO_DEV=m

CONFIG_VIDEO_CPIA=m

CONFIG_VIDEO_CPIA_PP=m

For autoloading of all those modules you need to tell modutils some

stuff. Add the following line to your modutils config-file

(e.g. /etc/modules.conf or wherever your distribution does store that

stuff):

options parport_pc io=0x378 irq=7 dma=3

alias char-major-81 cpia_pp

The first line tells the dma/irq channels to use. Those _must_ match

the settings of your BIOS. Do NOT simply use the values above.  See

Documentation/parport.txt for more information about this. The second

line associates the video-device file with the driver. Of cause you

can also load the modules once upon boot (usually done in /etc/modules).

Linked into the kernel:

=======================

Make sure you have selected the following kernel options. Note that

you cannot compile the parport-stuff as modules and the cpia-driver

statically (the other way round is okay though).

The cpia-stuff is in the section 'Character devices -> Video For Linux'.

CONFIG_PARPORT=y

CONFIG_PARPORT_PC=y

CONFIG_PARPORT_PC_FIFO=y

CONFIG_PARPORT_1284=y

CONFIG_VIDEO_DEV=y

CONFIG_VIDEO_CPIA=y

CONFIG_VIDEO_CPIA_PP=y

To use DMA/irq you will need to tell the kernel upon boot time the

hardware configuration of the parport. You can give the boot-parameter

at the LILO-prompt or specify it in lilo.conf. I use the following

append-line in lilo.conf:

        append="parport=0x378,7,3"

See Documentation/parport.txt for more information about the

configuration of the parport and the values given above. Do not simply

use the values given above.

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FEATURES:

- mmap/read v4l-interface (but no overlay)

- image formats: CIF/QCIF, SIF/QSIF, various others used by isabel;

  note: all sizes except CIF/QCIF are implemented by clipping, i.e.

  pixels are not uploaded from the camera

- palettes: VIDEO_PALETTE_GRAY, VIDEO_PALETTE_RGB565, VIDEO_PALETTE_RGB555,

  VIDEO_PALETTE_RGB24, VIDEO_PALETTE_RGB32, VIDEO_PALETTE_YUYV,

  VIDEO_PALETTE_UYVY, VIDEO_PALETTE_YUV422

- state information (color balance, exposure, ...) is preserved between

  device opens

- complete control over camera via proc-interface (_all_ camera settings are

  supported), there is also a python-gtk application available for this [3]

- works under SMP (but the driver is completely serialized and synchronous)

  so you get no benefit from SMP, but at least it does not crash your box

- might work for non-Intel architecture, let us know about this

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TESTED APPLICATIONS:

- a simple test application based on Xt is available at [3]

- another test-application based on gqcam-0.4 (uses GTK)

- gqcam-0.6 should work

- xawtv-3.x (also the webcam software)

- xawtv-2.46

- w3cam (cgi-interface and vidcat, e.g. you may try out 'vidcat  |xv

  -maxpect -root -quit +noresetroot -rmode 5 -')

- vic, the MBONE video conferencing tool (version 2.8ucl4-1)

- isabel 3R4beta (barely working, but AFAICT all the problems are on

  their side)

- camserv-0.40

See [3] for pointers to v4l-applications.

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KNOWN PROBLEMS:

- some applications do not handle the image format correctly, you will

  see strange horizontal stripes instead of a nice picture -> make sure

  your application does use a supported image size or queries the driver

  for the actually used size (reason behind this: the camera cannot

  provide any image format, so if size NxM is requested the driver will

  use a format to the closest fitting N1xM1, the application should now

  query for this granted size, most applications do not).

- all the todo ;)

- if there is not enough light and the picture is too dark try to

  adjust the SetSensorFPS setting, automatic frame rate adjustment

  has its price

- do not try out isabel 3R4beta (built 135), you will be disappointed

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TODO:

- multiple camera support (struct camera or something) - This should work,

  but hasn't been tested yet.

- architecture independence?

- SMP-safe asynchronous mmap interface

- nibble mode for old parport interfaces

- streaming capture, this should give a performance gain

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IMPLEMENTATION NOTES:

The camera can act in two modes, streaming or grabbing. Right now a

polling grab-scheme is used. Maybe interrupt driven streaming will be

used for a asynchronous mmap interface in the next major release of the

driver. This might give a better frame rate.

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THANKS (in no particular order):

- Scott J. Bertin  for cleanups, the proc-filesystem

  and much more

- Henry Bruce  for providing developers information about

  the CPiA chip, I wish all companies would treat Linux as seriously

- Karoly Erdei  and RISC-Linz for being

  my boss ;) resp. my employer and for providing me the hardware and

  allow me to devote some working time to this project

- Manuel J. Petit de Gabriel  for providing help

  with Isabel (http://isabel.dit.upm.es/)

- Bas Huisman  for writing the initial parport code

- Jarl Totland  for setting up the mailing list

  and maintaining the web-server[3]

- Chris Whiteford  for fixes related to the

  1.02 firmware

- special kudos to all the tester whose machines crashed and/or

  will crash. :)

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REFERENCES

   1. http://www.risc.uni-linz.ac.at/people/ppregler

      mailto:Peter_Pregler@email.com

   2. see the file COPYING in the top directory of the kernel tree

   3. http://webcam.sourceforge.net/