[media] doc-rst: add documentation for cpia2 driver
Convert the documentation to rst, merge the two files and add to the index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab
parent
f3d295c5e2
commit
ba9f270e01
|
|
@ -1,6 +1,13 @@
|
|||
$Id: README,v 1.7 2005/08/29 23:39:57 sbertin Exp $
|
||||
The cpia2 driver
|
||||
================
|
||||
|
||||
1. Introduction
|
||||
Authors: Peter Pregler <Peter_Pregler@email.com>,
|
||||
Scott J. Bertin <scottbertin@yahoo.com>, and
|
||||
Jarl Totland <Jarl.Totland@bdc.no> for the original cpia driver, which
|
||||
this one was modelled from.
|
||||
|
||||
Introduction
|
||||
------------
|
||||
|
||||
This is a driver for STMicroelectronics's CPiA2 (second generation
|
||||
Colour Processor Interface ASIC) based cameras. This camera outputs an MJPEG
|
||||
|
|
@ -15,7 +22,9 @@ contains usb specific functions. The main reason for this was the size of the
|
|||
module was getting out of hand, so I separated them. It is not likely that
|
||||
there will be a parallel port version.
|
||||
|
||||
FEATURES:
|
||||
Features
|
||||
--------
|
||||
|
||||
- Supports cameras with the Vision stv6410 (CIF) and stv6500 (VGA) cmos
|
||||
sensors. I only have the vga sensor, so can't test the other.
|
||||
- Image formats: VGA, QVGA, CIF, QCIF, and a number of sizes in between.
|
||||
|
|
@ -27,30 +36,28 @@ FEATURES:
|
|||
- Adjust brightness, color, contrast while streaming.
|
||||
- Flicker control settable for 50 or 60 Hz mains frequency.
|
||||
|
||||
2. Making and installing the stv672 driver modules:
|
||||
Making and installing the stv672 driver modules
|
||||
-----------------------------------------------
|
||||
|
||||
Requirements:
|
||||
-------------
|
||||
This should work with 2.4 (2.4.23 and later) and 2.6 kernels, but has
|
||||
only been tested on 2.6. Video4Linux must be either compiled into the kernel or
|
||||
Requirements
|
||||
~~~~~~~~~~~~
|
||||
|
||||
Video4Linux must be either compiled into the kernel or
|
||||
available as a module. Video4Linux2 is automatically detected and made
|
||||
available at compile time.
|
||||
|
||||
Compiling:
|
||||
----------
|
||||
As root, do a make install. This will compile and install the modules
|
||||
into the media/video directory in the module tree. For 2.4 kernels, use
|
||||
Makefile_2.4 (aka do make -f Makefile_2.4 install).
|
||||
Setup
|
||||
~~~~~
|
||||
|
||||
Setup:
|
||||
------
|
||||
Use 'modprobe cpia2' to load and 'modprobe -r cpia2' to unload. This
|
||||
may be done automatically by your distribution.
|
||||
|
||||
3. Driver options
|
||||
Driver options
|
||||
~~~~~~~~~~~~~~
|
||||
|
||||
============== ========================================================
|
||||
Option Description
|
||||
------ -----------
|
||||
============== ========================================================
|
||||
video_nr video device to register (0=/dev/video0, etc)
|
||||
range -1 to 64. default is -1 (first available)
|
||||
If you have more than 1 camera, this MUST be -1.
|
||||
|
|
@ -61,46 +68,64 @@ may be done automatically by your distribution.
|
|||
flicker_mode 0 to disable, or 1 to enable flicker reduction.
|
||||
(default 0). This is only effective if the camera
|
||||
uses a stv0672 coprocessor.
|
||||
============== ========================================================
|
||||
|
||||
Setting the options
|
||||
~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
Setting the options:
|
||||
--------------------
|
||||
If you are using modules, edit /etc/modules.conf and add an options
|
||||
line like this:
|
||||
|
||||
.. code-block:: none
|
||||
|
||||
options cpia2 num_buffers=3 buffer_size=65535
|
||||
|
||||
If the driver is compiled into the kernel, at boot time specify them
|
||||
like this:
|
||||
|
||||
.. code-block:: none
|
||||
|
||||
cpia2.num_buffers=3 cpia2.buffer_size=65535
|
||||
|
||||
What buffer size should I use?
|
||||
------------------------------
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
The maximum image size depends on the alternate you choose, and the
|
||||
frame rate achieved by the camera. If the compression engine is able to
|
||||
keep up with the frame rate, the maximum image size is given by the table
|
||||
below.
|
||||
|
||||
The compression engine starts out at maximum compression, and will
|
||||
increase image quality until it is close to the size in the table. As long
|
||||
as the compression engine can keep up with the frame rate, after a short time
|
||||
the images will all be about the size in the table, regardless of resolution.
|
||||
|
||||
At low alternate settings, the compression engine may not be able to
|
||||
compress the image enough and will reduce the frame rate by producing larger
|
||||
images.
|
||||
|
||||
The default of 68k should be good for most users. This will handle
|
||||
any alternate at frame rates down to 15fps. For lower frame rates, it may
|
||||
be necessary to increase the buffer size to avoid having frames dropped due
|
||||
to insufficient space.
|
||||
|
||||
Image size(bytes)
|
||||
========== ========== ======== =====
|
||||
Alternate bytes/ms 15fps 30fps
|
||||
========== ========== ======== =====
|
||||
2 128 8533 4267
|
||||
3 384 25600 12800
|
||||
4 640 42667 21333
|
||||
5 768 51200 25600
|
||||
6 896 59733 29867
|
||||
7 1023 68200 34100
|
||||
========== ========== ======== =====
|
||||
|
||||
Table: Image size(bytes)
|
||||
|
||||
|
||||
How many buffers should I use?
|
||||
------------------------------
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
For normal streaming, 3 should give the best results. With only 2,
|
||||
it is possible for the camera to finish sending one image just after a
|
||||
program has started reading the other. If this happens, the driver must drop
|
||||
|
|
@ -110,21 +135,56 @@ If the camera can send multiple images before a read finishes, it could
|
|||
overwrite the third buffer before the read finishes, leading to a corrupt
|
||||
image. Single and double buffering have extra checks to avoid overwriting.
|
||||
|
||||
4. Using the camera
|
||||
Using the camera
|
||||
~~~~~~~~~~~~~~~~
|
||||
|
||||
We are providing a modified gqcam application to view the output. In
|
||||
order to avoid confusion, here it is called mview. There is also the qx5view
|
||||
program which can also control the lights on the qx5 microscope. MJPEG Tools
|
||||
(http://mjpeg.sourceforge.net) can also be used to record from the camera.
|
||||
|
||||
5. Notes to developers:
|
||||
Notes to developers
|
||||
~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
- This is a driver version stripped of the 2.4 back compatibility
|
||||
and old MJPEG ioctl API. See cpia2.sf.net for 2.4 support.
|
||||
|
||||
6. Thanks:
|
||||
Programmer's overview of cpia2 driver
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
- Peter Pregler <Peter_Pregler@email.com>,
|
||||
Scott J. Bertin <scottbertin@yahoo.com>, and
|
||||
Jarl Totland <Jarl.Totland@bdc.no> for the original cpia driver, which
|
||||
this one was modelled from.
|
||||
Cpia2 is the second generation video coprocessor from VLSI Vision Ltd (now a
|
||||
division of ST Microelectronics). There are two versions. The first is the
|
||||
STV0672, which is capable of up to 30 frames per second (fps) in frame sizes
|
||||
up to CIF, and 15 fps for VGA frames. The STV0676 is an improved version,
|
||||
which can handle up to 30 fps VGA. Both coprocessors can be attached to two
|
||||
CMOS sensors - the vvl6410 CIF sensor and the vvl6500 VGA sensor. These will
|
||||
be referred to as the 410 and the 500 sensors, or the CIF and VGA sensors.
|
||||
|
||||
The two chipsets operate almost identically. The core is an 8051 processor,
|
||||
running two different versions of firmware. The 672 runs the VP4 video
|
||||
processor code, the 676 runs VP5. There are a few differences in register
|
||||
mappings for the two chips. In these cases, the symbols defined in the
|
||||
header files are marked with VP4 or VP5 as part of the symbol name.
|
||||
|
||||
The cameras appear externally as three sets of registers. Setting register
|
||||
values is the only way to control the camera. Some settings are
|
||||
interdependant, such as the sequence required to power up the camera. I will
|
||||
try to make note of all of these cases.
|
||||
|
||||
The register sets are called blocks. Block 0 is the system block. This
|
||||
section is always powered on when the camera is plugged in. It contains
|
||||
registers that control housekeeping functions such as powering up the video
|
||||
processor. The video processor is the VP block. These registers control
|
||||
how the video from the sensor is processed. Examples are timing registers,
|
||||
user mode (vga, qvga), scaling, cropping, framerates, and so on. The last
|
||||
block is the video compressor (VC). The video stream sent from the camera is
|
||||
compressed as Motion JPEG (JPEGA). The VC controls all of the compression
|
||||
parameters. Looking at the file cpia2_registers.h, you can get a full view
|
||||
of these registers and the possible values for most of them.
|
||||
|
||||
One or more registers can be set or read by sending a usb control message to
|
||||
the camera. There are three modes for this. Block mode requests a number
|
||||
of contiguous registers. Random mode reads or writes random registers with
|
||||
a tuple structure containing address/value pairs. The repeat mode is only
|
||||
used by VP4 to load a firmware patch. It contains a starting address and
|
||||
a sequence of bytes to be written into a gpio port.
|
||||
|
|
|
|||
|
|
@ -1,38 +0,0 @@
|
|||
Programmer's View of Cpia2
|
||||
|
||||
Cpia2 is the second generation video coprocessor from VLSI Vision Ltd (now a
|
||||
division of ST Microelectronics). There are two versions. The first is the
|
||||
STV0672, which is capable of up to 30 frames per second (fps) in frame sizes
|
||||
up to CIF, and 15 fps for VGA frames. The STV0676 is an improved version,
|
||||
which can handle up to 30 fps VGA. Both coprocessors can be attached to two
|
||||
CMOS sensors - the vvl6410 CIF sensor and the vvl6500 VGA sensor. These will
|
||||
be referred to as the 410 and the 500 sensors, or the CIF and VGA sensors.
|
||||
|
||||
The two chipsets operate almost identically. The core is an 8051 processor,
|
||||
running two different versions of firmware. The 672 runs the VP4 video
|
||||
processor code, the 676 runs VP5. There are a few differences in register
|
||||
mappings for the two chips. In these cases, the symbols defined in the
|
||||
header files are marked with VP4 or VP5 as part of the symbol name.
|
||||
|
||||
The cameras appear externally as three sets of registers. Setting register
|
||||
values is the only way to control the camera. Some settings are
|
||||
interdependant, such as the sequence required to power up the camera. I will
|
||||
try to make note of all of these cases.
|
||||
|
||||
The register sets are called blocks. Block 0 is the system block. This
|
||||
section is always powered on when the camera is plugged in. It contains
|
||||
registers that control housekeeping functions such as powering up the video
|
||||
processor. The video processor is the VP block. These registers control
|
||||
how the video from the sensor is processed. Examples are timing registers,
|
||||
user mode (vga, qvga), scaling, cropping, framerates, and so on. The last
|
||||
block is the video compressor (VC). The video stream sent from the camera is
|
||||
compressed as Motion JPEG (JPEGA). The VC controls all of the compression
|
||||
parameters. Looking at the file cpia2_registers.h, you can get a full view
|
||||
of these registers and the possible values for most of them.
|
||||
|
||||
One or more registers can be set or read by sending a usb control message to
|
||||
the camera. There are three modes for this. Block mode requests a number
|
||||
of contiguous registers. Random mode reads or writes random registers with
|
||||
a tuple structure containing address/value pairs. The repeat mode is only
|
||||
used by VP4 to load a firmware patch. It contains a starting address and
|
||||
a sequence of bytes to be written into a gpio port.
|
||||
|
|
@ -1,3 +1,10 @@
|
|||
The cx18 driver
|
||||
===============
|
||||
|
||||
.. note::
|
||||
|
||||
This documentation is outdated.
|
||||
|
||||
Some notes regarding the cx18 driver for the Conexant CX23418 MPEG
|
||||
encoder chip:
|
||||
|
||||
|
|
|
|||
|
|
@ -21,4 +21,6 @@ License".
|
|||
fourcc
|
||||
cardlist
|
||||
cafe_ccic
|
||||
cpia2
|
||||
cx18
|
||||
zr364xx
|
||||
|
|
|
|||
Loading…
Reference in New Issue