Creative Video Blaster WebCam II VfW and Twain Drivers (Windows NT4)
==========================================================================
Version 1.03. 8th January 1999
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Introduction
============
This file describes how to install and use the Windows NT4 Video for Windows
and Twain drivers for the Creative Video Blaster WebCam II.
Installation
============
Simply run the installation program.
The following driver files are installed
VVLPPC2.DLL - VfW Capture Driver
VVLPPC2.DLL - Parallel port kernel mode driver
VVLDEC32.DLL - Decode module
VVLCODEC.DLL - YUV to RGB codec for all YUV FOURCCs
VVLPPC2.DS - Twain driver
TWAIN.DLL - Twain system file
TWAIN_32.DLL - Twain system file
TWUNK_16.DLL - Twain system file
TWUNK_32.DLL - Twain system file
The camera is visible under Control Panel|Multimedia|Advanced|Video Capture
Devices|Creative Video Blaster WebCam II
Parallel Port Types
===================
Parallel Port Transfer Modes
----------------------------
The driver supports 4 different parallel port transfer modes. Which setting
the driver is currently using can be found by looking in Control Panel under
Multimedia|Advanced|Video Capture Devices|Creative Video Blaster WebCam II|Properties|Settings.
4 Bit Mode
Sometimes called "compatiblity" or "AT" mode, it uses the 8 data lines only
for the sending of control data to the camera. All status and image data is
transfered to the PC via the 5 status lines.
ECP Mode
ECP is an acronym for "Extended Capabilites Port", and is a Microsoft/Hewlett
Packard standard for fast bidirectional parallel port hardware. Image data is
transfered to the host using the data lines in bidirectional mode with
hardware in the parallel port doing the byte level handshaking and flow
control.
ECP DMA
If the PC has a parallel port that supports ECP transfers, and that port has
been allocated a free DMA channel and interrupt, then the driver will attempt
to use DMA to transfer data from the parallel port into system memory. This
has two benefits it increases the maximum transfer rate through the port, and
it allows the transfer to happen "in the background" while the processor
does other useful work.
Fast DMA
Most PC's based on Intel chipsets have the facility to do what is termed
"Type F (Fast)" DMA transfers to system memory. When this is possible
DMA transfers over the PCI bus to system memory are greatly speeded up
resulting in far less slowing down of the processor while DMA transfers
are happening in the background. Unfortunately, the Intel chipsets can
only support two "Type F" DMA channels, and these may have been claimed
by other device drivers before the camera is started. Sound cards are the
most common devices to utilise these channels.
Whether the camera has been able to acquire a "Type F" channel can be found
by checking the Control Panel|Multimedia|Advanced|Video Capture Devices|
Creative Video Blaster WebCam II|Properties|Settings dialog.
Note that many PCs can support ECP modes and above, but are factory configured
to 4 bit mode. You can change this by altering the parallel port mode in the
PC's BIOS setup utility from 4bit to ECP. It is strongly recommend that you do this
to improve camera performance.
Transfer Type Back-off
----------------------
Each time the driver starts it checks with the Windows Configuration Manager
to find out what type of parallel port the camera is attached to. It will
then attempt to use the fastest transfer mode possible supported by that
port. During the camera initialisation phase the intergrity of the data
transfer of images from camera to PC is tested. If it is detected that data
corruption has occured, or the entire transfer failed, the driver will
automatically "back-off" and attempt to use a slower, and hopefully more
reliable transfer mode.
Back-off can also be manually implemented
DisableFDMA=1
Prevents the driver from trying to acquire a "Type F" DMA channel.
DisableDMA=1
Prevents the driver trying to use ECP DMA to transfer data.
This mode must be used with multiprocessor PCs
DisableECP=1
Prevents the driver from using any ECP transfer modes. It will only attempt
to use 4 Bit Mode to communicate with the driver.
You can also add these entries manually if required by adding DWORD values with
the above names to the registry tree HKLM\Software\Vision\PPC2. Note that if the
driver has backed off, you will see an asterisk at the end of the transfer mode
description in the driver's properties dialox box.
Note that these entries will be maintained when the camera is plugged into a different
parallel port on the same PC.
Dialog Box Controls
===================
Camera Settings Dialog Box
--------------------------
Brightness
Moving this to the right increases the brightness of the image
Contrast
Controls the contrast of the image. Moving to right increases the color
contrast.
Color
Controls the color saturation of the image.
Compression Control
The slider acts as an image quality control. Moving to the right increases
image quality, at the expense of image framerate, while moving to the left
decreases image quality, but give a higher framerate. If your video
conferencing application is slow, try decreasing the image quality (move
the slider to the left).
Optimize for Video Preview
Use this setting if you are looking at local video or want to capture a
video sequence to a file. This setting allows the driver to use a large
proportion of the available frametime to capture the best, and fastest,
video possible.
Optimize for Video Conferencing
Use this setting if you are using the camera with a videoconferencing
application. This compression setting limits the proportion of the
available frametime that the driver will use. Thus allowing the
videoconferencing application time to perform audio and video
compression.
Restore Defaults
This restores factory settings for the controls in the Camera Settings
dialog. Brightness, Contrast, Colour and Compression Control are all set
to their default value of 50.
Advanced Settings Dialog Box
----------------------------
Lighting
This lets you select for your current lighting condition, and is
particularly useful in low lighting conditions. Note - The setting selected
will affect the maximum framerate available from the camera, as the medium
and low settings slow the camera down to improve sensitivity.
Note - this control is disabled when the "Automatic Lighting" feature is
enabled (default).
Automatic Lighting
When this is checked the camera will automtically adjust the Lighting
setting based on the current conditions. When Automatic Lighting is selected
the setting that is being used is shown by the greyed out Lighting radio
buttons.
Backlit
This makes the auto exposure controller attempt to correctly expose the
centre portion of the the image, while disregarding bright objects around
the periphery of the scene. It works well for "head and shoulders" type
scenes. Unchecking this box sets the exposure controller use a "flat",
equally weighted, algorithm.
Banding Filter
This removes the horizontal banding that sometimes appears in the scenes
lit by artifical mains lighting. This banding is caused by the mains
lighting flickering on and off at the mains supply frequency. When the
banding filter is selected the "Filter Type", see below, must be set
appropriately.
Filter Type
Set this to match the frequency of the mains supply in your country. This
is 60Hz in the USA, and 50Hz in the UK.
Zoom control
The driver supports a zoom mode on image sizes up to 176x144. Enabling this
feature allows you to pan and tilt a 176x144 capture window within the full
352x288 capture area.
Supported Formats (aka FourCCs)
===============================
24 Bit RGB 16 Bit RGB 8 Bit RGB YUV
704 X 576 Yes - - -
640 x 480 Yes - - -
352 x 288 Yes Yes Yes Yes
320 x 240 Yes Yes Yes Yes
* 176 x 144 Yes Yes Yes Yes
160 x 120 Yes Yes Yes Yes
* default image size for the camera
The YUV column refers to the various YUV image formats (also known as
four character codes) that the driver supports. These are:
- YV12
- I420
- UYVY
- YUY2
Image sizes other than those tabulated above may be used. However the
following restrictions apply:
- Images sizes : rows must be a factor of 8 and columms must be factors of 4
For image sizes greater than 352x288, the above boundaries
are doubled, ie 16 rows and 8 columns
- Minimum number of columms is 8, and the minimum number of rows is 4, but
it doesn't give much of an image.
- Maximum image size is 704 x 576.
- Images sizes greater than 352 x 288 are only supported in 24 bit RGB mode.
Limitations
===========
Driver Settings
---------------
Most settings are saved in an initialisation file, called vvlcpia.ini, and
restored when a new session is started. The ones that aren't are :-
Zoom : the driver always starts unzoomed
TWAIN Driver
============
Introduction
------------
A 32bit Twain driver is also included in the installation. It allows any
Twain enabled application to capture a still image from the parallel port
camera. To use the camera, select the Twain driver is called
Creative Video Blaster WebCam II before trying to acquire an image.
The driver supports native, file and memory capture of 8 and 24 bit RGB images.
Using the Twain driver
----------------------
The dialogue box features a preview window displaying the current camera
image, and has a number of controls for tuning and capturing an image.
- Button to set the image size and format. The display updates to reflect
any new settings. The image is scaled to fit the preview box. This may
result in a distorted image being seen. This is purely a feature of the
preview windows, and the image will appear correctly when it is displayed
by your application.
- Button to set the brightness/contrast/colour and compression controls.
- Button to capture an image from the camera
- Button to freeze the image. A frozen image may be captured any number of
times. The image is frozen automatically when the capture button is
pressed, and the button text changed to "Resume". Pressing it will restart
the video camera display.
Note - Some applications only allow the capture of a single image before
unloading the Twain driver. If this is the case, you won't be able
to capture the same image more than once.
- Button to close the driver.
The dialog box may disappear after the image has been captured. This is
entirely under the control of the application that loaded the driver. If it
does disappear, choose Acquire to capture another image.
Limitations
-----------
Currently only RGB24 colour is supported and driver will prevent selection of other
formats.
Changes since version 1.02
==========================
- Fast DMA now available on more PCs
- Fixed bug that sometimes caused LPT port could to be incorrectly reported
- Backlit mode if now off by default to give a better exposed image
- The back-off state is not written back to registry
Download Driver Pack
After your driver has been downloaded, follow these simple steps to install it.
Expand the archive file (if the download file is in zip or rar format).
If the expanded file has an .exe extension, double click it and follow the installation instructions.
Otherwise, open Device Manager by right-clicking the Start menu and selecting Device Manager.
Find the device and model you want to update in the device list.
Double-click on it to open the Properties dialog box.
From the Properties dialog box, select the Driver tab.
Click the Update Driver button, then follow the instructions.
Very important: You must reboot your system to ensure that any driver updates have taken effect.
For more help, visit our Driver Support section for step-by-step videos on how to install drivers for every file type.