pjWebCam Documentation
Version 1.0

Overview

pjWebCam is a simple application to enable a windows video capture device to be accessed across an intranet or internet.

Features

HTTP Server

This turns the machine that the camera is attached to into an HTTP (web) server. This responds to blank http requests by sending the current image from the camera.

Optionally a refresh interval can be configured, which will cause some browsers to effect a "client pull" on the image at the selected interval.

FTP Client

Each time an image is captured (at the end of each capture interval, or as a result of the user pressing the take button) the Image can be uploaded to an FTP server.

Local Save

Each time an image is captured (at the end of each capture interval, or as a result of the user pressing the take button) the Image can be saved locally. Incremental filenames are not currently supported.

Captioned Images

Captured images can be captioned. This caption uses a user defined, font, colors and message which can use escape sequences to include time strings (using standard C strftime escapes), using the host machines current locale settings.

Configuration

Legal Information

This program is copyright © Paul Roberts 1998.

This program is based in part on the work of the Independent Jpeg Group

This program is licensed free of charge and can be freely distributed provided this file is distributed with it and that there are no charges beyond those necessary for administrative purposes.

BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

I Wrote This

I Welcome your input and constructive criticism but may not have time to respond.

Top

Top

Capture Settings

Capture Interval

This is the number of interval units between captures.

Interval Units

This is the units to use for counting capture intervals, options are...

• Seconds
• Minutes
• Hours
• Days
• Weeks

Time Remaining

This displays the amount of time remaining until the next automatic capture.

Top

Video Settings

Preview Video

If this button is selected a video capture preview is displayed.

Source

Adjust settings for the video source.

Format

Adjust video format options.

Display

Adjust video display options.

Quality

This specifies the "quality" setting to be used when encoding the jpeg file. This is a value between 0 and 100 where 0 represents the lowest quality (best compression) and 100 the highest quality (least compression). The table shows the effects on file size of 5 different quality settings.

Quality	Size in k	Image
0	3
25	7
50	9
75	13
100	60

Details

This shows a summary of the current image capture options.

Top

HTTP Server

Enable HTTP

If this is checked then pjWebCam operates as a simple HTTP server. Using the port number etc. specified in the http settings dialog.

HTTP Settings

This opens the http settings dialog.

HTTP Settings Dialog

Port Number

This specifies the port number that the http server listens on. The default port for http is 80, a common alternative (to avoid clashing with another webserver on the same address, or to avoid using a privilidged port) is 8080.

Client Pull Refresh

If this is checked then the server will send and Http header asking the web client to perform a client pull after the time specified by the refresh interval.

Refresh Interval

This is the number of seconds the client should wait before performing a client pull.

Top

FTP Settings

Enable FTP

If this is checked then each time pjWebCam captures and image it is uploaded to the ftp server specified in the ftp settings dialog.

FTP Settings

This opens the ftp settings dialog.

FTP Settings Dialog

Username

This specifies the username to use when logging on to the ftp server.

Password

This specifies the password to use when logging on to the ftp server. The password is stored (like all other pjWebCam configuration information) in the registry. It is encrypted using a relatively simple encryption mechanism. There is a potential security risk. If someone has access to your registry they could break the encryption, given sufficient time and expertise, thus giving them access to your ftp account.

Account

This specifies an account name to connect to the ftp server with. This is not tested because i couldn't find an FTP server that uses this facility. The likelyhood is that you will not need to enter anything in this box.

Server

This is the internet address of your ftp server.

Directory

This is the subdirectory on that server that you wish to store the image file in.

Filename

This is the filename that you wish to store.

Top

Caption Settings

Caption Image

If this is checked then any captured image has a caption using the settings specified in the caption settings dialog.

Caption Settings

This opens the caption settings dialog.

Caption Settings Dialog

Caption

This specifies the string to be used as a caption. The following escapes are used to insert date and time information into the string.

Escape	Meaning
%a	Abbreviated weekday name
%A	Full weekday name
%b	Abbreviated month name
%B	Full month name
%c	Date and time representation, appropriate for locale
%d	Day of month as decimal number (01 - 31)
%H	Hour in 24-hour format (00 - 23)
%I	Hour in 12-hour format (01 - 12)
%j	Day of year as decimal number (001 - 366)
%m	Month as decimal number (01 - 12)
%M	Minute as decimal number (00 - 59)
%p	Current locale's A.M./P.M. indicator for 12-hour clock
%S	Second as decimal number (00 - 59)
%U	Week of year as decimal number, with Sunday as first day of week (00 - 51)
%w	Weekday as decimal number (0 - 6; Sunday is 0)
%W	Week of year as decimal number, with Monday as first day of week (00 - 51)
%x	Date representation for current locale
%X	Time representation for current locale
%y	Year without century, as decimal number (00 - 99)
%Y	Year with century, as decimal number
%z, %Z	Time-zone name or abbreviation; no characters if time zone is unknown
%%	Percent sign

A flag # can be inserted in any escape, changing the meanings as follows

Escape	Meaning
%#a, %#A, %#b, %#B, %#p, %#X, %#z, %#Z, %#%	# flag is ignored
%#c	Long date and time representation, appropriate for locale.
%#x	Long date representation for current locale
%#d, %#H, %#I, %#j, %#m, %#M, %#S, %#U, %#w, %#W, %#y, %#Y	removes leading zeros (if any)

Vertical Position

Specifies the vertical position of the caption.

Horizontal Position

Specifies the horizontal position of the caption.

Transparent

If this is checked then the Caption is drawn onto the image transparantly, other wise the text is drawn in a box.

Caption Font

Clicking this button allows you to select a caption font.

Foreground Colour

Clicking this button allows you to select the foreground colour of the caption.

Background Colour

Clicking this button allows you to select the background colour of the caption. This is the colour of the box that the text is drawn onto unless transparent is selected, in which case this is used as the outline colour for the text.

Caption Preview

Top

File Settings

Save File

If this is checked then the captured image is saved locally.

Filename

This is the filename of the image to save.

Browse

This button allows you to browse for a filename to save as.

Top

Other

Progress Indicator

This shows an indication of outstanding file transfers.

Take

This button causes a capture to happen immediately, resetting the timer.

About

Displays copyright information about pjWebCam.

Exit

Closes pjWebCam.

log

This shows a log of actions in the current session.