NAME
zbarcam - scan and decode bar codes from a video device
SYNOPSIS
zbarcam [-qv] [--quiet] [--nodisplay] [--xml] [--verbose[=n]]
[--prescale=WxH] [-S[symbology.]config[=value]]
[--set [symbology.]config[=value]] [device]
zbarcam {-h | --help | --version}
DESCRIPTION
zbarcam scans a video4linux video source (eg, a webcam) for bar codes
and prints any decoded data to the standard output. The video stream is
also displayed to the screen.
device is the path to the video4linux (version 1 or 2) character device
special file (major number 81 and minor number 0 thru 63). It defaults
to /dev/video0
The underlying library currently supports EAN-13 (including UPC and
ISBN subsets), EAN-8, Code 128, Code 39, and Interleaved 2 of 5
symbologies. The specific type of each detected symbol is printed with
the decoded data.
OPTIONS
This program follows the usual GNU command line syntax. Single letter
options may be bundled, long options start with two dashes (‘-´).
-h, --help
Print a short help message describing command line options to
standard output and exit
--version
Print program version information to standard output and exit
-v, --verbose[=n]
Increase debug output level. Multiple -v options create more spew.
Alternatively specify n to set the debug level directly
-S[symbology.]config[=value], --set [symbology.]config[=value]
Set decoder configuration option config for symbology to value.
value defaults to 1 if omitted. symbology is one of ean13, ean8,
upca, upce, isbn13, isbn10, i25, code39, code128 or the special
value *. If symbology is omitted or *, the config will be set for
all applicable symbologies. These are the currently recognized
configs. Prefix a config with "no-" to negate it. Not all configs
are appropriate for every symbology.
enable
Control decoding/reporting of a symbology. For symbologies
which are just subsets of ean13 (upca, upce, isbn13, isbn10),
this config controls whether the subsets are detected and
reported as such. These special cases are disabled by default,
all other symbologies default to enabled
disable
Antonym for enable
emit-check
Control whether check digits are included in the decoded
output. Enabled by default. This config does not apply for
code128, which never returns the check digit. It also not apply
for cases where the check digit is disabled (see add-check).
Check digits are currently not implemented for i25 or code39
add-check
Enable decode and verification of a check digit for symbologies
where it is optional: this will include code39 and i25, neither
of which implements the check digit yet
ascii
Enable escape sequences that encode the full ASCII character
set. This would apply to code39, except that it´s not
implemented either...
position
Enable collection of symbol position information. Enabled by
default. Currently, the position information is unusable, so
you can save a few cycles by disabling this.
min-length=n, max-length=n
Bound the number of decoded characters in a valid symbol. If a
decode result is outside the configured min/max range
(inclusive), it will not be reported. Set to 0 to disable the
corresponding check. This setting applies to variable-length
symbologies: i25, code39, code128 and pdf417. min-length
defaults to 6 for i25 and 1 for code39 (per Code 39
autodiscrimination recommendation); all others default to 0
x-density=n, y-density=n
Adjust the density of the scanner passes. Lower values scan
more of the image at the cost of decreased performance. Setting
to 0 disables scanning along that axis. Defaults are both 1.
-q, --quiet
Quiet operation; disable the audible beep otherwise emitted when a
symbol is decoded
--nodisplay
Disable output video window. Video input will be scanned until the
program is interrupted or otherwise signaled
--xml
Stream results using an XML output format. This format wraps the
raw data from the symbol with information about the scan in an easy
to parse format. The latest schema is available from
http://zbar.sourceforge.net/2008/barcode.xsd
--raw
Use raw symbol data output format. This format prints symbol data
separated by newlines without the additional symbology type
information that is printed by default
--prescale=WxH
Request video input scaling from the camera driver. Possibly useful
for reducing huge frames to achieve a higher frame rate. Note that
the driver may adjust or completely ignore the scaling request
EXAMPLES
Scan for barcodes using the second video device and pipe the resulting
data through a script that searches for each code in a database and
does something useful with them:
zbarcam /dev/video1 | upcrpc.py
The upcrpc.py example script included in the examples/ subdirectory of
the distribution will make an XMLRPC call to a popular internet UPC
database and print the product description if found.
Scan for barcodes using the default video device and stream results to
stdout in XML format, also disable recognition of Interleaved 2 of 5
codes to prevent confusion with other symbologies or background noise:
zbarcam --xml -Si25.disable
Scan only for Code 39, without using the preview window - maybe for a
fixed installation. To enable only Code 39, first all symbologies are
disabled, then Code 39 is re-enabled:
zbarcam --nodisplay -Sdisable -Scode39.enable
SEE ALSO
zbarimg(1)
http://zbar.sf.net/
BUGS
See http://sf.net/tracker/?group_id=189236&atid=928515
AUTHOR
Jeff Brown <spadix@users.sourceforge.net>
Lead developer
COPYRIGHT
Copyright © 2007-2009 Jeff Brown
All Rights Reserved