| Top |  |
 |
 |
 |
Object Hierarchy
GObject ╰── GInitiallyUnowned ╰── GstObject ╰── GstElement ╰── GstBaseTransform ╰── GstVideoFilter ╰── GstZBar
Description
Detect bar codes in the video streams and send them as element messages to
the GstBus if .“message” property is TRUE.
If the .“attach-frame” property is TRUE, the posted barcode message
includes a sample of the frame where the barcode was detected (Since 1.6).
The element generate messages namedbarcode. The structure containes these fields:
GstClockTime
timestamp: the timestamp of the buffer that triggered the message.gchar *
type: the symbol type.gchar *
symbol: the deteted bar code data.gint
quality: an unscaled, relative quantity: larger values are better than smaller values.GstSample
frame: the frame in which the barcode message was detected, if the .“attach-frame” property was set toTRUE(Since 1.6)
Example launch lines
1 |
gst-launch-1.0 -m v4l2src ! videoconvert ! zbar ! videoconvert ! xvimagesink |
This pipeline will detect barcodes and send them as messages.
1 |
gst-launch-1.0 -m v4l2src ! tee name=t ! queue ! videoconvert ! zbar ! fakesink t. ! queue ! xvimagesink |
Same as above, but running the filter on a branch to keep the display in color
Synopsis
Element Information
plugin |
zbar |
author |
Stefan Kost <ensonic@users.sf.net> |
class |
Filter/Analyzer/Video |
Element Pads
name |
sink |
direction |
sink |
presence |
always |
details |
video/x-raw, format=(string){ Y800, I420, YV12, NV12, NV21, Y41B, Y42B, YUV9, YVU9 }, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2147483647/1 ] |
name |
src |
direction |
source |
presence |
always |
details |
video/x-raw, format=(string){ Y800, I420, YV12, NV12, NV21, Y41B, Y42B, YUV9, YVU9 }, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2147483647/1 ] |
Property Details
The “message” property
“message” gboolean
Post a barcode message for each detected code.
Flags: Read / Write
Default value: TRUE
The “cache” property
“cache” gboolean
Enable or disable the inter-image result cache.
Flags: Read / Write
Default value: FALSE
The “attach-frame” property
“attach-frame” gboolean
Attach a frame dump to each barcode message.
Flags: Read / Write
Default value: FALSE