zbar

zbar

Properties

gboolean message Read / Write
gboolean cache Read / Write
gboolean attach-frame Read / Write

Types and Values

struct GstZBar

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 named

"barcode". 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 to TRUE (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 ]

Functions

Types and Values

struct GstZBar

struct GstZBar;

Opaque data structure.

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