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GObject
╰── GInitiallyUnowned
╰── GstObject
╰── GstElement
╰── GstBaseSink
╰── GstVideoSink
╰── GstGdkPixbufSink
This sink element takes RGB or RGBA images as input and wraps them into GdkPixbuf objects, for easy saving to file via the GdkPixbuf library API or displaying in Gtk+ applications (e.g. using the GtkImage widget).
There are two ways to use this element and obtain the GdkPixbuf objects created:
"preroll-pixbuf"
or "pixbuf" on the bus, which
will be posted whenever an image would usually be rendered. See below for
more details on these messages and how to extract the pixbuf object
contained in them.
The primary purpose of this element is to abstract away the GstBuffer to GdkPixbuf conversion. Other than that it's very similar to the fakesink element.
This element is meant for easy no-hassle video snapshotting. It is not suitable for video playback or video display at high framerates. Use ximagesink, xvimagesink or some other suitable video sink in connection with the GstXOverlay interface instead if you want to do video playback.
"preroll-pixbuf"
or "pixbuf" on the bus (this
can be disabled by setting the “post-messages” property
to FALSE though). The element message structure has the following fields:
"pixbuf": the GdkPixbuf object
"pixel-aspect-ratio": the pixel aspect
ratio (PAR) of the input image (this field contains a GstFraction); the
PAR is usually 1:1 for images, but is often something non-1:1 in the case
of video input. In this case the image may be distorted and you may need
to rescale it accordingly before saving it to file or displaying it. This
can easily be done using gdk_pixbuf_scale() (the reason this is not done
automatically is that the application will often scale the image anyway
according to the size of the output window, in which case it is much more
efficient to only scale once rather than twice). You can put a videoscale
element and a capsfilter element with
video/x-raw-rgb,pixel-aspect-ratio=(fraction)1/1 caps
in front of this element to make sure the pixbufs always have a 1:1 PAR.
1 |
gst-launch-1.0 -m -v videotestsrc num-buffers=1 ! gdkpixbufsink |
plugin |
gdkpixbuf |
author |
Tim-Philipp Müller <tim centricular net> |
class |
Sink/Video |
name |
sink |
direction |
sink |
presence |
always |
details |
video/x-raw, format=(string)RGB, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2147483647/1 ] |
| video/x-raw, format=(string)RGBA, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2147483647/1 ] |