mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-23 18:21:04 +00:00
fab64c0b3a
Plugins know that they will be initialized after Gst was initialized so they can call the initialization function dedicated for the python bindings Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2675>
53 lines
2.1 KiB
Python
Executable file
53 lines
2.1 KiB
Python
Executable file
#!/usr/bin/python3
|
|
# exampleTransform.py
|
|
# 2019 Daniel Klamt <graphics@pengutronix.de>
|
|
|
|
# Inverts a grayscale image in place, requires numpy.
|
|
#
|
|
# gst-launch-1.0 videotestsrc ! ExampleTransform ! videoconvert ! xvimagesink
|
|
|
|
import gi
|
|
gi.require_version('Gst', '1.0')
|
|
gi.require_version('GstBase', '1.0')
|
|
gi.require_version('GstVideo', '1.0')
|
|
|
|
from gi.repository import Gst, GObject, GstBase, GstVideo
|
|
|
|
import numpy as np
|
|
|
|
Gst.init_python()
|
|
FIXED_CAPS = Gst.Caps.from_string('video/x-raw,format=GRAY8,width=[1,2147483647],height=[1,2147483647]')
|
|
|
|
class ExampleTransform(GstBase.BaseTransform):
|
|
__gstmetadata__ = ('ExampleTransform Python','Transform',
|
|
'example gst-python element that can modify the buffer gst-launch-1.0 videotestsrc ! ExampleTransform ! videoconvert ! xvimagesink', 'dkl')
|
|
|
|
__gsttemplates__ = (Gst.PadTemplate.new("src",
|
|
Gst.PadDirection.SRC,
|
|
Gst.PadPresence.ALWAYS,
|
|
FIXED_CAPS),
|
|
Gst.PadTemplate.new("sink",
|
|
Gst.PadDirection.SINK,
|
|
Gst.PadPresence.ALWAYS,
|
|
FIXED_CAPS))
|
|
|
|
def do_set_caps(self, incaps, outcaps):
|
|
struct = incaps.get_structure(0)
|
|
self.width = struct.get_int("width").value
|
|
self.height = struct.get_int("height").value
|
|
return True
|
|
|
|
def do_transform_ip(self, buf):
|
|
try:
|
|
with buf.map(Gst.MapFlags.READ | Gst.MapFlags.WRITE) as info:
|
|
# Create a NumPy ndarray from the memoryview and modify it in place:
|
|
A = np.ndarray(shape = (self.height, self.width), dtype = np.uint8, buffer = info.data)
|
|
A[:] = np.invert(A)
|
|
|
|
return Gst.FlowReturn.OK
|
|
except Gst.MapError as e:
|
|
Gst.error("Mapping error: %s" % e)
|
|
return Gst.FlowReturn.ERROR
|
|
|
|
GObject.type_register(ExampleTransform)
|
|
__gstelementfactory__ = ("ExampleTransform", Gst.Rank.NONE, ExampleTransform)
|