minimal example of linking problem

1 files changed, 73 insertions, 0 deletions

diff --git a/voctocore/experiments/binlinktest.py b/voctocore/experiments/binlinktest.py
new file mode 100755
index 0000000..92d02ca
--- /dev/null
+++ b/voctocore/experiments/binlinktest.py
@@ -0,0 +1,73 @@
+#!/usr/bin/python3
+import gi, time
+
+gi.require_version('Gst', '1.0')
+from gi.repository import GLib, Gst, GObject
+
+GObject.threads_init()
+Gst.init(None)
+
+class SrcBin(Gst.Bin):
+	def __init__(self):
+		super().__init__()
+		self.src = Gst.ElementFactory.make('videotestsrc', 'src')
+		self.add(self.src)
+
+		self.add_pad(
+			Gst.GhostPad.new('src', self.src.get_static_pad('src'))
+		)
+
+class SinkBin(Gst.Bin):
+	def __init__(self):
+		super().__init__()
+		self.sink = Gst.ElementFactory.make('autovideosink', 'sink')
+		self.add(self.sink)
+
+		self.add_pad(
+			Gst.GhostPad.new('sink', self.sink.get_static_pad('sink'))
+		)
+
+class MixBin(Gst.Bin):
+	def __init__(self):
+		super().__init__()
+		self.mix = Gst.ElementFactory.make('videomixer', 'src')
+		self.add(self.mix)
+
+		self.add_pad(
+			Gst.GhostPad.new('src', self.mix.get_static_pad('src'))
+		)
+
+	def add_src(self, src):
+		sinkpad = self.mix.get_request_pad('sink_%u')
+		sinkpad.set_property('alpha', 0.75)
+		src = src.get_static_pad('src')
+
+		print(src.link(sinkpad)) # Error => GST_PAD_LINK_WRONG_HIERARCHY
+
+class Example:
+	def __init__(self):
+		self.mainloop = GObject.MainLoop()
+		self.pipeline = Gst.Pipeline()
+
+		self.src = SrcBin()
+		self.sink = SinkBin()
+		self.mix = MixBin()
+
+		# Add elements to pipeline
+		self.pipeline.add(self.src)
+		self.pipeline.add(self.sink)
+		self.pipeline.add(self.mix)
+
+		self.mix.add_src(self.src)
+		self.mix.link(self.sink)
+
+	def run(self):
+		self.pipeline.set_state(Gst.State.PLAYING)
+		self.mainloop.run()
+
+	def kill(self):
+		self.pipeline.set_state(Gst.State.NULL)
+		self.mainloop.quit()
+
+example = Example()
+example.run()