voctocore/lib/videomix.py



#!/usr/bin/python3
import time, logging
from gi.repository import GLib, Gst

from lib.config import Config

class VideoMix(Gst.Bin):
    log = logging.getLogger('VideoMix')
    sinkpads = []

    def __init__(self):
        super().__init__()

        self.mixer = Gst.ElementFactory.make('videomixer', 'mixer')
        self.scale = Gst.ElementFactory.make('videoscale', 'scale')
        self.conv = Gst.ElementFactory.make('videoconvert', 'conv')

        self.add(self.mixer)
        self.add(self.scale)
        self.add(self.conv)

        caps = Gst.Caps.from_string(Config.get('mix', 'outputcaps'))
        self.mixer.link_filtered(self.scale, caps)
        self.scale.link(self.conv)

        self.add_pad(
            Gst.GhostPad.new('src', self.conv.get_static_pad('src'))
        )

    # I don't know how to create a on-request ghost-pad
    def add_source(self, src):
        self.log.info('adding source %s', src.get_name())
        sinkpad = self.mixer.get_request_pad('sink_%u')
        sinkpad.set_property('alpha', 1)
        self.sinkpads.append(sinkpad)

        #srcpad = src.get_compatible_pad(sinkpad, None)
        #srcpad.link(sinkpad)
        src.link(self.mixer) # linking ghost pads

    def set_active(self, target):
        self.log.info('setting source #%u active', target)
        for idx, sinkpad in enumerate(self.sinkpads):
            sinkpad.set_property('alpha', int(target == idx))