path: root/voctogui/lib/videodisplay.py

import logging
from gi.repository import Gst, Gtk

class VideoDisplay:
    """ Displays a Voctomix-Video-Stream into a GtkWidget """

    def __init__(self, port, videowidget, audiolevelwidget=None, playaudio=False):
        self.log = logging.getLogger('VideoDisplay[%u]' % port)

        pipeline = """
            videotestsrc !
            timeoverlay !
            video/x-raw,width=1920,height=1080 !
            xvimagesink name=v
        """.format(
            port=port
        )

        if audiolevelwidget or playaudio:
            pipeline += """
                audiotestsrc wave=blue-noise !
                audio/x-raw !
                level name=lvl interval=50000000 !
            """

            if playaudio:
                pipeline += """
                    alsasink
                """
            else:
                pipeline += """
                    fakesink
                """

        self.log.info('launching gstreamer-pipeline for widget %s "%s":\n%s', videowidget.get_name(), Gtk.Buildable.get_name(videowidget), pipeline)

        self.pipeline = Gst.parse_launch(pipeline)

        videowidget.realize()
        self.xid = videowidget.get_property('window').get_xid()

        bus = self.pipeline.get_bus()
        bus.add_signal_watch()
        bus.enable_sync_message_emission()

        bus.connect('message::error', self.on_error)
        bus.connect("sync-message::element", self.on_syncmsg)

        if audiolevelwidget:
            self.levelrms = [0, 0]
            self.audiolevelwidget = audiolevelwidget
            self.audiolevelwidget.connect('draw', self.on_level_draw)
            bus.connect("message::element", self.on_level)

    def run(self):
        self.pipeline.set_state(Gst.State.PLAYING)

    def set_overlay_callback(self, callback):
        if callback:
            if not self.draw_callback:
                self.draw_callback = self.pipeline.get_by_name('overlay').connect('draw', callback)
        else:
            print('disconnect')
            self.pipeline.get_by_name('overlay').disconnect(self.draw_callback)
            self.draw_callback = None

    def on_syncmsg(self, bus, msg):
        if msg.get_structure().get_name() == "prepare-window-handle":
                self.log.info('setting xvimagesink window-handle to %s', self.xid)
                msg.src.set_window_handle(self.xid)

    def on_error(self, bus, msg):
        self.log.error('on_error(): %s', msg.parse_error())

    def on_level_draw(self, widget, cr):
        cr.set_source_rgb(1, 1, 1)
        cr.set_line_width(10)

        cr.move_to(15, 0)
        cr.line_to(15, self.levelrms[0]*-20)
        cr.stroke()

    def on_level(self, bus, msg):
        if msg.src.name != 'lvl':
            return

        if msg.type != Gst.MessageType.ELEMENT:
            return

        self.levelpeaks = msg.get_structure().get_value('peak')
        self.levelrms = msg.get_structure().get_value('rms')
        self.audiolevelwidget.queue_draw()