Example for using tee for both playing and saving audio

gst_tee_example.py

#!/usr/bin/env python3
import gi
import threading
gi.require_version('Gst', '1.0')
gi.require_version('GstBase', '1.0')
gi.require_version('Gtk', '3.0')
from gi.repository import GObject, Gst

# Initialize threads
GObject.threads_init()

# Initialize GStreamer
Gst.init(None)

# Handle song metadata
def on_tag(bus, msg):
    taglist = msg.parse_tag()
    print('%s: %s' % (taglist.nth_tag_name(0), taglist.get_string(taglist.nth_tag_name(0)).value))

# Create a custom bin element, that will serve as audio sink to
# player bin. Audio filters will be added to this sink.
audio_sink = Gst.Bin.new('audiosink')

# Create tee
tee = Gst.ElementFactory.make('tee')
audio_sink.add(tee)

q1 = Gst.ElementFactory.make('queue')
audio_sink.add(q1)
tee_q1_pad = tee.get_request_pad("src_%u")
q1_pad = q1.get_static_pad('sink')
tee_q1_pad.link(q1_pad)

q2 = Gst.ElementFactory.make('queue')
audio_sink.add(q2)
tee_q2_pad = tee.get_request_pad("src_%u")
q2_pad = q2.get_static_pad('sink')
tee_q2_pad.link(q2_pad)

# Queue #1: Encode audio to vorbis and save in ogg file
# -----------------------------------------------------
encoder = Gst.ElementFactory.make('vorbisenc')
audio_sink.add(encoder)
q1.link(encoder)

oggmux = Gst.ElementFactory.make('oggmux')
audio_sink.add(oggmux)
encoder.link(oggmux)

filesink = Gst.ElementFactory.make('filesink')
filesink.set_property('location', r'/home/user/test.ogg')
filesink.set_property('sync', 'true')
audio_sink.add(filesink)
oggmux.link(filesink)


# Queue #2: Play audio with sound card
# -----------------------------------------------------

# Create element to play the pipeline to hardware
sink = Gst.ElementFactory.make('autoaudiosink')
audio_sink.add(sink)
q2.link(sink)

audio_sink.add_pad(Gst.GhostPad.new('sink', tee.get_static_pad('sink')))

# Create playbin and add the custom audio sink to it
player = Gst.ElementFactory.make("playbin", "player")
player.props.audio_sink = audio_sink

# Set URI to online radio
player.set_property('uri', 'http://stream.radioreklama.bg:80/radio1rock.ogg')

# Start playing
player.set_state(Gst.State.PLAYING)

# Listen for metadata
bus = player.get_bus()
bus.enable_sync_message_emission()
bus.add_signal_watch()
bus.connect('message::tag', on_tag)

loop = GObject.MainLoop()
threading.Thread(target=loop.run).start()

# Let user stop player gracefully
input('Press enter to change output file location on the fly...')
# TODO: do not interrupt playback
player.set_state(Gst.State.READY)
filesink.set_property('location', r'/home/user/test2.ogg')
player.set_state(Gst.State.PLAYING)

# Let user stop player gracefully
input('Press enter to stop playing...')

# Stop loop
player.set_state(Gst.State.NULL)
loop.quit()