cycle_sinks.py

#!/usr/bin/env python3

from subprocess import check_output
from re import findall, DOTALL, MULTILINE
import psutil

def log(s):
    check_output(['logger', '-t', __file__, s])

inputs = findall(r'.*?index: (\d+).*?sink: (\d+).*?application\.process\.id = "(\d+)"',
                 check_output(['pacmd', 'list-sink-inputs']).decode("utf-8"), DOTALL|MULTILINE)
log("Discovered inputs %s" % inputs)
sinks = findall(r'index: (\d+)', check_output(['pacmd', 'list-sinks']).decode("utf-8"))
focused_window = check_output(['xdotool', 'getwindowfocus'])
focused_pid = check_output(['xdotool', 'getwindowpid', focused_window]).strip().decode("utf-8")

for app in inputs:
    p = psutil.Process(int(app[2]))
    ppid = p.ppid()
    log("Checking if app with pid %s (ppid %s, sink %s) is pid %s \n" % (app[2], ppid, app[0], focused_pid ))
    if app[2] == focused_pid or str(ppid) == focused_pid:
        # find new sink index
        index = 0
        for i in range(len(sinks)):
            if sinks[i] == app[1]:
                index = (i + 1) % len(sinks) # rotation
                break

        log("Switching app %s to input %s" % (app[0], sinks[index]))
        check_output(['pacmd', 'move-sink-input', app[0], sinks[index] ])
        #break