#!/usr/bin/env python

# -----------------------------------------------------------------------
# Implementation of the following:
# 
# 1. Setup ECI to read audio from file, apply a 100Hz lowpass filter, and 
#    send it to the soundcard (/dev/dsp).
# 2. Every second, check the current position. If the stream has
#    been running for over 15 seconds, exit immediately. Also,
#    every second, increase the lowpass filter's cutoff frequency
#    by 500Hz.
# 3. Stop the stream (if not already finished) and disconnect the 
#    chainsetup. Print chain operator status info.
# -----------------------------------------------------------------------

import time
from pyeca import *
e = ECA_CONTROL_INTERFACE()
e.command("cs-add play_chainsetup")
e.command("c-add 1st_chain")
e.command("ai-add foo.wav")
e.command("ao-add /dev/dsp")
e.command("cop-add -efl:100")
e.command("cop-select 1")
e.command("copp-select 1")
e.command("cs-connect")
e.command("start")
cutoff_inc = 500.0
while 1:
    time.sleep(1)
    e.command("engine-status")
    if e.last_string() != "running": break
    e.command("get-position")
    curpos = e.last_float()
    if curpos > 15: break
    e.command("copp-get")
    next_cutoff = cutoff_inc + e.last_float()
    e.command_float_arg("copp-set", next_cutoff)
e.command("stop")
e.command("cs-disconnect")
e.command("cop-status")
print "Chain operator status: ", e.last_string()