<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def voip_play2(s1, **kargs):
 """ Same than voip_play, but will play both incoming and outcoming packets. The sound will surely suffer distortion. Only supports sniffing. .. seealso:: voip_play to play only incoming packets. """

    dsp, rd = os.popen2(sox_base % "-c 2")
    global x1, x2
    x1 = ""
    x2 = ""

    def play(pkt):
        global x1, x2
        if not pkt:
            return
        if not pkt.haslayer(UDP) or not pkt.haslayer(IP):
            return
        ip = pkt.getlayer(IP)
        if s1 in [ip.src, ip.dst]:
            if ip.dst == s1:
                x1 += pkt.getlayer(conf.raw_layer).load[12:]
            else:
                x2 += pkt.getlayer(conf.raw_layer).load[12:]
            x1, x2, r = _merge_sound_bytes(x1, x2)
            dsp.write(r)

    sniff(store=0, prn=play, **kargs)