Make a PulseAudio audio file player.

.gitignore

@@ -1 +1,2 @@
 *.test
+/fone/fone

fone/main.go

@@ -0,0 +1,179 @@
+package main
+
+// #cgo pkg-config: libpulse-simple
+// #include <stdlib.h>
+// #include <pulse/simple.h>
+// #include <pulse/error.h>
+import "C"
+
+import (
+	"errors"
+	"flag"
+	"github.com/jart/gosip/dsp"
+	"github.com/jart/gosip/rtp"
+	"github.com/jart/gosip/sdp"
+	"github.com/jart/gosip/sip"
+	"github.com/jart/gosip/util"
+	"net"
+	"os"
+	"time"
+	"unsafe"
+)
+
+const (
+	hz       = 8000
+	chans    = 1
+	ptime    = 20
+	ssize    = 2
+	psamps   = hz / (1000 / ptime) * chans
+	pbytes   = psamps * ssize
+	filename = "/var/lib/asterisk/sounds/en/cc-yougotpranked.s16"
+)
+
+var (
+	address      = flag.String("sipAddress", ":9020", "Listen address")
+	paServerFlag = flag.String("paServer", "", "Pulse Audio server name")
+	paSinkFlag   = flag.String("paSink", "", "Pulse Audio device or sink name")
+	paName       = C.CString("fone")
+)
+
+func main() {
+	pa, err := makePulseAudio(C.PA_STREAM_PLAYBACK, filename)
+	if err != nil {
+		panic(err)
+	}
+	defer C.pa_simple_free(pa)
+	defer C.pa_simple_flush(pa, nil)
+
+	f, err := os.Open(filename)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	tick := time.NewTicker(ptime * time.Millisecond)
+	defer tick.Stop()
+	func() {
+		for {
+			var buf [pbytes]byte
+			select {
+			case <-tick.C:
+				got, _ := f.Read(buf[:])
+				if got < pbytes {
+					return
+				}
+				var paerr C.int
+				if C.pa_simple_write(pa, unsafe.Pointer(&buf[0]), pbytes, &paerr) != 0 {
+					panic(C.GoString(C.pa_strerror(paerr)))
+				}
+			}
+		}
+	}()
+	os.Exit(0)
+
+	// Create RTP audio session.
+	rs, err := rtp.NewSession("")
+	if err != nil {
+		panic(err)
+	}
+	defer rs.Close()
+	rtpPort := uint16(rs.Sock.LocalAddr().(*net.UDPAddr).Port)
+
+	invite := &sip.Msg{
+		Method:  sip.MethodInvite,
+		Request: &sip.URI{User: "echo", Host: "127.0.0.1", Port: 5060},
+		Payload: &sdp.SDP{
+			Origin: sdp.Origin{ID: util.GenerateOriginID()},
+			Audio: &sdp.Media{
+				Port:   rtpPort,
+				Codecs: []sdp.Codec{sdp.ULAWCodec, sdp.DTMFCodec},
+			},
+		},
+	}
+
+	// Create a SIP phone call.
+	dl, err := sip.NewDialog(invite)
+	if err != nil {
+		panic(err)
+	}
+
+	// We're going to send white noise every 20ms.
+	var frame rtp.Frame
+	awgn := dsp.NewAWGN(-45.0)
+	ticker := time.NewTicker(20 * time.Millisecond)
+	defer ticker.Stop()
+
+	// Hangup after 200ms.
+	death := time.After(200 * time.Millisecond)
+
+	// Let's GO!
+	var answered bool
+	for {
+		select {
+		case <-ticker.C:
+			for n := 0; n < 160; n++ {
+				frame[n] = awgn.Get()
+			}
+			if err := rs.Send(&frame); err != nil {
+				panic("RTP send failed: " + err.Error())
+			}
+		case err := <-dl.OnErr:
+			panic(err)
+		case state := <-dl.OnState:
+			switch state {
+			case sip.DialogAnswered:
+				answered = true
+			case sip.DialogHangup:
+				if !answered {
+					panic("Call didn't get answered!")
+				}
+				return
+			}
+		case rs.Peer = <-dl.OnPeer:
+		case frame := <-rs.C:
+			rs.R <- frame
+		case err := <-rs.E:
+			panic("RTP recv failed: " + err.Error())
+			rs.CloseAfterError()
+			dl.Hangup <- true
+		case <-death:
+			dl.Hangup <- true
+		}
+	}
+}
+
+func makePulseAudio(direction C.pa_stream_direction_t, streamName string) (*C.pa_simple, error) {
+	var ss C.pa_sample_spec
+	ss.format = C.PA_SAMPLE_S16NE
+	ss.rate = hz
+	ss.channels = chans
+
+	var ba C.pa_buffer_attr
+	ba.maxlength = pbytes * 4
+	ba.tlength = pbytes
+	ba.prebuf = pbytes * 2
+	ba.minreq = pbytes
+	ba.fragsize = 0xffffffff
+
+	var paServer *C.char
+	if *paServerFlag != "" {
+		paServer = C.CString(*paServerFlag)
+		defer C.free(unsafe.Pointer(paServer))
+	}
+
+	var paSink *C.char
+	if *paSinkFlag != "" {
+		paSink = C.CString(*paSinkFlag)
+		defer C.free(unsafe.Pointer(paSink))
+	}
+
+	paStreamName := C.CString(streamName)
+	defer C.free(unsafe.Pointer(paStreamName))
+
+	var paerr C.int
+	pa := C.pa_simple_new(paServer, paName, direction, paSink, paStreamName, &ss, nil, &ba, &paerr)
+	if pa == nil {
+		return nil, errors.New(C.GoString(C.pa_strerror(paerr)))
+	}
+	return pa, nil
+}