Add audio prompts.

build/sip/Dockerfile

@@ -29,6 +29,7 @@ COPY go.sum .
 RUN go mod download
 
 # copy source
+COPY res/ res/
 COPY cmd/ cmd/
 COPY pkg/ pkg/
 COPY version/ version/

build/test/Dockerfile

@@ -21,7 +21,7 @@ WORKDIR /workspace
 # install deps
 RUN apt-get update && \
     apt-get install -y \
-    curl 
+    curl libopus-dev libopusfile-dev
 
 RUN if [ "$TARGETPLATFORM" = "linux/arm64" ]; then GOARCH=arm64; else GOARCH=amd64; fi && \
     curl -L -o /tmp/go.tar.gz "https://go.dev/dl/go1.20.7.linux-$GOARCH.tar.gz"
@@ -34,6 +34,7 @@ COPY go.sum .
 RUN go mod download
 
 # copy source
+COPY res/ res/
 COPY pkg/ pkg/
 COPY version/ version/
 

pkg/sip/media.go

@@ -15,19 +15,23 @@
 package sip
 
 import (
+	"bytes"
 	"encoding/binary"
 	"log"
 	"net"
 	"sync/atomic"
 	"time"
 
+	"github.com/at-wat/ebml-go"
+	"github.com/at-wat/ebml-go/webm"
 	"github.com/pion/rtp"
 	"github.com/pion/webrtc/v3"
 	"github.com/pion/webrtc/v3/pkg/media"
 	"github.com/zaf/g711"
 	"gopkg.in/hraban/opus.v2"
 
 	"github.com/livekit/sip/pkg/mixer"
+	"github.com/livekit/sip/res"
 
 	lksdk "github.com/livekit/server-sdk-go"
 )
@@ -37,6 +41,44 @@ const (
 	sampleRate = 8000
 )
 
+type mediaRes struct {
+	enterPin [][]int16
+	roomJoin [][]int16
+	wrongPin [][]int16
+}
+
+func (s *Server) initMediaRes() {
+	s.res.enterPin = audioFileToFrames(res.EnterPinMkv)
+	s.res.roomJoin = audioFileToFrames(res.RoomJoinMkv)
+	s.res.wrongPin = audioFileToFrames(res.WrongPinMkv)
+}
+
+func audioFileToFrames(data []byte) [][]int16 {
+	var ret struct {
+		Header  webm.EBMLHeader `ebml:"EBML"`
+		Segment webm.Segment    `ebml:"Segment"`
+	}
+	if err := ebml.Unmarshal(bytes.NewReader(data), &ret); err != nil {
+		panic(err)
+	}
+
+	var frames [][]int16
+	for _, cluster := range ret.Segment.Cluster {
+		for _, block := range cluster.SimpleBlock {
+			for _, data := range block.Data {
+				decoded := g711.DecodeUlaw(data)
+				pcm := make([]int16, 0, len(decoded)/2)
+				for i := 0; i < len(decoded); i += 2 {
+					sample := binary.LittleEndian.Uint16(decoded[i:])
+					pcm = append(pcm, int16(sample))
+				}
+				frames = append(frames, pcm)
+			}
+		}
+	}
+	return frames
+}
+
 type mediaData struct {
 	conn  *net.UDPConn
 	mix   *mixer.Mixer
@@ -246,11 +288,24 @@ func (c *inboundCall) createLiveKitParticipant(roomName, participantIdentity str
 
 func (c *inboundCall) joinRoom(roomName, identity string) {
 	log.Printf("Bridging SIP call %q -> %q to room %q (as %q)\n", c.from.Address.User, c.to.Address.User, roomName, identity)
+	c.playAudio(c.s.res.roomJoin)
 	if err := c.createLiveKitParticipant(roomName, identity); err != nil {
 		log.Println(err)
 	}
 }
 
-func (c *inboundCall) playPleaseEnterPin() {
-	// FIXME: play "Please enter room pin" audio
+func (c *inboundCall) playAudio(frames [][]int16) {
+	input := c.media.mix.AddInput()
+	defer c.media.mix.RemoveInput(input)
+
+	tick := time.NewTicker(20 * time.Millisecond)
+	defer tick.Stop()
+	for range tick.C {
+		if len(frames) == 0 {
+			break
+		}
+		samples := frames[0]
+		frames = frames[1:]
+		input.Push(samples)
+	}
 }

pkg/sip/media_test.go

@@ -0,0 +1,16 @@
+package sip
+
+import (
+	"testing"
+
+	"github.com/livekit/sip/res"
+)
+
+func TestDecodeRes(t *testing.T) {
+	res := res.EnterPinMkv
+	frames := audioFileToFrames(res)
+	for i, f := range frames {
+		t.Log(i, len(f))
+	}
+	t.Log(len(frames))
+}

pkg/sip/server.go

@@ -18,7 +18,6 @@ import (
 	"context"
 	"fmt"
 	"log"
-	"net"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -27,6 +26,7 @@ import (
 	"github.com/emiago/sipgo/sip"
 	"github.com/icholy/digest"
 	"github.com/pion/sdp/v2"
+	"golang.org/x/exp/maps"
 
 	"github.com/livekit/sip/pkg/config"
 )
@@ -56,27 +56,27 @@ type (
 		authenticationHandler authenticationHandlerFunc
 		dispatchRuleHandler   dispatchRuleHandlerFunc
 		conf                  *config.Config
+
+		res mediaRes
 	}
 
 	inProgressInvite struct {
 		from      string
 		challenge digest.Challenge
 	}
-
-	activeInvite struct {
-		udpConn *net.UDPConn
-	}
 )
 
 func NewServer(conf *config.Config, authenticationHandler authenticationHandlerFunc, dispatchRuleHandler dispatchRuleHandlerFunc) *Server {
-	return &Server{
+	s := &Server{
 		conf:                  conf,
 		publicIp:              getPublicIP(),
 		activeCalls:           make(map[string]*inboundCall),
 		inProgressInvites:     []*inProgressInvite{},
 		authenticationHandler: authenticationHandler,
 		dispatchRuleHandler:   dispatchRuleHandler,
 	}
+	s.initMediaRes()
+	return s
 }
 
 func getTagValue(req *sip.Request) (string, error) {
@@ -274,7 +274,7 @@ func (c *inboundCall) runMedia(offerData []byte) ([]byte, error) {
 func (c *inboundCall) pinPrompt() {
 	log.Printf("Requesting Pin for SIP call %q -> %q\n", c.from.Address.User, c.to.Address.User)
 	const pinLimit = 16
-	c.playPleaseEnterPin()
+	c.playAudio(c.s.res.enterPin)
 	pin := ""
 	noPin := false
 	for {
@@ -293,10 +293,8 @@ func (c *inboundCall) pinPrompt() {
 
 				log.Printf("Checking Pin for SIP call %q -> %q = %q (noPin = %v)\n", c.from.Address.User, c.to.Address.User, pin, noPin)
 				roomName, identity, requirePin, reject := c.s.dispatchRuleHandler(c.from.Address.User, c.to.Address.User, c.src, pin, noPin)
-				if reject {
-					c.Close()
-					return
-				} else if requirePin || roomName == "" {
+				if reject || requirePin || roomName == "" {
+					c.playAudio(c.s.res.wrongPin)
 					c.Close()
 					return
 				}
@@ -306,6 +304,7 @@ func (c *inboundCall) pinPrompt() {
 			// Gather pin numbers
 			pin += string(b)
 			if len(pin) > pinLimit {
+				c.playAudio(c.s.res.wrongPin)
 				c.Close()
 				return
 			}
@@ -321,6 +320,7 @@ func (c *inboundCall) Close() error {
 	delete(c.s.activeCalls, c.tag)
 	c.s.cmu.Unlock()
 	c.closeMedia()
+	// FIXME: drop the actual call
 	return nil
 }
 
@@ -366,6 +366,13 @@ func (s *Server) Start() error {
 }
 
 func (s *Server) Stop() error {
+	s.cmu.Lock()
+	calls := maps.Values(s.activeCalls)
+	s.activeCalls = make(map[string]*inboundCall)
+	s.cmu.Unlock()
+	for _, c := range calls {
+		c.Close()
+	}
 	if s.sipSrv != nil {
 		return s.sipSrv.Close()
 	}

res/embed.go

@@ -0,0 +1,12 @@
+package res
+
+import _ "embed"
+
+//go:embed enter_pin.mkv
+var EnterPinMkv []byte
+
+//go:embed room_join.mkv
+var RoomJoinMkv []byte
+
+//go:embed wrong_pin.mkv
+var WrongPinMkv []byte