fix(command): fixed problem with spawning zombie process in spock com…

…mand

cmd/komputer/main.go

@@ -61,7 +61,6 @@ func init() {
 	})
 }
 
-// TODO Export registration commends to CLI tool
 func init() {
 	checkEnvVariables("APPLICATION_ID", "SERVER_GUID")
 

go.mod

@@ -8,7 +8,6 @@ require (
 )
 
 require (
-	github.com/bwmarrin/dgvoice v0.0.0-20210225172318-caaac756e02e // indirect
 	github.com/golang/snappy v0.0.1 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/gorilla/websocket v1.4.2 // indirect

internal/assets/audio.go

@@ -24,7 +24,7 @@ func GetAudioPaths(filename string) ([]string, error) {
 		return nil, err
 	}
 
-	var paths = make([]string, len(ls))
+	var paths []string
 
 	for _, d := range ls {
 		fName := d.Name()

internal/command/spock.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"github.com/bwmarrin/dgvoice"
 	"github.com/bwmarrin/discordgo"
 	"github.com/wittano/komputer/internal/assets"
 	"github.com/wittano/komputer/internal/interaction"
@@ -58,9 +57,10 @@ func execSpookSpeak(ctx context.Context, s *discordgo.Session, i *discordgo.Inte
 		ch := make(chan bool)
 		SpockMusicStopCh[i.GuildID] = ch
 
-		// TODO Rewrite this function cause ffmpeg generate zombie process
-		// TODO Add multi-server playing same song
-		dgvoice.PlayAudioFile(voiceJoin, path[rand.Int()%len(path)], ch)
+		songPath := path[rand.Int()%len(path)]
+		if err = voice.PlayAudio(voiceJoin, songPath, ch); err != nil {
+			log.Error(ctx, fmt.Sprintf("Failed play '%s' audio", songPath), err)
+		}
 
 		voiceJoin.Disconnect()
 	}()

internal/voice/audio.go

@@ -0,0 +1,126 @@
+package voice
+
+import (
+	"bufio"
+	"encoding/binary"
+	"errors"
+	"github.com/bwmarrin/discordgo"
+	"io"
+	"layeh.com/gopus"
+	"os/exec"
+	"strconv"
+	"syscall"
+)
+
+const (
+	channels  int = 2                   // 1 for mono, 2 for stereo
+	frameRate int = 48000               // audio sampling rate
+	frameSize int = 960                 // uint16 size of each audio frame
+	maxBytes      = (frameSize * 2) * 2 // max size of opus data
+)
+
+func PlayAudio(vc *discordgo.VoiceConnection, path string, stop <-chan bool) (err error) {
+	cmd := exec.Command("ffmpeg", "-i", path, "-f", "s16le", "-ar", strconv.Itoa(frameRate), "-ac", strconv.Itoa(channels), "pipe:1")
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Setpgid: true,
+	}
+
+	ffmpegout, err := cmd.StdoutPipe()
+	if err != nil {
+		return
+	}
+
+	ffmpegbuf := bufio.NewReaderSize(ffmpegout, 16384)
+
+	// Starts the ffmpeg command
+	err = cmd.Start()
+	if err != nil {
+		return
+	}
+
+	defer cmd.Wait()
+
+	//when stop is sent, kill ffmpeg
+	go func() {
+		<-stop
+		cmd.Process.Kill()
+	}()
+
+	// Send "speaking" packet over the voice websocket
+	err = vc.Speaking(true)
+	if err != nil {
+		return
+	}
+
+	// Send not "speaking" packet over the websocket when we finish
+	defer func() {
+		err := vc.Speaking(false)
+		if err != nil {
+			return
+		}
+	}()
+
+	send := make(chan []int16, 2)
+	defer close(send)
+
+	stopPlaying := make(chan bool)
+	go func() {
+		sendPCM(vc, send)
+		stopPlaying <- true
+	}()
+
+	for {
+		// read data from ffmpeg stdout
+		audiobuf := make([]int16, frameSize*channels)
+		err = binary.Read(ffmpegbuf, binary.LittleEndian, &audiobuf)
+		if err == io.EOF || err == io.ErrUnexpectedEOF {
+			return
+		}
+		if err != nil {
+			return
+		}
+
+		// Send received PCM to the sendPCM channel
+		select {
+		case send <- audiobuf:
+		case <-stopPlaying:
+			return
+		}
+	}
+}
+
+func sendPCM(v *discordgo.VoiceConnection, pcm chan []int16) (err error) {
+	if pcm == nil {
+		return nil
+	}
+
+	opusEncoder, err := gopus.NewEncoder(frameRate, channels, gopus.Audio)
+
+	if err != nil {
+		return
+	}
+
+	for {
+
+		// read pcm from chan, exit if channel is closed.
+		recv, ok := <-pcm
+		if !ok {
+			return errors.New("PCM Channel closed")
+		}
+
+		// try encoding pcm frame with Opus
+		opus, err := opusEncoder.Encode(recv, frameSize, maxBytes)
+		if err != nil {
+			return err
+		}
+
+		if v.Ready == false || v.OpusSend == nil {
+			// Sending errors here might not be suited
+			return nil
+		}
+		// send encoded opus data to the sendOpus channel
+		v.OpusSend <- opus
+	}
+
+	return
+}