From 8cf0ace67ec1e267ad0f4e9a2f9123df48a27c1f Mon Sep 17 00:00:00 2001
From: Mitchell <mgerb42@gmail.com>
Date: Tue, 23 Oct 2018 20:18:21 -0500
Subject: [PATCH] decode full opus stream at one time - fixes #22

---
 server/bothandlers/sounds.go | 30 +++++++++++++++---------------
 server/util/audio.go         | 34 +++++++++++++++-------------------
 2 files changed, 30 insertions(+), 34 deletions(-)

diff --git a/server/bothandlers/sounds.go b/server/bothandlers/sounds.go
index 6685063..c0878b1 100644
--- a/server/bothandlers/sounds.go
+++ b/server/bothandlers/sounds.go
@@ -220,7 +220,7 @@ func (conn *AudioConnection) playSoundsInQueue() {
 	conn.toggleSoundPlayingLock(true)
 
 	// Start speaking.
-	_ = conn.VoiceConnection.Speaking(true)
+	conn.VoiceConnection.Speaking(true)
 
 	for {
 		select {
@@ -240,7 +240,7 @@ func (conn *AudioConnection) playSoundsInQueue() {
 
 		default:
 			// Stop speaking
-			_ = conn.VoiceConnection.Speaking(false)
+			conn.VoiceConnection.Speaking(false)
 			conn.toggleSoundPlayingLock(false)
 			return
 		}
@@ -293,33 +293,33 @@ func writePacketsToFile(username string, packets chan *discordgo.Packet) {
 		os.Mkdir(config.Config.ClipsPath, os.ModePerm)
 	}
 
-	// grab everything from the voice packet channel and dump it to the file
-	// close when there is nothing left
-	// split audio into specific voice streams
-	pcmOut := map[uint32][]int16{}
+	opusData := map[uint32][][]byte{}
 
 loop:
 	for {
 		select {
 		case p := <-packets:
-			// convert opus to pcm
-			pcm, err := util.OpusToPCM(p.Opus, sampleRate, channels)
-			if err != nil {
-				log.Error(err)
-				return
-			}
-			pcmOut[p.SSRC] = append(pcmOut[p.SSRC], pcm...)
+			// separate opus data for each channel
+			opusData[p.SSRC] = append(opusData[p.SSRC], p.Opus)
 		default:
 			break loop
 		}
 	}
 
-	for key, pcmData := range pcmOut {
+	for key, opus := range opusData {
+
+		pcmData, err := util.OpusToPCM(opus, sampleRate, channels)
+
+		if err != nil {
+			log.Error(err)
+			continue
+		}
+
 		// construct filename
 		timestamp := time.Now().UTC().Format("2006-01-02") + "-" + strconv.Itoa(int(time.Now().Unix()))
 		filename := config.Config.ClipsPath + "/" + timestamp + "-" + strconv.Itoa(int(key)) + "-" + username + ".wav"
 
-		err := util.SavePCMToWavFile(pcmData, filename, sampleRate, channels)
+		err = util.SavePCMToWavFile(pcmData, filename, sampleRate, channels)
 
 		if err != nil {
 			log.Error(err)
diff --git a/server/util/audio.go b/server/util/audio.go
index 8091789..850fd34 100644
--- a/server/util/audio.go
+++ b/server/util/audio.go
@@ -90,30 +90,26 @@ func GetFileExtension(path, fileName string) (string, error) {
 	return "", errors.New("file not found")
 }
 
-// cache the opusDecoder so we don't have to make a new one every time
-// was causing audio issues creating a new instance of this every time
-var opusDecoder *opus.Decoder
-
 // OpusToPCM - convert opus to pcm
-func OpusToPCM(data []byte, sampleRate, channels int) ([]int16, error) {
-	if opusDecoder == nil {
-		var err error
-		opusDecoder, err = opus.NewDecoder(sampleRate, channels)
-		if err != nil {
-			return []int16{}, err
-		}
-	}
-
-	// create pcm list with more than enough space
-	pcm := make([]int16, 10000)
-	n, err := opusDecoder.Decode(data, pcm)
+func OpusToPCM(opusData [][]byte, sampleRate, channels int) ([]int16, error) {
+	opusDecoder, err := opus.NewDecoder(sampleRate, channels)
+	pcm := []int16{}
 
 	if err != nil {
-		return []int16{}, err
+		return pcm, err
 	}
 
-	// trim the remaining space
-	pcm = pcm[:n*channels]
+	for _, o := range opusData {
+		// create pcm slice with more than enough space
+		p := make([]int16, 10000)
+		n, err := opusDecoder.Decode(o, p)
+
+		if err != nil {
+			return pcm, err
+		}
+
+		pcm = append(pcm, p[:n*channels]...)
+	}
 
 	return pcm, nil
 }