From 79ee4e06f350d6e5405611fcb3ff8883ff736c88 Mon Sep 17 00:00:00 2001
From: Alessandro Ros <aler9.dev@gmail.com>
Date: Tue, 27 Jun 2023 22:36:29 +0200
Subject: [PATCH] webrtc: add option to disable audio effects (#1908) (#1989)

---
 internal/core/webrtc_http_server.go     |  1 +
 internal/core/webrtc_manager.go         |  1 +
 internal/core/webrtc_publish_index.html | 14 ++++++++++++++
 internal/core/webrtc_session.go         | 25 +++++++++++++++++++------
 4 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/internal/core/webrtc_http_server.go b/internal/core/webrtc_http_server.go
index f7edd842..16e58a5a 100644
--- a/internal/core/webrtc_http_server.go
+++ b/internal/core/webrtc_http_server.go
@@ -305,6 +305,7 @@ func (s *webRTCHTTPServer) onRequest(ctx *gin.Context) {
 				audioCodec:   ctx.Query("audio_codec"),
 				videoBitrate: ctx.Query("video_bitrate"),
 				audioBitrate: ctx.Query("audio_bitrate"),
+				audioVoice:   ctx.Query("audio_voice") == "true",
 			})
 			if res.err != nil {
 				if res.errStatusCode != 0 {
diff --git a/internal/core/webrtc_manager.go b/internal/core/webrtc_manager.go
index 23f85bad..95e982e4 100644
--- a/internal/core/webrtc_manager.go
+++ b/internal/core/webrtc_manager.go
@@ -138,6 +138,7 @@ type webRTCSessionNewReq struct {
 	audioCodec   string
 	videoBitrate string
 	audioBitrate string
+	audioVoice   bool
 	res          chan webRTCSessionNewRes
 }
 
diff --git a/internal/core/webrtc_publish_index.html b/internal/core/webrtc_publish_index.html
index 44adf3dc..dda86de4 100644
--- a/internal/core/webrtc_publish_index.html
+++ b/internal/core/webrtc_publish_index.html
@@ -75,6 +75,11 @@ select {
 
             audio bitrate (kbps):
             <input id="audio_bitrate" type="text" value="32" />
+
+            <div>
+                <input id="audio_voice" type="checkbox" checked>
+                <label for="audio_voice">optimize for voice</label>
+            </div>
         </div>
         <div id="submit_line">
             <button id="publish_confirm">publish</button>
@@ -226,12 +231,14 @@ class Transmitter {
                 const audioCodec = document.getElementById('audio_codec').value;
                 const videoBitrate = document.getElementById('video_bitrate').value;
                 const audioBitrate = document.getElementById('audio_bitrate').value;
+                const audioVoice = document.getElementById('audio_voice').checked;
 
                 const p = new URLSearchParams(window.location.search);
                 p.set('video_codec', videoCodec);
                 p.set('audio_codec', audioCodec);
                 p.set('video_bitrate', videoBitrate);
                 p.set('audio_bitrate', audioBitrate);
+                p.set('audio_voice', audioVoice ? 'true' : 'false');
 
                 fetch(new URL('whip', window.location.href) + '?' + p.toString(), {
                     method: 'POST',
@@ -362,6 +369,13 @@ const onPublish = () => {
             audio = {
                 deviceId: audioId,
             };
+
+            const voice = document.getElementById('audio_voice').checked;
+            if (!voice) {
+                audio.autoGainControl = false;
+                audio.echoCancellation = false;
+                audio.noiseSuppression = false;
+            }
         }
 
         navigator.mediaDevices.getUserMedia({ video, audio })
diff --git a/internal/core/webrtc_session.go b/internal/core/webrtc_session.go
index be961448..fdd51365 100644
--- a/internal/core/webrtc_session.go
+++ b/internal/core/webrtc_session.go
@@ -61,7 +61,12 @@ func findOpusPayloadFormat(attributes []sdp.Attribute) int {
 	return 0
 }
 
-func editAnswer(offer *webrtc.SessionDescription, videoBitrateStr string, audioBitrateStr string) error {
+func editAnswer(
+	offer *webrtc.SessionDescription,
+	videoBitrateStr string,
+	audioBitrateStr string,
+	audioVoice bool,
+) error {
 	var sd sdp.SessionDescription
 	err := sd.Unmarshal([]byte(offer.SDP))
 	if err != nil {
@@ -97,10 +102,18 @@ func editAnswer(offer *webrtc.SessionDescription, videoBitrateStr string, audioB
 				if pl != 0 {
 					for i, attr := range media.Attributes {
 						if attr.Key == "fmtp" && strings.HasPrefix(attr.Value, strconv.FormatInt(int64(pl), 10)+" ") {
-							media.Attributes[i] = sdp.Attribute{
-								Key: "fmtp",
-								Value: strconv.FormatInt(int64(pl), 10) + " stereo=1;sprop-stereo=1;maxaveragebitrate=" +
-									strconv.FormatUint(audioBitrate*1024, 10),
+							if audioVoice {
+								media.Attributes[i] = sdp.Attribute{
+									Key: "fmtp",
+									Value: strconv.FormatInt(int64(pl), 10) + " minptime=10;useinbandfec=1;maxaveragebitrate=" +
+										strconv.FormatUint(audioBitrate*1024, 10),
+								}
+							} else {
+								media.Attributes[i] = sdp.Attribute{
+									Key: "fmtp",
+									Value: strconv.FormatInt(int64(pl), 10) + " stereo=1;sprop-stereo=1;maxaveragebitrate=" +
+										strconv.FormatUint(audioBitrate*1024, 10),
+								}
 							}
 						}
 					}
@@ -368,7 +381,7 @@ func (s *webRTCSession) runPublish() (int, error) {
 	tmp := pc.LocalDescription()
 	answer = *tmp
 
-	err = editAnswer(&answer, s.req.videoBitrate, s.req.audioBitrate)
+	err = editAnswer(&answer, s.req.videoBitrate, s.req.audioBitrate, s.req.audioVoice)
 	if err != nil {
 		return http.StatusBadRequest, err
 	}