fix stereo for chormium browsers.

client/src/neko/base.ts

@@ -286,6 +286,10 @@ export abstract class BaseClient extends EventEmitter<BaseEvents> {
 
     try {
       const d = await this._peer.createAnswer()
+
+      // add stereo=1 to answer sdp to enable stereo audio for chromium
+      d.sdp = d.sdp?.replace(/(stereo=1;)?useinbandfec=1/, 'useinbandfec=1;stereo=1')
+
       this._peer!.setLocalDescription(d)
 
       this._ws!.send(

docs/changelog.md

@@ -4,6 +4,7 @@
 
 ### Bugs
 - Fixed TCP mux occasional freeze by adding write buffer to it.
+- Fixed stereo problem in chromium-based browsers, where it was only as mono by adding `stereo=1` to opus SDP to clients answer.
 
 ## [n.eko v2.7](https://github.com/m1k1o/neko/releases/tag/v2.7)
 

server/internal/types/codec/codecs.go

@@ -118,7 +118,7 @@ func Opus() RTPCodec {
 			MimeType:     webrtc.MimeTypeOpus,
 			ClockRate:    48000,
 			Channels:     2,
-			SDPFmtpLine:  "useinbandfec=1",
+			SDPFmtpLine:  "useinbandfec=1;stereo=1",
 			RTCPFeedback: []webrtc.RTCPFeedback{},
 		},
 	}