fix(stream): isolate H264 subscribers

Keep slow WebRTC consumers from blocking the shared H264 source by dropping buffered frames until the next keyframe. Restore the WebRTC NACK and RTCP report interceptors while retaining a safe RTP MTU, and enable linker --as-needed for libkvm to remove unused OpenCV dependencies.

server/service/stream/h264_source.go

@@ -15,10 +15,11 @@ type H264Frame struct {
 }
 
 type H264Subscription struct {
-	frames chan H264Frame
+	frames             chan H264Frame
-	done   chan struct{}
+	done               chan struct{}
-	closed atomic.Bool
+	closed             atomic.Bool
-	once   sync.Once
+	once               sync.Once
+	waitingForKeyframe bool
 }
 
 type H264Source struct {
@@ -147,11 +148,38 @@ func (s *H264Subscription) send(frame H264Frame) bool {
 	if s.closed.Load() {
 		return false
 	}
+	if s.waitingForKeyframe {
+		if frame.Result != 3 {
+			return false
+		}
+		s.waitingForKeyframe = false
+	}
 
 	select {
 	case s.frames <- frame:
 		return true
 	case <-s.done:
 		return false
+	default:
+	}
+
+	for {
+		select {
+		case <-s.frames:
+		case <-s.done:
+			return false
+		default:
+			s.waitingForKeyframe = true
+			if frame.Result != 3 {
+				return false
+			}
+			s.waitingForKeyframe = false
+			select {
+			case s.frames <- frame:
+				return true
+			case <-s.done:
+				return false
+			}
+		}
 	}
 }

server/service/stream/webrtc/h264.go

@@ -164,9 +164,16 @@ func createPeerConnection(iceServers []webrtc.ICEServer, mediaEngine *webrtc.Med
 
 	apiOptions := []func(api *webrtc.API){
 		webrtc.WithSettingEngine(settingEngine),
-		webrtc.WithInterceptorRegistry(&interceptor.Registry{}),
 	}
 	if mediaEngine != nil {
+		registry := &interceptor.Registry{}
+		if err := webrtc.ConfigureNack(mediaEngine, registry); err != nil {
+			return nil, err
+		}
+		if err := webrtc.ConfigureRTCPReports(registry); err != nil {
+			return nil, err
+		}
+		apiOptions = append(apiOptions, webrtc.WithInterceptorRegistry(registry))
 		apiOptions = append(apiOptions, webrtc.WithMediaEngine(mediaEngine))
 	}
 

server/service/stream/webrtc/manager.go

@@ -15,7 +15,7 @@ func NewWebRTCManager() *WebRTCManager {
 	m := &WebRTCManager{
 		clients: make(map[*websocket.Conn]*Client),
 		videoPacketizer: rtp.NewPacketizer(
-			1450,
+			1200,
 			100,
 			0x1234ABCD,
 			&codecs.H264Payloader{},

support/sg2002/additional/kvm/CMakeLists.txt

@@ -1,5 +1,6 @@
 list(APPEND ADD_REQUIREMENTS vision basic peripheral)
 list(APPEND ADD_INCLUDE "include")
+list(APPEND ADD_LINK_DEFINITIONS_PRIVATE -Wl,--as-needed)
 
 append_srcs_dir(ADD_SRCS "src")