Add lastKeyFrameSeen to status endpoint

internal/webrtc/keyframe_detector.go

@@ -0,0 +1,26 @@
+package webrtc
+
+import (
+	"github.com/pion/rtp"
+)
+
+const (
+	naluTypeBitmask = 0x1F
+
+	idrNALUType = 5
+	spsNALUType = 7
+	ppsNALUType = 8
+)
+
+func isKeyframe(pkt *rtp.Packet, codec videoTrackCodec, depacketizer rtp.Depacketizer) bool {
+	if codec == videoTrackCodecH264 {
+		nalu, err := depacketizer.Unmarshal(pkt.Payload)
+		if err != nil || len(nalu) < 6 {
+			return false
+		}
+
+		firstNaluType := nalu[4] & naluTypeBitmask
+		return firstNaluType == idrNALUType || firstNaluType == spsNALUType || firstNaluType == ppsNALUType
+	}
+	return false
+}

internal/webrtc/webrtc.go

@@ -53,8 +53,9 @@ type (
 	}
 
 	videoTrack struct {
-		rid             string
-		packetsReceived atomic.Uint64
+		rid              string
+		packetsReceived  atomic.Uint64
+		lastKeyFrameSeen atomic.Value
 	}
 
 	videoTrackCodec int
@@ -151,6 +152,7 @@ func addTrack(stream *stream, rid string) (*videoTrack, error) {
 	}
 
 	t := &videoTrack{rid: rid}
+	t.lastKeyFrameSeen.Store(time.Time{})
 	stream.videoTracks = append(stream.videoTracks, t)
 	return t, nil
 }
@@ -371,8 +373,9 @@ func Configure() {
 }
 
 type StreamStatusVideo struct {
-	RID             string `json:"rid"`
-	PacketsReceived uint64 `json:"packetsReceived"`
+	RID              string    `json:"rid"`
+	PacketsReceived  uint64    `json:"packetsReceived"`
+	LastKeyFrameSeen time.Time `json:"lastKeyFrameSeen"`
 }
 
 type StreamStatus struct {
@@ -418,9 +421,15 @@ func GetStreamStatuses() []StreamStatus {
 
 		streamStatusVideo := []StreamStatusVideo{}
 		for _, videoTrack := range stream.videoTracks {
+			var lastKeyFrameSeen time.Time
+			if v, ok := videoTrack.lastKeyFrameSeen.Load().(time.Time); ok {
+				lastKeyFrameSeen = v
+			}
+
 			streamStatusVideo = append(streamStatusVideo, StreamStatusVideo{
-				RID:             videoTrack.rid,
-				PacketsReceived: videoTrack.packetsReceived.Load(),
+				RID:              videoTrack.rid,
+				PacketsReceived:  videoTrack.packetsReceived.Load(),
+				LastKeyFrameSeen: lastKeyFrameSeen,
 			})
 		}
 

internal/webrtc/whip.go

@@ -6,9 +6,11 @@ import (
 	"log"
 	"math"
 	"strings"
+	"time"
 
 	"github.com/pion/rtcp"
 	"github.com/pion/rtp"
+	"github.com/pion/rtp/codecs"
 	"github.com/pion/webrtc/v4"
 )
 
@@ -65,6 +67,16 @@ func videoWriter(remoteTrack *webrtc.TrackRemote, stream *stream, peerConnection
 	rtpPkt := &rtp.Packet{}
 	codec := getVideoTrackCodec(remoteTrack.Codec().RTPCodecCapability.MimeType)
 
+	var depacketizer rtp.Depacketizer
+	switch codec {
+	case videoTrackCodecH264:
+		depacketizer = &codecs.H264Packet{}
+	case videoTrackCodecVP8:
+		depacketizer = &codecs.VP8Packet{}
+	case videoTrackCodecVP9:
+		depacketizer = &codecs.VP9Packet{}
+	}
+
 	lastTimestamp := uint32(0)
 	lastTimestampSet := false
 
@@ -88,6 +100,10 @@ func videoWriter(remoteTrack *webrtc.TrackRemote, stream *stream, peerConnection
 
 		videoTrack.packetsReceived.Add(1)
 
+		if isKeyframe(rtpPkt, codec, depacketizer) {
+			videoTrack.lastKeyFrameSeen.Store(time.Now())
+		}
+
 		rtpPkt.Extension = false
 		rtpPkt.Extensions = nil