Merge pull request #293 from kerberos-io/feature/live-preview-http-transfer

feature/live-preview-http-transfer

README.md

@@ -231,9 +231,9 @@ Next to attaching the configuration file, it is also possible to override the co
 | `AGENT_MQTT_PASSWORD`                       | Password of the MQTT broker.                                                                    | ""                             |
 | `AGENT_REALTIME_PROCESSING`                 | If `AGENT_REALTIME_PROCESSING` set to `true`, the agent will send key frames to the topic       | ""                             |
 | `AGENT_REALTIME_PROCESSING_TOPIC`           | The topic to which keyframes will be sent in base64 encoded format.                             | ""                             |
-| `AGENT_STUN_URI`                            | When using WebRTC, you'll need to provide a STUN server.                                        | "stun:turn.kerberos.io:8443"   |
+| `AGENT_STUN_URI`                            | When using WebRTC, you'll need to provide a STUN server.                                        | "stun:turn-fra1.kerberos.io:3478"|
 | `AGENT_FORCE_TURN`                          | Force using a TURN server, by generating relay candidates only.                                 | "false"                        |
-| `AGENT_TURN_URI`                            | When using WebRTC, you'll need to provide a TURN server.                                        | "turn:turn.kerberos.io:8443"   |
+| `AGENT_TURN_URI`                            | When using WebRTC, you'll need to provide a TURN server.                                        | "turn:turn-fra1.kerberos.io:3478"|
 | `AGENT_TURN_USERNAME`                       | TURN username used for WebRTC.                                                                  | "username1"                    |
 | `AGENT_TURN_PASSWORD`                       | TURN password used for WebRTC.                                                                  | "password1"                    |
 | `AGENT_CLOUD`                               | Store recordings in Kerberos Hub (s3), Kerberos Vault (kstorage), or Dropbox (dropbox).         | "s3"                           |

machinery/cmd/mp4analyze/main.go

@@ -1,19 +1,24 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
+	"sort"
 
 	"github.com/Eyevinn/mp4ff/avc"
 	mp4ff "github.com/Eyevinn/mp4ff/mp4"
 )
 
 func main() {
-	if len(os.Args) < 2 {
-		fmt.Println("usage: mp4analyze <file.mp4>")
+	fromFlag := flag.Int64("from", -1, "start of the detailed inspection window (track timescale units); default auto-detects the largest keyframe gap")
+	toFlag := flag.Int64("to", -1, "end of the detailed inspection window (track timescale units); default auto-detected")
+	flag.Parse()
+	if flag.NArg() < 1 {
+		fmt.Println("usage: mp4analyze [-from N] [-to N] <file.mp4>")
 		os.Exit(1)
 	}
-	f, err := os.Open(os.Args[1])
+	f, err := os.Open(flag.Arg(0))
 	if err != nil {
 		panic(err)
 	}
@@ -110,7 +115,7 @@ func main() {
 				tid := traf.Tfhd.TrackID
 				tfdt := traf.Tfdt.BaseMediaDecodeTime()
 				offset := uint64(0)
-				var keys []uint64    // keyframe offset-from-tfdt
+				var keys []uint64 // keyframe offset-from-tfdt
 				var durs []uint64
 				zeroDur := 0
 				nSamples := 0
@@ -157,16 +162,21 @@ func main() {
 		if i > 0 {
 			gap = int64(k) - int64(allKeyGlobal[i-1])
 		}
-		flag := ""
+		seam := ""
 		if i > 1 {
 			prevGap := int64(allKeyGlobal[i-1]) - int64(allKeyGlobal[i-2])
 			if gap > 0 && prevGap > 0 && gap*2 < prevGap {
-				flag = fmt.Sprintf("  <== SEAM? gap=%d < prevGap/2=%d", gap, prevGap/2)
+				seam = fmt.Sprintf("  <== SEAM? gap=%d < prevGap/2=%d", gap, prevGap/2)
 			}
 		}
-		fmt.Printf("  kf#%02d dt=%d gap=%d%s\n", i, k, gap, flag)
+		fmt.Printf("  kf#%02d dt=%d gap=%d%s\n", i, k, gap, seam)
 	}
 
+	// Choose the detailed-inspection window. By default centre it on the largest
+	// keyframe gap (the most likely artifact location); -from/-to override.
+	winLo, winHi := inspectWindow(allKeyGlobal, *fromFlag, *toFlag)
+	fmt.Printf("=== detailed inspection window: dts %d..%d ===\n", winLo, winHi)
+
 	// Full sample timeline: DTS, CTS (=DTS+cto), composition offset, NAL types,
 	// to detect PTS non-monotonicity / gaps / param-set changes at the seam.
 	fmt.Println("=== per-sample timeline (full) — checking PTS monotonicity & nal types ===")
@@ -201,9 +211,11 @@ func main() {
 				if lastDTS >= 0 && dts < lastDTS {
 					anomaly += fmt.Sprintf(" <== DTS BACKWARDS (prev=%d)", lastDTS)
 				}
-				isSync := s.Flags&0x02000000 == 0 && (s.Flags>>24)&0x03 == 0x02
-				// Only print near the seam region and any anomalies, to keep output small.
-				near := dts >= 7800 && dts <= 8700
+				// sample_is_non_sync_sample is bit 16 (0x00010000); a sync sample
+				// has it clear and sample_depends_on==2 (i.e. an I-frame).
+				isSync := s.Flags&0x00010000 == 0 && (s.Flags>>24)&0x03 == 0x02
+				// Only print inside the inspection window and any anomalies, to keep output small.
+				near := dts >= winLo && dts <= winHi
 				if near || anomaly != "" {
 					fmt.Printf("  s%04d frag%d dts=%d cts=%d cto=%d dur=%d size=%d sync=%v nal=%v%s\n",
 						sampIdx, fragIdx, dts, cts, s.CompositionTimeOffset, s.Dur, len(s.Data), isSync, nals, anomaly)
@@ -293,10 +305,12 @@ func main() {
 		}
 	}
 
-	sliceHeaders(parsed, trex)
+	sliceHeaders(parsed, trex, winLo, winHi)
+
+	summary(parsed, trex)
 }
 
-func sliceHeaders(parsed *mp4ff.File, trex *mp4ff.TrexBox) {
+func sliceHeaders(parsed *mp4ff.File, trex *mp4ff.TrexBox, winLo, winHi int64) {
 	// Build SPS/PPS maps from avcC.
 	spsMap := map[uint32]*avc.SPS{}
 	ppsMap := map[uint32]*avc.PPS{}
@@ -322,7 +336,7 @@ func sliceHeaders(parsed *mp4ff.File, trex *mp4ff.TrexBox) {
 		}
 	}
 
-	fmt.Println("=== slice headers near seam (frame_num / poc / idr_pic_id) ===")
+	fmt.Println("=== slice headers in inspection window (frame_num / poc / idr_pic_id) ===")
 	fragIdx := 0
 	sampIdx := 0
 	for _, seg := range parsed.Segments {
@@ -334,7 +348,7 @@ func sliceHeaders(parsed *mp4ff.File, trex *mp4ff.TrexBox) {
 			}
 			for _, s := range fs {
 				dts := int64(s.DecodeTime)
-				if dts < 6800 || dts > 9400 {
+				if dts < winLo || dts > winHi {
 					sampIdx++
 					continue
 				}
@@ -423,3 +437,200 @@ func nalsByType(b []byte, want int) [][]byte {
 	}
 	return out
 }
+
+// inspectWindow returns the [lo,hi] decode-time range (track timescale units)
+// for which sample-level detail is printed. Explicit -from/-to win; otherwise
+// the window auto-centres on the largest gap between consecutive video
+// keyframes — the most likely location of a visible artifact — with a margin on
+// each side so the frames leading into and out of the gap are shown too.
+func inspectWindow(keyDecodeTimes []uint64, from, to int64) (int64, int64) {
+	if from >= 0 || to >= 0 {
+		if from < 0 {
+			from = 0
+		}
+		if to < 0 {
+			to = from + 2000
+		}
+		return from, to
+	}
+	if len(keyDecodeTimes) < 2 {
+		return 0, 1 << 62
+	}
+	worstIdx, worstGap := 1, uint64(0)
+	for i := 1; i < len(keyDecodeTimes); i++ {
+		if g := keyDecodeTimes[i] - keyDecodeTimes[i-1]; g > worstGap {
+			worstGap = g
+			worstIdx = i
+		}
+	}
+	const margin = 500
+	lo := int64(keyDecodeTimes[worstIdx-1]) - margin
+	if lo < 0 {
+		lo = 0
+	}
+	return lo, int64(keyDecodeTimes[worstIdx]) + margin
+}
+
+// summary prints a compact, generic health report so a recording can be
+// validated at a glance without reading the full per-sample dump above.
+func summary(parsed *mp4ff.File, trex *mp4ff.TrexBox) {
+	fmt.Println("=== SUMMARY (health checks) ===")
+
+	videoTracks, audioTracks := 0, 0
+	var videoTimescale uint64 = 1
+	if parsed.Init != nil && parsed.Init.Moov != nil {
+		for _, trak := range parsed.Init.Moov.Traks {
+			switch trak.Mdia.Hdlr.HandlerType {
+			case "vide":
+				videoTracks++
+				if trak.Mdia.Mdhd.Timescale != 0 {
+					videoTimescale = uint64(trak.Mdia.Mdhd.Timescale)
+				}
+			case "soun":
+				audioTracks++
+			}
+		}
+	}
+	fmt.Printf("  tracks: %d video, %d audio\n", videoTracks, audioTracks)
+	if audioTracks == 0 {
+		fmt.Println("    note: no audio track is embedded in this file")
+	}
+
+	type fragStat struct {
+		idx     int
+		tfdt    uint64
+		dur     uint64
+		nSamp   int
+		nKeys   int
+		zeroDur int
+		fps     float64
+	}
+	var stats []fragStat
+	var keyTimes []uint64
+	var fpsArr []float64
+	tfdtGaps := 0
+	var prevEnd uint64
+	havePrev := false
+	fi := 0
+	for _, seg := range parsed.Segments {
+		for _, fr := range seg.Fragments {
+			for _, traf := range fr.Moof.Trafs {
+				if traf.Tfhd.TrackID != 1 {
+					continue
+				}
+				st := fragStat{idx: fi, tfdt: traf.Tfdt.BaseMediaDecodeTime()}
+				off := uint64(0)
+				for _, trun := range traf.Truns {
+					for _, s := range trun.Samples {
+						st.nSamp++
+						if (s.Flags>>24)&0x03 == 0x02 {
+							st.nKeys++
+							keyTimes = append(keyTimes, st.tfdt+off)
+						}
+						if s.Dur == 0 {
+							st.zeroDur++
+						}
+						off += uint64(s.Dur)
+					}
+				}
+				st.dur = off
+				d := st.dur
+				if d == 0 {
+					d = 1
+				}
+				st.fps = float64(st.nSamp) * float64(videoTimescale) / float64(d)
+				fpsArr = append(fpsArr, st.fps)
+				if havePrev && st.tfdt != prevEnd {
+					tfdtGaps++
+				}
+				prevEnd = st.tfdt + st.dur
+				havePrev = true
+				stats = append(stats, st)
+			}
+			fi++
+		}
+	}
+
+	medFps := medianFloat(fpsArr)
+	fmt.Printf("  fragments: %d (video timescale=%d, median %.1f fps)\n", len(stats), videoTimescale, medFps)
+	lowFps := 0
+	totalZero := 0
+	for _, st := range stats {
+		totalZero += st.zeroDur
+		flagStr := ""
+		if medFps > 0 && st.fps < medFps*0.9 {
+			lowFps++
+			flagStr = "  <== LOW FRAME RATE — likely dropped frames"
+		}
+		fmt.Printf("    frag%02d tfdt=%-6d dur=%-5d samples=%-3d keyframes=%d zeroDur=%d fps=%.1f%s\n",
+			st.idx, st.tfdt, st.dur, st.nSamp, st.nKeys, st.zeroDur, st.fps, flagStr)
+	}
+
+	var gaps []uint64
+	for i := 1; i < len(keyTimes); i++ {
+		gaps = append(gaps, keyTimes[i]-keyTimes[i-1])
+	}
+	irregular := 0
+	if len(gaps) > 0 {
+		med := medianUint(gaps)
+		mn, mx := gaps[0], gaps[0]
+		for _, g := range gaps {
+			if g < mn {
+				mn = g
+			}
+			if g > mx {
+				mx = g
+			}
+			// Flag intervals that deviate by more than ~50% from the median GOP.
+			if med > 0 && (g*2 > med*3 || g*2 < med) {
+				irregular++
+			}
+		}
+		fmt.Printf("  keyframe gaps: min=%d median=%d max=%d  irregular=%d/%d\n", mn, med, mx, irregular, len(gaps))
+	}
+	fmt.Printf("  tfdt discontinuities: %d\n", tfdtGaps)
+	fmt.Printf("  zero-duration samples: %d\n", totalZero)
+
+	fmt.Println("  verdict:")
+	clean := true
+	if audioTracks == 0 {
+		fmt.Println("    - no audio track (expected if this recording is video-only)")
+	}
+	if lowFps > 0 {
+		clean = false
+		fmt.Printf("    - %d fragment(s) have a reduced frame rate (dropped frames) — likely source of the artifacts\n", lowFps)
+	}
+	if irregular > 0 {
+		clean = false
+		fmt.Printf("    - %d irregular keyframe interval(s)\n", irregular)
+	}
+	if tfdtGaps > 0 {
+		clean = false
+		fmt.Printf("    - %d timeline (tfdt) discontinuity(ies)\n", tfdtGaps)
+	}
+	if totalZero > 0 {
+		clean = false
+		fmt.Printf("    - %d zero-duration sample(s)\n", totalZero)
+	}
+	if clean {
+		fmt.Println("    - container structure looks healthy")
+	}
+}
+
+func medianUint(v []uint64) uint64 {
+	if len(v) == 0 {
+		return 0
+	}
+	c := append([]uint64(nil), v...)
+	sort.Slice(c, func(i, j int) bool { return c[i] < c[j] })
+	return c[len(c)/2]
+}
+
+func medianFloat(v []float64) float64 {
+	if len(v) == 0 {
+		return 0
+	}
+	c := append([]float64(nil), v...)
+	sort.Float64s(c)
+	return c[len(c)/2]
+}

machinery/data/config/config.json

@@ -106,9 +106,9 @@
 	"mqtturi": "tcp://mqtt.kerberos.io:1883",
 	"mqtt_username": "",
 	"mqtt_password": "",
-	"stunuri": "stun:turn.kerberos.io:8443",
 	"turn_force": "false",
-	"turnuri": "turn:turn.kerberos.io:8443",
+	"stunuri": "stun:turn-fra1.kerberos.io:3478",
+	"turnuri": "turn:turn-fra1.kerberos.io:3478",
 	"turn_username": "username1",
 	"turn_password": "password1",
 	"heartbeaturi": "",

machinery/src/cloud/cloud.go

@@ -2,6 +2,7 @@ package cloud
 
 import (
 	"bytes"
+	"context"
 	"crypto/tls"
 	"encoding/base64"
 	"encoding/json"
@@ -21,6 +22,7 @@ import (
 	"time"
 
 	"github.com/kerberos-io/agent/machinery/src/capture"
+	"github.com/kerberos-io/agent/machinery/src/cloud/livesnapshot"
 	"github.com/kerberos-io/agent/machinery/src/encryption"
 	"github.com/kerberos-io/agent/machinery/src/log"
 	"github.com/kerberos-io/agent/machinery/src/models"
@@ -528,6 +530,7 @@ loop:
 						"onvif_events_list": %s,
 						"cameraConnected": "%s",
 						"hasBackChannel": "%s",
+						"livePreviewHttp": true,
 						"numberoffiles" : "33",
 						"timestamp" : 1564747908,
 						"cameratype" : "IPCamera",
@@ -684,7 +687,35 @@ func HandleLiveStreamSD(livestreamCursor *packets.QueueCursor, configuration *mo
 				hubKey = config.HubKey
 			}
 
-			lastLivestreamRequest := int64(0)
+			lastLivestreamRequestMQTT := int64(0)
+			lastLivestreamRequestHTTP := int64(0)
+
+			// HTTP transport (preferred when this agent is paired with a Kerberos
+			// Hub): ship preview frames to hub-api over HTTPS instead of pushing
+			// (large, base64) images through the MQTT broker. Viewers opt in per
+			// session via the "http" transport on their keepalive; the legacy MQTT
+			// push is kept for viewers (older frontends) that don't, and as a fallback.
+			region := ""
+			if config.S3 != nil {
+				region = config.S3.Region
+			}
+			var snapshotPublisher *livesnapshot.Publisher
+			if config.HubURI != "" && config.HubKey != "" {
+				snapshotPublisher = livesnapshot.NewPublisher(livesnapshot.PublisherConfig{
+					HubURI:        config.HubURI,
+					HubKey:        config.HubKey,
+					HubPrivateKey: config.HubPrivateKey,
+					Region:        region,
+					DeviceKey:     deviceId,
+				})
+				log.Log.Info("cloud.HandleLiveStreamSD(): HTTP preview transport ENABLED; frames go to " + strings.TrimRight(config.HubURI, "/") + "/storage/snapshot when a viewer requests it (kept off MQTT).")
+			} else {
+				log.Log.Info("cloud.HandleLiveStreamSD(): HTTP preview transport DISABLED (Hub not configured: HubURI/HubKey empty); preview frames are pushed over MQTT.")
+			}
+
+			// Track the transport actually used so we log only when it changes; the
+			// loop runs once per keyframe and logging every frame would be noise.
+			lastTransport := ""
 
 			var cursorError error
 			var pkt packets.Packet
@@ -695,20 +726,74 @@ func HandleLiveStreamSD(livestreamCursor *packets.QueueCursor, configuration *mo
 					continue
 				}
 				now := time.Now().Unix()
+				// Drain both viewer keepalive channels (non-blocking): one for the
+				// HTTP transport, one for the legacy MQTT push.
 				select {
 				case <-communication.HandleLiveSD:
-					lastLivestreamRequest = now
+					lastLivestreamRequestMQTT = now
 				default:
 				}
-				if now-lastLivestreamRequest > 3 {
+				select {
+				case <-communication.HandleLiveSDHTTP:
+					lastLivestreamRequestHTTP = now
+				default:
+				}
+
+				mqttViewerActive := now-lastLivestreamRequestMQTT <= 3
+				httpViewerActive := now-lastLivestreamRequestHTTP <= 3
+				if !mqttViewerActive && !httpViewerActive {
 					continue
 				}
-				log.Log.Info("cloud.HandleLiveStreamSD(): Sending base64 encoded images to MQTT.")
-				img, err := rtspClient.DecodePacket(pkt)
-				if err == nil {
-					imageResized, _ := utils.ResizeImage(&img, uint(config.Capture.IPCamera.BaseWidth), uint(config.Capture.IPCamera.BaseHeight))
-					bytes, _ := utils.ImageToBytes(imageResized)
 
+				img, err := rtspClient.DecodePacket(pkt)
+				if err != nil {
+					continue
+				}
+				imageResized, _ := utils.ResizeImage(&img, uint(config.Capture.IPCamera.BaseWidth), uint(config.Capture.IPCamera.BaseHeight))
+				bytes, _ := utils.ImageToBytes(imageResized)
+
+				// Prefer HTTP for viewers that asked for it. Only if that did not
+				// deliver (Hub not configured, or the upload failed) do we also push
+				// over MQTT, so a new frontend can still fall back to its MQTT path.
+				httpPushed := false
+				var httpErr error
+				if httpViewerActive && snapshotPublisher != nil {
+					ctx, cancel := context.WithTimeout(context.Background(), 4*time.Second)
+					httpErr = snapshotPublisher.PublishSnapshot(ctx, bytes)
+					if httpErr == nil {
+						httpPushed = true
+					}
+					cancel()
+				}
+
+				pushMQTT := mqttViewerActive || (httpViewerActive && !httpPushed)
+
+				// Log only when the effective transport changes, so an operator can
+				// tell at a glance whether a device's preview travels over HTTP or
+				// MQTT (and why it fell back) without per-frame log spam.
+				transport := ""
+				if httpPushed {
+					transport = "http"
+				} else if pushMQTT {
+					transport = "mqtt"
+				}
+				if transport != "" && transport != lastTransport {
+					if transport == "http" {
+						log.Log.Info("cloud.HandleLiveStreamSD(): delivering preview frames over HTTP for device " + deviceId + ".")
+					} else {
+						reason := "viewer requested MQTT (older frontend)"
+						if httpViewerActive && snapshotPublisher == nil {
+							reason = "viewer asked for HTTP but Hub is not configured"
+						} else if httpViewerActive && httpErr != nil {
+							reason = "HTTP upload failed, falling back: " + httpErr.Error()
+						}
+						log.Log.Info("cloud.HandleLiveStreamSD(): delivering preview frames over MQTT for device " + deviceId + " (" + reason + ").")
+					}
+					lastTransport = transport
+				}
+
+				if pushMQTT {
+					log.Log.Debug("cloud.HandleLiveStreamSD(): Sending base64 encoded images to MQTT.")
 					chunking := config.Capture.LiveviewChunking
 
 					if chunking == "true" {

machinery/src/cloud/livehls.go

@@ -0,0 +1,177 @@
+package cloud
+
+import (
+	"time"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+
+	"github.com/kerberos-io/agent/machinery/src/capture"
+	"github.com/kerberos-io/agent/machinery/src/cloud/livehls"
+	"github.com/kerberos-io/agent/machinery/src/log"
+	"github.com/kerberos-io/agent/machinery/src/models"
+	"github.com/kerberos-io/agent/machinery/src/packets"
+)
+
+// hlsViewerTimeoutSeconds is how long the agent keeps shipping live HLS segments
+// after the last viewer keepalive. It is a few seconds longer than the segment
+// duration so a viewer whose keepalive is briefly delayed does not cause the
+// session to flap. When it lapses the session is torn down to stop wasting
+// upload bandwidth when nobody is watching.
+const hlsViewerTimeoutSeconds = 8
+
+// hlsReadyReannounceSeconds throttles how often the agent re-announces an
+// already-ready session over MQTT in response to viewer keepalives. The initial
+// "receive-hls-ready" is a one-shot fired when the first segment lands; a viewer
+// that connects or hard-refreshes after that (while the session is still alive)
+// missed it, so we re-announce on subsequent keepalives. Viewers dedupe by
+// session id, so a re-announce for a session they already play is a no-op. ~2s
+// gets a refreshed viewer playing well within its connection timeout without
+// spamming the control plane.
+const hlsReadyReannounceSeconds = 2
+
+
+// HandleLiveStreamHLS drives the live HLS producer. It mirrors HandleLiveStreamSD:
+// it reads the camera's packet stream from a Latest() cursor, and while a viewer
+// is active (kept alive via communication.HandleLiveHLS) it muxes the packets
+// into CMAF segments and ships them to hub-api, which stores each segment in an
+// ephemeral, short-TTL live window and serves the rolling playlist to viewers.
+//
+// A session is created lazily on the first keyframe seen while a viewer is active
+// and torn down once viewers go away, so an idle camera produces no live traffic.
+func HandleLiveStreamHLS(livestreamCursor *packets.QueueCursor, configuration *models.Configuration, communication *models.Communication, mqttClient mqtt.Client, _ capture.RTSPClient) {
+
+	log.Log.Debug("cloud.HandleLiveStreamHLS(): started")
+
+	config := configuration.Config
+
+	if config.Offline == "true" {
+		log.Log.Debug("cloud.HandleLiveStreamHLS(): stopping as Offline is enabled.")
+		return
+	}
+	if config.Capture.Liveview == "false" {
+		log.Log.Debug("cloud.HandleLiveStreamHLS(): stopping as Liveview is disabled.")
+		return
+	}
+	if config.HubURI == "" || config.HubKey == "" {
+		log.Log.Debug("cloud.HandleLiveStreamHLS(): stopping as the Hub is not configured (HubURI/HubKey).")
+		return
+	}
+
+	hubKey := config.HubKey
+	deviceId := config.Key
+
+	region := ""
+	if config.S3 != nil {
+		region = config.S3.Region
+	}
+
+	publisher := livehls.NewPublisher(livehls.PublisherConfig{
+		HubURI:        config.HubURI,
+		HubKey:        config.HubKey,
+		HubPrivateKey: config.HubPrivateKey,
+		Region:        region,
+		DeviceKey:     deviceId,
+	})
+
+	// Encoded dimensions are only needed for the avcC fallback path (an SPS that
+	// mp4ff's strict parser rejects); the main stream dimensions are a safe value.
+	width := uint16(config.Capture.IPCamera.Width)
+	height := uint16(config.Capture.IPCamera.Height)
+
+	var session *livehls.Session
+	lastViewerRequest := int64(0)
+	lastReadyAnnounce := int64(0)
+
+	var cursorError error
+	var pkt packets.Packet
+
+	for cursorError == nil {
+		pkt, cursorError = livestreamCursor.ReadPacket()
+
+		now := time.Now().Unix()
+		select {
+		case <-communication.HandleLiveHLS:
+			lastViewerRequest = now
+			// A keepalive may come from a viewer that just connected or hard-
+			// refreshed and therefore missed the one-shot readiness announcement
+			// fired when this session's first segment landed. Re-announce (throttled)
+			// so late/refreshed viewers learn the active session id; the frontend
+			// dedupes by session id, so this is a no-op for viewers already playing.
+			if session != nil && session.IsReady() && now-lastReadyAnnounce >= hlsReadyReannounceSeconds {
+				publishHLSReady(configuration, mqttClient, hubKey, deviceId, session.SessionID())
+				lastReadyAnnounce = now
+			}
+		default:
+		}
+
+		viewerActive := now-lastViewerRequest <= hlsViewerTimeoutSeconds
+
+		if !viewerActive {
+			// No viewer: stop and discard the session so we stop shipping segments.
+			if session != nil {
+				_ = session.Close()
+				log.Log.Info("cloud.HandleLiveStreamHLS(): no active viewers, stopped live HLS session " + session.SessionID())
+				session = nil
+			}
+			continue
+		}
+
+		if len(pkt.Data) == 0 || !pkt.IsVideo {
+			continue
+		}
+
+		// Start a session lazily, but only on a keyframe so the first segment opens
+		// on a random-access point.
+		if session == nil {
+			if !pkt.IsKeyFrame {
+				continue
+			}
+			session = livehls.NewSession(publisher, livehls.SessionOptions{
+				Codec:    pkt.Codec,
+				SPSNALUs: config.Capture.IPCamera.SPSNALUs,
+				PPSNALUs: config.Capture.IPCamera.PPSNALUs,
+				VPSNALUs: config.Capture.IPCamera.VPSNALUs,
+				Width:    width,
+				Height:   height,
+			})
+			session.SetOnReady(func(sessionID string) {
+				log.Log.Info("cloud.HandleLiveStreamHLS(): live HLS session ready, announcing " + sessionID)
+				publishHLSReady(configuration, mqttClient, hubKey, deviceId, sessionID)
+				lastReadyAnnounce = time.Now().Unix()
+			})
+			log.Log.Info("cloud.HandleLiveStreamHLS(): started live HLS session " + session.SessionID())
+		}
+
+		if err := session.WritePacket(pkt); err != nil {
+			log.Log.Error("cloud.HandleLiveStreamHLS(): " + err.Error())
+		}
+	}
+
+	if session != nil {
+		_ = session.Close()
+	}
+	log.Log.Debug("cloud.HandleLiveStreamHLS(): finished")
+}
+
+// publishHLSReady announces, over MQTT, that a live HLS session is available so
+// viewers can load the rolling playlist hub-api serves for {device}/{session}.
+func publishHLSReady(configuration *models.Configuration, mqttClient mqtt.Client, hubKey, deviceId, sessionID string) {
+	valueMap := map[string]interface{}{
+		"session": sessionID,
+		"device":  deviceId,
+	}
+	message := models.Message{
+		Payload: models.Payload{
+			Action:   "receive-hls-ready",
+			DeviceId: deviceId,
+			Value:    valueMap,
+		},
+	}
+	payload, err := models.PackageMQTTMessage(configuration, message)
+	if err == nil {
+		mqttClient.Publish("kerberos/hub/"+hubKey, 0, false, payload)
+		log.Log.Info("cloud.HandleLiveStreamHLS(): announced live HLS session " + sessionID)
+	} else {
+		log.Log.Error("cloud.HandleLiveStreamHLS(): failed to package receive-hls-ready message: " + err.Error())
+	}
+}

machinery/src/cloud/livehls/publisher.go

@@ -0,0 +1,202 @@
+// Package livehls implements the agent-side producer for live HLS streaming.
+//
+// It complements the recording pipeline: where recordings are muxed into one
+// fragmented MP4 and uploaded resumably (TUS) when complete, live HLS ships a
+// continuous series of small, independently-decodable CMAF segments to hub-api
+// the instant each is produced, so a browser can play a near-live HLS stream
+// without WebRTC/TURN (outbound HTTPS only).
+//
+// The wire contract (agent -> hub-api) intentionally mirrors the existing
+// header-based storage convention (X-Kerberos-Storage-Device / -FileName, plus
+// the Hub public/private key auth headers). hub-api authenticates the agent and
+// stores each segment in an ephemeral, short-TTL live window keyed by
+// {device}/{session}, which it serves straight back to the browser. The live
+// window is deliberately kept out of the vault and the recordings collection;
+// durable archival/DVR is a separate, later concern.
+//
+// Unlike recordings, live segments are NOT uploaded resumably: a 1-2s segment
+// that fails to upload is stale by the time a retry would land, so the publisher
+// is fire-and-forget and drops on failure (logged) rather than blocking the live
+// pipeline behind a retry/handshake.
+package livehls
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/kerberos-io/agent/machinery/src/log"
+	"github.com/kerberos-io/agent/machinery/src/video"
+)
+
+const (
+	// liveIngestPath is the hub-api endpoint that accepts a single live segment
+	// (or the init segment) and stores it in the ephemeral live window. hub-api
+	// distinguishes init vs media segment and the object name via the
+	// X-Kerberos-Live-* headers below, keeping a single route (mirrors the
+	// existing /storage/upload convention).
+	liveIngestPath = "/storage/live"
+
+	// Object names within a session. The init segment (ftyp+moov) is uploaded
+	// once per session; media segments are seg-<sequence>.m4s.
+	initObjectName = "init.mp4"
+
+	contentTypeInit    = "video/mp4"
+	contentTypeSegment = "video/iso.segment"
+
+	// Header names for the live ingest contract.
+	headerHubPublicKey  = "X-Kerberos-Hub-PublicKey"
+	headerHubPrivateKey = "X-Kerberos-Hub-PrivateKey"
+	headerHubRegion     = "X-Kerberos-Hub-Region"
+	headerStorageDevice = "X-Kerberos-Storage-Device"
+	headerLiveSession   = "X-Kerberos-Live-Session"
+	headerLiveName      = "X-Kerberos-Live-Name"
+	headerLiveSequence  = "X-Kerberos-Live-Sequence"
+	headerLiveDuration  = "X-Kerberos-Live-Duration"
+
+	// defaultPublishTimeout bounds a single segment upload. A live segment that
+	// cannot be delivered within roughly its own duration is stale, so the upload
+	// is abandoned (dropped) rather than allowed to back up the pipeline.
+	defaultPublishTimeout = 4 * time.Second
+)
+
+// PublisherConfig carries the hub endpoint and credentials needed to ship live
+// segments. It is populated from the agent's models.Config (HubURI/HubKey/...).
+type PublisherConfig struct {
+	HubURI        string // base hub-api URL, e.g. https://api.hub.example.com
+	HubKey        string // Hub public key (X-Kerberos-Hub-PublicKey)
+	HubPrivateKey string // Hub private key (X-Kerberos-Hub-PrivateKey)
+	Region        string // storage region (X-Kerberos-Hub-Region), may be empty
+	DeviceKey     string // device/camera key (X-Kerberos-Storage-Device)
+
+	// Timeout optionally overrides defaultPublishTimeout (used by tests).
+	Timeout time.Duration
+	// HTTPClient optionally injects a client (used by tests). When nil a
+	// redirect-credential-stripping client is created.
+	HTTPClient *http.Client
+}
+
+// Publisher ships init and media segments to hub-api over plain HTTP POST.
+//
+// It is safe for sequential use from a single live-stream goroutine. Methods are
+// fire-and-forget: they return an error for the caller to log, but the caller is
+// expected to continue (drop-on-fail) rather than retry.
+type Publisher struct {
+	cfg    PublisherConfig
+	client *http.Client
+}
+
+// NewPublisher builds a Publisher. The HTTP client strips the Hub credential
+// headers on a cross-host redirect (net/http does this for standard auth headers
+// but not custom-named ones), matching the recording upload client.
+func NewPublisher(cfg PublisherConfig) *Publisher {
+	client := cfg.HTTPClient
+	if client == nil {
+		timeout := cfg.Timeout
+		if timeout <= 0 {
+			timeout = defaultPublishTimeout
+		}
+		client = &http.Client{
+			Timeout:       timeout,
+			CheckRedirect: stripHubCredentialsOnCrossHostRedirect,
+		}
+	}
+	return &Publisher{cfg: cfg, client: client}
+}
+
+// PublishInit uploads the session's init segment (ftyp+moov). It must be called
+// (and succeed) before the player can use any media segment, so the caller
+// should treat a failure here as "session not yet established" and retry on the
+// next init opportunity rather than shipping media segments blindly.
+func (p *Publisher) PublishInit(ctx context.Context, sessionID string, data []byte) error {
+	return p.post(ctx, postParams{
+		sessionID:   sessionID,
+		name:        initObjectName,
+		contentType: contentTypeInit,
+		body:        data,
+	})
+}
+
+// PublishSegment uploads one media segment (styp+moof+mdat). The segment's
+// sequence number and duration travel in headers so hub-api can update the
+// rolling playlist window without parsing the box structure.
+func (p *Publisher) PublishSegment(ctx context.Context, sessionID string, seg video.LiveSegment) error {
+	return p.post(ctx, postParams{
+		sessionID:   sessionID,
+		name:        fmt.Sprintf("seg-%d.m4s", seg.SequenceNumber),
+		sequence:    seg.SequenceNumber,
+		durationMs:  seg.DurationMs,
+		hasSegment:  true,
+		contentType: contentTypeSegment,
+		body:        seg.Data,
+	})
+}
+
+type postParams struct {
+	sessionID   string
+	name        string
+	sequence    uint32
+	durationMs  uint64
+	hasSegment  bool
+	contentType string
+	body        []byte
+}
+
+// post performs a single fire-and-forget upload to the live ingest endpoint.
+func (p *Publisher) post(ctx context.Context, params postParams) error {
+	if p.cfg.HubURI == "" {
+		return fmt.Errorf("livehls: HubURI not configured")
+	}
+	if params.sessionID == "" {
+		return fmt.Errorf("livehls: empty session id")
+	}
+
+	url := strings.TrimRight(p.cfg.HubURI, "/") + liveIngestPath
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(params.body))
+	if err != nil {
+		return fmt.Errorf("livehls: build request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", params.contentType)
+	req.Header.Set(headerStorageDevice, p.cfg.DeviceKey)
+	req.Header.Set(headerLiveSession, params.sessionID)
+	req.Header.Set(headerLiveName, params.name)
+	if params.hasSegment {
+		req.Header.Set(headerLiveSequence, strconv.FormatUint(uint64(params.sequence), 10))
+		req.Header.Set(headerLiveDuration, strconv.FormatUint(params.durationMs, 10))
+	}
+	req.Header.Set(headerHubPublicKey, p.cfg.HubKey)
+	req.Header.Set(headerHubPrivateKey, p.cfg.HubPrivateKey)
+	req.Header.Set(headerHubRegion, p.cfg.Region)
+
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return fmt.Errorf("livehls: upload %s: %w", params.name, err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return fmt.Errorf("livehls: upload %s rejected: %s", params.name, resp.Status)
+	}
+	log.Log.Debug("livehls.Publisher.post(): shipped " + params.name + " for session " + params.sessionID)
+	return nil
+}
+
+// stripHubCredentialsOnCrossHostRedirect removes the Hub credential headers when
+// a redirect crosses to a different host. net/http strips standard sensitive
+// headers on a cross-host redirect but not custom-named ones, so without this the
+// Hub keys could leak to a redirect target.
+func stripHubCredentialsOnCrossHostRedirect(req *http.Request, via []*http.Request) error {
+	if len(via) == 0 {
+		return nil
+	}
+	if req.URL.Host != via[0].URL.Host {
+		req.Header.Del(headerHubPrivateKey)
+		req.Header.Del(headerHubPublicKey)
+	}
+	return nil
+}

machinery/src/cloud/livehls/publisher_test.go

@@ -0,0 +1,312 @@
+package livehls
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/kerberos-io/agent/machinery/src/packets"
+	"github.com/kerberos-io/agent/machinery/src/video"
+)
+
+// captured records one received upload for assertions.
+type captured struct {
+	path        string
+	method      string
+	contentType string
+	device      string
+	session     string
+	name        string
+	sequence    string
+	duration    string
+	hubPublic   string
+	hubPrivate  string
+	region      string
+	body        []byte
+}
+
+// newCapturingServer returns an httptest server that records every upload and
+// replies with the given status code.
+func newCapturingServer(t *testing.T, status int) (*httptest.Server, *[]captured, *sync.Mutex) {
+	t.Helper()
+	var mu sync.Mutex
+	var got []captured
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, _ := io.ReadAll(r.Body)
+		mu.Lock()
+		got = append(got, captured{
+			path:        r.URL.Path,
+			method:      r.Method,
+			contentType: r.Header.Get("Content-Type"),
+			device:      r.Header.Get(headerStorageDevice),
+			session:     r.Header.Get(headerLiveSession),
+			name:        r.Header.Get(headerLiveName),
+			sequence:    r.Header.Get(headerLiveSequence),
+			duration:    r.Header.Get(headerLiveDuration),
+			hubPublic:   r.Header.Get(headerHubPublicKey),
+			hubPrivate:  r.Header.Get(headerHubPrivateKey),
+			region:      r.Header.Get(headerHubRegion),
+			body:        body,
+		})
+		mu.Unlock()
+		w.WriteHeader(status)
+	}))
+	t.Cleanup(srv.Close)
+	return srv, &got, &mu
+}
+
+func testPublisher(hubURI string) *Publisher {
+	return NewPublisher(PublisherConfig{
+		HubURI:        hubURI,
+		HubKey:        "pub-key",
+		HubPrivateKey: "priv-key",
+		Region:        "eu-west",
+		DeviceKey:     "cam-1",
+		Timeout:       2 * time.Second,
+	})
+}
+
+func TestPublisherPublishInitSendsContractHeaders(t *testing.T) {
+	srv, got, mu := newCapturingServer(t, http.StatusOK)
+	p := testPublisher(srv.URL)
+
+	if err := p.PublishInit(context.Background(), "sess-1", []byte("INITBYTES")); err != nil {
+		t.Fatalf("PublishInit: %v", err)
+	}
+
+	mu.Lock()
+	defer mu.Unlock()
+	if len(*got) != 1 {
+		t.Fatalf("server received %d requests, want 1", len(*got))
+	}
+	c := (*got)[0]
+	if c.method != http.MethodPost {
+		t.Errorf("method=%s, want POST", c.method)
+	}
+	if c.path != liveIngestPath {
+		t.Errorf("path=%s, want %s", c.path, liveIngestPath)
+	}
+	if c.contentType != contentTypeInit {
+		t.Errorf("content-type=%s, want %s", c.contentType, contentTypeInit)
+	}
+	if c.device != "cam-1" {
+		t.Errorf("device=%s, want cam-1", c.device)
+	}
+	if c.session != "sess-1" {
+		t.Errorf("session=%s, want sess-1", c.session)
+	}
+	if c.name != initObjectName {
+		t.Errorf("name=%s, want %s", c.name, initObjectName)
+	}
+	if c.hubPublic != "pub-key" || c.hubPrivate != "priv-key" || c.region != "eu-west" {
+		t.Errorf("auth headers wrong: pub=%q priv=%q region=%q", c.hubPublic, c.hubPrivate, c.region)
+	}
+	if string(c.body) != "INITBYTES" {
+		t.Errorf("body=%q, want INITBYTES", string(c.body))
+	}
+	// init must NOT carry segment-only headers.
+	if c.sequence != "" || c.duration != "" {
+		t.Errorf("init should not send sequence/duration, got seq=%q dur=%q", c.sequence, c.duration)
+	}
+}
+
+func TestPublisherPublishSegmentSendsSequenceAndDuration(t *testing.T) {
+	srv, got, mu := newCapturingServer(t, http.StatusOK)
+	p := testPublisher(srv.URL)
+
+	seg := video.LiveSegment{SequenceNumber: 7, DurationMs: 1960, Data: []byte("SEGMENT")}
+	if err := p.PublishSegment(context.Background(), "sess-9", seg); err != nil {
+		t.Fatalf("PublishSegment: %v", err)
+	}
+
+	mu.Lock()
+	defer mu.Unlock()
+	c := (*got)[0]
+	if c.contentType != contentTypeSegment {
+		t.Errorf("content-type=%s, want %s", c.contentType, contentTypeSegment)
+	}
+	if c.name != "seg-7.m4s" {
+		t.Errorf("name=%s, want seg-7.m4s", c.name)
+	}
+	if c.sequence != "7" {
+		t.Errorf("sequence=%s, want 7", c.sequence)
+	}
+	if c.duration != "1960" {
+		t.Errorf("duration=%s, want 1960", c.duration)
+	}
+	if string(c.body) != "SEGMENT" {
+		t.Errorf("body=%q, want SEGMENT", string(c.body))
+	}
+}
+
+func TestPublisherReturnsErrorOnNon2xx(t *testing.T) {
+	srv, _, _ := newCapturingServer(t, http.StatusInternalServerError)
+	p := testPublisher(srv.URL)
+
+	err := p.PublishSegment(context.Background(), "s", video.LiveSegment{SequenceNumber: 1, Data: []byte("x")})
+	if err == nil {
+		t.Fatal("expected an error on 500 response")
+	}
+}
+
+func TestPublisherErrorsWithoutHubURI(t *testing.T) {
+	p := NewPublisher(PublisherConfig{DeviceKey: "cam"})
+	if err := p.PublishInit(context.Background(), "s", []byte("x")); err == nil {
+		t.Fatal("expected error when HubURI is empty")
+	}
+}
+
+// makeAnnexBVideoPacket builds a synthetic capture packet carrying one Annex B
+// H.264 access unit at the given decode time (ms).
+func makeAnnexBVideoPacket(isKey bool, timeMs int64) packets.Packet {
+	nalType := byte(0x01)
+	if isKey {
+		nalType = 0x65
+	}
+	data := []byte{0x00, 0x00, 0x00, 0x01, nalType}
+	for i := 0; i < 80; i++ {
+		data = append(data, byte(i))
+	}
+	return packets.Packet{
+		IsVideo:    true,
+		IsKeyFrame: isKey,
+		Codec:      "H264",
+		Data:       data,
+		TimeLegacy: time.Duration(timeMs) * time.Millisecond,
+	}
+}
+
+func TestSessionShipsInitThenSegmentsAndFiresReady(t *testing.T) {
+	srv, got, mu := newCapturingServer(t, http.StatusOK)
+	p := testPublisher(srv.URL)
+
+	sess := NewSession(p, SessionOptions{
+		Codec:           "H264",
+		SPSNALUs:        [][]byte{liveTestSPSForSession()},
+		PPSNALUs:        [][]byte{{0x68, 0xce, 0x38, 0x80}},
+		Width:           640,
+		Height:          480,
+		TargetSegmentMs: 2000,
+	})
+
+	var readyCalls int
+	var readySession string
+	sess.SetOnReady(func(id string) {
+		readyCalls++
+		readySession = id
+	})
+
+	// 4 GOPs of 25 frames @ 40ms = 1s GOPs => with 2s target, 2 segments emitted
+	// during streaming and a final one on Close.
+	const gopFrames, gops = 25, 4
+	for i := 0; i < gopFrames*gops; i++ {
+		isKey := i%gopFrames == 0
+		pkt := makeAnnexBVideoPacket(isKey, int64(i*40))
+		if err := sess.WritePacket(pkt); err != nil {
+			t.Fatalf("WritePacket(%d): %v", i, err)
+		}
+	}
+	// A non-video packet must be ignored.
+	if err := sess.WritePacket(packets.Packet{IsAudio: true, Data: []byte{1, 2, 3}}); err != nil {
+		t.Fatalf("WritePacket(audio): %v", err)
+	}
+	if err := sess.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	var initCount, segCount int
+	for _, c := range *got {
+		if c.name == initObjectName {
+			initCount++
+			if string(c.body[4:8]) != "ftyp" {
+				t.Errorf("init body is not an ftyp box: % x", c.body[:12])
+			}
+		} else {
+			segCount++
+			if c.session != sess.SessionID() {
+				t.Errorf("segment session=%s, want %s", c.session, sess.SessionID())
+			}
+		}
+	}
+	if initCount != 1 {
+		t.Errorf("init uploaded %d times, want exactly 1", initCount)
+	}
+	if segCount < 2 {
+		t.Errorf("got %d segment uploads, want >= 2", segCount)
+	}
+	if readyCalls != 1 {
+		t.Errorf("OnReady fired %d times, want exactly 1", readyCalls)
+	}
+	if readySession != sess.SessionID() {
+		t.Errorf("OnReady session=%s, want %s", readySession, sess.SessionID())
+	}
+}
+
+func TestSessionRetriesInitWhenFirstAttemptFails(t *testing.T) {
+	// Server fails the first N requests, then succeeds. This proves init is
+	// re-attempted (not dropped) so the session can still establish.
+	var mu sync.Mutex
+	var inits, segs int
+	failFirst := 1
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		mu.Lock()
+		defer mu.Unlock()
+		name := r.Header.Get(headerLiveName)
+		if name == initObjectName {
+			inits++
+			if inits <= failFirst {
+				w.WriteHeader(http.StatusBadGateway)
+				return
+			}
+		} else {
+			segs++
+		}
+		w.WriteHeader(http.StatusOK)
+	}))
+	t.Cleanup(srv.Close)
+
+	sess := NewSession(testPublisher(srv.URL), SessionOptions{
+		Codec:    "H264",
+		SPSNALUs: [][]byte{liveTestSPSForSession()},
+		PPSNALUs: [][]byte{{0x68, 0xce, 0x38, 0x80}},
+		Width:    640,
+		Height:   480,
+	})
+
+	var ready int
+	sess.SetOnReady(func(string) { ready++ })
+
+	for i := 0; i < 60; i++ {
+		isKey := i%25 == 0
+		if err := sess.WritePacket(makeAnnexBVideoPacket(isKey, int64(i*40))); err != nil {
+			t.Fatalf("WritePacket(%d): %v", i, err)
+		}
+	}
+	if err := sess.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	mu.Lock()
+	defer mu.Unlock()
+	if inits < 2 {
+		t.Errorf("init attempted %d times, want >= 2 (first failed then retried)", inits)
+	}
+	if segs < 1 {
+		t.Errorf("no segments delivered after init recovered (segs=%d)", segs)
+	}
+	if ready != 1 {
+		t.Errorf("OnReady fired %d times, want 1", ready)
+	}
+}
+
+// liveTestSPSForSession is the known-good baseline SPS reused across tests.
+func liveTestSPSForSession() []byte {
+	return []byte{0x67, 0x42, 0xc0, 0x1e, 0xd9, 0x00, 0xa0, 0x47, 0xfe, 0xc8}
+}

machinery/src/cloud/livehls/session.go

@@ -0,0 +1,255 @@
+package livehls
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/kerberos-io/agent/machinery/src/log"
+	"github.com/kerberos-io/agent/machinery/src/packets"
+	"github.com/kerberos-io/agent/machinery/src/video"
+)
+
+// DefaultTargetSegmentMs is the nominal live segment length. ~2s keeps standard
+// HLS latency reasonable (a player typically buffers ~3 segments) while staying
+// large enough that per-segment HTTP overhead is negligible.
+const DefaultTargetSegmentMs = 2000
+
+// Session ties a video.LiveSegmenter to a Publisher: it converts capture packets
+// into CMAF segments and ships each one to hub-api. Exactly one init segment is
+// delivered per session (re-attempted until it lands), after which media
+// segments are published and the OnReady signal fires once so the control plane
+// (MQTT) can tell viewers the live playlist exists.
+//
+// A Session is driven from a single goroutine (the live-stream loop); its methods
+// are not safe for concurrent use except SessionID, which is immutable.
+type Session struct {
+	id        string
+	publisher *Publisher
+	segmenter *video.LiveSegmenter
+
+	// newContext produces the per-upload context (timeout). Overridable in tests.
+	newContext func() (context.Context, context.CancelFunc)
+
+	mu            sync.Mutex
+	initBytes     []byte
+	initPublished bool
+	// lastInitAt is when the init segment was last (re)uploaded. The init is
+	// re-sent periodically so its short TTL in the hub live window never lapses
+	// mid-session; see refreshInitIfStale.
+	lastInitAt time.Time
+	readyFired bool
+	onReady    func(sessionID string)
+}
+
+// SessionOptions configures a live HLS session.
+type SessionOptions struct {
+	Codec           string   // "H264" or "H265"
+	SPSNALUs        [][]byte // parameter sets (raw or Annex B)
+	PPSNALUs        [][]byte //
+	VPSNALUs        [][]byte // H.265 only
+	Width           uint16   // encoded width (for the avcC fallback path)
+	Height          uint16   // encoded height
+	TargetSegmentMs uint64   // 0 => DefaultTargetSegmentMs
+}
+
+// NewSession builds a session with a fresh random id and wires the segmenter's
+// init/segment callbacks to the publisher.
+func NewSession(publisher *Publisher, opts SessionOptions) *Session {
+	target := opts.TargetSegmentMs
+	if target == 0 {
+		target = DefaultTargetSegmentMs
+	}
+	seg := video.NewLiveSegmenter(opts.Codec, opts.SPSNALUs, opts.PPSNALUs, opts.VPSNALUs, target)
+	seg.SetDimensions(opts.Width, opts.Height)
+
+	s := &Session{
+		id:        newSessionID(),
+		publisher: publisher,
+		segmenter: seg,
+		newContext: func() (context.Context, context.CancelFunc) {
+			return context.WithTimeout(context.Background(), defaultPublishTimeout)
+		},
+	}
+
+	// The segmenter emits the init segment exactly once; capture it and try to
+	// ship it. Failures here are non-fatal - publishInitIfNeeded re-attempts
+	// before the next media segment so a transient hub hiccup at startup does not
+	// permanently break the session.
+	seg.OnInit = func(initBytes []byte) error {
+		s.mu.Lock()
+		s.initBytes = append([]byte(nil), initBytes...)
+		s.mu.Unlock()
+		s.publishInitIfNeeded()
+		return nil
+	}
+
+	// Each completed media segment is shipped. We only publish a segment once the
+	// init segment has landed (a media segment is useless without it), and we fire
+	// OnReady after the first successfully shipped segment.
+	seg.OnSegment = func(segment video.LiveSegment) error {
+		if !s.publishInitIfNeeded() {
+			log.Log.Warning("livehls.Session: dropping segment " +
+				fmt.Sprintf("%d", segment.SequenceNumber) + " because init has not been delivered yet")
+			return nil
+		}
+		ctx, cancel := s.newContext()
+		defer cancel()
+		if err := s.publisher.PublishSegment(ctx, s.id, segment); err != nil {
+			log.Log.Warning("livehls.Session: " + err.Error())
+			return nil
+		}
+		s.fireReadyOnce()
+		// Keep the (write-once) init segment from ageing out of the live window
+		// while the session is still producing media.
+		s.refreshInitIfStale()
+		return nil
+	}
+
+	return s
+}
+
+// SessionID returns the immutable session identifier used in object keys and the
+// MQTT ready signal.
+func (s *Session) SessionID() string { return s.id }
+
+// IsReady reports whether the session has delivered its init segment and at
+// least one media segment, i.e. the playlist hub-api serves is now playable. It
+// lets the live-stream loop re-announce "receive-hls-ready" to viewers that join
+// or hard-refresh after the initial one-shot signal (which they would otherwise
+// never receive, leaving the stream blank until the session is recreated).
+func (s *Session) IsReady() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.readyFired
+}
+
+// SetOnReady registers a callback fired exactly once, after the first media
+// segment has been successfully delivered. Used to publish the MQTT
+// "receive-hls-ready" signal so viewers can load the playlist.
+func (s *Session) SetOnReady(fn func(sessionID string)) {
+	s.mu.Lock()
+	s.onReady = fn
+	s.mu.Unlock()
+}
+
+// WritePacket feeds one capture packet into the segmenter. Non-video packets are
+// ignored (the spike is video-only). The decode timestamp is derived exactly as
+// the recording muxer does: DTS = PTS - compositionOffset, with the composition
+// offset forwarded for correct B-frame presentation order.
+func (s *Session) WritePacket(pkt packets.Packet) error {
+	if !pkt.IsVideo {
+		return nil
+	}
+	pts := uint64(pkt.TimeLegacy.Milliseconds())
+	compositionOffset := pkt.CompositionTime
+	dts := pts
+	if compositionOffset > 0 && uint64(compositionOffset) <= pts {
+		dts = pts - uint64(compositionOffset)
+	} else if compositionOffset < 0 || uint64(compositionOffset) > pts {
+		// Guard against invalid offsets to avoid producing a CTS (DTS+CTO) jump.
+		compositionOffset = 0
+	}
+	return s.segmenter.WriteSample(pkt.IsKeyFrame, pkt.Data, dts, int32(compositionOffset))
+}
+
+// Close flushes any buffered sample and ships the final segment.
+func (s *Session) Close() error {
+	return s.segmenter.Close()
+}
+
+// publishInitIfNeeded ensures the init segment has been delivered, attempting an
+// upload if it has not. Returns true once init is known to be published.
+func (s *Session) publishInitIfNeeded() bool {
+	s.mu.Lock()
+	if s.initPublished {
+		s.mu.Unlock()
+		return true
+	}
+	initBytes := s.initBytes
+	s.mu.Unlock()
+
+	if len(initBytes) == 0 {
+		return false
+	}
+
+	ctx, cancel := s.newContext()
+	defer cancel()
+	if err := s.publisher.PublishInit(ctx, s.id, initBytes); err != nil {
+		log.Log.Warning("livehls.Session: init upload failed, will retry: " + err.Error())
+		return false
+	}
+
+	s.mu.Lock()
+	s.initPublished = true
+	s.lastInitAt = time.Now()
+	s.mu.Unlock()
+	log.Log.Info("livehls.Session: init segment delivered for session " + s.id)
+	return true
+}
+
+// initRefreshInterval is how often the init segment is re-uploaded so its TTL in
+// the hub-api live window never lapses mid-session. The init segment is otherwise
+// written only once per session; because the live window expires objects after a
+// short TTL (LiveSegmentTTLSeconds, 45s on the hub) the init would age out after
+// ~1 minute and the playlist's #EXT-X-MAP would start 404ing, stalling playback.
+// Re-uploading well inside that TTL keeps the init alive for the life of the
+// session while still letting it expire naturally once the session ends.
+const initRefreshInterval = 15 * time.Second
+
+// refreshInitIfStale re-uploads the init segment if it has not been refreshed
+// within initRefreshInterval, keeping its created_at (and thus its TTL) current
+// for as long as the session is producing segments. It is a no-op until the init
+// has first been published. Failures are non-fatal: the next segment retries.
+func (s *Session) refreshInitIfStale() {
+	s.mu.Lock()
+	if !s.initPublished || time.Since(s.lastInitAt) < initRefreshInterval {
+		s.mu.Unlock()
+		return
+	}
+	initBytes := s.initBytes
+	s.mu.Unlock()
+
+	if len(initBytes) == 0 {
+		return
+	}
+
+	ctx, cancel := s.newContext()
+	defer cancel()
+	if err := s.publisher.PublishInit(ctx, s.id, initBytes); err != nil {
+		log.Log.Warning("livehls.Session: init refresh failed, will retry: " + err.Error())
+		return
+	}
+
+	s.mu.Lock()
+	s.lastInitAt = time.Now()
+	s.mu.Unlock()
+	log.Log.Debug("livehls.Session: refreshed init segment TTL for session " + s.id)
+}
+
+// fireReadyOnce invokes the OnReady callback the first time it is called.
+func (s *Session) fireReadyOnce() {
+	s.mu.Lock()
+	if s.readyFired || s.onReady == nil {
+		s.mu.Unlock()
+		return
+	}
+	s.readyFired = true
+	fn := s.onReady
+	s.mu.Unlock()
+	fn(s.id)
+}
+
+// newSessionID returns a short, unique, URL-safe session identifier of the form
+// <unix-seconds>-<random-hex>.
+func newSessionID() string {
+	b := make([]byte, 4)
+	if _, err := rand.Read(b); err != nil {
+		// rand.Read essentially never fails; fall back to a time-only id.
+		return fmt.Sprintf("%d", time.Now().UnixNano())
+	}
+	return fmt.Sprintf("%d-%s", time.Now().Unix(), hex.EncodeToString(b))
+}

machinery/src/cloud/livesnapshot/publisher.go

@@ -0,0 +1,151 @@
+// Package livesnapshot implements the agent-side producer for the live-view
+// "preview" (SD) mode over HTTP.
+//
+// Historically the preview pipeline shipped each resized keyframe (a base64
+// JPEG, often chunked) to viewers over the MQTT broker. MQTT is a control plane
+// for small messages, so pushing ~1 image/second of base64 image data per
+// watched camera congests the broker and delays genuine control traffic. This
+// package moves those frames off MQTT: the agent POSTs the latest resized JPEG
+// straight to hub-api over plain HTTPS (outbound only), and viewers fetch it
+// back with their session token. Only the tiny "a viewer is watching" keepalive
+// stays on MQTT.
+//
+// The wire contract (agent -> hub-api) deliberately mirrors the live HLS ingest
+// and the existing storage-upload convention (X-Kerberos-Storage-Device plus the
+// Hub public/private key auth headers). hub-api authenticates the agent and
+// stores the frame in an ephemeral, short-TTL per-device slot which it serves
+// straight back to authorized viewers; the frame never enters the vault or the
+// recordings collection.
+//
+// Like live HLS segments, a preview frame is worthless once stale: a frame that
+// fails to upload is superseded by the next one a second later, so the publisher
+// is fire-and-forget and drops on failure (logged) rather than retrying.
+package livesnapshot
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/kerberos-io/agent/machinery/src/log"
+)
+
+const (
+	// snapshotIngestPath is the hub-api endpoint that accepts the latest preview
+	// frame and stores it in the device's ephemeral snapshot slot (mirrors the
+	// /storage/live live-HLS ingest convention).
+	snapshotIngestPath = "/storage/snapshot"
+
+	contentTypeJPEG = "image/jpeg"
+
+	// Header names for the snapshot ingest contract (shared with live HLS / storage).
+	headerHubPublicKey  = "X-Kerberos-Hub-PublicKey"
+	headerHubPrivateKey = "X-Kerberos-Hub-PrivateKey"
+	headerHubRegion     = "X-Kerberos-Hub-Region"
+	headerStorageDevice = "X-Kerberos-Storage-Device"
+
+	// defaultPublishTimeout bounds a single snapshot upload. Preview frames are
+	// produced roughly once a second from a single goroutine, so an upload that
+	// cannot land in a few seconds is abandoned rather than allowed to back up the
+	// preview loop behind a slow request.
+	defaultPublishTimeout = 4 * time.Second
+)
+
+// PublisherConfig carries the hub endpoint and credentials needed to ship
+// preview frames. It is populated from the agent's models.Config (the same
+// HubURI/HubKey/HubPrivateKey used by recordings and live HLS).
+type PublisherConfig struct {
+	HubURI        string // base hub-api URL, e.g. https://api.hub.example.com
+	HubKey        string // Hub public key (X-Kerberos-Hub-PublicKey)
+	HubPrivateKey string // Hub private key (X-Kerberos-Hub-PrivateKey)
+	Region        string // storage region (X-Kerberos-Hub-Region), may be empty
+	DeviceKey     string // device/camera key (X-Kerberos-Storage-Device)
+
+	// Timeout optionally overrides defaultPublishTimeout (used by tests).
+	Timeout time.Duration
+	// HTTPClient optionally injects a client (used by tests). When nil a
+	// redirect-credential-stripping client is created.
+	HTTPClient *http.Client
+}
+
+// Publisher ships the latest preview frame to hub-api over plain HTTP POST.
+//
+// It is safe for sequential use from a single live-stream goroutine. PublishSnapshot
+// is fire-and-forget: it returns an error for the caller to log, but the caller is
+// expected to continue (drop-on-fail) rather than retry.
+type Publisher struct {
+	cfg    PublisherConfig
+	client *http.Client
+}
+
+// NewPublisher builds a Publisher. The HTTP client strips the Hub credential
+// headers on a cross-host redirect (net/http does this for standard auth headers
+// but not custom-named ones), matching the recording/live-HLS upload clients.
+func NewPublisher(cfg PublisherConfig) *Publisher {
+	client := cfg.HTTPClient
+	if client == nil {
+		timeout := cfg.Timeout
+		if timeout <= 0 {
+			timeout = defaultPublishTimeout
+		}
+		client = &http.Client{
+			Timeout:       timeout,
+			CheckRedirect: stripHubCredentialsOnCrossHostRedirect,
+		}
+	}
+	return &Publisher{cfg: cfg, client: client}
+}
+
+// PublishSnapshot uploads a single resized preview frame (JPEG) as the device's
+// latest snapshot. It overwrites whatever frame was there before, so viewers
+// always fetch the most recent frame.
+func (p *Publisher) PublishSnapshot(ctx context.Context, jpeg []byte) error {
+	if p.cfg.HubURI == "" {
+		return fmt.Errorf("livesnapshot: HubURI not configured")
+	}
+	if len(jpeg) == 0 {
+		return fmt.Errorf("livesnapshot: empty snapshot body")
+	}
+
+	url := strings.TrimRight(p.cfg.HubURI, "/") + snapshotIngestPath
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(jpeg))
+	if err != nil {
+		return fmt.Errorf("livesnapshot: build request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", contentTypeJPEG)
+	req.Header.Set(headerStorageDevice, p.cfg.DeviceKey)
+	req.Header.Set(headerHubPublicKey, p.cfg.HubKey)
+	req.Header.Set(headerHubPrivateKey, p.cfg.HubPrivateKey)
+	req.Header.Set(headerHubRegion, p.cfg.Region)
+
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return fmt.Errorf("livesnapshot: upload snapshot: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return fmt.Errorf("livesnapshot: upload snapshot rejected: %s", resp.Status)
+	}
+	log.Log.Debug("livesnapshot.Publisher.PublishSnapshot(): shipped preview frame for device " + p.cfg.DeviceKey)
+	return nil
+}
+
+// stripHubCredentialsOnCrossHostRedirect removes the Hub credential headers when
+// a redirect crosses to a different host. net/http strips standard sensitive
+// headers on a cross-host redirect but not custom-named ones, so without this the
+// Hub keys could leak to a redirect target.
+func stripHubCredentialsOnCrossHostRedirect(req *http.Request, via []*http.Request) error {
+	if len(via) == 0 {
+		return nil
+	}
+	if req.URL.Host != via[0].URL.Host {
+		req.Header.Del(headerHubPrivateKey)
+		req.Header.Del(headerHubPublicKey)
+	}
+	return nil
+}

machinery/src/components/kerberos.go

@@ -70,8 +70,10 @@ func Bootstrap(ctx context.Context, configDirectory string, configuration *model
 	communication.HandleUpload = make(chan string, 1)
 	communication.HandleHeartBeat = make(chan string, 1)
 	communication.HandleLiveSD = make(chan int64, 1)
+	communication.HandleLiveSDHTTP = make(chan int64, 1)
 	communication.HandleLiveHDKeepalive = make(chan string, 1)
 	communication.HandleLiveHDPeers = make(chan string, 1)
+	communication.HandleLiveHLS = make(chan int64, 1)
 	communication.IsConfiguring = abool.New()
 
 	cameraSettings := &models.Camera{}
@@ -176,19 +178,10 @@ func RunAgent(configDirectory string, configuration *models.Configuration, commu
 	configuration.Config.Capture.IPCamera.Height = height
 
 	// Set the liveview width and height, this is used for the liveview and motion regions (drawing on the hub).
-	baseWidth := config.Capture.IPCamera.BaseWidth
-	baseHeight := config.Capture.IPCamera.BaseHeight
-	// If the liveview height is not set, we will calculate it based on the width and aspect ratio of the camera.
-	if baseWidth > 0 && baseHeight == 0 {
-		widthAspectRatio := float64(baseWidth) / float64(width)
-		configuration.Config.Capture.IPCamera.BaseHeight = int(float64(height) * widthAspectRatio)
-	} else if baseHeight > 0 && baseWidth > 0 {
-		configuration.Config.Capture.IPCamera.BaseHeight = baseHeight
-		configuration.Config.Capture.IPCamera.BaseWidth = baseWidth
-	} else {
-		configuration.Config.Capture.IPCamera.BaseHeight = height
-		configuration.Config.Capture.IPCamera.BaseWidth = width
-	}
+	// ResolveBaseDimensions gates the aspect-ratio compute on width/height > 0
+	// so a not-yet-probed stream can't poison the dimensions and crash resize.
+	configuration.Config.Capture.IPCamera.BaseWidth, configuration.Config.Capture.IPCamera.BaseHeight =
+		utils.ResolveBaseDimensions(config.Capture.IPCamera.BaseWidth, config.Capture.IPCamera.BaseHeight, width, height)
 
 	// Set the SPS and PPS values in the configuration.
 	configuration.Config.Capture.IPCamera.SPSNALUs = [][]byte{videoStream.SPS}
@@ -246,19 +239,8 @@ func RunAgent(configDirectory string, configuration *models.Configuration, commu
 
 		// If we have a substream, we need to set the width and height of the substream. (so we will override above information)
 		// Set the liveview width and height, this is used for the liveview and motion regions (drawing on the hub).
-		baseWidth := config.Capture.IPCamera.BaseWidth
-		baseHeight := config.Capture.IPCamera.BaseHeight
-		// If the liveview height is not set, we will calculate it based on the width and aspect ratio of the camera.
-		if baseWidth > 0 && baseHeight == 0 {
-			widthAspectRatio := float64(baseWidth) / float64(width)
-			configuration.Config.Capture.IPCamera.BaseHeight = int(float64(height) * widthAspectRatio)
-		} else if baseHeight > 0 && baseWidth > 0 {
-			configuration.Config.Capture.IPCamera.BaseHeight = baseHeight
-			configuration.Config.Capture.IPCamera.BaseWidth = baseWidth
-		} else {
-			configuration.Config.Capture.IPCamera.BaseHeight = height
-			configuration.Config.Capture.IPCamera.BaseWidth = width
-		}
+		configuration.Config.Capture.IPCamera.BaseWidth, configuration.Config.Capture.IPCamera.BaseHeight =
+			utils.ResolveBaseDimensions(config.Capture.IPCamera.BaseWidth, config.Capture.IPCamera.BaseHeight, width, height)
 	}
 
 	// We are creating a queue to store the RTSP frames in, these frames will be
@@ -304,6 +286,18 @@ func RunAgent(configDirectory string, configuration *models.Configuration, commu
 		go cloud.HandleLiveStreamSD(livestreamCursor, configuration, communication, mqttClient, rtspClient)
 	}
 
+	// Handle livestream HLS (adaptive segments over HTTP via hub-api -> vault).
+	// Uses the sub stream when available (lower bitrate, browser-friendly), else
+	// the main stream. Like SD it is viewer-keepalive gated and produces no
+	// traffic while nobody is watching.
+	if subStreamEnabled {
+		livestreamHLSCursor := subQueue.Latest()
+		go cloud.HandleLiveStreamHLS(livestreamHLSCursor, configuration, communication, mqttClient, rtspSubClient)
+	} else {
+		livestreamHLSCursor := queue.Latest()
+		go cloud.HandleLiveStreamHLS(livestreamHLSCursor, configuration, communication, mqttClient, rtspClient)
+	}
+
 	// Handle livestream HD (high resolution over WEBRTC)
 	communication.HandleLiveHDHandshake = make(chan models.LiveHDHandshake, 100)
 	if subStreamEnabled {

machinery/src/models/communication.go

@@ -37,9 +37,11 @@ type Communication struct {
 	HandleUpload          chan string
 	HandleHeartBeat       chan string
 	HandleLiveSD          chan int64
+	HandleLiveSDHTTP      chan int64
 	HandleLiveHDKeepalive chan string
 	HandleLiveHDHandshake chan LiveHDHandshake
 	HandleLiveHDPeers     chan string
+	HandleLiveHLS         chan int64
 	HandleONVIF           chan OnvifAction
 	IsConfiguring         *abool.AtomicBool
 	Queue                 *packets.Queue

machinery/src/models/mqtt.go

@@ -171,6 +171,19 @@ type UpdateConfigPayload struct {
 // We received a request SD stream request
 type RequestSDStreamPayload struct {
 	Timestamp int64 `json:"timestamp"` // timestamp
+	// Transport selects how the agent should deliver the preview frames for this
+	// viewer. "http" asks the agent to POST frames to hub-api (keeping them off
+	// MQTT); empty/absent means the legacy MQTT image push. Older agents simply
+	// ignore this unknown field and keep doing MQTT, and older frontends never set
+	// it — so new/old agents and frontends interoperate in every combination.
+	Transport string `json:"transport,omitempty"`
+}
+
+// We received a live HLS stream request. Like SD it is a simple viewer
+// keepalive: the agent owns the live HLS session, so the request only needs to
+// signal "a viewer is watching" to keep the segment pipeline alive.
+type RequestHLSStreamPayload struct {
+	Timestamp int64 `json:"timestamp"` // timestamp
 }
 
 // We received a request HD stream request

machinery/src/routers/mqtt/main.go

@@ -344,6 +344,8 @@ func MQTTListenerHandler(mqttClient mqtt.Client, hubKey string, configDirectory
 					go HandleRequestSDStream(mqttClient, hubKey, payload, configuration, communication)
 				case "request-hd-stream":
 					go HandleRequestHDStream(mqttClient, hubKey, payload, configuration, communication)
+				case "request-hls-stream":
+					go HandleRequestHLSStream(mqttClient, hubKey, payload, configuration, communication)
 				case "receive-hd-candidates":
 					go HandleReceiveHDCandidates(mqttClient, hubKey, payload, configuration, communication)
 				case "trigger-relay":
@@ -548,9 +550,20 @@ func HandleRequestSDStream(mqttClient mqtt.Client, hubKey string, payload models
 
 	if requestSDStreamPayload.Timestamp != 0 {
 		if communication.CameraConnected {
-			select {
-			case communication.HandleLiveSD <- time.Now().Unix():
-			default:
+			// A viewer that opted into the HTTP transport is signalled on a separate
+			// channel so the producer ships its frames to hub-api over HTTP instead of
+			// publishing them over MQTT. Any other (or absent) transport keeps the
+			// legacy MQTT image push, so older frontends behave exactly as before.
+			if requestSDStreamPayload.Transport == "http" {
+				select {
+				case communication.HandleLiveSDHTTP <- time.Now().Unix():
+				default:
+				}
+			} else {
+				select {
+				case communication.HandleLiveSD <- time.Now().Unix():
+				default:
+				}
 			}
 			log.Log.Info("routers.mqtt.main.HandleRequestSDStream(): received request to livestream.")
 		} else {
@@ -559,6 +572,30 @@ func HandleRequestSDStream(mqttClient mqtt.Client, hubKey string, payload models
 	}
 }
 
+// HandleRequestHLSStream is the viewer keepalive for live HLS. Like the SD
+// stream it simply signals that a viewer is watching; the agent owns the live
+// HLS session, so a single non-zero timestamp on the channel keeps the segment
+// pipeline alive (see cloud.HandleLiveStreamHLS). Viewers republish this
+// periodically; when the keepalives stop, the agent tears the session down.
+func HandleRequestHLSStream(mqttClient mqtt.Client, hubKey string, payload models.Payload, configuration *models.Configuration, communication *models.Communication) {
+	value := payload.Value
+	jsonData, _ := json.Marshal(value)
+	var requestHLSStreamPayload models.RequestHLSStreamPayload
+	json.Unmarshal(jsonData, &requestHLSStreamPayload)
+
+	if requestHLSStreamPayload.Timestamp != 0 {
+		if communication.CameraConnected {
+			select {
+			case communication.HandleLiveHLS <- time.Now().Unix():
+			default:
+			}
+			log.Log.Info("routers.mqtt.main.HandleRequestHLSStream(): received request to livestream over HLS.")
+		} else {
+			log.Log.Info("routers.mqtt.main.HandleRequestHLSStream(): received request to livestream over HLS, but camera is not connected.")
+		}
+	}
+}
+
 func HandleRequestHDStream(mqttClient mqtt.Client, hubKey string, payload models.Payload, configuration *models.Configuration, communication *models.Communication) {
 	value := payload.Value
 	// Convert map[string]interface{} to RequestHDStreamPayload

machinery/src/utils/main.go

@@ -427,12 +427,49 @@ func ResizeImage(img image.Image, newWidth uint, newHeight uint) (*image.Image,
 		return nil, errors.New("image is nil")
 	}
 
+	// Callers cast int->uint, so a negative or poisoned int (e.g. MinInt from
+	// `int(float * +Inf)` when the source width is 0) wraps to a near-MaxUint
+	// value here and crashes nfnt/resize's allocator with "makeslice: len out
+	// of range". Clamp anything past a sane camera ceiling to 0 ("auto" in
+	// nfnt — preserves aspect from the source).
+	const maxDim uint = 8192
+	if newWidth > maxDim {
+		newWidth = 0
+	}
+	if newHeight > maxDim {
+		newHeight = 0
+	}
+
 	// resize to width 640 using Lanczos resampling
 	// and preserve aspect ratio
 	m := resize.Resize(newWidth, newHeight, img, resize.Lanczos3)
 	return &m, nil
 }
 
+// ResolveBaseDimensions resolves the liveview/motion base dimensions for a
+// stream given the (optionally configured) base width/height and the camera's
+// probed source width/height. It returns the width and height that should be
+// stored on the configuration.
+//
+// The aspect-ratio branch is gated on width>0 && height>0: a not-yet-probed
+// stream has width=height=0, which previously made the ratio +Inf and
+// int(float * +Inf) yield MinInt. That poisoned value, later cast to uint at
+// the ResizeImage call sites, wrapped to ~MaxUint and crashed resize with
+// "makeslice: len out of range". When the source isn't probed yet we fall back
+// to the source dimensions (0,0 -> "auto") instead.
+func ResolveBaseDimensions(baseWidth, baseHeight, width, height int) (int, int) {
+	if baseWidth > 0 && baseHeight == 0 && width > 0 && height > 0 {
+		// Derive the height from the configured width and the source aspect ratio.
+		widthAspectRatio := float64(baseWidth) / float64(width)
+		return baseWidth, int(float64(height) * widthAspectRatio)
+	} else if baseHeight > 0 && baseWidth > 0 {
+		// Both base dimensions are configured; honor them as-is.
+		return baseWidth, baseHeight
+	}
+	// Nothing usable configured (or source not probed yet): use source dimensions.
+	return width, height
+}
+
 func ResizeHeightWithAspectRatio(newWidth int, width int, height int) (int, int) {
 	if newWidth <= 0 || width <= 0 || height <= 0 {
 		return width, height

machinery/src/utils/resize_test.go

@@ -0,0 +1,124 @@
+package utils
+
+import (
+	"image"
+	"math"
+	"testing"
+)
+
+func TestResolveBaseDimensions(t *testing.T) {
+	tests := []struct {
+		name                  string
+		baseWidth, baseHeight int
+		width, height         int
+		wantWidth, wantHeight int
+	}{
+		{
+			name:      "base width set, height derived from aspect ratio",
+			baseWidth: 640, baseHeight: 0,
+			width: 1920, height: 1080,
+			wantWidth: 640, wantHeight: 360,
+		},
+		{
+			name:      "both base dimensions configured are honored",
+			baseWidth: 640, baseHeight: 480,
+			width: 1920, height: 1080,
+			wantWidth: 640, wantHeight: 480,
+		},
+		{
+			name:      "no base configured falls back to source dimensions",
+			baseWidth: 0, baseHeight: 0,
+			width: 1920, height: 1080,
+			wantWidth: 1920, wantHeight: 1080,
+		},
+		{
+			// Regression: a not-yet-probed stream has width=height=0. The old
+			// aspect-ratio branch divided by zero (float * +Inf -> MinInt) and
+			// poisoned BaseHeight, later crashing resize with makeslice panic.
+			name:      "unprobed stream (width=0) does not poison dimensions",
+			baseWidth: 640, baseHeight: 0,
+			width: 0, height: 0,
+			wantWidth: 0, wantHeight: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotWidth, gotHeight := ResolveBaseDimensions(tt.baseWidth, tt.baseHeight, tt.width, tt.height)
+			if gotWidth != tt.wantWidth || gotHeight != tt.wantHeight {
+				t.Fatalf("ResolveBaseDimensions(%d,%d,%d,%d) = (%d,%d), want (%d,%d)",
+					tt.baseWidth, tt.baseHeight, tt.width, tt.height,
+					gotWidth, gotHeight, tt.wantWidth, tt.wantHeight)
+			}
+		})
+	}
+}
+
+func TestResolveBaseDimensionsNeverNegative(t *testing.T) {
+	// Whatever the inputs, the resolved dimensions must never be negative,
+	// otherwise the uint cast at the resize call sites wraps to ~MaxUint.
+	for _, c := range [][4]int{
+		{640, 0, 0, 0},
+		{640, 0, 0, 1080},
+		{640, 0, 1920, 0},
+		{0, 0, 0, 0},
+	} {
+		w, h := ResolveBaseDimensions(c[0], c[1], c[2], c[3])
+		if w < 0 || h < 0 {
+			t.Fatalf("ResolveBaseDimensions(%v) produced negative dims (%d,%d)", c, w, h)
+		}
+	}
+}
+
+func TestResizeImageClampsPoisonedDimensions(t *testing.T) {
+	src := image.NewRGBA(image.Rect(0, 0, 320, 240))
+
+	// uint(math.MinInt) is the value produced when a poisoned int (from
+	// int(float * +Inf)) is cast to uint at a call site. It must not panic
+	// nfnt/resize's allocator; it should fall back to source-aspect resize.
+	// Compute via a runtime int so the conversion doesn't overflow at compile time.
+	minInt := math.MinInt
+	poison := uint(minInt)
+
+	resized, err := ResizeImage(src, poison, poison)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if resized == nil {
+		t.Fatalf("expected an image, got nil")
+	}
+	b := (*resized).Bounds()
+	if b.Dx() != 320 || b.Dy() != 240 {
+		t.Fatalf("poisoned dims should fall back to source size, got %dx%d", b.Dx(), b.Dy())
+	}
+}
+
+func TestResizeImageClampsAboveCameraCeiling(t *testing.T) {
+	src := image.NewRGBA(image.Rect(0, 0, 320, 240))
+
+	// A width beyond any sane camera resolution is treated as "auto" (0).
+	resized, err := ResizeImage(src, 100000, 0)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	b := (*resized).Bounds()
+	if b.Dx() != 320 || b.Dy() != 240 {
+		t.Fatalf("oversized width should fall back to source size, got %dx%d", b.Dx(), b.Dy())
+	}
+}
+
+func TestResizeImageNormalResizeStillWorks(t *testing.T) {
+	src := image.NewRGBA(image.Rect(0, 0, 1920, 1080))
+
+	resized, err := ResizeImage(src, 640, 0)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	b := (*resized).Bounds()
+	if b.Dx() != 640 {
+		t.Fatalf("expected width 640, got %d", b.Dx())
+	}
+	if b.Dy() != 360 {
+		t.Fatalf("expected aspect-preserved height 360, got %d", b.Dy())
+	}
+}

machinery/src/video/livehls.go

@@ -0,0 +1,367 @@
+package video
+
+import (
+	"bytes"
+	"fmt"
+
+	mp4ff "github.com/Eyevinn/mp4ff/mp4"
+	"github.com/kerberos-io/agent/machinery/src/log"
+)
+
+// LiveSegmenter turns a live stream of Annex B video samples into HLS-ready
+// fragmented-MP4 (CMAF) output: ONE init segment (ftyp+moov) followed by a
+// series of INDEPENDENT media segments (styp+moof+mdat), each beginning with a
+// keyframe and carrying its own tfdt. This is the building block for the live
+// HLS pipeline (agent -> hub-api -> vault -> hub-frontend) and is intentionally
+// kept separate from the recording muxer in mp4.go:
+//
+//   - mp4.go writes ONE fragmented MP4 per recording (free-box placeholder up
+//     front, back-filled on Close). That layout is great for archived files but
+//     useless for live, where each segment must be shippable the instant it is
+//     produced and must decode on its own after the init segment.
+//   - LiveSegmenter emits discrete, self-contained segments via callbacks, so
+//     the transport (single-POST to hub-api, drop-on-failure) never has to wait
+//     for the recording to finish.
+//
+// Both producers use the SAME mp4ff fragment format, so live and archived video
+// share one toolchain on the player side (hls.js #EXT-X-MAP + byte-range parts).
+//
+// The spike scope is video-only H.264/H.265. Audio and multi-track interleaving
+// can be layered on later by adding tracks to the init segment and a second trun
+// to each fragment; nothing here precludes that.
+type LiveSegmenter struct {
+	// codec is "H264"/"H265" (case handled in buildInit).
+	codec string
+	// timescale is the media timescale used in the init segment. The agent's
+	// capture path feeds presentation timestamps in milliseconds, so a 1000-tick
+	// timescale keeps sample durations exact with no rescaling.
+	timescale uint32
+	// targetSegmentMs is the minimum amount of media a segment accumulates before
+	// the next keyframe is allowed to start a fresh segment. Keeping segments
+	// keyframe-aligned is what makes each one independently decodable.
+	targetSegmentMs uint64
+
+	spsNALUs [][]byte
+	ppsNALUs [][]byte
+	vpsNALUs [][]byte
+
+	// width/height are written into the visual sample entry. They are optional:
+	// on a successful strict SPS parse mp4ff derives them, but the manual avcC
+	// fallback (used for SPS that mp4ff cannot parse) needs them supplied.
+	width  uint16
+	height uint16
+
+	videoTrackID uint32
+
+	initSegment *mp4ff.InitSegment
+	initBytes   []byte
+	initEmitted bool
+
+	seg   *mp4ff.MediaSegment
+	frag  *mp4ff.Fragment
+	seqNr uint32
+
+	// started becomes true once the first segment has been opened.
+	started bool
+	// segStartPTS is the decode time (ms) of the first sample in the open
+	// segment; elapsed media is measured against it to decide segment cuts.
+	segStartPTS uint64
+	// segDurationMs accumulates the committed sample durations of the open
+	// segment so the playlist can advertise an accurate #EXTINF.
+	segDurationMs uint64
+
+	// pending holds the most recently received sample. Its duration is only known
+	// once the NEXT sample arrives (duration = nextPTS - thisPTS), mirroring the
+	// pending-sample pattern used by the recording muxer.
+	pending *mp4ff.FullSample
+	// lastDurationMs is the previous committed duration, reused to close out the
+	// final pending sample (and to bridge non-monotonic timestamps).
+	lastDurationMs uint64
+
+	// OnInit is invoked exactly once with the encoded init segment bytes before
+	// the first media segment is emitted. Optional.
+	OnInit func(initBytes []byte) error
+	// OnSegment is invoked once per completed media segment. Optional.
+	OnSegment func(seg LiveSegment) error
+}
+
+// LiveSegment is one independently-decodable CMAF media segment.
+type LiveSegment struct {
+	// SequenceNumber is the monotonically increasing fragment sequence number
+	// (also used as the moof sequence number and the seg-N.m4s index).
+	SequenceNumber uint32
+	// DurationMs is the summed sample duration of the segment, for #EXTINF.
+	DurationMs uint64
+	// Data is the complete styp+moof+mdat segment, ready to append after the init
+	// segment and hand to hls.js / a vault object.
+	Data []byte
+}
+
+// Sample-entry flags matching the recording muxer so live and archived fragments
+// describe random access points identically.
+//
+//	keyframe     0x02000000 = sampleDependsOn=2 (depends on nothing), sync sample
+//	non-keyframe 0x01010000 = sampleDependsOn=1, sampleIsNonSyncSample=1
+const (
+	liveSyncSampleFlags    uint32 = 0x02000000
+	liveNonSyncSampleFlags uint32 = 0x01010000
+	// liveFallbackDurationMs is used when a duration cannot be derived (first
+	// frame at Close, or non-monotonic timestamps) and no prior duration exists.
+	// ~33 ms approximates 30 fps and is only ever a single-frame nicety.
+	liveFallbackDurationMs uint64 = 33
+)
+
+// NewLiveSegmenter creates a video-only live segmenter for the given codec.
+// spsNALUs/ppsNALUs (and vpsNALUs for H.265) may be raw NAL units or Annex B
+// blobs with start codes; both are normalized. targetSegmentMs is clamped to a
+// sane floor so a misconfiguration cannot produce one-frame segments.
+func NewLiveSegmenter(codec string, spsNALUs, ppsNALUs, vpsNALUs [][]byte, targetSegmentMs uint64) *LiveSegmenter {
+	if targetSegmentMs < 500 {
+		targetSegmentMs = 500
+	}
+	return &LiveSegmenter{
+		codec:           codec,
+		timescale:       1000,
+		targetSegmentMs: targetSegmentMs,
+		spsNALUs:        spsNALUs,
+		ppsNALUs:        ppsNALUs,
+		vpsNALUs:        vpsNALUs,
+	}
+}
+
+// SetDimensions records the encoded video width/height in pixels. They are
+// written into the avc1/hvc1 visual sample entry and are required for the manual
+// descriptor fallback path (SPS that mp4ff's strict parser rejects).
+func (ls *LiveSegmenter) SetDimensions(width, height uint16) {
+	ls.width = width
+	ls.height = height
+}
+
+// InitSegment returns the encoded init segment bytes, building them on demand.
+// Useful for tests and for serving the #EXT-X-MAP target without waiting for the
+// first media segment.
+func (ls *LiveSegmenter) InitSegment() ([]byte, error) {
+	if ls.initBytes == nil {
+		if err := ls.buildInit(); err != nil {
+			return nil, err
+		}
+	}
+	return ls.initBytes, nil
+}
+
+// buildInit constructs the ftyp+moov init segment from the parameter sets.
+func (ls *LiveSegmenter) buildInit() error {
+	init := mp4ff.CreateEmptyInit()
+	init.AddEmptyTrack(ls.timescale, "video", "und")
+	trak := init.Moov.Traks[0]
+
+	switch ls.codec {
+	case "H264", "h264", "AVC", "avc", "AVC1", "avc1":
+		sps, pps := normalizeH264ParameterSets(ls.spsNALUs, ls.ppsNALUs)
+		if len(sps) == 0 || len(pps) == 0 {
+			return fmt.Errorf("livehls: missing H264 SPS/PPS (sps=%d pps=%d)", len(sps), len(pps))
+		}
+		// includePS=true stores SPS/PPS in the avcC so segments need not carry
+		// in-band parameter sets - browsers read them from the init segment. Some
+		// camera SPS variants trip mp4ff's strict parser (e.g. unusual VUI/SAR);
+		// fall back to a manually built avcC just like the recording muxer does so
+		// those cameras still produce a valid init segment.
+		if err := trak.SetAVCDescriptor("avc1", sps, pps, true); err != nil {
+			log.Log.Warning("livehls: SetAVCDescriptor failed, using manual avcC fallback: " + err.Error())
+			if fbErr := addAVCDescriptorFallback(trak, sps, pps, ls.width, ls.height); fbErr != nil {
+				return fmt.Errorf("livehls: AVC descriptor fallback: %w", fbErr)
+			}
+		}
+	case "H265", "h265", "HEVC", "hevc", "HVC1", "hvc1":
+		vps, sps, pps := normalizeH265ParameterSets(ls.vpsNALUs, ls.spsNALUs, ls.ppsNALUs)
+		if len(vps) == 0 || len(sps) == 0 || len(pps) == 0 {
+			return fmt.Errorf("livehls: missing H265 VPS/SPS/PPS (vps=%d sps=%d pps=%d)", len(vps), len(sps), len(pps))
+		}
+		if err := trak.SetHEVCDescriptor("hvc1", vps, sps, pps, [][]byte{}, true); err != nil {
+			return fmt.Errorf("livehls: SetHEVCDescriptor: %w", err)
+		}
+	default:
+		return fmt.Errorf("livehls: unsupported codec %q", ls.codec)
+	}
+
+	// Record the encoded dimensions in the track header when known.
+	if ls.width > 0 && ls.height > 0 {
+		trak.Tkhd.Width = mp4ff.Fixed32(uint32(ls.width) << 16)
+		trak.Tkhd.Height = mp4ff.Fixed32(uint32(ls.height) << 16)
+	}
+	// mdhd.Duration MUST be 0 for fragmented MP4 so players derive duration from
+	// the fragments rather than a (here unknown) total.
+	trak.Mdia.Mdhd.Duration = 0
+
+	ls.videoTrackID = trak.Tkhd.TrackID
+
+	var buf bytes.Buffer
+	if err := init.Encode(&buf); err != nil {
+		return fmt.Errorf("livehls: encode init: %w", err)
+	}
+	ls.initSegment = init
+	ls.initBytes = buf.Bytes()
+	return nil
+}
+
+// WriteSample feeds one Annex B access unit with its decode timestamp (DTS) in
+// milliseconds. The first sample of a session MUST be a keyframe; a non-keyframe
+// first sample is dropped (it could not be decoded without a preceding IDR).
+//
+// compositionOffsetMs is the CTS offset (PTS-DTS, for B-frame reordering) in
+// timescale ticks; pass 0 for streams without B-frames.
+func (ls *LiveSegmenter) WriteSample(isKeyframe bool, annexB []byte, ptsMs uint64, compositionOffsetMs int32) error {
+	// Lazily build + emit the init segment on the first accepted sample.
+	if ls.initBytes == nil {
+		if err := ls.buildInit(); err != nil {
+			return err
+		}
+	}
+	if !ls.initEmitted {
+		ls.initEmitted = true
+		if ls.OnInit != nil {
+			if err := ls.OnInit(ls.initBytes); err != nil {
+				return err
+			}
+		}
+	}
+
+	// A session must open on a random-access point; otherwise the first segment
+	// would reference frames that never arrived.
+	if !ls.started && !isKeyframe {
+		log.Log.Debug("LiveSegmenter.WriteSample(): dropping leading non-keyframe before first IDR")
+		return nil
+	}
+
+	lengthPrefixed, err := annexBToLengthPrefixed(annexB)
+	if err != nil {
+		return fmt.Errorf("livehls: convert AnnexB: %w", err)
+	}
+
+	// The previous sample's duration is the gap to this sample's PTS. Commit it
+	// to the (still open) current fragment before we consider rolling segments,
+	// because the pending sample always precedes this one in decode order.
+	if ls.pending != nil {
+		dur := ls.lastDurationMs
+		if ptsMs > ls.pending.DecodeTime {
+			dur = ptsMs - ls.pending.DecodeTime
+		}
+		if dur == 0 {
+			dur = liveFallbackDurationMs
+		}
+		ls.lastDurationMs = dur
+		ls.pending.Sample.Dur = uint32(dur)
+		if err := ls.commitPending(); err != nil {
+			return err
+		}
+	}
+
+	// At every keyframe, decide whether enough media has accumulated to close the
+	// open segment and start a new one. Cutting only on keyframes guarantees each
+	// segment is independently decodable.
+	if isKeyframe {
+		shouldCut := !ls.started || (ptsMs-ls.segStartPTS) >= ls.targetSegmentMs
+		if shouldCut {
+			if ls.started {
+				if err := ls.emitSegment(); err != nil {
+					return err
+				}
+			}
+			ls.openSegment(ptsMs)
+		}
+	}
+
+	// Stage this sample; its duration is filled in when the next sample arrives
+	// (or at Close()).
+	flags := liveNonSyncSampleFlags
+	if isKeyframe {
+		flags = liveSyncSampleFlags
+	}
+	ls.pending = &mp4ff.FullSample{
+		Sample: mp4ff.Sample{
+			Flags:                 flags,
+			Size:                  uint32(len(lengthPrefixed)),
+			CompositionTimeOffset: compositionOffsetMs,
+		},
+		DecodeTime: ptsMs,
+		Data:       lengthPrefixed,
+	}
+	return nil
+}
+
+// openSegment starts a fresh media segment (with CMAF styp) and an empty
+// single-track fragment whose moof sequence number is the segment index.
+func (ls *LiveSegmenter) openSegment(startPTS uint64) {
+	ls.seqNr++
+	ls.seg = mp4ff.NewMediaSegment() // includes a CMAF styp box by default
+	frag, err := mp4ff.CreateFragment(ls.seqNr, ls.videoTrackID)
+	if err != nil {
+		log.Log.Error("LiveSegmenter.openSegment(): CreateFragment failed: " + err.Error())
+		return
+	}
+	ls.seg.AddFragment(frag)
+	ls.frag = frag
+	ls.segStartPTS = startPTS
+	ls.segDurationMs = 0
+	ls.started = true
+}
+
+// commitPending appends the staged sample to the open fragment. The first sample
+// of a fragment seeds the tfdt baseMediaDecodeTime from its absolute DecodeTime,
+// which is what makes the segment independently seekable/decodable.
+func (ls *LiveSegmenter) commitPending() error {
+	if ls.pending == nil {
+		return nil
+	}
+	if ls.frag == nil {
+		// No open segment yet (e.g. pending set before the first keyframe cut). The
+		// keyframe path always opens a segment before staging, so this only guards
+		// against logic drift; drop rather than panic.
+		ls.pending = nil
+		return nil
+	}
+	if err := ls.frag.AddFullSampleToTrack(*ls.pending, ls.videoTrackID); err != nil {
+		return fmt.Errorf("livehls: AddFullSampleToTrack: %w", err)
+	}
+	ls.segDurationMs += uint64(ls.pending.Sample.Dur)
+	ls.pending = nil
+	return nil
+}
+
+// emitSegment encodes the open segment and hands it to OnSegment.
+func (ls *LiveSegmenter) emitSegment() error {
+	if ls.seg == nil {
+		return nil
+	}
+	var buf bytes.Buffer
+	if err := ls.seg.Encode(&buf); err != nil {
+		return fmt.Errorf("livehls: encode segment %d: %w", ls.seqNr, err)
+	}
+	out := LiveSegment{
+		SequenceNumber: ls.seqNr,
+		DurationMs:     ls.segDurationMs,
+		Data:           buf.Bytes(),
+	}
+	ls.seg = nil
+	ls.frag = nil
+	if ls.OnSegment != nil {
+		return ls.OnSegment(out)
+	}
+	return nil
+}
+
+// Close flushes the final pending sample and emits the last open segment. Call
+// once when the live session ends so no trailing media is lost.
+func (ls *LiveSegmenter) Close() error {
+	if ls.pending != nil {
+		dur := ls.lastDurationMs
+		if dur == 0 {
+			dur = liveFallbackDurationMs
+		}
+		ls.pending.Sample.Dur = uint32(dur)
+		if err := ls.commitPending(); err != nil {
+			return err
+		}
+	}
+	return ls.emitSegment()
+}

machinery/src/video/livehls_test.go

@@ -0,0 +1,371 @@
+package video
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	mp4ff "github.com/Eyevinn/mp4ff/mp4"
+)
+
+// Known-good minimal H.264 baseline parameter sets (640x480), reused from the
+// recording-muxer tests so the live segmenter is exercised against the exact
+// SPS/PPS mp4ff is already known to parse into an avcC descriptor.
+var (
+	liveTestSPS = []byte{0x67, 0x42, 0xc0, 0x1e, 0xd9, 0x00, 0xa0, 0x47, 0xfe, 0xc8}
+	liveTestPPS = []byte{0x68, 0xce, 0x38, 0x80}
+)
+
+// makeAnnexBFrame builds a single-NALU Annex B access unit: a 4-byte start code,
+// the NAL header (IDR=0x65 for keyframes, non-IDR=0x01 otherwise) and padding.
+func makeAnnexBFrame(isKey bool) []byte {
+	nalType := byte(0x01)
+	if isKey {
+		nalType = 0x65
+	}
+	frame := []byte{0x00, 0x00, 0x00, 0x01, nalType}
+	for i := 0; i < 100; i++ {
+		frame = append(frame, byte(i))
+	}
+	return frame
+}
+
+// isSyncSample reports whether a parsed sample is a random-access point
+// (sample_depends_on == 2 => "depends on nothing" => IDR/sync).
+func isSyncSample(s mp4ff.Sample) bool {
+	return (s.Flags>>24)&0x03 == 0x02
+}
+
+// TestLiveSegmenterProducesIndependentCMAFSegments feeds a synthetic H.264
+// stream (25 fps, 1s GOPs) through the live segmenter and asserts that:
+//   - exactly one init segment (ftyp+moov, single avc1 video track) is produced;
+//   - segments are cut on keyframe boundaries honoring the target duration;
+//   - every media segment carries a CMAF styp + exactly one moof+mdat fragment;
+//   - each segment begins with a sync sample and its tfdt equals the absolute
+//     decode time of that first sample (the property that makes it independently
+//     decodable after the init segment);
+//   - sample counts and durations are preserved end to end.
+func TestLiveSegmenterProducesIndependentCMAFSegments(t *testing.T) {
+	const (
+		frameDurMs = uint64(40) // 25 fps
+		gopFrames  = 25         // keyframe every 1000 ms
+		numGOPs    = 6
+		numFrames  = gopFrames * numGOPs // 150 frames, 6000 ms
+		targetMs   = uint64(2000)        // 2s segments => 2 GOPs each
+	)
+
+	seg := NewLiveSegmenter("H264", [][]byte{liveTestSPS}, [][]byte{liveTestPPS}, nil, targetMs)
+	seg.SetDimensions(640, 480)
+
+	var initBytes []byte
+	var initCalls int
+	var segments []LiveSegment
+	seg.OnInit = func(b []byte) error {
+		initCalls++
+		initBytes = append([]byte(nil), b...)
+		return nil
+	}
+	seg.OnSegment = func(s LiveSegment) error {
+		segments = append(segments, s)
+		return nil
+	}
+
+	for i := 0; i < numFrames; i++ {
+		isKey := i%gopFrames == 0
+		pts := uint64(i) * frameDurMs
+		if err := seg.WriteSample(isKey, makeAnnexBFrame(isKey), pts, 0); err != nil {
+			t.Fatalf("WriteSample(frame=%d): %v", i, err)
+		}
+	}
+	if err := seg.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	// --- Init segment: emitted exactly once, well-formed, single video track. ---
+	if initCalls != 1 {
+		t.Fatalf("OnInit called %d times, want 1", initCalls)
+	}
+	if len(initBytes) == 0 {
+		t.Fatal("init segment is empty")
+	}
+	parsedInit, err := mp4ff.DecodeFile(bytes.NewReader(initBytes))
+	if err != nil {
+		t.Fatalf("decode init: %v", err)
+	}
+	if parsedInit.Init == nil || parsedInit.Init.Ftyp == nil || parsedInit.Init.Moov == nil {
+		t.Fatal("init segment missing ftyp/moov")
+	}
+	if got := len(parsedInit.Init.Moov.Traks); got != 1 {
+		t.Fatalf("init moov has %d traks, want 1", got)
+	}
+
+	// --- Segment cut cadence: 6 GOPs at 2s target => 3 segments of 2 GOPs each. ---
+	const wantSegments = 3
+	if len(segments) != wantSegments {
+		t.Fatalf("got %d media segments, want %d", len(segments), wantSegments)
+	}
+	for i, s := range segments {
+		if want := uint32(i + 1); s.SequenceNumber != want {
+			t.Errorf("segment %d: SequenceNumber=%d, want %d", i, s.SequenceNumber, want)
+		}
+		if s.DurationMs != targetMs {
+			t.Errorf("segment %d: DurationMs=%d, want %d", i, s.DurationMs, targetMs)
+		}
+	}
+
+	// --- Each segment must decode INDEPENDENTLY after the init segment. ---
+	// Parsing init+oneSegment in isolation mirrors exactly what hls.js does with
+	// an #EXT-X-MAP init and a single media part.
+	var totalSamples, totalSync int
+	wantTFDT := []uint64{0, 2000, 4000}
+	for i, s := range segments {
+		standalone := append(append([]byte(nil), initBytes...), s.Data...)
+		parsed, err := mp4ff.DecodeFile(bytes.NewReader(standalone))
+		if err != nil {
+			t.Fatalf("segment %d: decode init+segment: %v", i, err)
+		}
+		if len(parsed.Segments) != 1 {
+			t.Fatalf("segment %d: parsed %d media segments, want 1", i, len(parsed.Segments))
+		}
+		mseg := parsed.Segments[0]
+		if mseg.Styp == nil {
+			t.Errorf("segment %d: missing CMAF styp box", i)
+		}
+		if len(mseg.Fragments) != 1 {
+			t.Fatalf("segment %d: %d fragments, want 1", i, len(mseg.Fragments))
+		}
+		fr := mseg.Fragments[0]
+		if got := fr.Moof.Mfhd.SequenceNumber; got != s.SequenceNumber {
+			t.Errorf("segment %d: moof sequence=%d, want %d", i, got, s.SequenceNumber)
+		}
+		traf := fr.Moof.Traf
+		if traf.Tfhd.TrackID != 1 {
+			t.Errorf("segment %d: track id=%d, want 1", i, traf.Tfhd.TrackID)
+		}
+		if got := traf.Tfdt.BaseMediaDecodeTime(); got != wantTFDT[i] {
+			t.Errorf("segment %d: tfdt baseMediaDecodeTime=%d, want %d", i, got, wantTFDT[i])
+		}
+
+		var samples []mp4ff.Sample
+		for _, trun := range traf.Truns {
+			samples = append(samples, trun.Samples...)
+		}
+		if len(samples) == 0 {
+			t.Fatalf("segment %d: no samples", i)
+		}
+		if !isSyncSample(samples[0]) {
+			t.Errorf("segment %d: first sample is not a keyframe/sync sample", i)
+		}
+		var segDur uint64
+		for j, smp := range samples {
+			totalSamples++
+			if isSyncSample(smp) {
+				totalSync++
+			}
+			segDur += uint64(smp.Dur)
+			if smp.Size == 0 {
+				t.Errorf("segment %d sample %d: zero size", i, j)
+			}
+		}
+		if segDur != s.DurationMs {
+			t.Errorf("segment %d: summed sample dur=%d, reported DurationMs=%d", i, segDur, s.DurationMs)
+		}
+	}
+
+	if totalSamples != numFrames {
+		t.Errorf("total samples across segments=%d, want %d", totalSamples, numFrames)
+	}
+	if totalSync != numGOPs {
+		t.Errorf("total sync samples=%d, want %d (one per GOP)", totalSync, numGOPs)
+	}
+}
+
+// TestLiveSegmenterDropsLeadingNonKeyframe verifies a session cannot open on a
+// non-IDR frame (which would reference frames that never arrived); such leading
+// samples are dropped until the first keyframe.
+func TestLiveSegmenterDropsLeadingNonKeyframe(t *testing.T) {
+	seg := NewLiveSegmenter("H264", [][]byte{liveTestSPS}, [][]byte{liveTestPPS}, nil, 1000)
+	seg.SetDimensions(640, 480)
+	var segments []LiveSegment
+	seg.OnSegment = func(s LiveSegment) error { segments = append(segments, s); return nil }
+
+	// Two P-frames before any IDR must be ignored.
+	if err := seg.WriteSample(false, makeAnnexBFrame(false), 0, 0); err != nil {
+		t.Fatalf("WriteSample(p0): %v", err)
+	}
+	if err := seg.WriteSample(false, makeAnnexBFrame(false), 40, 0); err != nil {
+		t.Fatalf("WriteSample(p1): %v", err)
+	}
+	// First IDR opens the session at decode time 0.
+	for i := 0; i < 25; i++ {
+		isKey := i == 0
+		if err := seg.WriteSample(isKey, makeAnnexBFrame(isKey), uint64(i)*40, 0); err != nil {
+			t.Fatalf("WriteSample(%d): %v", i, err)
+		}
+	}
+	if err := seg.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	if len(segments) == 0 {
+		t.Fatal("expected at least one segment after the first IDR")
+	}
+	initBytes, err := seg.InitSegment()
+	if err != nil {
+		t.Fatalf("InitSegment: %v", err)
+	}
+	standalone := append(append([]byte(nil), initBytes...), segments[0].Data...)
+	parsed, err := mp4ff.DecodeFile(bytes.NewReader(standalone))
+	if err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+	traf := parsed.Segments[0].Fragments[0].Moof.Traf
+	if got := traf.Tfdt.BaseMediaDecodeTime(); got != 0 {
+		t.Errorf("first segment tfdt=%d, want 0 (session opens on the IDR)", got)
+	}
+	var first mp4ff.Sample
+	for _, trun := range traf.Truns {
+		if len(trun.Samples) > 0 {
+			first = trun.Samples[0]
+			break
+		}
+	}
+	if !isSyncSample(first) {
+		t.Error("first committed sample must be the IDR, not a dropped P-frame")
+	}
+}
+
+// renderLiveMediaPlaylist renders a live (no #EXT-X-ENDLIST) fMP4 HLS media
+// playlist for the given segments. This mirrors the shape hub-api will serve for
+// live streams: an #EXT-X-MAP init segment followed by one #EXTINF per CMAF part.
+// In production hub-api emits a sliding WINDOW of the most recent segments and
+// advances #EXT-X-MEDIA-SEQUENCE; here we list the whole synthetic capture for a
+// self-contained, inspectable bundle.
+func renderLiveMediaPlaylist(initURI string, segs []LiveSegment, mediaSequence uint32) string {
+	var maxDurMs uint64
+	for _, s := range segs {
+		if s.DurationMs > maxDurMs {
+			maxDurMs = s.DurationMs
+		}
+	}
+	target := uint64(math.Ceil(float64(maxDurMs) / 1000.0))
+	if target == 0 {
+		target = 1
+	}
+
+	var b strings.Builder
+	b.WriteString("#EXTM3U\n")
+	b.WriteString("#EXT-X-VERSION:7\n")
+	fmt.Fprintf(&b, "#EXT-X-TARGETDURATION:%d\n", target)
+	fmt.Fprintf(&b, "#EXT-X-MEDIA-SEQUENCE:%d\n", mediaSequence)
+	b.WriteString("#EXT-X-INDEPENDENT-SEGMENTS\n")
+	fmt.Fprintf(&b, "#EXT-X-MAP:URI=%q\n", initURI)
+	for _, s := range segs {
+		fmt.Fprintf(&b, "#EXTINF:%.3f,\n", float64(s.DurationMs)/1000.0)
+		fmt.Fprintf(&b, "seg-%d.m4s\n", s.SequenceNumber)
+	}
+	// NOTE: deliberately no #EXT-X-ENDLIST - its absence is what marks the
+	// playlist as live so hls.js keeps polling for new segments.
+	return b.String()
+}
+
+// TestLiveSegmenterWritesHLSBundle runs the segmenter over a synthetic stream and
+// writes a complete on-disk fMP4 HLS bundle (init.mp4 + seg-N.m4s + a live
+// stream.m3u8). It validates the playlist shape and that every referenced file
+// exists, then logs the output directory so the structure can be eyeballed.
+//
+// Set LIVEHLS_OUT=/some/dir to keep the bundle for manual inspection (e.g. serve
+// it and point hls.js at stream.m3u8); otherwise a temp dir is used and removed.
+//
+// The frames here are synthetic (valid fMP4 boxing, non-decodable payloads), so
+// this validates CONTAINER/playlist structure, not pixel decode - the round-trip
+// assertions in TestLiveSegmenterProducesIndependentCMAFSegments cover decodable
+// box layout.
+func TestLiveSegmenterWritesHLSBundle(t *testing.T) {
+	const (
+		frameDurMs = uint64(40)
+		gopFrames  = 25
+		numGOPs    = 6
+		numFrames  = gopFrames * numGOPs
+		targetMs   = uint64(2000)
+	)
+
+	outDir := os.Getenv("LIVEHLS_OUT")
+	if outDir == "" {
+		outDir = t.TempDir()
+	} else {
+		if err := os.MkdirAll(outDir, 0o755); err != nil {
+			t.Fatalf("mkdir %s: %v", outDir, err)
+		}
+	}
+
+	seg := NewLiveSegmenter("H264", [][]byte{liveTestSPS}, [][]byte{liveTestPPS}, nil, targetMs)
+	seg.SetDimensions(640, 480)
+
+	var segments []LiveSegment
+	seg.OnInit = func(b []byte) error {
+		return os.WriteFile(filepath.Join(outDir, "init.mp4"), b, 0o644)
+	}
+	seg.OnSegment = func(s LiveSegment) error {
+		segments = append(segments, s)
+		name := fmt.Sprintf("seg-%d.m4s", s.SequenceNumber)
+		return os.WriteFile(filepath.Join(outDir, name), s.Data, 0o644)
+	}
+
+	for i := 0; i < numFrames; i++ {
+		isKey := i%gopFrames == 0
+		if err := seg.WriteSample(isKey, makeAnnexBFrame(isKey), uint64(i)*frameDurMs, 0); err != nil {
+			t.Fatalf("WriteSample(%d): %v", i, err)
+		}
+	}
+	if err := seg.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+	if len(segments) == 0 {
+		t.Fatal("no segments produced")
+	}
+
+	playlist := renderLiveMediaPlaylist("init.mp4", segments, segments[0].SequenceNumber)
+	if err := os.WriteFile(filepath.Join(outDir, "stream.m3u8"), []byte(playlist), 0o644); err != nil {
+		t.Fatalf("write playlist: %v", err)
+	}
+
+	// --- Validate the live playlist shape. ---
+	mustContain := []string{
+		"#EXTM3U",
+		"#EXT-X-VERSION:7",
+		"#EXT-X-TARGETDURATION:2",
+		"#EXT-X-MEDIA-SEQUENCE:1",
+		`#EXT-X-MAP:URI="init.mp4"`,
+		"#EXT-X-INDEPENDENT-SEGMENTS",
+	}
+	for _, tag := range mustContain {
+		if !strings.Contains(playlist, tag) {
+			t.Errorf("playlist missing %q\n---\n%s", tag, playlist)
+		}
+	}
+	if strings.Contains(playlist, "#EXT-X-ENDLIST") {
+		t.Error("live playlist must NOT contain #EXT-X-ENDLIST")
+	}
+	if got, want := strings.Count(playlist, "#EXTINF:"), len(segments); got != want {
+		t.Errorf("playlist has %d #EXTINF entries, want %d", got, want)
+	}
+
+	// --- Every referenced file must exist on disk. ---
+	if _, err := os.Stat(filepath.Join(outDir, "init.mp4")); err != nil {
+		t.Errorf("init.mp4 missing: %v", err)
+	}
+	for _, s := range segments {
+		name := fmt.Sprintf("seg-%d.m4s", s.SequenceNumber)
+		if _, err := os.Stat(filepath.Join(outDir, name)); err != nil {
+			t.Errorf("%s missing: %v", name, err)
+		}
+	}
+
+	t.Logf("wrote HLS bundle to %s (%d segments)\n%s", outDir, len(segments), playlist)
+}
+

machinery/src/video/mp4.go

@@ -33,13 +33,18 @@ const MacEpochOffset uint64 = 2082844800
 const FragmentDurationMs = 3000
 
 // SeamGapDivisor controls loop-seam detection. A keyframe is treated as an
-// upstream loop/restart seam when it arrives in less than (previous keyframe
-// interval / SeamGapDivisor) — i.e. far sooner than the established keyframe
-// cadence. Comparing against the *previous* interval (rather than a fixed
-// millisecond threshold) makes the check scale automatically with the camera's
-// configured GOP size: it works the same whether keyframes are 0.5s, 1s, 2s or
-// more apart, and does not misfire on legitimately short-GOP or all-intra
-// streams (where every interval is similar, so none looks anomalously short).
+// upstream loop/restart seam when it arrives in less than (smallest normal
+// keyframe interval / SeamGapDivisor) — i.e. far sooner than the camera's
+// tightest established keyframe cadence.
+//
+// The reference is the running *minimum* keyframe interval, NOT the immediately
+// preceding one. Variable-GOP ("smart codec") cameras lengthen the GOP during
+// static scenes and shorten it again on motion, so consecutive intervals differ
+// wildly (e.g. 2000 ms then 500 ms). Comparing against the previous interval
+// then flags every normal short GOP that happens to follow a long static GOP as
+// a seam and drops healthy video. Comparing against the minimum cadence instead
+// scales with any configured GOP size (0.5s, 1s, 2s, ...) yet never mistakes the
+// camera's own normal cadence for a premature seam IDR.
 const SeamGapDivisor = 2
 
 type MP4 struct {
@@ -85,7 +90,8 @@ type MP4 struct {
 	FragmentKeyframeCount   int               // Keyframes in the current fragment
 	PendingSampleIsKeyframe bool              // Whether the pending video sample is a keyframe
 	LastKeyframeRawPTS      uint64            // Raw PTS of the most recently seen keyframe (across fragments)
-	LastKeyframeGapMs       uint64            // Interval (ms) between the two most recent keyframes; reference cadence for seam detection
+	LastKeyframeGapMs       uint64            // Interval (ms) between the two most recent keyframes (diagnostic only)
+	MinKeyframeGapMs        uint64            // Smallest keyframe interval (ms) seen so far; the camera's tightest cadence and the reference for seam detection
 	gopBuffer               []bufferedSample  // Current, not-yet-committed GOP (video frames + interleaved audio), held so a loop-seam GOP can be dropped before it reaches the file
 }
 
@@ -333,23 +339,40 @@ func (mp4 *MP4) AddSampleToTrack(trackID uint32, isKeyframe bool, data []byte, p
 	// buffered GOP is genuine (commit it) or the truncated tail GOP at an upstream
 	// loop/restart seam (drop it).
 	//
-	// The GOP size is configurable per camera, so we do NOT compare against a
-	// fixed millisecond threshold. Instead we compare this keyframe interval to
-	// the previous one and only flag a *sudden* shortening: a seam IDR arrives in
-	// less than (previous interval / SeamGapDivisor). Deriving the threshold from
-	// the observed cadence keeps detection correct for any configured GOP (0.5s,
-	// 1s, 2s, ...) and avoids false positives on steady short-GOP / all-intra
-	// streams (where consecutive intervals are similar, so none looks anomalously
-	// short). Because the reference is the immediately preceding interval, a burst
-	// of close keyframes only drops a single GOP instead of cascading.
+	// A genuine loop/restart seam has TWO signatures that must BOTH hold; we never
+	// drop a GOP on the interval alone, because variable-GOP ("smart codec")
+	// cameras legitimately shorten the GOP on motion:
+	//
+	//  1. The new keyframe arrives much sooner than the camera's tightest normal
+	//     cadence: gap*SeamGapDivisor < MinKeyframeGapMs (the running MINIMUM
+	//     interval). Using the minimum — not the previous interval — means a
+	//     normal short GOP that merely follows a long static GOP (2000 ms -> 500 ms)
+	//     is NOT flagged, while a true premature restart still is.
+	//  2. The GOP we just buffered is actually TRUNCATED — far shorter than a full
+	//     GOP. A real seam cuts a GOP off mid-stream, leaving only a handful of
+	//     frames; a healthy GOP (even a legitimately short one) is left intact and
+	//     must be committed in full. We require the buffered tail to be under half
+	//     the minimum normal GOP length to qualify as truncated.
+	//
+	// Deriving both thresholds from the observed cadence keeps detection correct
+	// for any configured GOP size (0.5s, 1s, 2s, ...) and stops the heuristic from
+	// discarding healthy video.
 	seam := false
 	if mp4.LastKeyframeRawPTS > 0 && pts > mp4.LastKeyframeRawPTS {
 		gap := pts - mp4.LastKeyframeRawPTS
-		if mp4.LastKeyframeGapMs > 0 && gap*SeamGapDivisor < mp4.LastKeyframeGapMs {
+		bufferedVideo := mp4.bufferedVideoCount()
+		// Frames a full GOP at the tightest normal cadence would contain.
+		fullGopFrames := mp4.expectedGopFrames(gap)
+		closeKeyframe := mp4.MinKeyframeGapMs > 0 && gap*SeamGapDivisor < mp4.MinKeyframeGapMs
+		truncatedTail := fullGopFrames > 0 && bufferedVideo*2 < fullGopFrames
+		if closeKeyframe && truncatedTail {
 			seam = true
-			log.Log.Warning(fmt.Sprintf("mp4.AddSampleToTrack(): dropping truncated GOP at unexpectedly close keyframe (interval=%d ms, previous interval=%d ms, buffered samples=%d) - likely upstream loop/restart discontinuity", gap, mp4.LastKeyframeGapMs, len(mp4.gopBuffer)))
+			log.Log.Warning(fmt.Sprintf("mp4.AddSampleToTrack(): dropping truncated GOP at premature keyframe (interval=%d ms, min interval=%d ms, buffered video frames=%d of ~%d) - likely upstream loop/restart discontinuity", gap, mp4.MinKeyframeGapMs, bufferedVideo, fullGopFrames))
 		}
 		mp4.LastKeyframeGapMs = gap
+		if !seam && (mp4.MinKeyframeGapMs == 0 || gap < mp4.MinKeyframeGapMs) {
+			mp4.MinKeyframeGapMs = gap
+		}
 	}
 	mp4.LastKeyframeRawPTS = pts
 
@@ -372,6 +395,70 @@ func (mp4 *MP4) AddSampleToTrack(trackID uint32, isKeyframe bool, data []byte, p
 	return nil
 }
 
+// bufferedVideoCount returns how many video-track samples are currently held in
+// the GOP buffer (interleaved audio samples are ignored). It measures how
+// complete the buffered GOP is, used to tell a truncated seam tail from a
+// healthy — possibly legitimately short — GOP.
+func (mp4 *MP4) bufferedVideoCount() uint64 {
+	var n uint64
+	for _, s := range mp4.gopBuffer {
+		if s.trackID == uint32(mp4.VideoTrack) {
+			n++
+		}
+	}
+	return n
+}
+
+// expectedGopFrames estimates how many video frames a full GOP at the camera's
+// tightest normal cadence (MinKeyframeGapMs) would contain, using the video
+// frame interval inferred from the buffered GOP. gap is the current keyframe
+// interval, used as a fallback frame-duration source. Returns 0 when there is
+// not yet enough information to judge (so callers must not treat a GOP as
+// truncated without a reliable estimate).
+func (mp4 *MP4) expectedGopFrames(gap uint64) uint64 {
+	cadence := mp4.MinKeyframeGapMs
+	if cadence == 0 {
+		return 0
+	}
+	frameDur := mp4.bufferedVideoFrameDuration()
+	if frameDur == 0 {
+		// Fall back to deriving a per-frame duration from the buffered tail across
+		// the current interval; if that is unavailable too, we cannot estimate.
+		if n := mp4.bufferedVideoCount(); n > 0 && gap > 0 {
+			frameDur = gap / n
+		}
+	}
+	if frameDur == 0 {
+		return 0
+	}
+	return cadence / frameDur
+}
+
+// bufferedVideoFrameDuration returns the average per-frame duration (in PTS
+// units) of the video samples currently buffered, derived from the PTS deltas
+// between consecutive video frames. Returns 0 when fewer than two video frames
+// are buffered.
+func (mp4 *MP4) bufferedVideoFrameDuration() uint64 {
+	var prev uint64
+	havePrev := false
+	var sum, count uint64
+	for _, s := range mp4.gopBuffer {
+		if s.trackID != uint32(mp4.VideoTrack) {
+			continue
+		}
+		if havePrev && s.pts > prev {
+			sum += s.pts - prev
+			count++
+		}
+		prev = s.pts
+		havePrev = true
+	}
+	if count == 0 {
+		return 0
+	}
+	return sum / count
+}
+
 // commitBufferedGOP writes every sample currently held in gopBuffer to the file
 // in arrival order, then clears the buffer. Committing in arrival order
 // preserves the original audio/video interleave and lets commitSampleToTrack's

machinery/src/video/mp4_variablegop_test.go

@@ -0,0 +1,129 @@
+package video
+
+import (
+	"os"
+	"testing"
+
+	mp4ff "github.com/Eyevinn/mp4ff/mp4"
+	"github.com/kerberos-io/agent/machinery/src/models"
+)
+
+// TestMP4VariableGOPKeepsHealthyShortGOP reproduces the adam-drive regression:
+// a variable-GOP ("smart codec") camera lengthens its keyframe interval during a
+// static scene (e.g. 500ms -> 1500/2000ms) and then drops back to its normal
+// 500ms cadence on motion. That normal, FULL 500ms GOP arrives much sooner than
+// the immediately preceding (long, static) GOP.
+//
+// The previous heuristic compared the new keyframe interval against the *previous*
+// interval and dropped the GOP whenever gap < previousInterval/2 — so every normal
+// 500ms keyframe following a long static GOP was misclassified as a premature
+// loop/restart seam and a whole healthy GOP (~15 frames) was discarded. In the
+// field this silently deleted ~0.5s of video on virtually every recording from
+// such cameras, producing a freeze/jump artifact.
+//
+// After the fix the seam check compares against the running MINIMUM cadence and
+// additionally requires the buffered GOP to be genuinely truncated, so a full
+// healthy GOP is always kept regardless of how long the preceding GOP was. This
+// test asserts that NO frames are dropped for a pure variable-GOP stream.
+func TestMP4VariableGOPKeepsHealthyShortGOP(t *testing.T) {
+	tmpFile, err := os.CreateTemp("", "test_variable_gop_*.mp4")
+	if err != nil {
+		t.Fatalf("create temp: %v", err)
+	}
+	tmpFile.Close()
+	defer os.Remove(tmpFile.Name())
+
+	sps := []byte{0x67, 0x42, 0xc0, 0x1e, 0xd9, 0x00, 0xa0, 0x47, 0xfe, 0xc8}
+	pps := []byte{0x68, 0xce, 0x38, 0x80}
+	mp4Video := NewMP4(tmpFile.Name(), [][]byte{sps}, [][]byte{pps}, nil, 60)
+	mp4Video.SetWidth(1920)
+	mp4Video.SetHeight(1080)
+	v := mp4Video.AddVideoTrack("H264")
+
+	mk := func(k bool) []byte {
+		nt := byte(0x01)
+		if k {
+			nt = 0x65
+		}
+		f := []byte{0, 0, 0, 1, nt}
+		for i := 0; i < 200; i++ {
+			f = append(f, byte(i))
+		}
+		return f
+	}
+
+	const frameDur = uint64(33)
+	pts := uint64(0)
+	emitFrame := func(isKey bool) {
+		mp4Video.AddSampleToTrack(v, isKey, mk(isKey), pts, 0)
+		pts += frameDur
+	}
+	// emitGOP emits a complete GOP of exactly frames frames: a leading keyframe
+	// followed by frames-1 P-frames. Every GOP here is healthy and complete; only
+	// its length varies, exactly as a smart-codec camera varies the GOP.
+	emitGOP := func(frames int) {
+		emitFrame(true)
+		for i := 0; i < frames-1; i++ {
+			emitFrame(false)
+		}
+	}
+
+	// Normal cadence is 15 frames (~500ms). The camera then lengthens the GOP for
+	// several static scenes (45 and 60 frames, ~1500ms and ~2000ms) before
+	// dropping back to the normal 15-frame GOP on motion — the transition the old
+	// heuristic wrongly treated as a seam. The whole sequence is then repeated to
+	// cover multiple long->short transitions.
+	gopLengths := []int{15, 15, 45, 15, 60, 15, 15, 45, 15, 15, 60, 15}
+	totalEmittedFrames := 0
+	emittedKeyframes := 0
+	for _, n := range gopLengths {
+		emitGOP(n)
+		totalEmittedFrames += n
+		emittedKeyframes++
+	}
+
+	mp4Video.Close(&models.Config{Signing: &models.Signing{PrivateKey: ""}})
+
+	f, err := os.Open(tmpFile.Name())
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	defer f.Close()
+	parsed, err := mp4ff.DecodeFile(f)
+	if err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+
+	totalSamples := 0
+	totalSync := 0
+	for _, seg := range parsed.Segments {
+		for _, fr := range seg.Fragments {
+			for _, traf := range fr.Moof.Trafs {
+				if traf.Tfhd.TrackID != 1 {
+					continue
+				}
+				for _, trun := range traf.Truns {
+					for _, s := range trun.Samples {
+						totalSamples++
+						// sample_depends_on == 2 => "does not depend on others" => IDR/sync.
+						if (s.Flags>>24)&0x03 == 0x02 {
+							totalSync++
+						}
+					}
+				}
+			}
+		}
+	}
+
+	// Every GOP is healthy, so nothing must be dropped: all keyframes and all
+	// frames must survive. A shortfall means a normal variable-GOP keyframe was
+	// misclassified as a seam.
+	if totalSync != emittedKeyframes {
+		t.Errorf("got %d keyframes in output, want %d - a healthy variable-GOP keyframe was wrongly dropped as a seam",
+			totalSync, emittedKeyframes)
+	}
+	if totalSamples != totalEmittedFrames {
+		t.Errorf("got %d video samples in output, want %d - a healthy variable-GOP GOP was wrongly dropped as a seam",
+			totalSamples, totalEmittedFrames)
+	}
+}