feat: add support for utc_head

cmd/livesim2/app/configurl.go

@@ -29,7 +29,7 @@ type UTCTimingMethod string
 
 const (
 	UtcTimingDirect     UTCTimingMethod = "direct"
-	UtcTimingHead       UTCTimingMethod = "head" // Note, not supported
+	UtcTimingHead       UTCTimingMethod = "head"
 	UtcTimingNtp        UTCTimingMethod = "ntp"
 	UtcTimingSntp       UTCTimingMethod = "sntp"
 	UtcTimingHttpXSDate UTCTimingMethod = "httpxsdate"
@@ -42,6 +42,7 @@ const (
 	UtcTimingSntpServer   = "time.kfki.hu"
 	UtcTimingHttpServer   = "http://time.akamai.com/?iso"
 	UtcTimingHttpServerMS = "http://time.akamai.com/?isoms"
+	UtcTimingHeadAsset    = "/static/time.txt"
 )
 
 type ResponseConfig struct {

cmd/livesim2/app/configurl_test.go

@@ -20,18 +20,18 @@ func TestProcessURLCfg(t *testing.T) {
 		err         string
 	}{
 		{
-			url:         "/livesim2/utc_direct-ntp-sntp-httpxsdate-httpiso/asset/x.mpd",
+			url:         "/livesim2/utc_direct-ntp-sntp-httpxsdate-httpiso-head/asset/x.mpd",
 			nowMS:       0,
 			contentPart: "asset/x.mpd",
 			wantedCfg: &ResponseConfig{
-				URLParts:                     []string{"", "livesim2", "utc_direct-ntp-sntp-httpxsdate-httpiso", "asset", "x.mpd"},
+				URLParts:                     []string{"", "livesim2", "utc_direct-ntp-sntp-httpxsdate-httpiso-head", "asset", "x.mpd"},
 				URLContentIdx:                3,
 				StartTimeS:                   0,
 				TimeShiftBufferDepthS:        Ptr(defaultTimeShiftBufferDepthS),
 				StartNr:                      Ptr(0),
 				AvailabilityTimeCompleteFlag: true,
 				TimeSubsDurMS:                defaultTimeSubsDurMS,
-				UTCTimingMethods:             []UTCTimingMethod{"direct", "ntp", "sntp", "httpxsdate", "httpiso"},
+				UTCTimingMethods:             []UTCTimingMethod{"direct", "ntp", "sntp", "httpxsdate", "httpiso", "head"},
 			},
 			err: "",
 		},
@@ -48,19 +48,6 @@ func TestProcessURLCfg(t *testing.T) {
 			},
 			err: `key="utc", val="unknown" is not a valid UTC timing method`,
 		},
-		{
-			url:         "/livesim/utc_head/asset.mpd",
-			nowMS:       0,
-			contentPart: "asset.mpd",
-			wantedCfg: &ResponseConfig{
-				StartTimeS:                   0,
-				TimeShiftBufferDepthS:        Ptr(defaultTimeShiftBufferDepthS),
-				StartNr:                      Ptr(0),
-				AvailabilityTimeCompleteFlag: true,
-				TimeSubsDurMS:                defaultTimeSubsDurMS,
-			},
-			err: `key="utc", val="head", UTC timing method "head" not supported`,
-		},
 		{
 			url:         "/livesim2/utc_none/asset.mpd",
 			nowMS:       0,

cmd/livesim2/app/handler_livesim.go

@@ -36,6 +36,7 @@ func (s *Server) livesimHandlerFunc(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, msg, http.StatusInternalServerError)
 		return
 	}
+	fullHost := getSchemeAndHost(r)
 
 	var nowMS int // Set from query string or from wall-clock
 	q := r.URL.Query()
@@ -80,7 +81,7 @@ func (s *Server) livesimHandlerFunc(w http.ResponseWriter, r *http.Request) {
 		_, mpdName := path.Split(contentPart)
 		cfg.SetScheme(s.Cfg.Scheme, r)
 		cfg.SetHost(s.Cfg.Host, r)
-		err := writeLiveMPD(log, w, cfg, a, mpdName, nowMS)
+		err := writeLiveMPD(log, w, cfg, a, mpdName, fullHost, nowMS)
 		if err != nil {
 			// TODO. Add more granular errors like 404 not found
 			msg := fmt.Sprintf("liveMPD: %s", err)
@@ -112,10 +113,18 @@ func (s *Server) livesimHandlerFunc(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func writeLiveMPD(log *zerolog.Logger, w http.ResponseWriter, cfg *ResponseConfig, a *asset, mpdName string, nowMS int) error {
+func getSchemeAndHost(r *http.Request) string {
+	scheme := "http"
+	if r.TLS != nil {
+		scheme = "https"
+	}
+	return fmt.Sprintf("%s://%s", scheme, r.Host)
+}
+
+func writeLiveMPD(log *zerolog.Logger, w http.ResponseWriter, cfg *ResponseConfig, a *asset, mpdName, host string, nowMS int) error {
 	work := make([]byte, 0, 1024)
 	buf := bytes.NewBuffer(work)
-	lMPD, err := LiveMPD(a, mpdName, cfg, nowMS)
+	lMPD, err := LiveMPD(a, mpdName, cfg, host, nowMS)
 	if err != nil {
 		return fmt.Errorf("convertToLive: %w", err)
 	}

cmd/livesim2/app/livempd.go

@@ -43,7 +43,7 @@ func calcWrapTimes(a *asset, cfg *ResponseConfig, nowMS int, tsbd m.Duration) wr
 }
 
 // LiveMPD generates a dynamic configured MPD for a VoD asset.
-func LiveMPD(a *asset, mpdName string, cfg *ResponseConfig, nowMS int) (*m.MPD, error) {
+func LiveMPD(a *asset, mpdName string, cfg *ResponseConfig, host string, nowMS int) (*m.MPD, error) {
 	mpd, err := a.getVodMPD(mpdName)
 	if err != nil {
 		return nil, err
@@ -90,7 +90,7 @@ func LiveMPD(a *asset, mpdName string, cfg *ResponseConfig, nowMS int) (*m.MPD,
 		}
 	}
 
-	addUTCTimings(mpd, cfg)
+	addUTCTimings(mpd, cfg, host)
 
 	afterStop := false
 	endTimeMS := nowMS
@@ -525,7 +525,7 @@ func lastSegAvailTimeS(cfg *ResponseConfig, lsi lastSegInfo) float64 {
 }
 
 // addUTCTimings adds the UTCTiming elements to the MPD.
-func addUTCTimings(mpd *m.MPD, cfg *ResponseConfig) {
+func addUTCTimings(mpd *m.MPD, cfg *ResponseConfig, host string) {
 	if len(cfg.UTCTimingMethods) == 0 {
 		// default if none is set. Use HTTP with ms precision.
 		mpd.UTCTimings = []*m.DescriptorType{
@@ -564,6 +564,11 @@ func addUTCTimings(mpd *m.MPD, cfg *ResponseConfig) {
 				SchemeIdUri: "urn:mpeg:dash:utc:http-iso:2014",
 				Value:       UtcTimingHttpServerMS,
 			}
+		case UtcTimingHead:
+			ut = &m.DescriptorType{
+				SchemeIdUri: "urn:mpeg:dash:utc:http-head:2014",
+				Value:       fmt.Sprintf("%s%s", host, UtcTimingHeadAsset),
+			}
 		case UtcTimingNone:
 			cfg.UTCTimingMethods = nil
 			return // no UTCTiming elements

cmd/livesim2/app/livempd_test.go

@@ -62,7 +62,7 @@ func TestLiveMPD(t *testing.T) {
 		cfg := NewResponseConfig()
 		nowMS := 100_000
 		// Number template
-		liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, nowMS)
+		liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, "", nowMS)
 		assert.NoError(t, err)
 		assert.Equal(t, "dynamic", *liveMPD.Type)
 		assert.Equal(t, m.DateTime("1970-01-01T00:00:00Z"), liveMPD.AvailabilityStartTime)
@@ -83,7 +83,7 @@ func TestLiveMPD(t *testing.T) {
 		}
 		// SegmentTimeline with $Time$
 		cfg.SegTimelineFlag = true
-		liveMPD, err = LiveMPD(asset, tc.mpdName, cfg, nowMS)
+		liveMPD, err = LiveMPD(asset, tc.mpdName, cfg, "", nowMS)
 		assert.NoError(t, err)
 		assert.Equal(t, "dynamic", *liveMPD.Type)
 		assert.Equal(t, m.DateTime("1970-01-01T00:00:00Z"), liveMPD.AvailabilityStartTime)
@@ -133,7 +133,7 @@ func TestLiveMPDWithTimeSubs(t *testing.T) {
 		cfg.TimeSubsStpp = []string{"en", "sv"}
 		nowMS := 100_000
 		// Number template
-		liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, nowMS)
+		liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, "", nowMS)
 		assert.NoError(t, err)
 		assert.Equal(t, "dynamic", *liveMPD.Type)
 		aSets := liveMPD.Periods[0].AdaptationSets
@@ -208,7 +208,7 @@ func TestSegmentTimes(t *testing.T) {
 		}
 		for nowS := tc.startTimeS; nowS < tc.endTimeS; nowS++ {
 			nowMS := nowS * 1000
-			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, nowMS)
+			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, "", nowMS)
 			wantedStartNr := (nowS - 62) / 2 // Sliding window of 60s + one segment
 			assert.NoError(t, err)
 			for _, as := range liveMPD.Periods[0].AdaptationSets {
@@ -460,7 +460,7 @@ func TestPublishTime(t *testing.T) {
 			}
 			err := verifyAndFillConfig(cfg, tc.nowMS)
 			require.NoError(t, err)
-			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, tc.nowMS)
+			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, "", tc.nowMS)
 			assert.NoError(t, err)
 			assert.Equal(t, m.ConvertToDateTimeS(int64(tc.availabilityStartTime)), liveMPD.AvailabilityStartTime)
 			assert.Equal(t, m.DateTime(tc.wantedPublishTime), liveMPD.PublishTime)
@@ -532,7 +532,7 @@ func TestNormalAvailabilityTimeOffset(t *testing.T) {
 			cfg.SegTimelineFlag = tc.segTimelineTime
 			sc := strConvAccErr{}
 			cfg.AvailabilityTimeOffsetS = sc.AtofInf("ato", tc.ato)
-			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, tc.nowMS)
+			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, "", tc.nowMS)
 			if tc.wantedErr != "" {
 				assert.EqualError(t, err, tc.wantedErr)
 				return
@@ -602,7 +602,7 @@ func TestUTCTiming(t *testing.T) {
 			}
 			err := verifyAndFillConfig(cfg, tc.nowMS)
 			require.NoError(t, err)
-			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, tc.nowMS)
+			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, "", tc.nowMS)
 			assert.NoError(t, err)
 			assert.Equal(t, m.DateTime(tc.wantedPublishTime), liveMPD.PublishTime)
 			assert.Equal(t, tc.wantedUTCTimings, len(liveMPD.UTCTimings))
@@ -700,7 +700,7 @@ func TestMultiPeriod(t *testing.T) {
 			default: // $Number$
 				// no flag
 			}
-			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, tc.nowMS)
+			liveMPD, err := LiveMPD(asset, tc.mpdName, cfg, "", tc.nowMS)
 			if tc.wantedErr != "" {
 				assert.EqualError(t, err, tc.wantedErr)
 				return
@@ -754,7 +754,7 @@ func TestRelStartStopTimeIntoLocation(t *testing.T) {
 		asset, ok := am.findAsset(contentPart)
 		require.True(t, ok)
 		_, mpdName := path.Split(contentPart)
-		liveMPD, err := LiveMPD(asset, mpdName, cfg, c.nowMS)
+		liveMPD, err := LiveMPD(asset, mpdName, cfg, "", c.nowMS)
 		require.NoError(t, err)
 		require.Equal(t, c.wantedLocation, string(liveMPD.Location[0]), "the right location element is not inserted")
 	}

cmd/livesim2/app/routes.go

@@ -30,6 +30,7 @@ func (s *Server) Routes(ctx context.Context) error {
 	s.Router.MethodFunc("GET", "/config", s.configHandlerFunc)
 	s.Router.MethodFunc("GET", "/assets", s.assetsHandlerFunc)
 	s.Router.MethodFunc("GET", "/static/*", s.embeddedStaticHandlerFunc)
+	s.Router.MethodFunc("HEAD", "/static/*", s.embeddedStaticHandlerFunc)
 	// LiveRouter is mounted at /livesim2
 	s.LiveRouter.MethodFunc("GET", "/*", s.livesimHandlerFunc)
 	s.LiveRouter.MethodFunc("HEAD", "/*", s.livesimHandlerFunc)

cmd/livesim2/app/static/time.txt

@@ -0,0 +1 @@
+Used for UTCTiming in head mode.

cmd/livesim2/app/strconv.go

@@ -80,10 +80,8 @@ func (s *strConvAccErr) SplitUTCTimings(key, val string) []UTCTimingMethod {
 		utcVal := UTCTimingMethod(val)
 		switch utcVal {
 		case UtcTimingDirect, UtcTimingNtp, UtcTimingSntp, UtcTimingHttpXSDate, UtcTimingHttpISO,
-			UtcTimingNone:
+			UtcTimingNone, UtcTimingHead:
 			utcTimingMethods[i] = utcVal
-		case UtcTimingHead:
-			s.err = fmt.Errorf("key=%q, val=%q, UTC timing method %q not supported", key, val, UtcTimingHead)
 		default:
 			s.err = fmt.Errorf("key=%q, val=%q is not a valid UTC timing method", key, val)
 		}