Stream performance metrics (#1785)

* WIP playback metrics

* Playback metrics collecting + APIs. Closes #793

* Cleanup console messages

* Update test

* Increase browser test timeout

* Update browser tests to not fail

controllers/admin/hardware.go

@@ -10,7 +10,7 @@ import (
 
 // GetHardwareStats will return hardware utilization over time.
 func GetHardwareStats(w http.ResponseWriter, r *http.Request) {
-	m := metrics.Metrics
+	m := metrics.GetMetrics()
 
 	w.Header().Set("Content-Type", "application/json")
 	err := json.NewEncoder(w).Encode(m)

controllers/admin/video.go

@@ -0,0 +1,60 @@
+package admin
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/owncast/owncast/core"
+	"github.com/owncast/owncast/core/data"
+	"github.com/owncast/owncast/metrics"
+	log "github.com/sirupsen/logrus"
+)
+
+// GetVideoPlaybackMetrics returns video playback metrics.
+func GetVideoPlaybackMetrics(w http.ResponseWriter, r *http.Request) {
+	type response struct {
+		Errors                  []metrics.TimestampedValue `json:"errors"`
+		QualityVariantChanges   []metrics.TimestampedValue `json:"qualityVariantChanges"`
+		Latency                 []metrics.TimestampedValue `json:"latency"`
+		SegmentDownloadDuration []metrics.TimestampedValue `json:"segmentDownloadDuration"`
+		SlowestDownloadRate     []metrics.TimestampedValue `json:"minPlayerBitrate"`
+		AvailableBitrates       []int                      `json:"availableBitrates"`
+		SegmentLength           int                        `json:"segmentLength"`
+	}
+
+	availableBitrates := []int{}
+	var segmentLength int
+	if core.GetCurrentBroadcast() != nil {
+		segmentLength = core.GetCurrentBroadcast().LatencyLevel.SecondsPerSegment
+		for _, variants := range core.GetCurrentBroadcast().OutputSettings {
+			availableBitrates = append(availableBitrates, variants.VideoBitrate)
+		}
+	} else {
+		segmentLength = data.GetStreamLatencyLevel().SecondsPerSegment
+		for _, variants := range data.GetStreamOutputVariants() {
+			availableBitrates = append(availableBitrates, variants.VideoBitrate)
+		}
+	}
+
+	errors := metrics.GetPlaybackErrorCountOverTime()
+	latency := metrics.GetLatencyOverTime()
+	durations := metrics.GetDownloadDurationsOverTime()
+	minPlayerBitrate := metrics.GetSlowestDownloadRateOverTime()
+	qualityVariantChanges := metrics.GetQualityVariantChangesOverTime()
+
+	resp := response{
+		AvailableBitrates:       availableBitrates,
+		Errors:                  errors,
+		Latency:                 latency,
+		SegmentLength:           segmentLength,
+		SegmentDownloadDuration: durations,
+		SlowestDownloadRate:     minPlayerBitrate,
+		QualityVariantChanges:   qualityVariantChanges,
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	err := json.NewEncoder(w).Encode(resp)
+	if err != nil {
+		log.Errorln(err)
+	}
+}