snapshot of https://github.com/livekit/livekit.git @ 08c5433449c106943231037d0b892895f6e92d3b (2026-09-15)

pkg/sfu/streamtracker/streamtracker_packet.go

@@ -0,0 +1,141 @@
+// Copyright 2023 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package streamtracker
+
+import (
+	"time"
+
+	"github.com/livekit/protocol/logger"
+)
+
+// --------------------------------------------
+
+type StreamTrackerPacketConfig struct {
+	SamplesRequired uint32        `yaml:"samples_required,omitempty"` // number of samples needed per cycle
+	CyclesRequired  uint32        `yaml:"cycles_required,omitempty"`  // number of cycles needed to be active
+	CycleDuration   time.Duration `yaml:"cycle_duration,omitempty"`
+}
+
+var (
+	DefaultStreamTrackerPacketConfigVideo = map[int32]StreamTrackerPacketConfig{
+		0: {SamplesRequired: 1,
+			CyclesRequired: 4,
+			CycleDuration:  500 * time.Millisecond,
+		},
+		1: {SamplesRequired: 5,
+			CyclesRequired: 20,
+			CycleDuration:  500 * time.Millisecond,
+		},
+		2: {SamplesRequired: 5,
+			CyclesRequired: 20,
+			CycleDuration:  500 * time.Millisecond,
+		},
+	}
+
+	DefaultStreamTrackerPacketConfigScreenshare = map[int32]StreamTrackerPacketConfig{
+		0: {
+			SamplesRequired: 1,
+			CyclesRequired:  1,
+			CycleDuration:   2 * time.Second,
+		},
+		1: {
+			SamplesRequired: 1,
+			CyclesRequired:  1,
+			CycleDuration:   2 * time.Second,
+		},
+		2: {
+			SamplesRequired: 1,
+			CyclesRequired:  1,
+			CycleDuration:   2 * time.Second,
+		},
+	}
+)
+
+// --------------------------------------------
+
+type StreamTrackerPacketParams struct {
+	Config StreamTrackerPacketConfig
+	Logger logger.Logger
+}
+
+type StreamTrackerPacket struct {
+	params StreamTrackerPacketParams
+
+	countSinceLast uint32 // number of packets received since last check
+
+	initialized bool
+
+	cycleCount uint32
+}
+
+func NewStreamTrackerPacket(params StreamTrackerPacketParams) StreamTrackerImpl {
+	return &StreamTrackerPacket{
+		params: params,
+	}
+}
+
+func (s *StreamTrackerPacket) Start() {
+}
+
+func (s *StreamTrackerPacket) Stop() {
+}
+
+func (s *StreamTrackerPacket) Reset() {
+	s.countSinceLast = 0
+	s.cycleCount = 0
+
+	s.initialized = false
+}
+
+func (s *StreamTrackerPacket) GetCheckInterval() time.Duration {
+	return s.params.Config.CycleDuration
+}
+
+func (s *StreamTrackerPacket) Observe(_hasMarker bool, _ts uint32) StreamStatusChange {
+	if !s.initialized {
+		// first packet
+		s.initialized = true
+		s.countSinceLast = 1
+		return StreamStatusChangeActive
+	}
+
+	s.countSinceLast++
+	return StreamStatusChangeNone
+}
+
+func (s *StreamTrackerPacket) CheckStatus() StreamStatusChange {
+	if !s.initialized {
+		// should not be getting called when not initialized, but be safe
+		return StreamStatusChangeNone
+	}
+
+	if s.countSinceLast >= s.params.Config.SamplesRequired {
+		s.cycleCount++
+	} else {
+		s.cycleCount = 0
+	}
+
+	statusChange := StreamStatusChangeNone
+	if s.cycleCount == 0 {
+		// no packets seen for a period, flip to stopped
+		statusChange = StreamStatusChangeStopped
+	} else if s.cycleCount >= s.params.Config.CyclesRequired {
+		// packets seen for some time after resume, flip to active
+		statusChange = StreamStatusChangeActive
+	}
+
+	s.countSinceLast = 0
+	return statusChange
+}