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

pkg/sfu/videolayerselector/vp9.go

@@ -0,0 +1,108 @@
+// 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 videolayerselector
+
+import (
+	"github.com/pion/rtp/codecs"
+
+	"github.com/livekit/livekit-server/pkg/sfu/buffer"
+	"github.com/livekit/protocol/logger"
+)
+
+type VP9 struct {
+	*Base
+}
+
+func NewVP9(logger logger.Logger) *VP9 {
+	return &VP9{
+		Base: NewBase(logger),
+	}
+}
+
+func NewVP9FromOther(vls VideoLayerSelector) *VP9 {
+	return &VP9{Base: vls.getBase()}
+}
+
+func (v *VP9) IsOvershootOkay() bool {
+	return false
+}
+
+func (v *VP9) Select(extPkt *buffer.ExtPacket, _layer int32) (result VideoLayerSelectorResult) {
+	vp9, ok := extPkt.Payload.(codecs.VP9Packet)
+	if !ok {
+		return
+	}
+
+	currentLayer := v.currentLayer
+	if v.currentLayer != v.targetLayer {
+		updatedLayer := v.currentLayer
+
+		if !v.currentLayer.IsValid() {
+			if !extPkt.IsKeyFrame {
+				return
+			}
+
+			updatedLayer = extPkt.VideoLayer
+		} else {
+			if v.currentLayer.Temporal != v.targetLayer.Temporal {
+				if v.currentLayer.Temporal < v.targetLayer.Temporal {
+					// temporal scale up
+					if extPkt.VideoLayer.Temporal > v.currentLayer.Temporal && extPkt.VideoLayer.Temporal <= v.targetLayer.Temporal && vp9.U && vp9.B {
+						currentLayer.Temporal = extPkt.VideoLayer.Temporal
+						updatedLayer.Temporal = extPkt.VideoLayer.Temporal
+					}
+				} else {
+					// temporal scale down
+					if vp9.E {
+						updatedLayer.Temporal = v.targetLayer.Temporal
+					}
+				}
+			}
+
+			if v.currentLayer.Spatial != v.targetLayer.Spatial {
+				if v.currentLayer.Spatial < v.targetLayer.Spatial {
+					// spatial scale up
+					if extPkt.VideoLayer.Spatial > v.currentLayer.Spatial && extPkt.VideoLayer.Spatial <= v.targetLayer.Spatial && !vp9.P && vp9.B {
+						currentLayer.Spatial = extPkt.VideoLayer.Spatial
+						updatedLayer.Spatial = extPkt.VideoLayer.Spatial
+					}
+				} else {
+					// spatial scale down
+					if vp9.E {
+						updatedLayer.Spatial = v.targetLayer.Spatial
+					}
+				}
+			}
+		}
+
+		if updatedLayer != v.currentLayer {
+			result.IsSwitching = true
+			if !v.currentLayer.IsValid() && updatedLayer.IsValid() {
+				result.IsResuming = true
+			}
+
+			v.previousLayer = v.currentLayer
+			v.currentLayer = updatedLayer
+		}
+	}
+
+	result.RTPMarker = extPkt.Packet.Marker
+	if vp9.E && extPkt.VideoLayer.Spatial == currentLayer.Spatial && (vp9.P || v.targetLayer.Spatial <= v.currentLayer.Spatial) {
+		result.RTPMarker = true
+	}
+	result.IsSelected = !extPkt.VideoLayer.GreaterThan(currentLayer)
+	result.IsRelevant = true
+	return
+}