Move video output validation to protocol (#233)

ingress/errors.go

@@ -3,7 +3,18 @@ package ingress
 import "errors"
 
 var (
-	ErrIngressOutOfDate = errors.New("trying to ovewrite an ingress with an older version")
-	ErrIngressTimedOut  = errors.New("ingress timed out")
-	ErrNoResponse       = errors.New("no response from ingress service")
+	ErrIngressOutOfDate        = errors.New("trying to ovewrite an ingress with an older version")
+	ErrIngressTimedOut         = errors.New("ingress timed out")
+	ErrNoResponse              = errors.New("no response from ingress service")
+	ErrInvalidOutputDimensions = NewInvalidVideoParamsError("invalid output media dimensions")
 )
+
+type InvalidVideoParamsError string
+
+func NewInvalidVideoParamsError(s string) InvalidVideoParamsError {
+	return InvalidVideoParamsError(s)
+}
+
+func (s InvalidVideoParamsError) Error() string {
+	return "invalid video parameters: " + string(s)
+}

ingress/validation.go

@@ -0,0 +1,40 @@
+package ingress
+
+import (
+	"github.com/livekit/protocol/livekit"
+)
+
+func ValidateVideoOptionsConsistency(options *livekit.IngressVideoOptions) error {
+	layersByQuality := make(map[livekit.VideoQuality]*livekit.VideoLayer)
+
+	for _, layer := range options.Layers {
+		if layer.Height == 0 || layer.Width == 0 {
+			return ErrInvalidOutputDimensions
+		}
+
+		if layer.Bitrate == 0 {
+			return NewInvalidVideoParamsError("invalid bitrate")
+		}
+
+		if _, ok := layersByQuality[layer.Quality]; ok {
+			return NewInvalidVideoParamsError("more than one layer with the same quality level")
+		}
+		layersByQuality[layer.Quality] = layer
+	}
+
+	var oldLayerArea uint32
+	for q := livekit.VideoQuality_LOW; q <= livekit.VideoQuality_HIGH; q++ {
+		layer, ok := layersByQuality[q]
+		if !ok {
+			continue
+		}
+		layerArea := layer.Width * layer.Height
+
+		if layerArea <= oldLayerArea {
+			return NewInvalidVideoParamsError("video layers do not have increasing pixel count with increasing quality")
+		}
+		oldLayerArea = layerArea
+	}
+
+	return nil
+}