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server/vendor/github.com/pion/sdp/v3/extmap.go

@@ -0,0 +1,111 @@
+// SPDX-FileCopyrightText: 2023 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+package sdp
+
+import (
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+// Default ext values
+const (
+	DefExtMapValueABSSendTime     = 1
+	DefExtMapValueTransportCC     = 2
+	DefExtMapValueSDESMid         = 3
+	DefExtMapValueSDESRTPStreamID = 4
+
+	ABSSendTimeURI     = "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time"
+	TransportCCURI     = "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01"
+	SDESMidURI         = "urn:ietf:params:rtp-hdrext:sdes:mid"
+	SDESRTPStreamIDURI = "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id"
+	AudioLevelURI      = "urn:ietf:params:rtp-hdrext:ssrc-audio-level"
+)
+
+// ExtMap represents the activation of a single RTP header extension
+type ExtMap struct {
+	Value     int
+	Direction Direction
+	URI       *url.URL
+	ExtAttr   *string
+}
+
+// Clone converts this object to an Attribute
+func (e *ExtMap) Clone() Attribute {
+	return Attribute{Key: "extmap", Value: e.string()}
+}
+
+// Unmarshal creates an Extmap from a string
+func (e *ExtMap) Unmarshal(raw string) error {
+	parts := strings.SplitN(raw, ":", 2)
+	if len(parts) != 2 {
+		return fmt.Errorf("%w: %v", errSyntaxError, raw)
+	}
+
+	fields := strings.Fields(parts[1])
+	if len(fields) < 2 {
+		return fmt.Errorf("%w: %v", errSyntaxError, raw)
+	}
+
+	valdir := strings.Split(fields[0], "/")
+	value, err := strconv.ParseInt(valdir[0], 10, 64)
+	if (value < 1) || (value > 246) {
+		return fmt.Errorf("%w: %v -- extmap key must be in the range 1-256", errSyntaxError, valdir[0])
+	}
+	if err != nil {
+		return fmt.Errorf("%w: %v", errSyntaxError, valdir[0])
+	}
+
+	var direction Direction
+	if len(valdir) == 2 {
+		direction, err = NewDirection(valdir[1])
+		if err != nil {
+			return err
+		}
+	}
+
+	uri, err := url.Parse(fields[1])
+	if err != nil {
+		return err
+	}
+
+	if len(fields) == 3 {
+		tmp := fields[2]
+		e.ExtAttr = &tmp
+	}
+
+	e.Value = int(value)
+	e.Direction = direction
+	e.URI = uri
+	return nil
+}
+
+// Marshal creates a string from an ExtMap
+func (e *ExtMap) Marshal() string {
+	return e.Name() + ":" + e.string()
+}
+
+func (e *ExtMap) string() string {
+	output := fmt.Sprintf("%d", e.Value)
+	dirstring := e.Direction.String()
+	if dirstring != directionUnknownStr {
+		output += "/" + dirstring
+	}
+
+	if e.URI != nil {
+		output += " " + e.URI.String()
+	}
+
+	if e.ExtAttr != nil {
+		output += " " + *e.ExtAttr
+	}
+
+	return output
+}
+
+// Name returns the constant name of this object
+func (e *ExtMap) Name() string {
+	return "extmap"
+}