add RTP-Info header

pkg/headers/rtpinfo.go

@@ -0,0 +1,87 @@
+package headers
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/aler9/gortsplib/pkg/base"
+)
+
+// RTPInfoEntry is an entry of an RTP-Info header.
+type RTPInfoEntry struct {
+	URL            *base.URL
+	SequenceNumber uint16
+	RTPTime        uint32
+}
+
+// RTPInfo is a RTP-Info header.
+type RTPInfo []RTPInfoEntry
+
+// ReadRTPInfo decodes a RTP-Info header.
+func ReadRTPInfo(v base.HeaderValue) (*RTPInfo, error) {
+	if len(v) == 0 {
+		return nil, fmt.Errorf("value not provided")
+	}
+
+	if len(v) > 1 {
+		return nil, fmt.Errorf("value provided multiple times (%v)", v)
+	}
+
+	h := &RTPInfo{}
+
+	for _, tmp := range strings.Split(v[0], ",") {
+		e := RTPInfoEntry{}
+
+		for _, kv := range strings.Split(tmp, ";") {
+			tmp := strings.SplitN(kv, "=", 2)
+			if len(tmp) != 2 {
+				return nil, fmt.Errorf("unable to parse key-value (%v)", kv)
+			}
+
+			k, v := tmp[0], tmp[1]
+			switch k {
+			case "url":
+				vu, err := base.ParseURL(v)
+				if err != nil {
+					return nil, err
+				}
+				e.URL = vu
+
+			case "seq":
+				vi, err := strconv.ParseUint(v, 10, 16)
+				if err != nil {
+					return nil, err
+				}
+				e.SequenceNumber = uint16(vi)
+
+			case "rtptime":
+				vi, err := strconv.ParseUint(v, 10, 32)
+				if err != nil {
+					return nil, err
+				}
+				e.RTPTime = uint32(vi)
+
+			default:
+				return nil, fmt.Errorf("invalid key: %v", k)
+			}
+		}
+
+		*h = append(*h, e)
+	}
+
+	return h, nil
+}
+
+// Write encodes a RTP-Info header.
+func (h RTPInfo) Write() base.HeaderValue {
+	var rets []string
+
+	for _, e := range h {
+		rets = append(rets, "url="+e.URL.String()+
+			";seq="+strconv.FormatUint(uint64(e.SequenceNumber), 10)+
+			";rtptime="+strconv.FormatUint(uint64(e.RTPTime), 10))
+	}
+
+	return base.HeaderValue{strings.Join(rets, ",")}
+}