stream/mts/encoder.go: writing psi based on time interval rather than number of packets interval

stream/mts/encoder.go

@@ -122,7 +122,7 @@ var (
 )
 
 const (
-	psiSndCnt = 7
+	psiInterval = 1 * time.Second
 )
 
 // timeLocation holds time and location data
@@ -199,9 +199,10 @@ type Encoder struct {
 	tsSpace       [PacketSize]byte
 	pesSpace      [pes.MaxPesSize]byte
 
-	psiCount int
-
 	continuity map[int]byte
+
+	now         time.Time
+	psiLastTime time.Time
 }
 
 // NewEncoder returns an Encoder with the specified frame rate.
@@ -233,12 +234,15 @@ const (
 // generate handles the incoming data and generates equivalent mpegts packets -
 // sending them to the output channel.
 func (e *Encoder) Encode(nalu []byte) error {
-	if e.psiCount <= 0 {
+	e.now = time.Now()
+	if e.now.Sub(e.psiLastTime) > psiInterval {
 		err := e.writePSI()
 		if err != nil {
 			return err
 		}
+		e.psiLastTime = e.now
 	}
+
 	// Prepare PES data.
 	pesPkt := pes.Packet{
 		StreamID:     streamID,
@@ -269,7 +273,6 @@ func (e *Encoder) Encode(nalu []byte) error {
 			pusi = false
 		}
 		_, err := e.dst.Write(pkt.Bytes(e.tsSpace[:PacketSize]))
-		e.psiCount--
 		if err != nil {
 			return err
 		}
@@ -318,7 +321,6 @@ func (e *Encoder) writePSI() error {
 	if err != nil {
 		return err
 	}
-	e.psiCount = psiSndCnt
 	return nil
 }