mts: add getters and setters with mutex to the TimeLocation struct.

stream/mts/encoder.go

@@ -30,6 +30,7 @@ package mts
 
 import (
 	"io"
+	"sync"
 	"time"
 
 	"bitbucket.org/ausocean/av/stream/mts/pes"
@@ -124,21 +125,46 @@ const (
 	psiSendCount  = 7
 )
 
-type TimeLocation struct {
-	Time     uint64
-	Location string
+// TimeLocation can hold time and location data for the insertion into mpegts
+// packets.
+type timeLocation struct {
+	sync.RWMutex
+	time     uint64
+	location string
 }
 
-var metaData = TimeLocation{}
-
-func SetTimeStamp(t uint64) {
-	metaData.Time = t
+// SetTimeStamp sets the time field of a TimeLocation.
+func (tl *timeLocation) SetTimeStamp(t uint64) {
+	tl.Lock()
+	tl.time = t
+	tl.Unlock()
 }
 
-func SetLocation(g string) {
-	metaData.Location = g
+// GetTimeStamp returns the location of a TimeLocation.
+func (tl *timeLocation) GetTimeStamp() uint64 {
+	tl.RLock()
+	defer tl.RUnlock()
+	return tl.time
 }
 
+// SetLocation sets the location of a TimeLocation.
+func (tl *timeLocation) SetLocation(l string) {
+	tl.Lock()
+	tl.location = l
+	tl.Unlock()
+}
+
+// GetLocation returns the location of a TimeLocation.
+func (tl *timeLocation) GetLocation() string {
+	tl.RLock()
+	defer tl.RUnlock()
+	return tl.location
+}
+
+// MetData will hold time and location data which may be set externally if
+// this data is available. It is then inserted into mpegts packets outputted.
+var MetaData timeLocation
+
 var (
 	patTable = standardPat.Bytes()
 	pmtTable = standardPmtTimeLocation.Bytes()
@@ -269,11 +295,11 @@ func (e *Encoder) writePSI() error {
 	}
 
 	// Update pmt table time and location.
-	err = psi.UpdateTime(pmtTable, metaData.Time)
+	err = psi.UpdateTime(pmtTable, MetaData.GetTimeStamp())
 	if err != nil {
 		return err
 	}
-	err = psi.UpdateLocation(pmtTable, metaData.Location)
+	err = psi.UpdateLocation(pmtTable, MetaData.GetLocation())
 	if err != nil {
 		return nil
 	}