container/mts: using RealTime type from utils package instead of global vars with mutator functions

container/mts/encoder.go

@@ -29,7 +29,6 @@ import (
 	"fmt"
 	"io"
 	"strconv"
-	"sync"
 	"time"
 
 	"bitbucket.org/ausocean/av/codec/h264"
@@ -37,8 +36,43 @@ import (
 	"bitbucket.org/ausocean/av/container/mts/meta"
 	"bitbucket.org/ausocean/av/container/mts/pes"
 	"bitbucket.org/ausocean/av/container/mts/psi"
+	"bitbucket.org/ausocean/utils/realtime"
 )
 
+// Media type values.
+// TODO: reference relevant specifications.
+const (
+	H264ID        = 27
+	H265ID        = 36
+	audioStreamID = 0xc0 // First audio stream ID.
+)
+
+// Constants used to communicate which media codec will be packetized.
+const (
+	EncodeH264 = iota
+	EncodeH265
+	EncodeAudio
+)
+
+// Time-related constants.
+const (
+	// ptsOffset is the offset added to the clock to determine
+	// the current presentation timestamp.
+	ptsOffset = 700 * time.Millisecond
+
+	// PCRFrequency is the base Program Clock Reference frequency in Hz.
+	PCRFrequency = 90000
+
+	// PTSFrequency is the presentation timestamp frequency in Hz.
+	PTSFrequency = 90000
+
+	// MaxPTS is the largest PTS value (i.e., for a 33-bit unsigned integer).
+	MaxPTS = (1 << 33) - 1
+)
+
+// If we are not using NAL based PSI intervals then we will send PSI every 7 packets.
+const psiSendCount = 7
+
 // Some common manifestations of PSI.
 var (
 	// StandardPAT is a minimal PAT.
@@ -77,87 +111,20 @@ var (
 	}
 )
 
-const (
-	psiInterval  = 1 * time.Second
-	psiSendCount = 7
-)
-
 // Meta allows addition of metadata to encoded mts from outside of this pkg.
 // See meta pkg for usage.
 //
 // TODO: make this not global.
 var Meta *meta.Data
 
+// This will help us obtain a realtime for timestamp meta encoding.
+var RealTime = realtime.NewRealTime()
+
 var (
 	patTable = StandardPAT.Bytes()
 	pmtTable []byte
 )
 
-const (
-	H264ID        = 27
-	H265ID        = 36
-	audioStreamID = 0xc0 // First audio stream ID.
-)
-
-// Constants used to communicate which media codec will be packetized.
-const (
-	EncodeH264 = iota
-	EncodeH265
-	EncodeAudio
-)
-
-// Time-related constants.
-const (
-	// ptsOffset is the offset added to the clock to determine
-	// the current presentation timestamp.
-	ptsOffset = 700 * time.Millisecond
-
-	// PCRFrequency is the base Program Clock Reference frequency in Hz.
-	PCRFrequency = 90000
-
-	// PTSFrequency is the presentation timestamp frequency in Hz.
-	PTSFrequency = 90000
-
-	// MaxPTS is the largest PTS value (i.e., for a 33-bit unsigned integer).
-	MaxPTS = (1 << 33) - 1
-)
-
-// Globals for use in keeping real time.
-var (
-	realRefTime time.Time      // Holds a reference real time given to SetTime.
-	sysRefTime  time.Time      // Holds a system reference time set when realRefTime is obtained.
-	timeIsSet   bool           // Indicates if the time has been set.
-	mu          = sync.Mutex{} // Used when accessing/mutating above time vars.
-)
-
-// SetTime allows setting of current time. This is useful if the system running
-// this encoder does not have time keeping. The user may wish to obtain an
-// accurate time from an NTP server or local machine and pass to this function.
-func SetTime(t time.Time) {
-	mu.Lock()
-	realRefTime = t
-	sysRefTime = time.Now()
-	timeIsSet = true
-	mu.Unlock()
-}
-
-// Time provides either a real time that has been calculated from a reference
-// set by SetTime, or using the current system time.
-func Time() time.Time {
-	mu.Lock()
-	t := realRefTime.Add(time.Now().Sub(sysRefTime))
-	mu.Unlock()
-	return t
-}
-
-// TimeIsSet returns true if SetTime has been used to set a real reference time.
-func TimeIsSet() bool {
-	mu.Lock()
-	b := timeIsSet
-	mu.Unlock()
-	return b
-}
-
 // Encoder encapsulates properties of an MPEG-TS generator.
 type Encoder struct {
 	dst io.WriteCloser
@@ -373,8 +340,8 @@ func (e *Encoder) ccFor(pid int) byte {
 // contained in the global Meta struct.
 func updateMeta(b []byte) ([]byte, error) {
 	p := psi.PSIBytes(b)
-	if TimeIsSet() {
+	if RealTime.IsSet() {
-		Meta.Add("ts", strconv.Itoa(int(Time().Unix())))
+		Meta.Add("ts", strconv.Itoa(int(RealTime.Get().Unix())))
 	}
 	err := p.AddDescriptor(psi.MetadataTag, Meta.Encode())
 	return []byte(p), err

revid/senders.go

@@ -118,7 +118,7 @@ func extractMeta(r string, log func(lvl int8, msg string, args ...interface{}))
 		log(logger.Warning, pkg+"No timestamp in reply")
 	} else {
 		log(logger.Debug, fmt.Sprintf("%v got timestamp: %v", pkg, t))
-		mts.SetTime(time.Unix(int64(t), 0))
+		mts.RealTime.Set(time.Unix(int64(t), 0))
 	}
 
 	// Extract location from reply