codecutil, revid: make codec a type and make const strings for metadata keys

codec/codecutil/list.go

@@ -24,10 +24,13 @@ LICENSE
 
 package codecutil
 
+// Codec represents a media codec.
+type Codec uint8
+
 // A global list containing all available codecs for reference in any application.
-// When adding or removing a codec from this list, the numCodecs const must be updated.
+// When adding or removing a codec from this list, the corresponding codec string const must be updated below.
 const (
-	Undef = iota
+	Undef Codec = iota
 	PCM
 	ADPCM
 	H264
@@ -37,7 +40,35 @@ const (
 	maxCodec
 )
 
-// IsValid recieves an int representing a codec and checks if it is valid.
-func IsValid(codec uint8) bool {
-	return 0 < codec && codec < maxCodec
+const (
+	pcmStr   = "pcm"
+	adpcmStr = "adpcm"
+	h264Str  = "h264"
+	h265Str  = "h265"
+	mjpegStr = "mjpeg"
+	jpegStr  = "jpeg"
+)
+
+// IsValid checks if a codec is a known and valid codec.
+func (c Codec) IsValid() bool {
+	return 0 < c && c < maxCodec
+}
+
+func (c Codec) String() string {
+	switch c {
+	case PCM:
+		return pcmStr
+	case ADPCM:
+		return adpcmStr
+	case H264:
+		return h264Str
+	case H265:
+		return h265Str
+	case MJPEG:
+		return mjpegStr
+	case JPEG:
+		return jpegStr
+	default:
+		return ""
+	}
 }

container/mts/encoder.go

@@ -101,6 +101,13 @@ const (
 	defaultMediaPID  = PIDVideo
 )
 
+// Used to consistently read and write MTS metadata entries.
+const (
+	WriteRateStr = "writeRate"
+	TSStr        = "ts"
+	LocStr       = "loc"
+)
+
 // Meta allows addition of metadata to encoded mts from outside of this pkg.
 // See meta pkg for usage.
 //
@@ -164,7 +171,7 @@ func NewEncoder(dst io.WriteCloser, log logger.LoggerIF, options ...func(*Encode
 	}
 	log.Debug("encoder options applied")
 
-	Meta.Add("writeRate", fmt.Sprintf("%f", 1/float64(e.writePeriod.Seconds())))
+	Meta.Add(WriteRateStr, fmt.Sprintf("%f", 1/float64(e.writePeriod.Seconds())))
 
 	e.pmt.SyntaxSection.SpecificData.(*psi.PMT).StreamSpecificData.StreamType = e.streamID
 	e.pmt.SyntaxSection.SpecificData.(*psi.PMT).StreamSpecificData.PID = e.mediaPID
@@ -332,7 +339,7 @@ func updateMeta(b []byte, log logger.LoggerIF) ([]byte, error) {
 	p := psi.PSIBytes(b)
 	if RealTime.IsSet() {
 		t := strconv.Itoa(int(RealTime.Get().Unix()))
-		Meta.Add("ts", t)
+		Meta.Add(TSStr, t)
 		log.Debug("latest time added to meta", "time", t)
 	}
 	err := p.AddDescriptor(psi.MetadataTag, Meta.Encode())

container/mts/encoder_test.go

@@ -276,7 +276,7 @@ func TestMetaEncode1(t *testing.T) {
 		t.Fatalf("could not create encoder, failed with error: %v", err)
 	}
 
-	Meta.Add("ts", "12345678")
+	Meta.Add(TSStr, "12345678")
 	if err := e.writePSI(); err != nil {
 		t.Errorf("unexpected error: %v\n", err.Error())
 	}
@@ -313,8 +313,8 @@ func TestMetaEncode2(t *testing.T) {
 		t.Fatalf("could not create MTS encoder, failed with error: %v", err)
 	}
 
-	Meta.Add("ts", "12345678")
-	Meta.Add("loc", "1234,4321,1234")
+	Meta.Add(TSStr, "12345678")
+	Meta.Add(LocStr, "1234,4321,1234")
 	if err := e.writePSI(); err != nil {
 		t.Errorf("did not expect error: %v from writePSI", err.Error())
 	}
@@ -350,8 +350,8 @@ func TestExtractMeta(t *testing.T) {
 		t.Fatalf("could not create MTS encoder, failed with error: %v", err)
 	}
 
-	Meta.Add("ts", "12345678")
-	Meta.Add("loc", "1234,4321,1234")
+	Meta.Add(TSStr, "12345678")
+	Meta.Add(LocStr, "1234,4321,1234")
 	if err := e.writePSI(); err != nil {
 		t.Errorf("did not expect error: %v", err.Error())
 	}

revid/audio_linux.go

@@ -36,6 +36,15 @@ import (
 	"bitbucket.org/ausocean/utils/logger"
 )
 
+// Used to reliably read, write, and test audio metadata entry keys.
+const (
+	SampleRateStr = "sampleRate"
+	ChannelsStr   = "channels"
+	PeriodStr     = "period"
+	BitDepthStr   = "bitDepth"
+	CodecStr      = "codec"
+)
+
 func (r *Revid) setupAudio() error {
 	// Create new ALSA device.
 	d := alsa.New(r.cfg.Logger)
@@ -59,19 +68,11 @@ func (r *Revid) setupAudio() error {
 	r.lexTo = l.Lex
 
 	// Add metadata.
-	mts.Meta.Add("sampleRate", strconv.Itoa(int(r.cfg.SampleRate)))
-	mts.Meta.Add("channels", strconv.Itoa(int(r.cfg.Channels)))
-	mts.Meta.Add("period", fmt.Sprintf("%.6f", r.cfg.RecPeriod))
-	mts.Meta.Add("bitDepth", strconv.Itoa(int(r.cfg.BitDepth)))
-
-	switch r.cfg.InputCodec {
-	case codecutil.PCM:
-		mts.Meta.Add("codec", "pcm")
-	case codecutil.ADPCM:
-		mts.Meta.Add("codec", "adpcm")
-	default:
-		r.cfg.Logger.Log(logger.Fatal, "no audio codec set in config")
-	}
+	mts.Meta.Add(SampleRateStr, strconv.Itoa(int(r.cfg.SampleRate)))
+	mts.Meta.Add(ChannelsStr, strconv.Itoa(int(r.cfg.Channels)))
+	mts.Meta.Add(PeriodStr, fmt.Sprintf("%.6f", r.cfg.RecPeriod))
+	mts.Meta.Add(BitDepthStr, strconv.Itoa(int(r.cfg.BitDepth)))
+	mts.Meta.Add(CodecStr, r.cfg.InputCodec.String())
 
 	return nil
 }

revid/config/config.go

@@ -29,6 +29,7 @@ package config
 import (
 	"time"
 
+	"bitbucket.org/ausocean/av/codec/codecutil"
 	"bitbucket.org/ausocean/utils/logger"
 )
 
@@ -168,7 +169,7 @@ type Config struct {
 	// InputCodec defines the input codec we wish to use, and therefore defines the
 	// lexer for use in the pipeline. This defaults to H264, but H265 is also a
 	// valid option if we expect this from the input.
-	InputCodec uint8
+	InputCodec codecutil.Codec
 
 	// InputPath defines the input file location for File Input. This must be
 	// defined if File input is to be used.

revid/config/variables.go

@@ -299,19 +299,7 @@ var Variables = []struct {
 		Name:  KeyInputCodec,
 		Type_: "enum:H264,H265,MJPEG,JPEG,PCM,ADPCM",
 		Update: func(c *Config, v string) {
-			c.InputCodec = parseEnum(
-				KeyInputCodec,
-				v,
-				map[string]uint8{
-					"h264":  codecutil.H264,
-					"h265":  codecutil.H265,
-					"mjpeg": codecutil.MJPEG,
-					"jpeg":  codecutil.JPEG,
-					"pcm":   codecutil.PCM,
-					"adpcm": codecutil.ADPCM,
-				},
-				c,
-			)
+			c.InputCodec = codecutil.FromString(v)
 		},
 		Validate: func(c *Config) {
 			switch c.InputCodec {

revid/senders.go

@@ -153,7 +153,7 @@ func extractMeta(r string, log func(lvl int8, msg string, args ...interface{}))
 		log(logger.Debug, "No location in reply")
 	} else {
 		log(logger.Debug, fmt.Sprintf("got location: %v", g))
-		mts.Meta.Add("loc", g)
+		mts.Meta.Add(LocStr, g)
 	}
 
 	return nil