revid: added basic PCM lexer and started adding startMic() func to revid setup.

codec/lex/lex.go

@@ -36,6 +36,10 @@ import (
 	"time"
 )
 
+const (
+	audioChunkSize = 16000
+)
+
 var noDelay = make(chan time.Time)
 
 func init() {
@@ -245,3 +249,28 @@ func MJPEG(dst io.Writer, src io.Reader, delay time.Duration) error {
 		}
 	}
 }
+
+func PCM(dst io.Writer, src io.Reader, delay time.Duration) error {
+	var tick <-chan time.Time
+	if delay == 0 {
+		tick = noDelay
+	} else {
+		ticker := time.NewTicker(delay)
+		defer ticker.Stop()
+		tick = ticker.C
+	}
+
+	r := bufio.NewReader(src)
+	for {
+		buf := make([]byte, 0, audioChunkSize)
+		_, err := r.Read(buf)
+		if err != nil {
+			return err
+		}
+		<-tick
+		_, err = dst.Write(buf)
+		if err != nil {
+			return err
+		}
+	}
+}

revid/revid.go

@@ -668,6 +668,13 @@ func (r *Revid) setupInputForFile() error {
 	return nil
 }
 
+// startMic is used to start capturing audio from an audio device and processing it.
+func startMic() {
+
+	go processFrom(stream, r.config.Rate)
+	return nil
+}
+
 func (r *Revid) processFrom(read io.Reader, delay time.Duration) {
 	r.config.Logger.Log(logger.Info, pkg+"reading input data")
 	r.err <- r.lexTo(r.buffer, read, delay)