From e0ec6a8dc980cfb8e01e80130509ff0f385ad5dd Mon Sep 17 00:00:00 2001
From: Trek H <trek.hopton@gmail.com>
Date: Wed, 17 Apr 2019 23:11:23 +0930
Subject: [PATCH] revid: added basic PCM lexer and started adding startMic()
 func to revid setup.

---
 codec/lex/lex.go | 29 +++++++++++++++++++++++++++++
 revid/revid.go   |  7 +++++++
 2 files changed, 36 insertions(+)

diff --git a/codec/lex/lex.go b/codec/lex/lex.go
index da0dd1b6..a3d05df5 100644
--- a/codec/lex/lex.go
+++ b/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
+		}
+	}
+}
diff --git a/revid/revid.go b/revid/revid.go
index d8068115..64fad64b 100644
--- a/revid/revid.go
+++ b/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)