device/file & revid/pipeline.go: add looping functionality to file device and removing from processFrom

device/file/file.go

@@ -82,7 +82,26 @@ func (m *AVFile) Stop() error {
 // called and Stop has since been called, an error is returned.
 func (m *AVFile) Read(p []byte) (int, error) {
 	if m.f != nil {
-		return m.f.Read(p)
+		n, err := m.f.Read()
+		if err != nil {
+			// In the case that we reach end of file but loop is true, we want to
+			// seek to start and keep reading from there.
+			if err == io.EOF && m.cfg.Loop {
+				_, err = m.f.Seek(0,io.SeekStart)
+				if err != nil {
+					return 0, fmt.Errorf("could not seek to start of file for input loop: %w",err)
+				}
+
+				// Now that we've seeked to start, let's try reading again.
+				n, err = m.f.Read()
+				if err != nil {
+					return n, fmt.Errorf("could not read after start seek: %w",err)
+				}
+				return n, nil
+			}
+			return n, err
+		}
+		return n, nil  
 	}
 	return 0, errors.New("AV file is closed")
 }

revid/pipeline.go

@@ -332,7 +332,6 @@ func (r *Revid) setLexer(c uint8, isRTSP bool) error {
 func (r *Revid) processFrom(in device.AVDevice, delay time.Duration) {
 	defer r.wg.Done()
 
-	for l := true; l; l = r.cfg.Loop {
 	err := in.Start()
 	if err != nil {
 		r.err <- fmt.Errorf("could not start input device: %w", err)
@@ -361,12 +360,4 @@ func (r *Revid) processFrom(in device.AVDevice, delay time.Duration) {
 	} else {
 		r.cfg.Logger.Log(logger.Info, "input stopped")
 	}
-
-		// If we're looping and we get a stop signal we return.
-		select {
-		case <-r.stop:
-			return
-		default:
-		}
-	}
 }