revid: add stop signal channel to allow pause in loop mode

revid/revid.go

@@ -116,6 +116,9 @@ type Revid struct {
 
 	// bitrate is used for bitrate calculations.
 	bitrate bitrate.Calculator
+
+	// stop used used to signal stopping when looping an input.
+	stop chan struct{}
 }
 
 // New returns a pointer to a new Revid with the desired configuration, and/or
@@ -440,6 +443,8 @@ func (r *Revid) Start() error {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
+	r.stop = make(chan struct{})
+
 	r.cfg.Logger.Log(logger.Debug, "resetting revid")
 	err := r.reset(r.cfg)
 	if err != nil {
@@ -475,6 +480,8 @@ func (r *Revid) Stop() {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
+	close(r.stop)
+
 	r.cfg.Logger.Log(logger.Debug, "stopping input")
 	err := r.input.Stop()
 	if err != nil {
@@ -904,5 +911,12 @@ 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:
+		}
 	}
 }