simplify examples (#389)

examples/client-read-format-h264-save-to-disk/mpegts_muxer.go

@@ -18,12 +18,11 @@ type mpegtsMuxer struct {
 	sps []byte
 	pps []byte
 
-	f                *os.File
-	b                *bufio.Writer
-	w                *mpegts.Writer
-	track            *mpegts.Track
-	dtsExtractor     *h264.DTSExtractor
-	firstIDRReceived bool
+	f            *os.File
+	b            *bufio.Writer
+	w            *mpegts.Writer
+	track        *mpegts.Track
+	dtsExtractor *h264.DTSExtractor
 }
 
 // newMPEGTSMuxer allocates a mpegtsMuxer.
@@ -103,26 +102,18 @@ func (e *mpegtsMuxer) encode(au [][]byte, pts time.Duration) error {
 
 	var dts time.Duration
 
-	if !e.firstIDRReceived {
+	if e.dtsExtractor == nil {
 		// skip samples silently until we find one with a IDR
 		if !idrPresent {
 			return nil
 		}
-
-		e.firstIDRReceived = true
 		e.dtsExtractor = h264.NewDTSExtractor()
+	}
 
-		var err error
-		dts, err = e.dtsExtractor.Extract(au, pts)
-		if err != nil {
-			return err
-		}
-	} else {
-		var err error
-		dts, err = e.dtsExtractor.Extract(au, pts)
-		if err != nil {
-			return err
-		}
+	var err error
+	dts, err = e.dtsExtractor.Extract(au, pts)
+	if err != nil {
+		return err
 	}
 
 	// encode into MPEG-TS