client: turn ReadFrames into OnPacketRTP, OnPacketRTCP

examples/client-read-h264/main.go

@@ -14,7 +14,54 @@ import (
 // 3. get H264 NALUs of that track
 
 func main() {
-	c := gortsplib.Client{}
+	var h264Track int
+	var dec *rtph264.Decoder
+
+	c := gortsplib.Client{
+		// called before sending a PLAY request
+		OnPlay: func(c *gortsplib.Client) {
+			// find the H264 track
+			h264Track = func() int {
+				for i, track := range c.Tracks() {
+					if track.IsH264() {
+						return i
+					}
+				}
+				return -1
+			}()
+			if h264Track < 0 {
+				panic(fmt.Errorf("H264 track not found"))
+			}
+			fmt.Printf("H264 track is number %d\n", h264Track+1)
+
+			// instantiate a RTP/H264 decoder
+			dec = rtph264.NewDecoder()
+		},
+		// called when a RTP packet arrives
+		OnPacketRTP: func(c *gortsplib.Client, trackID int, payload []byte) {
+			if trackID != h264Track {
+				return
+			}
+
+			// parse RTP packets
+			var pkt rtp.Packet
+			err := pkt.Unmarshal(payload)
+			if err != nil {
+				return
+			}
+
+			// decode H264 NALUs from RTP packets
+			nalus, _, err := dec.Decode(&pkt)
+			if err != nil {
+				return
+			}
+
+			// print NALUs
+			for _, nalu := range nalus {
+				fmt.Printf("received H264 NALU of size %d\n", len(nalu))
+			}
+		},
+	}
 
 	// connect to the server and start reading all tracks
 	err := c.DialRead("rtsp://localhost:8554/mystream")
@@ -23,50 +70,7 @@ func main() {
 	}
 	defer c.Close()
 
-	// find the H264 track
-	h264Track := func() int {
-		for i, track := range c.Tracks() {
-			if track.IsH264() {
-				return i
-			}
-		}
-		return -1
-	}()
-	if h264Track < 0 {
-		panic(fmt.Errorf("H264 track not found"))
-	}
-	fmt.Printf("H264 track is number %d\n", h264Track+1)
-
-	// instantiate a RTP/H264 decoder
-	dec := rtph264.NewDecoder()
-
 	// read packets
-	err = c.ReadFrames(func(trackID int, streamType gortsplib.StreamType, payload []byte) {
-		if streamType != gortsplib.StreamTypeRTP {
-			return
-		}
-
-		if trackID != h264Track {
-			return
-		}
-
-		// parse RTP packets
-		var pkt rtp.Packet
-		err := pkt.Unmarshal(payload)
-		if err != nil {
-			return
-		}
-
-		// decode H264 NALUs from RTP packets
-		nalus, _, err := dec.Decode(&pkt)
-		if err != nil {
-			return
-		}
-
-		// print NALUs
-		for _, nalu := range nalus {
-			fmt.Printf("received H264 NALU of size %d\n", len(nalu))
-		}
-	})
+	err = c.ReadFrames()
 	panic(err)
 }