add client-read-aac example

README.md

@@ -55,6 +55,7 @@ Features:
 * [client-read-pause](examples/client-read-pause/main.go)
 * [client-read-h264](examples/client-read-h264/main.go)
 * [client-read-h264-save-to-disk](examples/client-read-h264-save-to-disk/main.go)
+* [client-read-aac](examples/client-read-aac/main.go)
 * [client-publish-h264](examples/client-publish-h264/main.go)
 * [client-publish-aac](examples/client-publish-aac/main.go)
 * [client-publish-opus](examples/client-publish-opus/main.go)

examples/client-read-aac/main.go

@@ -0,0 +1,107 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/aler9/gortsplib"
+	"github.com/aler9/gortsplib/pkg/base"
+	"github.com/aler9/gortsplib/pkg/rtpaac"
+	"github.com/pion/rtp"
+)
+
+// This example shows how to
+// 1. connect to a RTSP server and read all tracks on a path
+// 2. check whether there's an AAC track
+// 3. get AAC AUs of that track
+
+func main() {
+	c := gortsplib.Client{}
+
+	// parse URL
+	u, err := base.ParseURL("rtsp://localhost:8554/mystream")
+	if err != nil {
+		panic(err)
+	}
+
+	// connect to the server
+	err = c.Start(u.Scheme, u.Host)
+	if err != nil {
+		panic(err)
+	}
+
+	// get available methods
+	_, err = c.Options(u)
+	if err != nil {
+		panic(err)
+	}
+
+	// find published tracks
+	tracks, baseURL, _, err := c.Describe(u)
+	if err != nil {
+		panic(err)
+	}
+
+	// find the AAC track
+	aacTrack := func() int {
+		for i, track := range tracks {
+			if track.IsAAC() {
+				return i
+			}
+		}
+		return -1
+	}()
+	if aacTrack < 0 {
+		panic("AAC track not found")
+	}
+
+	// get track config
+	aacConf, err := tracks[aacTrack].ExtractConfigAAC()
+	if err != nil {
+		panic(err)
+	}
+
+	// setup decoder
+	dec := rtpaac.NewDecoder(aacConf.SampleRate)
+
+	// called when a RTP packet arrives
+	c.OnPacketRTP = func(trackID int, payload []byte) {
+		if trackID != aacTrack {
+			return
+		}
+
+		// parse RTP packet
+		var pkt rtp.Packet
+		err := pkt.Unmarshal(payload)
+		if err != nil {
+			return
+		}
+
+		// decode AAC AUs from RTP packets
+		aus, _, err := dec.Decode(&pkt)
+		if err != nil {
+			return
+		}
+
+		// print AUs
+		for _, au := range aus {
+			fmt.Printf("received AAC AU of size %d\n", len(au))
+		}
+	}
+
+	// setup all tracks
+	for _, t := range tracks {
+		_, err := c.Setup(true, baseURL, t, 0, 0)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	// start reading tracks
+	_, err = c.Play(nil)
+	if err != nil {
+		panic(err)
+	}
+
+	// wait until a fatal error
+	panic(c.Wait())
+}

examples/client-read-h264-save-to-disk/mpegtsencoder.go

@@ -125,6 +125,6 @@ func (e *mpegtsEncoder) encode(nalus [][]byte, pts time.Duration) error {
 		return err
 	}
 
-	fmt.Println("wrote ts packet")
+	fmt.Println("wrote TS packet")
 	return nil
 }