replace client-read-h264 example with client-read-h264-decode

examples/client-read-h264-decode/main.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"log"
+
+	"github.com/aler9/gortsplib"
+	"github.com/aler9/gortsplib/pkg/base"
+	"github.com/aler9/gortsplib/pkg/rtph264"
+	"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 H264 track
+// 3. decode H264 NALUs of that track into raw frames
+// This example requires the ffmpeg libraries, that can be installed in this way:
+// apt install -y libavformat-dev libswscale-dev gcc pkg-config
+
+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)
+	}
+	defer c.Close()
+
+	// 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 H264 track
+	h264Track := func() int {
+		for i, track := range tracks {
+			if _, ok := track.(*gortsplib.TrackH264); ok {
+				return i
+			}
+		}
+		return -1
+	}()
+	if h264Track < 0 {
+		panic("H264 track not found")
+	}
+
+	// setup RTP->H264 decoder
+	rtpDec := rtph264.NewDecoder()
+
+	// setup H264->raw frames decoder
+	h264dec, err := newH264Decoder()
+	if err != nil {
+		panic(err)
+	}
+	defer h264dec.close()
+
+	// called when a RTP packet arrives
+	c.OnPacketRTP = func(trackID int, payload []byte) {
+		if trackID != h264Track {
+			return
+		}
+
+		// parse RTP packet
+		var pkt rtp.Packet
+		err := pkt.Unmarshal(payload)
+		if err != nil {
+			return
+		}
+
+		// decode H264 NALUs from the RTP packet
+		nalus, _, err := rtpDec.Decode(&pkt)
+		if err != nil {
+			return
+		}
+
+		for _, nalu := range nalus {
+			// decode raw frames from H264 NALUs
+			img, err := h264dec.decode(nalu)
+			if err != nil {
+				panic(err)
+			}
+
+			// wait for a frame
+			if img == nil {
+				continue
+			}
+
+			log.Printf("decoded frame with size %v", img.Bounds().Max)
+		}
+	}
+
+	// start reading tracks
+	err = c.SetupAndPlay(tracks, baseURL)
+	if err != nil {
+		panic(err)
+	}
+
+	// wait until a fatal error
+	panic(c.Wait())
+}