add server-h264-from-disk example (#719) (#727)

examples/server-h264-from-disk/main.go

@@ -0,0 +1,242 @@
+package main
+
+import (
+	"crypto/rand"
+	"fmt"
+	"log"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/bluenviron/gortsplib/v4"
+	"github.com/bluenviron/gortsplib/v4/pkg/base"
+	"github.com/bluenviron/gortsplib/v4/pkg/description"
+	"github.com/bluenviron/gortsplib/v4/pkg/format"
+	"github.com/bluenviron/mediacommon/v2/pkg/formats/mpegts"
+)
+
+// This example shows how to
+// 1. create a RTSP server which accepts plain connections
+// 2. read from disk a MPEG-TS file which contains a H264 track
+// 3. serve the content of the file to connected readers
+
+func findTrack(r *mpegts.Reader) (*mpegts.Track, error) {
+	for _, track := range r.Tracks() {
+		if _, ok := track.Codec.(*mpegts.CodecH264); ok {
+			return track, nil
+		}
+	}
+	return nil, fmt.Errorf("H264 track not found")
+}
+
+func randUint32() (uint32, error) {
+	var b [4]byte
+	_, err := rand.Read(b[:])
+	if err != nil {
+		return 0, err
+	}
+	return uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3]), nil
+}
+
+type serverHandler struct {
+	server *gortsplib.Server
+	stream *gortsplib.ServerStream
+	mutex  sync.RWMutex
+}
+
+// called when a connection is opened.
+func (sh *serverHandler) OnConnOpen(ctx *gortsplib.ServerHandlerOnConnOpenCtx) {
+	log.Printf("conn opened")
+}
+
+// called when a connection is closed.
+func (sh *serverHandler) OnConnClose(ctx *gortsplib.ServerHandlerOnConnCloseCtx) {
+	log.Printf("conn closed (%v)", ctx.Error)
+}
+
+// called when a session is opened.
+func (sh *serverHandler) OnSessionOpen(ctx *gortsplib.ServerHandlerOnSessionOpenCtx) {
+	log.Printf("session opened")
+}
+
+// called when a session is closed.
+func (sh *serverHandler) OnSessionClose(ctx *gortsplib.ServerHandlerOnSessionCloseCtx) {
+	log.Printf("session closed")
+}
+
+// called when receiving a DESCRIBE request.
+func (sh *serverHandler) OnDescribe(ctx *gortsplib.ServerHandlerOnDescribeCtx) (*base.Response, *gortsplib.ServerStream, error) {
+	log.Printf("describe request")
+
+	sh.mutex.RLock()
+	defer sh.mutex.RUnlock()
+
+	return &base.Response{
+		StatusCode: base.StatusOK,
+	}, sh.stream, nil
+}
+
+// called when receiving a SETUP request.
+func (sh *serverHandler) OnSetup(ctx *gortsplib.ServerHandlerOnSetupCtx) (*base.Response, *gortsplib.ServerStream, error) {
+	log.Printf("setup request")
+
+	sh.mutex.RLock()
+	defer sh.mutex.RUnlock()
+
+	return &base.Response{
+		StatusCode: base.StatusOK,
+	}, sh.stream, nil
+}
+
+// called when receiving a PLAY request.
+func (sh *serverHandler) OnPlay(ctx *gortsplib.ServerHandlerOnPlayCtx) (*base.Response, error) {
+	log.Printf("play request")
+
+	return &base.Response{
+		StatusCode: base.StatusOK,
+	}, nil
+}
+
+func readVideoFile(stream *gortsplib.ServerStream, media *description.Media, forma *format.H264) {
+	// open a file in MPEG-TS format
+	f, err := os.Open("myvideo.ts")
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	// setup MPEG-TS parser
+	r := &mpegts.Reader{R: f}
+	err = r.Initialize()
+	if err != nil {
+		panic(err)
+	}
+
+	// find the H264 track inside the file
+	track, err := findTrack(r)
+	if err != nil {
+		panic(err)
+	}
+
+	// setup H264 -> RTP encoder
+	rtpEnc, err := forma.CreateEncoder()
+	if err != nil {
+		panic(err)
+	}
+
+	randomStart, err := randUint32()
+	if err != nil {
+		panic(err)
+	}
+
+	timeDecoder := mpegts.TimeDecoder{}
+	timeDecoder.Initialize()
+
+	var firstDTS *int64
+	var startTime time.Time
+
+	// setup a callback that is called whenever a H264 access unit is read from the file
+	r.OnDataH264(track, func(pts, dts int64, au [][]byte) error {
+		dts = timeDecoder.Decode(dts)
+		pts = timeDecoder.Decode(pts)
+
+		// sleep between access units
+		if firstDTS != nil {
+			timeDrift := time.Duration(dts-*firstDTS)*time.Second/90000 - time.Since(startTime)
+			if timeDrift > 0 {
+				time.Sleep(timeDrift)
+			}
+		} else {
+			startTime = time.Now()
+			firstDTS = &dts
+		}
+
+		log.Printf("writing access unit with pts=%d dts=%d", pts, dts)
+
+		// wrap the access unit into RTP packets
+		packets, err := rtpEnc.Encode(au)
+		if err != nil {
+			return err
+		}
+
+		// set packet timestamp
+		// we don't have to perform any conversion
+		// since H264 clock rate is the same in both MPEG-TS and RTSP
+		for _, packet := range packets {
+			packet.Timestamp = uint32(int64(randomStart) + pts)
+		}
+
+		// write RTP packets to the server
+		for _, packet := range packets {
+			err := stream.WritePacketRTP(media, packet)
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+
+	for {
+		err := r.Read()
+		if err != nil {
+			panic(err)
+		}
+	}
+}
+
+func main() {
+	h := &serverHandler{}
+
+	// prevent clients from connecting to the server until the stream is properly set up
+	h.mutex.Lock()
+
+	// create the server
+	h.server = &gortsplib.Server{
+		Handler:           h,
+		RTSPAddress:       ":8554",
+		UDPRTPAddress:     ":8000",
+		UDPRTCPAddress:    ":8001",
+		MulticastIPRange:  "224.1.0.0/16",
+		MulticastRTPPort:  8002,
+		MulticastRTCPPort: 8003,
+	}
+
+	// start the server
+	err := h.server.Start()
+	if err != nil {
+		panic(err)
+	}
+
+	// create a RTSP description that contains a H264 format
+	forma := &format.H264{
+		PayloadTyp:        96,
+		PacketizationMode: 1,
+	}
+	desc := &description.Session{
+		Medias: []*description.Media{{
+			Type:    description.MediaTypeVideo,
+			Formats: []format.Format{forma},
+		}},
+	}
+
+	// create a server stream
+	h.stream = &gortsplib.ServerStream{
+		Server: h.server,
+		Desc:   desc,
+	}
+	err = h.stream.Initialize()
+	if err != nil {
+		panic(err)
+	}
+
+	// in a separate routine, read the MPEG-TS file
+	go readVideoFile(h.stream, desc.Medias[0], forma)
+
+	// allow clients to connect
+	h.mutex.Unlock()
+
+	// wait until a fatal error
+	log.Printf("server is ready on %s", h.server.RTSPAddress)
+	panic(h.server.Wait())
+}