Fix busy RTSP backchannel

README.md

@@ -2,9 +2,9 @@
 
 **go2rtc** - ultimate camera streaming application with support RTSP, WebRTC, FFmpeg, RTMP, etc.
 
-- zero-dependency and zero-config small [app for all OS](#installation) (Windows, macOS, Linux, ARM)
+- zero-dependency and zero-config small [app for all OS](#go2rtc-binary) (Windows, macOS, Linux, ARM)
 - zero-delay for all supported protocols (lowest possible streaming latency)
-- zero-load on CPU for supported codecs
+- low CPU load for supported codecs
 - on the fly transcoding for unsupported codecs via [FFmpeg](#source-ffmpeg)
 - multi-source 2-way [codecs negotiation](#codecs-negotiation)
 - streaming from private networks via [Ngrok](#module-webrtc)
@@ -14,7 +14,7 @@
 - [webrtc](https://github.com/pion/webrtc) go library and whole [@pion](https://github.com/pion) team
 - series of streaming projects from [@deepch](https://github.com/deepch)
 - [rtsp-simple-server](https://github.com/aler9/rtsp-simple-server) idea from [@aler9](https://github.com/aler9)
-- [GStreamer](https://gstreamer.freedesktop.org/) multimedia framework pipeline idea
+- [GStreamer](https://gstreamer.freedesktop.org/) framework pipeline idea
 - [MediaSoup](https://mediasoup.org/) framework routing idea
 
 ## Codecs negotiation
@@ -76,7 +76,7 @@ Download binary for your OS from [latest release](https://github.com/AlexxIT/go2
 - `go2rtc_mac_amd64` - Mac with Intel
 - `go2rtc_mac_arm64` - Mac with M1
 
-Don't forget to fix the rights `chmod +x go2rtc_linux_xxx` on Linux and Mac.
+Don't forget to fix the rights `chmod +x go2rtc_xxx_xxx` on Linux and Mac.
 
 ### go2rtc: Home Assistant Add-on
 
@@ -103,7 +103,7 @@ Create file `go2rtc.yaml` next to the app.
 - `api` server will start on default **1984 port**
 - `rtsp` server will start on default **8554 port**
 - `webrtc` will use random UDP port for each connection
-- `ffmpeg` will use default transcoding options (you need to install it [manually](https://ffmpeg.org/))
+- `ffmpeg` will use default transcoding options (you may install it [manually](https://ffmpeg.org/))
 
 Available modules:
 
@@ -118,7 +118,7 @@ Available modules:
 
 ### Module: Streams
 
-**go2rtc** support different stream source types. You can config only one link as stream source or multiple.
+**go2rtc** support different stream source types. You can config one or multiple link as stream source.
 
 Available source types:
 
@@ -128,6 +128,8 @@ Available source types:
 - [exec](#source-exec) - advanced FFmpeg and GStreamer integration
 - [hass](#source-hass) - Home Assistant integration
 
+**PS.** You can use sources like `MJPEG`, `HLS` and others via FFmpeg integration.
+
 #### Source: RTSP
 
 - Support **RTSP and RTSPS** links with multiple video and audio tracks
@@ -274,9 +276,9 @@ rtsp:
 
 ### Module: WebRTC
 
-WebRTC usually works without problems in the local network. But external access may require additional settings. It depends on what type of internet do you have.
+WebRTC usually works without problems in the local network. But external access may require additional settings. It depends on what type of Internet do you have.
 
-- by default, WebRTC use two random UDP ports for each connection (for video and audio)
+- by default, WebRTC use two random UDP ports for each connection (video and audio)
 - you can enable one additional TCP port for all connections and use it for external access
 
 **Static public IP**
@@ -405,10 +407,9 @@ In other cases you need to use IP-address of server with **go2rtc** application.
 2. Add generic camera with RTSP link:
    - Hass > Settings > Integrations > Add Integration > [Generic Camera](https://my.home-assistant.io/redirect/config_flow_start/?domain=generic) > `rtsp://...` or `rtmp://...`
 3. Use Picture Entity or Picture Glance lovelace card
+   - you can use either direct RTSP links to cameras or take RTSP streams from **go2rtc**
 4. Open full screen card - this is should be WebRTC stream
 
-- you can use either direct RTSP links to cameras or take RTSP streams from **go2rtc**
-
 PS. Default Home Assistant lovelace cards don't support 2-way audio. You can use 2-way audio from [Add-on Web UI](https://my.home-assistant.io/redirect/supervisor_addon/?addon=a889bffc_go2rtc&repository_url=https%3A%2F%2Fgithub.com%2FAlexxIT%2Fhassio-addons). But you need use HTTPS to access the microphone. This is a browser restriction and cannot be avoided.
 
 ### Module: Log

cmd/api/api.go

@@ -9,8 +9,6 @@ import (
 	"github.com/rs/zerolog"
 	"net"
 	"net/http"
-	"os"
-	"strconv"
 )
 
 func Init() {
@@ -39,9 +37,7 @@ func Init() {
 
 	HandleFunc("/api/frame.mp4", frameHandler)
 	HandleFunc("/api/frame.raw", frameHandler)
-	HandleFunc("/api/stack", stackHandler)
 	HandleFunc("/api/streams", streamsHandler)
-	HandleFunc("/api/exit", exitHandler)
 	HandleFunc("/api/ws", apiWS)
 
 	// ensure we can listen without errors
@@ -99,12 +95,6 @@ func streamsHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func exitHandler(w http.ResponseWriter, r *http.Request) {
-	s := r.URL.Query().Get("code")
-	code, _ := strconv.Atoi(s)
-	os.Exit(code)
-}
-
 func apiWS(w http.ResponseWriter, r *http.Request) {
 	ctx := new(Context)
 	if err := ctx.Upgrade(w, r); err != nil {

cmd/debug/debug.go

@@ -0,0 +1,27 @@
+package debug
+
+import (
+	"github.com/AlexxIT/go2rtc/cmd/api"
+	"github.com/AlexxIT/go2rtc/cmd/streams"
+	"github.com/AlexxIT/go2rtc/pkg/streamer"
+	"net/http"
+	"os"
+	"strconv"
+)
+
+func Init() {
+	api.HandleFunc("/api/stack", stackHandler)
+	api.HandleFunc("/api/exit", exitHandler)
+
+	streams.HandleFunc("null", nullHandler)
+}
+
+func exitHandler(_ http.ResponseWriter, r *http.Request) {
+	s := r.URL.Query().Get("code")
+	code, _ := strconv.Atoi(s)
+	os.Exit(code)
+}
+
+func nullHandler(string) (streamer.Producer, error) {
+	return nil, nil
+}

cmd/debug/stack.go

@@ -1,4 +1,4 @@
-package api
+package debug
 
 import (
 	"bytes"

cmd/rtsp/rtsp.go

@@ -65,8 +65,17 @@ func rtspHandler(url string) (streamer.Producer, error) {
 	if err = conn.Dial(); err != nil {
 		return nil, err
 	}
+
+	conn.Backchannel = true
 	if err = conn.Describe(); err != nil {
-		return nil, err
+		// second try without backchannel, we need to reconnect
+		if err = conn.Dial(); err != nil {
+			return nil, err
+		}
+		conn.Backchannel = false
+		if err = conn.Describe(); err != nil {
+			return nil, err
+		}
 	}
 
 	return conn, nil

cmd/streams/producer.go

@@ -2,6 +2,7 @@ package streams
 
 import (
 	"github.com/AlexxIT/go2rtc/pkg/streamer"
+	"sync"
 )
 
 type state byte
@@ -21,15 +22,19 @@ type Producer struct {
 	tracks  []*streamer.Track
 
 	state state
+	mx    sync.Mutex
 }
 
 func (p *Producer) GetMedias() []*streamer.Media {
+	p.mx.Lock()
+	defer p.mx.Unlock()
+
 	if p.state == stateNone {
 		log.Debug().Str("url", p.url).Msg("[streams] probe producer")
 
 		var err error
 		p.element, err = GetProducer(p.url)
-		if err != nil {
+		if err != nil || p.element == nil {
 			log.Error().Err(err).Str("url", p.url).Msg("[streams] probe producer")
 			return nil
 		}
@@ -41,6 +46,9 @@ func (p *Producer) GetMedias() []*streamer.Media {
 }
 
 func (p *Producer) GetTrack(media *streamer.Media, codec *streamer.Codec) *streamer.Track {
+	p.mx.Lock()
+	defer p.mx.Unlock()
+
 	if p.state == stateMedias {
 		p.state = stateTracks
 	}
@@ -61,6 +69,9 @@ func (p *Producer) GetTrack(media *streamer.Media, codec *streamer.Codec) *strea
 // internals
 
 func (p *Producer) start() {
+	p.mx.Lock()
+	defer p.mx.Unlock()
+
 	if p.state != stateTracks {
 		return
 	}
@@ -72,10 +83,18 @@ func (p *Producer) start() {
 }
 
 func (p *Producer) stop() {
+	p.mx.Lock()
+
 	log.Debug().Str("url", p.url).Msg("[streams] stop producer")
 
-	_ = p.element.Stop()
+	if p.element != nil {
-	p.element = nil
+		_ = p.element.Stop()
+		p.element = nil
+	} else {
+		log.Warn().Str("url", p.url).Msg("[streams] stop empty producer")
+	}
 	p.tracks = nil
 	p.state = stateNone
+
+	p.mx.Unlock()
 }

cmd/streams/stream.go

@@ -2,6 +2,7 @@ package streams
 
 import (
 	"encoding/json"
+	"errors"
 	"github.com/AlexxIT/go2rtc/pkg/streamer"
 )
 
@@ -78,7 +79,7 @@ func (s *Stream) AddConsumer(cons streamer.Consumer) (err error) {
 
 	// can't match tracks for consumer
 	if len(consumer.tracks) == 0 {
-		return nil
+		return errors.New("couldn't find the matching tracks")
 	}
 
 	s.consumers = append(s.consumers, consumer)

cmd/streams/stream_test.go

@@ -2,6 +2,7 @@ package streams
 
 import (
 	"github.com/AlexxIT/go2rtc/pkg/fake"
+	"github.com/AlexxIT/go2rtc/pkg/rtsp"
 	"github.com/AlexxIT/go2rtc/pkg/streamer"
 	"github.com/stretchr/testify/assert"
 	"testing"
@@ -103,7 +104,7 @@ a=control:streamid=0
 
 func TestRouting(t *testing.T) {
 	prod := &fake.Producer{}
-	prod.Medias, _ = streamer.UnmarshalRTSPSDP([]byte(dahuaSimple))
+	prod.Medias, _ = rtsp.UnmarshalSDP([]byte(dahuaSimple))
 	assert.Len(t, prod.Medias, 3)
 
 	HandleFunc("fake", func(url string) (streamer.Producer, error) {

cmd/webrtc/webrtc.go

@@ -108,6 +108,7 @@ func offerHandler(ctx *api.Context, msg *streamer.Message) {
 	// 2. AddConsumer, so we get new tracks
 	if err = stream.AddConsumer(conn); err != nil {
 		log.Warn().Err(err).Msg("[api.webrtc] add consumer")
+		_ = conn.Conn.Close()
 		ctx.Error(err)
 		return
 	}

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"github.com/AlexxIT/go2rtc/cmd/api"
 	"github.com/AlexxIT/go2rtc/cmd/app"
+	"github.com/AlexxIT/go2rtc/cmd/debug"
 	"github.com/AlexxIT/go2rtc/cmd/exec"
 	"github.com/AlexxIT/go2rtc/cmd/ffmpeg"
 	"github.com/AlexxIT/go2rtc/cmd/hass"
@@ -33,6 +34,7 @@ func main() {
 	mse.Init()
 
 	ngrok.Init()
+	debug.Init()
 
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)

pkg/rtsp/conn.go

@@ -50,6 +50,8 @@ type Conn struct {
 
 	// public
 
+	Backchannel bool
+
 	Medias    []*streamer.Media
 	Session   string
 	UserAgent string
@@ -106,6 +108,9 @@ func (c *Conn) Dial() (err error) {
 	//if c.state != StateClientInit {
 	//	panic("wrong state")
 	//}
+	if c.conn != nil && c.auth != nil {
+		c.auth.Reset()
+	}
 
 	c.conn, err = net.DialTimeout(
 		"tcp", c.URL.Host, 10*time.Second,
@@ -146,7 +151,9 @@ func (c *Conn) Request(req *tcp.Request) error {
 	}
 
 	c.sequence++
-	req.Header.Set("CSeq", strconv.Itoa(c.sequence))
+	// important to send case sensitive CSeq
+	// https://github.com/AlexxIT/go2rtc/issues/7
+	req.Header["CSeq"] = []string{strconv.Itoa(c.sequence)}
 
 	c.auth.Write(req)
 
@@ -256,21 +263,17 @@ func (c *Conn) Describe() error {
 		Method: MethodDescribe,
 		URL:    c.URL,
 		Header: map[string][]string{
-			"Accept":  {"application/sdp"},
+			"Accept": {"application/sdp"},
-			"Require": {"www.onvif.org/ver20/backchannel"},
 		},
 	}
 
+	if c.Backchannel {
+		req.Header.Set("Require", "www.onvif.org/ver20/backchannel")
+	}
+
 	res, err := c.Do(req)
 	if err != nil {
-		if res != nil {
+		return err
-			// if we have answer - give second chanse without onvif header
-			req.Header.Del("Require")
-			res, err = c.Do(req)
-		}
-		if err != nil {
-			return err
-		}
 	}
 
 	if val := res.Header.Get("Content-Base"); val != "" {
@@ -280,13 +283,7 @@ func (c *Conn) Describe() error {
 		}
 	}
 
-	// fix bug in Sonoff camera SDP "o=- 1 1 IN IP4 rom t_rtsplin"
+	c.Medias, err = UnmarshalSDP(res.Body)
-	// TODO: make some universal fix
-	if i := bytes.Index(res.Body, []byte("rom t_rtsplin")); i > 0 {
-		res.Body[i+3] = '_'
-	}
-
-	c.Medias, err = streamer.UnmarshalRTSPSDP(res.Body)
 	if err != nil {
 		return err
 	}
@@ -372,9 +369,10 @@ func (c *Conn) SetupMedia(
 
 	// Transport: RTP/AVP/TCP;unicast;interleaved=10-11;ssrc=10117CB7
 	// Transport: RTP/AVP/TCP;unicast;destination=192.168.1.123;source=192.168.10.12;interleaved=0
+	// Transport: RTP/AVP/TCP;ssrc=22345682;interleaved=0-1
 	s := res.Header.Get("Transport")
 	// TODO: rewrite
-	if !strings.HasPrefix(s, "RTP/AVP/TCP;unicast") {
+	if !strings.HasPrefix(s, "RTP/AVP/TCP;") {
 		return nil, fmt.Errorf("wrong transport: %s", s)
 	}
 
@@ -477,7 +475,7 @@ func (c *Conn) Accept() error {
 				return errors.New("wrong content type")
 			}
 
-			c.Medias, err = streamer.UnmarshalRTSPSDP(req.Body)
+			c.Medias, err = UnmarshalSDP(req.Body)
 			if err != nil {
 				return err
 			}
@@ -726,17 +724,35 @@ type RTCP struct {
 	Packets []rtcp.Packet
 }
 
-func between(s, sub1, sub2 string) (res string, ok1 bool, ok2 bool) {
+const sdpHeader = `v=0
-	i := strings.Index(s, sub1)
+o=- 0 0 IN IP4 0.0.0.0
-	if i >= 0 {
+s=-
-		ok1 = true
+t=0 0`
-		s = s[i+len(sub1):]
+
+func UnmarshalSDP(rawSDP []byte) ([]*streamer.Media, error) {
+	medias, err := streamer.UnmarshalSDP(rawSDP)
+	if err != nil {
+		// fix SDP header for some cameras
+		i := bytes.Index(rawSDP, []byte("\nm="))
+		if i > 0 {
+			rawSDP = append([]byte(sdpHeader), rawSDP[i:]...)
+			medias, err = streamer.UnmarshalSDP(rawSDP)
+		}
+		if err != nil {
+			return nil, err
+		}
 	}
 
-	i = strings.Index(s, sub2)
+	// fix bug in ONVIF spec
-	if i >= 0 {
+	// https://www.onvif.org/specs/stream/ONVIF-Streaming-Spec-v241.pdf
-		return s[:i], ok1, true
+	for _, media := range medias {
+		switch media.Direction {
+		case streamer.DirectionRecvonly, "":
+			media.Direction = streamer.DirectionSendonly
+		case streamer.DirectionSendonly:
+			media.Direction = streamer.DirectionRecvonly
+		}
 	}
 
-	return s, ok1, false
+	return medias, nil
 }

pkg/streamer/media.go

@@ -180,26 +180,6 @@ func UnmarshalSDP(rawSDP []byte) ([]*Media, error) {
 	return medias, nil
 }
 
-func UnmarshalRTSPSDP(rawSDP []byte) ([]*Media, error) {
-	medias, err := UnmarshalSDP(rawSDP)
-	if err != nil {
-		return nil, err
-	}
-
-	// fix bug in ONVIF spec
-	// https://www.onvif.org/specs/stream/ONVIF-Streaming-Spec-v241.pdf
-	for _, media := range medias {
-		switch media.Direction {
-		case DirectionRecvonly, "":
-			media.Direction = DirectionSendonly
-		case DirectionSendonly:
-			media.Direction = DirectionRecvonly
-		}
-	}
-
-	return medias, nil
-}
-
 func MarshalSDP(medias []*Media) ([]byte, error) {
 	sd := &sdp.SessionDescription{}
 

pkg/tcp/auth.go

@@ -80,6 +80,12 @@ func (a *Auth) Write(req *Request) {
 	}
 }
 
+func (a *Auth) Reset() {
+	if a.Method == AuthDigest {
+		a.Method = AuthUnknown
+	}
+}
+
 func Between(s, sub1, sub2 string) string {
 	i := strings.Index(s, sub1)
 	if i < 0 {

pkg/tcp/textproto.go

@@ -47,10 +47,13 @@ func ReadResponse(r *bufio.Reader) (*Response, error) {
 	if err != nil {
 		return nil, err
 	}
+	if line == "" {
+		return nil, errors.New("empty response on RTSP request")
+	}
 
 	ss := strings.SplitN(line, " ", 3)
 	if len(ss) != 3 {
-		return nil, errors.New("malformed response")
+		return nil, fmt.Errorf("malformed response: %s", line)
 	}
 
 	res := &Response{

scripts/build_win64.cmd

@@ -0,0 +1,4 @@
+@SET GOOS=windows
+@SET GOARCH=amd64
+cd ..
+go build -ldflags "-s -w" -trimpath && upx-3.96 go2rtc.exe