install go2rtc on bob

installs_on_host/go2rtc/pkg/core/README.md

@@ -0,0 +1,40 @@
+## PCM
+
+**RTSP**
+
+- PayloadType=10 - L16/44100/2 - Linear PCM 16-bit big endian
+- PayloadType=11 - L16/44100/1 - Linear PCM 16-bit big endian
+
+https://en.wikipedia.org/wiki/RTP_payload_formats
+
+**Apple QuickTime**
+
+- `raw` - 16-bit data is stored in little endian format
+- `twos` - 16-bit data is stored in big endian format
+- `sowt` - 16-bit data is stored in little endian format
+- `in24` - denotes 24-bit, big endian
+- `in32` - denotes 32-bit, big endian
+- `fl32` - denotes 32-bit floating point PCM
+- `fl64` - denotes 64-bit floating point PCM
+- `alaw` - denotes A-law logarithmic PCM
+- `ulaw` - denotes mu-law logarithmic PCM
+
+https://wiki.multimedia.cx/index.php/PCM
+
+**FFmpeg RTSP**
+
+```
+pcm_s16be, 44100 Hz, stereo => 10
+pcm_s16be, 48000 Hz, stereo => 96 L16/48000/2
+pcm_s16be, 44100 Hz, mono   => 11
+
+pcm_s16le, 48000 Hz, stereo => 96 (b=AS:1536)
+pcm_s16le, 44100 Hz, stereo => 96 (b=AS:1411)
+pcm_s16le, 16000 Hz, stereo => 96 (b=AS:512)
+pcm_s16le, 8000 Hz, stereo  => 96 (b=AS:256)
+
+pcm_s16le, 48000 Hz, mono   => 96 (b=AS:768)
+pcm_s16le, 44100 Hz, mono   => 96 (b=AS:705)
+pcm_s16le, 16000 Hz, mono   => 96 (b=AS:256)
+pcm_s16le, 8000 Hz, mono    => 96 (b=AS:128)
+```

installs_on_host/go2rtc/pkg/core/codec.go

@@ -0,0 +1,284 @@
+package core
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"strings"
+	"unicode"
+
+	"github.com/pion/sdp/v3"
+)
+
+type Codec struct {
+	Name        string // H264, PCMU, PCMA, opus...
+	ClockRate   uint32 // 90000, 8000, 16000...
+	Channels    uint8  // 0, 1, 2
+	FmtpLine    string
+	PayloadType uint8
+}
+
+// MarshalJSON - return FFprobe compatible output
+func (c *Codec) MarshalJSON() ([]byte, error) {
+	info := map[string]any{}
+	if name := FFmpegCodecName(c.Name); name != "" {
+		info["codec_name"] = name
+		info["codec_type"] = c.Kind()
+	}
+	if c.Name == CodecH264 {
+		profile, level := DecodeH264(c.FmtpLine)
+		if profile != "" {
+			info["profile"] = profile
+			info["level"] = level
+		}
+	}
+	if c.ClockRate != 0 && c.ClockRate != 90000 {
+		info["sample_rate"] = c.ClockRate
+	}
+	if c.Channels > 0 {
+		info["channels"] = c.Channels
+	}
+	return json.Marshal(info)
+}
+
+func FFmpegCodecName(name string) string {
+	switch name {
+	case CodecH264:
+		return "h264"
+	case CodecH265:
+		return "hevc"
+	case CodecJPEG:
+		return "mjpeg"
+	case CodecRAW:
+		return "rawvideo"
+	case CodecPCMA:
+		return "pcm_alaw"
+	case CodecPCMU:
+		return "pcm_mulaw"
+	case CodecPCM:
+		return "pcm_s16be"
+	case CodecPCML:
+		return "pcm_s16le"
+	case CodecAAC:
+		return "aac"
+	case CodecOpus:
+		return "opus"
+	case CodecVP8:
+		return "vp8"
+	case CodecVP9:
+		return "vp9"
+	case CodecAV1:
+		return "av1"
+	case CodecELD:
+		return "aac/eld"
+	case CodecFLAC:
+		return "flac"
+	case CodecMP3:
+		return "mp3"
+	}
+	return name
+}
+
+func (c *Codec) String() (s string) {
+	s = c.Name
+	if c.ClockRate != 0 && c.ClockRate != 90000 {
+		s += fmt.Sprintf("/%d", c.ClockRate)
+	}
+	if c.Channels > 0 {
+		s += fmt.Sprintf("/%d", c.Channels)
+	}
+	return
+}
+
+func (c *Codec) IsRTP() bool {
+	return c.PayloadType != PayloadTypeRAW
+}
+
+func (c *Codec) IsVideo() bool {
+	return c.Kind() == KindVideo
+}
+
+func (c *Codec) IsAudio() bool {
+	return c.Kind() == KindAudio
+}
+
+func (c *Codec) Kind() string {
+	return GetKind(c.Name)
+}
+
+func (c *Codec) PrintName() string {
+	switch c.Name {
+	case CodecAAC:
+		return "AAC"
+	case CodecPCM:
+		return "S16B"
+	case CodecPCML:
+		return "S16L"
+	}
+	return c.Name
+}
+
+func (c *Codec) Clone() *Codec {
+	clone := *c
+	return &clone
+}
+
+func (c *Codec) Match(remote *Codec) bool {
+	switch remote.Name {
+	case CodecAll, CodecAny:
+		return true
+	}
+
+	return c.Name == remote.Name &&
+		(c.ClockRate == remote.ClockRate || remote.ClockRate == 0) &&
+		(c.Channels == remote.Channels || remote.Channels == 0)
+}
+
+func UnmarshalCodec(md *sdp.MediaDescription, payloadType string) *Codec {
+	c := &Codec{PayloadType: byte(Atoi(payloadType))}
+
+	for _, attr := range md.Attributes {
+		switch {
+		case c.Name == "" && attr.Key == "rtpmap" && strings.HasPrefix(attr.Value, payloadType):
+			i := strings.IndexByte(attr.Value, ' ')
+			ss := strings.Split(attr.Value[i+1:], "/")
+
+			c.Name = strings.ToUpper(ss[0])
+			// fix tailing space: `a=rtpmap:96 H264/90000 `
+			c.ClockRate = uint32(Atoi(strings.TrimRightFunc(ss[1], unicode.IsSpace)))
+
+			if len(ss) == 3 && ss[2] == "2" {
+				c.Channels = 2
+			}
+		case c.FmtpLine == "" && attr.Key == "fmtp" && strings.HasPrefix(attr.Value, payloadType):
+			if i := strings.IndexByte(attr.Value, ' '); i > 0 {
+				c.FmtpLine = attr.Value[i+1:]
+			}
+		}
+	}
+
+	switch c.Name {
+	case "PCM":
+		// https://www.reddit.com/r/Hikvision/comments/17elxex/comment/k642g2r/
+		// check pkg/rtsp/rtsp_test.go TestHikvisionPCM
+		c.Name = CodecPCML
+	case "":
+		// https://en.wikipedia.org/wiki/RTP_payload_formats
+		switch payloadType {
+		case "0":
+			c.Name = CodecPCMU
+			c.ClockRate = 8000
+		case "8":
+			c.Name = CodecPCMA
+			c.ClockRate = 8000
+		case "10":
+			c.Name = CodecPCM
+			c.ClockRate = 44100
+			c.Channels = 2
+		case "11":
+			c.Name = CodecPCM
+			c.ClockRate = 44100
+		case "14":
+			c.Name = CodecMP3
+			c.ClockRate = 90000 // it's not real sample rate
+		case "26":
+			c.Name = CodecJPEG
+			c.ClockRate = 90000
+		case "96", "97", "98":
+			if len(md.Bandwidth) == 0 {
+				c.Name = payloadType
+				break
+			}
+
+			// FFmpeg + RTSP + pcm_s16le = doesn't pass info about codec name and params
+			// so try to guess the codec based on bitrate
+			// https://github.com/AlexxIT/go2rtc/issues/523
+			switch md.Bandwidth[0].Bandwidth {
+			case 128:
+				c.ClockRate = 8000
+			case 256:
+				c.ClockRate = 16000
+			case 384:
+				c.ClockRate = 24000
+			case 512:
+				c.ClockRate = 32000
+			case 705:
+				c.ClockRate = 44100
+			case 768:
+				c.ClockRate = 48000
+			case 1411:
+				// default Windows DShow
+				c.ClockRate = 44100
+				c.Channels = 2
+			case 1536:
+				// default Linux ALSA
+				c.ClockRate = 48000
+				c.Channels = 2
+			default:
+				c.Name = payloadType
+				break
+			}
+
+			c.Name = CodecPCML
+		default:
+			c.Name = payloadType
+		}
+	}
+
+	return c
+}
+
+func DecodeH264(fmtp string) (profile string, level byte) {
+	if ps := Between(fmtp, "sprop-parameter-sets=", ","); ps != "" {
+		if sps, _ := base64.StdEncoding.DecodeString(ps); len(sps) >= 4 {
+			switch sps[1] {
+			case 0x42:
+				profile = "Baseline"
+			case 0x4D:
+				profile = "Main"
+			case 0x58:
+				profile = "Extended"
+			case 0x64:
+				profile = "High"
+			default:
+				profile = fmt.Sprintf("0x%02X", sps[1])
+			}
+
+			level = sps[3]
+		}
+	}
+	return
+}
+
+func ParseCodecString(s string) *Codec {
+	var codec Codec
+
+	ss := strings.Split(s, "/")
+	switch strings.ToLower(ss[0]) {
+	case "pcm_s16be", "s16be", "pcm":
+		codec.Name = CodecPCM
+	case "pcm_s16le", "s16le", "pcml":
+		codec.Name = CodecPCML
+	case "pcm_alaw", "alaw", "pcma", "g711a":
+		codec.Name = CodecPCMA
+	case "pcm_mulaw", "mulaw", "pcmu", "g711u":
+		codec.Name = CodecPCMU
+	case "aac", "mpeg4-generic":
+		codec.Name = CodecAAC
+	case "opus":
+		codec.Name = CodecOpus
+	case "flac":
+		codec.Name = CodecFLAC
+	default:
+		return nil
+	}
+
+	if len(ss) >= 2 {
+		codec.ClockRate = uint32(Atoi(ss[1]))
+	}
+	if len(ss) >= 3 {
+		codec.Channels = uint8(Atoi(ss[2]))
+	}
+
+	return &codec
+}

installs_on_host/go2rtc/pkg/core/connection.go

@@ -0,0 +1,144 @@
+package core
+
+import (
+	"io"
+	"net/http"
+	"reflect"
+	"sync/atomic"
+)
+
+func NewID() uint32 {
+	return id.Add(1)
+}
+
+// Deprecated: use NewID instead
+func ID(v any) uint32 {
+	p := uintptr(reflect.ValueOf(v).UnsafePointer())
+	return 0x8000_0000 | uint32(p)
+}
+
+var id atomic.Uint32
+
+type Info interface {
+	SetProtocol(string)
+	SetRemoteAddr(string)
+	SetSource(string)
+	SetURL(string)
+	WithRequest(*http.Request)
+	GetSource() string
+}
+
+// Connection just like webrtc.PeerConnection
+// - ID and RemoteAddr used for building Connection(s) graph
+// - FormatName, Protocol, RemoteAddr, Source, URL, SDP, UserAgent used for info about Connection
+// - FormatName and Protocol has FFmpeg compatible names
+// - Transport used for auto closing on Stop
+type Connection struct {
+	ID         uint32 `json:"id,omitempty"`
+	FormatName string `json:"format_name,omitempty"` // rtsp, webrtc, mp4, mjpeg, mpjpeg...
+	Protocol   string `json:"protocol,omitempty"`    // tcp, udp, http, ws, pipe...
+	RemoteAddr string `json:"remote_addr,omitempty"` // host:port other info
+	Source     string `json:"source,omitempty"`
+	URL        string `json:"url,omitempty"`
+	SDP        string `json:"sdp,omitempty"`
+	UserAgent  string `json:"user_agent,omitempty"`
+
+	Medias    []*Media    `json:"medias,omitempty"`
+	Receivers []*Receiver `json:"receivers,omitempty"`
+	Senders   []*Sender   `json:"senders,omitempty"`
+	Recv      int         `json:"bytes_recv,omitempty"`
+	Send      int         `json:"bytes_send,omitempty"`
+
+	Transport any `json:"-"`
+}
+
+func (c *Connection) GetMedias() []*Media {
+	return c.Medias
+}
+
+func (c *Connection) GetTrack(media *Media, codec *Codec) (*Receiver, error) {
+	for _, receiver := range c.Receivers {
+		if receiver.Codec == codec {
+			return receiver, nil
+		}
+	}
+	receiver := NewReceiver(media, codec)
+	c.Receivers = append(c.Receivers, receiver)
+	return receiver, nil
+}
+
+func (c *Connection) Stop() error {
+	for _, receiver := range c.Receivers {
+		receiver.Close()
+	}
+	for _, sender := range c.Senders {
+		sender.Close()
+	}
+	if closer, ok := c.Transport.(io.Closer); ok {
+		return closer.Close()
+	}
+	return nil
+}
+
+// Deprecated:
+func (c *Connection) Codecs() []*Codec {
+	codecs := make([]*Codec, len(c.Senders))
+	for i, sender := range c.Senders {
+		codecs[i] = sender.Codec
+	}
+	return codecs
+}
+
+func (c *Connection) SetProtocol(s string) {
+	c.Protocol = s
+}
+
+func (c *Connection) SetRemoteAddr(s string) {
+	if c.RemoteAddr == "" {
+		c.RemoteAddr = s
+	} else {
+		c.RemoteAddr += " forwarded " + s
+	}
+}
+
+func (c *Connection) SetSource(s string) {
+	c.Source = s
+}
+
+func (c *Connection) SetURL(s string) {
+	c.URL = s
+}
+
+func (c *Connection) WithRequest(r *http.Request) {
+	if r.Header.Get("Upgrade") == "websocket" {
+		c.Protocol = "ws"
+	} else {
+		c.Protocol = "http"
+	}
+
+	c.RemoteAddr = r.RemoteAddr
+	if remote := r.Header.Get("X-Forwarded-For"); remote != "" {
+		c.RemoteAddr += " forwarded " + remote
+	}
+
+	c.UserAgent = r.UserAgent()
+}
+
+func (c *Connection) GetSource() string {
+	return c.Source
+}
+
+// Create like os.Create, init Consumer with existing Transport
+func Create(w io.Writer) (*Connection, error) {
+	return &Connection{Transport: w}, nil
+}
+
+// Open like os.Open, init Producer from existing Transport
+func Open(r io.Reader) (*Connection, error) {
+	return &Connection{Transport: r}, nil
+}
+
+// Dial like net.Dial, init Producer via Dialing
+func Dial(rawURL string) (*Connection, error) {
+	return &Connection{}, nil
+}

installs_on_host/go2rtc/pkg/core/core.go

@@ -0,0 +1,97 @@
+package core
+
+import "encoding/json"
+
+const (
+	DirectionRecvonly = "recvonly"
+	DirectionSendonly = "sendonly"
+	DirectionSendRecv = "sendrecv"
+)
+
+const (
+	KindVideo = "video"
+	KindAudio = "audio"
+)
+
+const (
+	CodecH264 = "H264" // payloadType: 96
+	CodecH265 = "H265"
+	CodecVP8  = "VP8"
+	CodecVP9  = "VP9"
+	CodecAV1  = "AV1"
+	CodecJPEG = "JPEG" // payloadType: 26
+	CodecRAW  = "RAW"
+
+	CodecPCMU = "PCMU" // payloadType: 0
+	CodecPCMA = "PCMA" // payloadType: 8
+	CodecAAC  = "MPEG4-GENERIC"
+	CodecOpus = "OPUS" // payloadType: 111
+	CodecG722 = "G722"
+	CodecMP3  = "MPA" // payload: 14, aka MPEG-1 Layer III
+	CodecPCM  = "L16" // Linear PCM (big endian)
+
+	CodecPCML = "PCML" // Linear PCM (little endian)
+
+	CodecELD  = "ELD" // AAC-ELD
+	CodecFLAC = "FLAC"
+
+	CodecAll = "ALL"
+	CodecAny = "ANY"
+)
+
+const PayloadTypeRAW byte = 255
+
+type Producer interface {
+	// GetMedias - return Media(s) with local Media.Direction:
+	// - recvonly for Producer Video/Audio
+	// - sendonly for Producer backchannel
+	GetMedias() []*Media
+
+	// GetTrack - return Receiver, that can only produce rtp.Packet(s)
+	GetTrack(media *Media, codec *Codec) (*Receiver, error)
+
+	// Deprecated: rename to Run()
+	Start() error
+
+	// Deprecated: rename to Close()
+	Stop() error
+}
+
+type Consumer interface {
+	// GetMedias - return Media(s) with local Media.Direction:
+	// - sendonly for Consumer Video/Audio
+	// - recvonly for Consumer backchannel
+	GetMedias() []*Media
+
+	AddTrack(media *Media, codec *Codec, track *Receiver) error
+
+	// Deprecated: rename to Close()
+	Stop() error
+}
+
+type Mode byte
+
+const (
+	ModeActiveProducer Mode = iota + 1 // typical source (client)
+	ModePassiveConsumer
+	ModePassiveProducer
+	ModeActiveConsumer
+)
+
+func (m Mode) String() string {
+	switch m {
+	case ModeActiveProducer:
+		return "active producer"
+	case ModePassiveConsumer:
+		return "passive consumer"
+	case ModePassiveProducer:
+		return "passive producer"
+	case ModeActiveConsumer:
+		return "active consumer"
+	}
+	return "unknown"
+}
+
+func (m Mode) MarshalJSON() ([]byte, error) {
+	return json.Marshal(m.String())
+}

installs_on_host/go2rtc/pkg/core/core_test.go

@@ -0,0 +1,134 @@
+package core
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type producer struct {
+	Medias    []*Media
+	Receivers []*Receiver
+
+	id byte
+}
+
+func (p *producer) GetMedias() []*Media {
+	return p.Medias
+}
+
+func (p *producer) GetTrack(_ *Media, codec *Codec) (*Receiver, error) {
+	for _, receiver := range p.Receivers {
+		if receiver.Codec == codec {
+			return receiver, nil
+		}
+	}
+	receiver := NewReceiver(nil, codec)
+	p.Receivers = append(p.Receivers, receiver)
+	return receiver, nil
+}
+
+func (p *producer) Start() error {
+	pkt := &Packet{Payload: []byte{p.id}}
+	p.Receivers[0].Input(pkt)
+	return nil
+}
+
+func (p *producer) Stop() error {
+	for _, receiver := range p.Receivers {
+		receiver.Close()
+	}
+	return nil
+}
+
+type consumer struct {
+	Medias  []*Media
+	Senders []*Sender
+
+	cache chan byte
+}
+
+func (c *consumer) GetMedias() []*Media {
+	return c.Medias
+}
+
+func (c *consumer) AddTrack(_ *Media, _ *Codec, track *Receiver) error {
+	c.cache = make(chan byte, 1)
+	sender := NewSender(nil, track.Codec)
+	sender.Output = func(packet *Packet) {
+		c.cache <- packet.Payload[0]
+	}
+	sender.HandleRTP(track)
+	c.Senders = append(c.Senders, sender)
+	return nil
+}
+
+func (c *consumer) Stop() error {
+	for _, sender := range c.Senders {
+		sender.Close()
+	}
+	return nil
+}
+
+func (c *consumer) read() byte {
+	return <-c.cache
+}
+
+func TestName(t *testing.T) {
+	GetProducer := func(b byte) Producer {
+		return &producer{
+			Medias: []*Media{
+				{
+					Kind:      KindVideo,
+					Direction: DirectionRecvonly,
+					Codecs: []*Codec{
+						{Name: CodecH264},
+					},
+				},
+			},
+			id: b,
+		}
+	}
+
+	// stage1
+	prod1 := GetProducer(1)
+	cons2 := &consumer{}
+
+	media1 := prod1.GetMedias()[0]
+	track1, _ := prod1.GetTrack(media1, media1.Codecs[0])
+
+	_ = cons2.AddTrack(nil, nil, track1)
+
+	_ = prod1.Start()
+	require.Equal(t, byte(1), cons2.read())
+
+	// stage2
+	prod2 := GetProducer(2)
+	media2 := prod2.GetMedias()[0]
+	require.NotEqual(t, fmt.Sprintf("%p", media1), fmt.Sprintf("%p", media2))
+	track2, _ := prod2.GetTrack(media2, media2.Codecs[0])
+	track1.Replace(track2)
+
+	_ = prod1.Stop()
+
+	_ = prod2.Start()
+	require.Equal(t, byte(2), cons2.read())
+
+	// stage3
+	_ = prod2.Stop()
+}
+
+func TestStripUserinfo(t *testing.T) {
+	s := `streams:
+  test:
+    - ffmpeg:rtsp://username:password@10.1.2.3:554/stream1
+    - ffmpeg:rtsp://10.1.2.3:554/stream1@#video=copy
+`
+	s = StripUserinfo(s)
+	require.Equal(t, `streams:
+  test:
+    - ffmpeg:rtsp://***@10.1.2.3:554/stream1
+    - ffmpeg:rtsp://10.1.2.3:554/stream1@#video=copy
+`, s)
+}

installs_on_host/go2rtc/pkg/core/helpers.go

@@ -0,0 +1,94 @@
+package core
+
+import (
+	"crypto/rand"
+	"runtime"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	BufferSize      = 64 * 1024 // 64K
+	ConnDialTimeout = 5 * time.Second
+	ConnDeadline    = 5 * time.Second
+	ProbeTimeout    = 5 * time.Second
+)
+
+// Now90000 - timestamp for Video (clock rate = 90000 samples per second)
+func Now90000() uint32 {
+	return uint32(time.Duration(time.Now().UnixNano()) * 90000 / time.Second)
+}
+
+const symbols = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_"
+
+// RandString base10 - numbers, base16 - hex, base36 - digits+letters
+// base64 - URL safe symbols, base0 - crypto random
+func RandString(size, base byte) string {
+	b := make([]byte, size)
+	if _, err := rand.Read(b); err != nil {
+		panic(err)
+	}
+	if base == 0 {
+		return string(b)
+	}
+	for i := byte(0); i < size; i++ {
+		b[i] = symbols[b[i]%base]
+	}
+	return string(b)
+}
+
+func Before(s, sep string) string {
+	if i := strings.Index(s, sep); i > 0 {
+		return s[:i]
+	}
+	return s
+}
+
+func Between(s, sub1, sub2 string) string {
+	i := strings.Index(s, sub1)
+	if i < 0 {
+		return ""
+	}
+	s = s[i+len(sub1):]
+
+	if i = strings.Index(s, sub2); i >= 0 {
+		return s[:i]
+	}
+
+	return s
+}
+
+func Atoi(s string) (i int) {
+	if s != "" {
+		i, _ = strconv.Atoi(s)
+	}
+	return
+}
+
+// ParseByte - fast parsing string to byte function
+func ParseByte(s string) (b byte) {
+	for i, ch := range []byte(s) {
+		ch -= '0'
+		if ch > 9 {
+			return 0
+		}
+		if i > 0 {
+			b *= 10
+		}
+		b += ch
+	}
+	return
+}
+
+func Assert(ok bool) {
+	if !ok {
+		_, file, line, _ := runtime.Caller(1)
+		panic(file + ":" + strconv.Itoa(line))
+	}
+}
+
+func Caller() string {
+	_, file, line, _ := runtime.Caller(1)
+	return file + ":" + strconv.Itoa(line)
+}

installs_on_host/go2rtc/pkg/core/listener.go

@@ -0,0 +1,18 @@
+package core
+
+type EventFunc func(msg any)
+
+// Listener base struct for all classes with support feedback
+type Listener struct {
+	events []EventFunc
+}
+
+func (l *Listener) Listen(f EventFunc) {
+	l.events = append(l.events, f)
+}
+
+func (l *Listener) Fire(msg any) {
+	for _, f := range l.events {
+		f(msg)
+	}
+}

installs_on_host/go2rtc/pkg/core/media.go

@@ -0,0 +1,211 @@
+package core
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/pion/sdp/v3"
+)
+
+// Media take best from:
+// - deepch/vdk/format/rtsp/sdp.Media
+// - pion/sdp.MediaDescription
+type Media struct {
+	Kind      string   `json:"kind,omitempty"`      // video or audio
+	Direction string   `json:"direction,omitempty"` // sendonly, recvonly
+	Codecs    []*Codec `json:"codecs,omitempty"`
+
+	ID string `json:"id,omitempty"` // MID for WebRTC, Control for RTSP
+}
+
+func (m *Media) String() string {
+	s := fmt.Sprintf("%s, %s", m.Kind, m.Direction)
+	for _, codec := range m.Codecs {
+		name := codec.String()
+
+		if strings.Contains(s, name) {
+			continue
+		}
+
+		s += ", " + name
+	}
+	return s
+}
+
+func (m *Media) MarshalJSON() ([]byte, error) {
+	return json.Marshal(m.String())
+}
+
+func (m *Media) Clone() *Media {
+	clone := *m
+	clone.Codecs = make([]*Codec, len(m.Codecs))
+	for i, codec := range m.Codecs {
+		clone.Codecs[i] = codec.Clone()
+	}
+	return &clone
+}
+
+func (m *Media) MatchMedia(remote *Media) (codec, remoteCodec *Codec) {
+	// check same kind and opposite dirrection
+	if m.Kind != remote.Kind ||
+		m.Direction == DirectionSendonly && remote.Direction != DirectionRecvonly ||
+		m.Direction == DirectionRecvonly && remote.Direction != DirectionSendonly {
+		return nil, nil
+	}
+
+	for _, codec = range m.Codecs {
+		for _, remoteCodec = range remote.Codecs {
+			if codec.Match(remoteCodec) {
+				return
+			}
+		}
+	}
+
+	return nil, nil
+}
+
+func (m *Media) MatchCodec(remote *Codec) *Codec {
+	for _, codec := range m.Codecs {
+		if codec.Match(remote) {
+			return codec
+		}
+	}
+	return nil
+}
+
+func (m *Media) MatchAll() bool {
+	for _, codec := range m.Codecs {
+		if codec.Name == CodecAll {
+			return true
+		}
+	}
+	return false
+}
+
+func (m *Media) Equal(media *Media) bool {
+	if media.ID != "" {
+		return m.ID == media.ID
+	}
+	return m.String() == media.String()
+}
+
+func GetKind(name string) string {
+	switch name {
+	case CodecH264, CodecH265, CodecVP8, CodecVP9, CodecAV1, CodecJPEG, CodecRAW:
+		return KindVideo
+	case CodecPCMU, CodecPCMA, CodecAAC, CodecOpus, CodecG722, CodecMP3, CodecPCM, CodecPCML, CodecELD, CodecFLAC:
+		return KindAudio
+	}
+	return ""
+}
+
+func MarshalSDP(name string, medias []*Media) ([]byte, error) {
+	sd := &sdp.SessionDescription{
+		Origin: sdp.Origin{
+			Username: "-", SessionID: 1, SessionVersion: 1,
+			NetworkType: "IN", AddressType: "IP4", UnicastAddress: "0.0.0.0",
+		},
+		SessionName: sdp.SessionName(name),
+		ConnectionInformation: &sdp.ConnectionInformation{
+			NetworkType: "IN", AddressType: "IP4", Address: &sdp.Address{
+				Address: "0.0.0.0",
+			},
+		},
+		TimeDescriptions: []sdp.TimeDescription{
+			{Timing: sdp.Timing{}},
+		},
+	}
+
+	for _, media := range medias {
+		if media.Codecs == nil {
+			continue
+		}
+
+		codec := media.Codecs[0]
+
+		switch codec.Name {
+		case CodecELD:
+			name = CodecAAC
+		case CodecPCML:
+			name = CodecPCM // beacuse we using pcm.LittleToBig for RTSP server
+		default:
+			name = codec.Name
+		}
+
+		md := &sdp.MediaDescription{
+			MediaName: sdp.MediaName{
+				Media:  media.Kind,
+				Protos: []string{"RTP", "AVP"},
+			},
+		}
+		md.WithCodec(codec.PayloadType, name, codec.ClockRate, uint16(codec.Channels), codec.FmtpLine)
+
+		if media.Direction != "" {
+			md.WithPropertyAttribute(media.Direction)
+		}
+
+		if media.ID != "" {
+			md.WithValueAttribute("control", media.ID)
+		}
+
+		sd.MediaDescriptions = append(sd.MediaDescriptions, md)
+	}
+
+	return sd.Marshal()
+}
+
+func UnmarshalMedia(md *sdp.MediaDescription) *Media {
+	m := &Media{
+		Kind: md.MediaName.Media,
+	}
+
+	for _, attr := range md.Attributes {
+		switch attr.Key {
+		case DirectionSendonly, DirectionRecvonly, DirectionSendRecv:
+			m.Direction = attr.Key
+		case "control", "mid":
+			m.ID = attr.Value
+		}
+	}
+
+	for _, format := range md.MediaName.Formats {
+		m.Codecs = append(m.Codecs, UnmarshalCodec(md, format))
+	}
+
+	return m
+}
+
+func ParseQuery(query map[string][]string) (medias []*Media) {
+	// set media candidates from query list
+	for key, values := range query {
+		switch key {
+		case KindVideo, KindAudio:
+			for _, value := range values {
+				media := &Media{Kind: key, Direction: DirectionSendonly}
+
+				for _, name := range strings.Split(value, ",") {
+					name = strings.ToUpper(name)
+
+					// check aliases
+					switch name {
+					case "", "COPY":
+						name = CodecAny
+					case "MJPEG":
+						name = CodecJPEG
+					case "AAC":
+						name = CodecAAC
+					case "MP3":
+						name = CodecMP3
+					}
+
+					media.Codecs = append(media.Codecs, &Codec{Name: name})
+				}
+
+				medias = append(medias, media)
+			}
+		}
+	}
+
+	return
+}

installs_on_host/go2rtc/pkg/core/media_test.go

@@ -0,0 +1,64 @@
+package core
+
+import (
+	"fmt"
+	"net/url"
+	"testing"
+
+	"github.com/pion/sdp/v3"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSDP(t *testing.T) {
+	medias := []*Media{{
+		Kind: KindAudio, Direction: DirectionSendonly,
+		Codecs: []*Codec{
+			{Name: CodecPCMU, ClockRate: 8000},
+		},
+	}}
+
+	data, err := MarshalSDP("go2rtc/1.0.0", medias)
+	assert.Empty(t, err)
+
+	sd := &sdp.SessionDescription{}
+	err = sd.Unmarshal(data)
+	assert.Empty(t, err)
+}
+
+func TestParseQuery(t *testing.T) {
+	u, _ := url.Parse("rtsp://localhost:8554/camera1")
+	medias := ParseQuery(u.Query())
+	assert.Nil(t, medias)
+
+	for _, rawULR := range []string{
+		"rtsp://localhost:8554/camera1?video",
+		"rtsp://localhost:8554/camera1?video=copy",
+		"rtsp://localhost:8554/camera1?video=any",
+	} {
+		u, _ = url.Parse(rawULR)
+		medias = ParseQuery(u.Query())
+		assert.Equal(t, []*Media{
+			{Kind: KindVideo, Direction: DirectionSendonly, Codecs: []*Codec{{Name: CodecAny}}},
+		}, medias)
+	}
+}
+
+func TestClone(t *testing.T) {
+	media1 := &Media{
+		Kind:      KindVideo,
+		Direction: DirectionRecvonly,
+		Codecs: []*Codec{
+			{Name: CodecPCMU, ClockRate: 8000},
+		},
+	}
+	media2 := media1.Clone()
+
+	p1 := fmt.Sprintf("%p", media1)
+	p2 := fmt.Sprintf("%p", media2)
+	require.NotEqualValues(t, p1, p2)
+
+	p3 := fmt.Sprintf("%p", media1.Codecs[0])
+	p4 := fmt.Sprintf("%p", media2.Codecs[0])
+	require.NotEqualValues(t, p3, p4)
+}

installs_on_host/go2rtc/pkg/core/node.go

@@ -0,0 +1,88 @@
+package core
+
+import (
+	"sync"
+
+	"github.com/pion/rtp"
+)
+
+//type Packet struct {
+//	Payload     []byte
+//	Timestamp   uint32 // PTS if DTS == 0 else DTS
+//	Composition uint32 // CTS = PTS-DTS (for support B-frames)
+//	Sequence    uint16
+//}
+
+type Packet = rtp.Packet
+
+// HandlerFunc - process input packets (just like http.HandlerFunc)
+type HandlerFunc func(packet *Packet)
+
+// Filter - a decorator for any HandlerFunc
+type Filter func(handler HandlerFunc) HandlerFunc
+
+// Node - Receiver or Sender or Filter (transform)
+type Node struct {
+	Codec  *Codec
+	Input  HandlerFunc
+	Output HandlerFunc
+
+	id     uint32
+	childs []*Node
+	parent *Node
+
+	mu sync.Mutex
+}
+
+func (n *Node) WithParent(parent *Node) *Node {
+	parent.AppendChild(n)
+	return n
+}
+
+func (n *Node) AppendChild(child *Node) {
+	n.mu.Lock()
+	n.childs = append(n.childs, child)
+	n.mu.Unlock()
+
+	child.parent = n
+}
+
+func (n *Node) RemoveChild(child *Node) {
+	n.mu.Lock()
+	for i, ch := range n.childs {
+		if ch == child {
+			n.childs = append(n.childs[:i], n.childs[i+1:]...)
+			break
+		}
+	}
+	n.mu.Unlock()
+}
+
+func (n *Node) Close() {
+	if parent := n.parent; parent != nil {
+		parent.RemoveChild(n)
+
+		if len(parent.childs) == 0 {
+			parent.Close()
+		}
+	} else {
+		for _, childs := range n.childs {
+			childs.Close()
+		}
+	}
+}
+
+func MoveNode(dst, src *Node) {
+	src.mu.Lock()
+	childs := src.childs
+	src.childs = nil
+	src.mu.Unlock()
+
+	dst.mu.Lock()
+	dst.childs = childs
+	dst.mu.Unlock()
+
+	for _, child := range childs {
+		child.parent = dst
+	}
+}

installs_on_host/go2rtc/pkg/core/readbuffer.go

@@ -0,0 +1,114 @@
+package core
+
+import (
+	"errors"
+	"io"
+)
+
+// ProbeSize
+// in my tests MPEG-TS 40Mbit/s 4K-video require more than 1MB for probe
+const ProbeSize = 5 * 1024 * 1024 // 5MB
+
+const (
+	BufferDisable       = 0
+	BufferDrainAndClear = -1
+)
+
+// ReadBuffer support buffering and Seek over buffer
+// positive BufferSize will enable buffering mode
+// Seek to negative offset will clear buffer
+// Seek with a positive BufferSize will continue buffering after the last read from the buffer
+// Seek with a negative BufferSize will clear buffer after the last read from the buffer
+// Read more than BufferSize will raise error
+type ReadBuffer struct {
+	io.Reader
+
+	BufferSize int
+
+	buf []byte
+	pos int
+}
+
+func NewReadBuffer(rd io.Reader) *ReadBuffer {
+	if rs, ok := rd.(*ReadBuffer); ok {
+		return rs
+	}
+	return &ReadBuffer{Reader: rd}
+}
+
+func (r *ReadBuffer) Read(p []byte) (n int, err error) {
+	// with zero buffer - read as usual
+	if r.BufferSize == BufferDisable {
+		return r.Reader.Read(p)
+	}
+
+	// if buffer not empty - read from it
+	if r.pos < len(r.buf) {
+		n = copy(p, r.buf[r.pos:])
+		r.pos += n
+		return
+	}
+
+	// with negative buffer - empty it and read as usual
+	if r.BufferSize < 0 {
+		r.BufferSize = BufferDisable
+		r.buf = nil
+		r.pos = 0
+
+		return r.Reader.Read(p)
+	}
+
+	n, err = r.Reader.Read(p)
+	if len(r.buf)+n > r.BufferSize {
+		return 0, errors.New("probe reader overflow")
+	}
+	r.buf = append(r.buf, p[:n]...)
+	r.pos += n
+	return
+}
+
+func (r *ReadBuffer) Close() error {
+	if closer, ok := r.Reader.(io.Closer); ok {
+		return closer.Close()
+	}
+	return nil
+}
+
+func (r *ReadBuffer) Seek(offset int64, whence int) (int64, error) {
+	var pos int
+	switch whence {
+	case io.SeekStart:
+		pos = int(offset)
+	case io.SeekCurrent:
+		pos = r.pos + int(offset)
+	case io.SeekEnd:
+		pos = len(r.buf) + int(offset)
+	}
+
+	// negative offset - empty buffer
+	if pos < 0 {
+		r.buf = nil
+		r.pos = 0
+	} else if pos >= len(r.buf) {
+		r.pos = len(r.buf)
+	} else {
+		r.pos = pos
+	}
+
+	return int64(r.pos), nil
+}
+
+func (r *ReadBuffer) Peek(n int) ([]byte, error) {
+	r.BufferSize = n
+	b := make([]byte, n)
+	if _, err := io.ReadAtLeast(r, b, n); err != nil {
+		return nil, err
+	}
+	r.Reset()
+	return b, nil
+}
+
+func (r *ReadBuffer) Reset() {
+	r.BufferSize = BufferDrainAndClear
+	r.pos = 0
+}

installs_on_host/go2rtc/pkg/core/readbuffer_test.go

@@ -0,0 +1,64 @@
+package core
+
+import (
+	"bytes"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestReadSeeker(t *testing.T) {
+	b := []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	buf := bytes.NewReader(b)
+
+	rd := NewReadBuffer(buf)
+	rd.BufferSize = ProbeSize
+
+	// 1. Read to buffer
+	b = make([]byte, 3)
+	n, err := rd.Read(b)
+	require.Nil(t, err)
+	require.Equal(t, []byte{0, 1, 2}, b[:n])
+
+	// 2. Seek to start
+	_, err = rd.Seek(0, io.SeekStart)
+	require.Nil(t, err)
+
+	// 3. Read from buffer
+	b = make([]byte, 2)
+	n, err = rd.Read(b)
+	require.Nil(t, err)
+	require.Equal(t, []byte{0, 1}, b[:n])
+
+	// 4. Read from buffer
+	n, err = rd.Read(b)
+	require.Nil(t, err)
+	require.Equal(t, []byte{2}, b[:n])
+
+	// 5. Read to buffer
+	n, err = rd.Read(b)
+	require.Nil(t, err)
+	require.Equal(t, []byte{3, 4}, b[:n])
+
+	// 6. Seek to start
+	_, err = rd.Seek(0, io.SeekStart)
+	require.Nil(t, err)
+
+	// 7. Disable buffer
+	rd.BufferSize = -1
+
+	// 8. Read from buffer
+	b = make([]byte, 10)
+	n, err = rd.Read(b)
+	require.Nil(t, err)
+	require.Equal(t, []byte{0, 1, 2, 3, 4}, b[:n])
+
+	// 9. Direct read
+	n, err = rd.Read(b)
+	require.Nil(t, err)
+	require.Equal(t, []byte{5, 6, 7, 8, 9}, b[:n])
+
+	// 10. Check buffer empty
+	require.Nil(t, rd.buf)
+}

installs_on_host/go2rtc/pkg/core/slices.go

@@ -0,0 +1,43 @@
+package core
+
+// This code copied from go1.21 for backward support in go1.20.
+// We need to support go1.20 for Windows 7
+
+// Index returns the index of the first occurrence of v in s,
+// or -1 if not present.
+func Index[S ~[]E, E comparable](s S, v E) int {
+	for i := range s {
+		if v == s[i] {
+			return i
+		}
+	}
+	return -1
+}
+
+// Contains reports whether v is present in s.
+func Contains[S ~[]E, E comparable](s S, v E) bool {
+	return Index(s, v) >= 0
+}
+
+type Ordered interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
+}
+
+// Max returns the maximal value in x. It panics if x is empty.
+// For floating-point E, Max propagates NaNs (any NaN value in x
+// forces the output to be NaN).
+func Max[S ~[]E, E Ordered](x S) E {
+	if len(x) < 1 {
+		panic("slices.Max: empty list")
+	}
+	m := x[0]
+	for i := 1; i < len(x); i++ {
+		if x[i] > m {
+			m = x[i]
+		}
+	}
+	return m
+}

installs_on_host/go2rtc/pkg/core/track.go

@@ -0,0 +1,217 @@
+package core
+
+import (
+	"encoding/json"
+	"errors"
+
+	"github.com/pion/rtp"
+)
+
+var ErrCantGetTrack = errors.New("can't get track")
+
+type Receiver struct {
+	Node
+
+	// Deprecated: should be removed
+	Media *Media `json:"-"`
+	// Deprecated: should be removed
+	ID byte `json:"-"` // Channel for RTSP, PayloadType for MPEG-TS
+
+	Bytes   int `json:"bytes,omitempty"`
+	Packets int `json:"packets,omitempty"`
+}
+
+func NewReceiver(media *Media, codec *Codec) *Receiver {
+	r := &Receiver{
+		Node:  Node{id: NewID(), Codec: codec},
+		Media: media,
+	}
+	r.Input = func(packet *Packet) {
+		r.Bytes += len(packet.Payload)
+		r.Packets++
+		for _, child := range r.childs {
+			child.Input(packet)
+		}
+	}
+	return r
+}
+
+// Deprecated: should be removed
+func (r *Receiver) WriteRTP(packet *rtp.Packet) {
+	r.Input(packet)
+}
+
+// Deprecated: should be removed
+func (r *Receiver) Senders() []*Sender {
+	if len(r.childs) > 0 {
+		return []*Sender{{}}
+	} else {
+		return nil
+	}
+}
+
+// Deprecated: should be removed
+func (r *Receiver) Replace(target *Receiver) {
+	MoveNode(&target.Node, &r.Node)
+}
+
+func (r *Receiver) Close() {
+	r.Node.Close()
+}
+
+type Sender struct {
+	Node
+
+	// Deprecated:
+	Media *Media `json:"-"`
+	// Deprecated:
+	Handler HandlerFunc `json:"-"`
+
+	Bytes   int `json:"bytes,omitempty"`
+	Packets int `json:"packets,omitempty"`
+	Drops   int `json:"drops,omitempty"`
+
+	buf  chan *Packet
+	done chan struct{}
+}
+
+func NewSender(media *Media, codec *Codec) *Sender {
+	var bufSize uint16
+
+	if GetKind(codec.Name) == KindVideo {
+		if codec.IsRTP() {
+			// in my tests 40Mbit/s 4K-video can generate up to 1500 items
+			// for the h264.RTPDepay => RTPPay queue
+			bufSize = 4096
+		} else {
+			bufSize = 64
+		}
+	} else {
+		bufSize = 128
+	}
+
+	buf := make(chan *Packet, bufSize)
+	s := &Sender{
+		Node:  Node{id: NewID(), Codec: codec},
+		Media: media,
+		buf:   buf,
+	}
+	s.Input = func(packet *Packet) {
+		s.mu.Lock()
+		// unblock write to nil chan - OK, write to closed chan - panic
+		select {
+		case s.buf <- packet:
+			s.Bytes += len(packet.Payload)
+			s.Packets++
+		default:
+			s.Drops++
+		}
+		s.mu.Unlock()
+	}
+	s.Output = func(packet *Packet) {
+		s.Handler(packet)
+	}
+	return s
+}
+
+// Deprecated: should be removed
+func (s *Sender) HandleRTP(parent *Receiver) {
+	s.WithParent(parent)
+	s.Start()
+}
+
+// Deprecated: should be removed
+func (s *Sender) Bind(parent *Receiver) {
+	s.WithParent(parent)
+}
+
+func (s *Sender) WithParent(parent *Receiver) *Sender {
+	s.Node.WithParent(&parent.Node)
+	return s
+}
+
+func (s *Sender) Start() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.buf == nil || s.done != nil {
+		return
+	}
+	s.done = make(chan struct{})
+
+	// pass buf directly so that it's impossible for buf to be nil
+	go func(buf chan *Packet) {
+		for packet := range buf {
+			s.Output(packet)
+		}
+		close(s.done)
+	}(s.buf)
+}
+
+func (s *Sender) Wait() {
+	if done := s.done; done != nil {
+		<-done
+	}
+}
+
+func (s *Sender) State() string {
+	if s.buf == nil {
+		return "closed"
+	}
+	if s.done == nil {
+		return "new"
+	}
+	return "connected"
+}
+
+func (s *Sender) Close() {
+	// close buffer if exists
+	s.mu.Lock()
+	if s.buf != nil {
+		close(s.buf) // exit from for range loop
+		s.buf = nil  // prevent writing to closed chan
+	}
+	s.mu.Unlock()
+
+	s.Node.Close()
+}
+
+func (r *Receiver) MarshalJSON() ([]byte, error) {
+	v := struct {
+		ID      uint32   `json:"id"`
+		Codec   *Codec   `json:"codec"`
+		Childs  []uint32 `json:"childs,omitempty"`
+		Bytes   int      `json:"bytes,omitempty"`
+		Packets int      `json:"packets,omitempty"`
+	}{
+		ID:      r.Node.id,
+		Codec:   r.Node.Codec,
+		Bytes:   r.Bytes,
+		Packets: r.Packets,
+	}
+	for _, child := range r.childs {
+		v.Childs = append(v.Childs, child.id)
+	}
+	return json.Marshal(v)
+}
+
+func (s *Sender) MarshalJSON() ([]byte, error) {
+	v := struct {
+		ID      uint32 `json:"id"`
+		Codec   *Codec `json:"codec"`
+		Parent  uint32 `json:"parent,omitempty"`
+		Bytes   int    `json:"bytes,omitempty"`
+		Packets int    `json:"packets,omitempty"`
+		Drops   int    `json:"drops,omitempty"`
+	}{
+		ID:      s.Node.id,
+		Codec:   s.Node.Codec,
+		Bytes:   s.Bytes,
+		Packets: s.Packets,
+		Drops:   s.Drops,
+	}
+	if s.parent != nil {
+		v.Parent = s.parent.id
+	}
+	return json.Marshal(v)
+}

installs_on_host/go2rtc/pkg/core/track_test.go

@@ -0,0 +1,53 @@
+package core
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSenser(t *testing.T) {
+	recv := make(chan *Packet) // blocking receiver
+
+	sender := NewSender(nil, &Codec{})
+	sender.Output = func(packet *Packet) {
+		recv <- packet
+	}
+	require.Equal(t, "new", sender.State())
+
+	sender.Start()
+	require.Equal(t, "connected", sender.State())
+
+	sender.Input(&Packet{})
+	sender.Input(&Packet{})
+
+	require.Equal(t, 2, sender.Packets)
+	require.Equal(t, 0, sender.Drops)
+
+	// important to read one before close
+	// because goroutine in Start() can run with nil chan
+	// it's OK in real life, but bad for test
+	_, ok := <-recv
+	require.True(t, ok)
+
+	sender.Close()
+	require.Equal(t, "closed", sender.State())
+
+	sender.Input(&Packet{})
+
+	require.Equal(t, 2, sender.Packets)
+	require.Equal(t, 1, sender.Drops)
+
+	// read 2nd
+	_, ok = <-recv
+	require.True(t, ok)
+
+	// read 3rd
+	select {
+	case <-recv:
+		ok = true
+	default:
+		ok = false
+	}
+	require.False(t, ok)
+}

installs_on_host/go2rtc/pkg/core/waiter.go

@@ -0,0 +1,74 @@
+package core
+
+import (
+	"sync"
+)
+
+// Waiter support:
+// - autotart on first Wait
+// - block new waiters after last Done
+// - safe Done after finish
+type Waiter struct {
+	sync.WaitGroup
+	mu    sync.Mutex
+	state int // state < 0 means finish
+	err   error
+}
+
+func (w *Waiter) Add(delta int) {
+	w.mu.Lock()
+	if w.state >= 0 {
+		w.state += delta
+		w.WaitGroup.Add(delta)
+	}
+	w.mu.Unlock()
+}
+
+func (w *Waiter) Wait() error {
+	w.mu.Lock()
+	// first wait auto start waiter
+	if w.state == 0 {
+		w.state++
+		w.WaitGroup.Add(1)
+	}
+	w.mu.Unlock()
+
+	w.WaitGroup.Wait()
+
+	return w.err
+}
+
+func (w *Waiter) Done(err error) {
+	w.mu.Lock()
+
+	// safe run Done only when have tasks
+	if w.state > 0 {
+		w.state--
+		w.WaitGroup.Done()
+	}
+
+	// block waiter for any operations after last done
+	if w.state == 0 {
+		w.state = -1
+		w.err = err
+	}
+
+	w.mu.Unlock()
+}
+
+func (w *Waiter) WaitChan() <-chan error {
+	var ch chan error
+
+	w.mu.Lock()
+
+	if w.state >= 0 {
+		ch = make(chan error)
+		go func() {
+			ch <- w.Wait()
+		}()
+	}
+
+	w.mu.Unlock()
+
+	return ch
+}

installs_on_host/go2rtc/pkg/core/worker.go

@@ -0,0 +1,52 @@
+package core
+
+import (
+	"time"
+)
+
+type Worker struct {
+	timer *time.Timer
+	done  chan struct{}
+}
+
+// NewWorker run f after d
+func NewWorker(d time.Duration, f func() time.Duration) *Worker {
+	timer := time.NewTimer(d)
+	done := make(chan struct{})
+
+	go func() {
+		for {
+			select {
+			case <-timer.C:
+				if d = f(); d > 0 {
+					timer.Reset(d)
+					continue
+				}
+			case <-done:
+				timer.Stop()
+			}
+			break
+		}
+	}()
+
+	return &Worker{timer: timer, done: done}
+}
+
+// Do - instant timer run
+func (w *Worker) Do() {
+	if w == nil {
+		return
+	}
+	w.timer.Reset(0)
+}
+
+func (w *Worker) Stop() {
+	if w == nil {
+		return
+	}
+
+	select {
+	case w.done <- struct{}{}:
+	default:
+	}
+}

installs_on_host/go2rtc/pkg/core/writebuffer.go

@@ -0,0 +1,114 @@
+package core
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+	"sync"
+)
+
+// WriteBuffer by defaul Write(s) to bytes.Buffer.
+// But after WriteTo to new io.Writer - calls Reset.
+// Reset will flush current buffer data to new writer and starts to Write to new io.Writer
+// WriteTo will be locked until Write fails or Close will be called.
+type WriteBuffer struct {
+	io.Writer
+	err   error
+	mu    sync.Mutex
+	wg    sync.WaitGroup
+	state byte
+}
+
+func NewWriteBuffer(wr io.Writer) *WriteBuffer {
+	if wr == nil {
+		wr = bytes.NewBuffer(nil)
+	}
+	return &WriteBuffer{Writer: wr}
+}
+
+func (w *WriteBuffer) Write(p []byte) (n int, err error) {
+	w.mu.Lock()
+	if w.err != nil {
+		err = w.err
+	} else if n, err = w.Writer.Write(p); err != nil {
+		w.err = err
+		w.done()
+	} else if f, ok := w.Writer.(http.Flusher); ok {
+		f.Flush()
+	}
+	w.mu.Unlock()
+	return
+}
+
+func (w *WriteBuffer) WriteTo(wr io.Writer) (n int64, err error) {
+	w.Reset(wr)
+	w.wg.Wait()
+	return 0, w.err // TODO: fix counter
+}
+
+func (w *WriteBuffer) Close() error {
+	if closer, ok := w.Writer.(io.Closer); ok {
+		return closer.Close()
+	}
+	w.mu.Lock()
+	w.done()
+	w.mu.Unlock()
+	return nil
+}
+
+func (w *WriteBuffer) Reset(wr io.Writer) {
+	w.mu.Lock()
+	w.add()
+	if buf, ok := w.Writer.(*bytes.Buffer); ok && buf.Len() != 0 {
+		if _, err := io.Copy(wr, buf); err != nil {
+			w.err = err
+			w.done()
+		}
+	}
+	w.Writer = wr
+	w.mu.Unlock()
+}
+
+const (
+	none = iota
+	start
+	end
+)
+
+func (w *WriteBuffer) add() {
+	if w.state == none {
+		w.state = start
+		w.wg.Add(1)
+	}
+}
+
+func (w *WriteBuffer) done() {
+	if w.state == start {
+		w.state = end
+		w.wg.Done()
+	}
+}
+
+// OnceBuffer will catch only first message
+type OnceBuffer struct {
+	buf []byte
+}
+
+func (o *OnceBuffer) Write(p []byte) (n int, err error) {
+	if o.buf == nil {
+		o.buf = p
+	}
+	return 0, io.EOF
+}
+
+func (o *OnceBuffer) WriteTo(w io.Writer) (n int64, err error) {
+	return io.Copy(w, bytes.NewReader(o.buf))
+}
+
+func (o *OnceBuffer) Buffer() []byte {
+	return o.buf
+}
+
+func (o *OnceBuffer) Len() int {
+	return len(o.buf)
+}