first commit

subscriber.go

@@ -0,0 +1,135 @@
+package engine
+
+import (
+	"context"
+	"fmt"
+	"github.com/Monibuca/engine/avformat"
+	"time"
+)
+
+type Subscriber interface {
+	Send(*avformat.SendPacket) error
+}
+
+type SubscriberInfo struct {
+	ID            string
+	TotalDrop     int //总丢帧
+	TotalPacket   int
+	Type          string
+	BufferLength  int
+	SubscribeTime time.Time
+}
+type OutputStream struct {
+	context.Context
+	*Room
+	SubscriberInfo
+	SendHandler      func(*avformat.SendPacket) error
+	Cancel           context.CancelFunc
+	Sign             string
+	VTSent           bool
+	ATSent           bool
+	VSentTime        uint32
+	ASentTime        uint32
+	packetQueue      chan *avformat.SendPacket
+	dropCount        int
+	OffsetTime       uint32
+	firstScreenIndex int
+}
+
+func (s *OutputStream) IsClosed() bool {
+	return s.Context != nil && s.Err() != nil
+}
+
+func (s *OutputStream) Close() {
+	if s.Cancel != nil {
+		s.Cancel()
+	}
+}
+func (s *OutputStream) Play(streamPath string) (err error) {
+	AllRoom.Get(streamPath).Subscribe(s)
+	defer s.UnSubscribe(s)
+	for {
+		select {
+		case <-s.Done():
+			return s.Err()
+		case p := <-s.packetQueue:
+			if err = s.SendHandler(p); err != nil {
+				s.Cancel() //此处为了使得IsClosed 返回true
+				return
+			}
+			p.Recycle()
+		}
+	}
+}
+func (s *OutputStream) sendPacket(packet *avformat.AVPacket, timestamp uint32) {
+	if !packet.IsAVCSequence && timestamp == 0 {
+		timestamp = 1 //防止为0
+	}
+	s.TotalPacket++
+	s.BufferLength = len(s.packetQueue)
+	if s.dropCount > 0 {
+		if packet.IsKeyFrame() {
+			fmt.Printf("%s drop packet:%d\n", s.ID, s.dropCount)
+			s.dropCount = 0 //退出丢包
+		} else {
+			s.dropCount++
+			s.TotalDrop++
+			return
+		}
+	}
+	if s.BufferLength == cap(s.packetQueue) {
+		s.dropCount++
+		s.TotalDrop++
+		packet.Recycle()
+	} else if !s.IsClosed() {
+		s.packetQueue <- avformat.NewSendPacket(packet, timestamp)
+	}
+}
+
+func (s *OutputStream) sendVideo(video *avformat.AVPacket) error {
+	isKF := video.IsKeyFrame()
+	if s.VTSent {
+		if s.FirstScreen == nil || s.firstScreenIndex == -1 {
+			s.sendPacket(video, video.Timestamp-s.VSentTime+s.OffsetTime)
+		} else if !isKF && s.firstScreenIndex < len(s.FirstScreen) {
+			firstScreen := s.FirstScreen[s.firstScreenIndex]
+			firstScreen.RefCount++
+			s.VSentTime = firstScreen.Timestamp - s.FirstScreen[0].Timestamp
+			s.sendPacket(firstScreen, s.VSentTime)
+			video.Recycle() //回收当前数据
+			s.firstScreenIndex++
+		} else {
+			s.firstScreenIndex = -1 //收到关键帧或者首屏缓冲已播完后退出首屏渲染模式
+			s.OffsetTime += s.VSentTime
+			s.VSentTime = video.Timestamp
+			s.sendPacket(video, s.OffsetTime)
+		}
+		return nil
+	}
+	//非首屏渲染模式跳过开头的非关键帧
+	if !isKF {
+		if s.FirstScreen == nil {
+			return nil
+		}
+	} else if s.FirstScreen != nil {
+		s.firstScreenIndex = -1 //跳过首屏渲染
+	}
+	s.VTSent = true
+	s.sendPacket(s.VideoTag, 0)
+	s.VSentTime = video.Timestamp
+	return s.sendVideo(video)
+}
+func (s *OutputStream) sendAudio(audio *avformat.AVPacket) error {
+	if s.ATSent {
+		if s.FirstScreen != nil && s.firstScreenIndex == -1 {
+			audio.Recycle()
+			return nil
+		}
+		s.sendPacket(audio, audio.Timestamp-s.ASentTime)
+		return nil
+	}
+	s.ATSent = true
+	s.sendPacket(s.AudioTag, 0)
+	s.ASentTime = audio.Timestamp
+	return s.sendAudio(audio)
+}