GOP追帧

2025-10-05 08:36:56 +08:00 · 2021-08-19 14:38:05 +08:00
parent 8b2f91b4de
commit 3a16fe7883
4 changed files with 84 additions and 90 deletions
--- a/ring.go
+++ b/ring.go
@@ -12,7 +12,7 @@ import (
 type DataItem struct {
 	Timestamp time.Time
 	Sequence  int
-	Value interface{}
+	Value     interface{}
 }

 // TODO: 池化，泛型
@@ -28,123 +28,123 @@ type RingBuffer struct {
 	context.Context
 }

-func (r *RingBuffer) Init(ctx context.Context, n int) *RingBuffer {
+func (rb *RingBuffer) Init(ctx context.Context, n int) *RingBuffer {
 	var flag int32
-	if r == nil {
-		r = &RingBuffer{Context: ctx, Ring: ring.New(n), Flag: &flag}
+	if rb == nil {
+		rb = &RingBuffer{Context: ctx, Ring: ring.New(n), Flag: &flag}
 	} else {
-		r.Ring = ring.New(n)
-		r.Context = ctx
-		r.Flag = &flag
+		rb.Ring = ring.New(n)
+		rb.Context = ctx
+		rb.Flag = &flag
 	}
-	for x := r.Ring; x.Value == nil; x = x.Next() {
+	for x := rb.Ring; x.Value == nil; x = x.Next() {
 		x.Value = new(LockItem)
 	}
-	r.Current().Lock()
-	return r
+	rb.Current().Lock()
+	return rb
 }

 func (rb RingBuffer) Clone() *RingBuffer {
 	return &rb
 }

-func (r RingBuffer) SubRing(rr *ring.Ring) *RingBuffer {
-	r.Ring = rr
-	return &r
+func (rb RingBuffer) SubRing(rr *ring.Ring) *RingBuffer {
+	rb.Ring = rr
+	return &rb
 }

-func (r *RingBuffer) CurrentValue() interface{} {
-	return r.Current().Value
+func (rb *RingBuffer) CurrentValue() interface{} {
+	return rb.Current().Value
 }

-func (r *RingBuffer) NextValue() interface{} {
-	return r.Next().Value.(*LockItem).Value
+func (rb *RingBuffer) NextValue() interface{} {
+	return rb.Next().Value.(*LockItem).Value
 }

-func (r *RingBuffer) Current() *LockItem {
-	return r.Ring.Value.(*LockItem)
+func (rb *RingBuffer) Current() *LockItem {
+	return rb.Ring.Value.(*LockItem)
 }

-func (r *RingBuffer) MoveNext() {
-	r.Ring = r.Next()
+func (rb *RingBuffer) MoveNext() {
+	rb.Ring = rb.Next()
 }

-func (r *RingBuffer) GetNext() *LockItem {
-	r.MoveNext()
-	return r.Current()
+func (rb *RingBuffer) GetNext() *LockItem {
+	rb.MoveNext()
+	return rb.Current()
 }

-func (r *RingBuffer) Read() interface{} {
-	current := r.Current()
+func (rb *RingBuffer) Read() interface{} {
+	current := rb.Current()
 	current.RLock()
 	defer current.RUnlock()
 	return current.Value
 }

-func (r *RingBuffer) Step() {
-	last := r.Current()
-	if atomic.CompareAndSwapInt32(r.Flag, 0, 1) {
-		current := r.GetNext()
+func (rb *RingBuffer) Step() {
+	last := rb.Current()
+	if atomic.CompareAndSwapInt32(rb.Flag, 0, 1) {
+		current := rb.GetNext()
 		current.Lock()
 		last.Unlock()
 		//Flag不为1代表被Dispose了，但尚未处理Done
-		if !atomic.CompareAndSwapInt32(r.Flag, 1, 0) {
+		if !atomic.CompareAndSwapInt32(rb.Flag, 1, 0) {
 			current.Unlock()
 		}
 	}
 }

-func (r *RingBuffer) Write(value interface{}) {
-	last := r.Current()
+func (rb *RingBuffer) Write(value interface{}) {
+	last := rb.Current()
 	last.Value = value
-	if atomic.CompareAndSwapInt32(r.Flag, 0, 1) {
-		current := r.GetNext()
+	if atomic.CompareAndSwapInt32(rb.Flag, 0, 1) {
+		current := rb.GetNext()
 		current.Lock()
 		last.Unlock()
 		//Flag不为1代表被Dispose了，但尚未处理Done
-		if !atomic.CompareAndSwapInt32(r.Flag, 1, 0) {
+		if !atomic.CompareAndSwapInt32(rb.Flag, 1, 0) {
 			current.Unlock()
 		}
 	}
 }

-func (r *RingBuffer) Dispose() {
-	current := r.Current()
-	if atomic.CompareAndSwapInt32(r.Flag, 0, 2) {
+func (rb *RingBuffer) Dispose() {
+	current := rb.Current()
+	if atomic.CompareAndSwapInt32(rb.Flag, 0, 2) {
 		current.Unlock()
-	} else if atomic.CompareAndSwapInt32(r.Flag, 1, 2) {
+	} else if atomic.CompareAndSwapInt32(rb.Flag, 1, 2) {
 		//当前是1代表正在写入，此时变成2，但是Done的任务得交给NextW来处理
-	} else if atomic.CompareAndSwapInt32(r.Flag, 0, 2) {
+	} else if atomic.CompareAndSwapInt32(rb.Flag, 0, 2) {
 		current.Unlock()
 	}
 }

-func (r *RingBuffer) read() reflect.Value {
-	return reflect.ValueOf(r.Read())
+func (rb *RingBuffer) read() reflect.Value {
+	return reflect.ValueOf(rb.Read())
 }

-func (r *RingBuffer) nextRead() reflect.Value {
-	r.MoveNext()
-	return r.read()
+func (rb *RingBuffer) nextRead() reflect.Value {
+	rb.MoveNext()
+	return rb.read()
 }

 // ReadLoop 循环读取，采用了反射机制，不适用高性能场景
 // handler入参可以传入回调函数或者channel
-func (r *RingBuffer) ReadLoop(handler interface{}) {
-	r.ReadLoopConditional(handler, func() bool {
-		return r.Err() == nil && *r.Flag != 2
+func (rb *RingBuffer) ReadLoop(handler interface{}) {
+	rb.ReadLoopConditional(handler, func() bool {
+		return rb.Err() == nil && *rb.Flag != 2
 	})
 }

 // goon判断函数用来判断是否继续读取,返回false将终止循环
-func (r *RingBuffer) ReadLoopConditional(handler interface{}, goon func() bool) {
+func (rb *RingBuffer) ReadLoopConditional(handler interface{}, goon func() bool) {
 	switch t := reflect.ValueOf(handler); t.Kind() {
 	case reflect.Chan:
-		for v := r.read(); goon(); v = r.nextRead() {
+		for v := rb.read(); goon(); v = rb.nextRead() {
 			t.Send(v)
 		}
 	case reflect.Func:
-		for args := []reflect.Value{r.read()}; goon(); args[0] = r.nextRead() {
+		for args := []reflect.Value{rb.read()}; goon(); args[0] = rb.nextRead() {
 			t.Call(args)
 		}
 	}
--- a/ring_av.go
+++ b/ring_av.go
@@ -3,7 +3,6 @@ package engine
 import (
 	"container/ring"
 	"context"
-	"reflect"
 	"runtime"
 	"time"
 )
@@ -11,8 +10,8 @@ import (
 type AVItem struct {
 	Timestamp uint32
 	Sequence  int
-	Value interface{}
-	canRead bool
+	Value     interface{}
+	canRead   bool
 }

 func (p *AVItem) Since(ts uint32) uint32 {
@@ -36,8 +35,8 @@ func (r *AVRing) Init(ctx context.Context, n int) *AVRing {
 	}
 	return r
 }
-func (rb AVRing) Clone() *AVRing {
-	return &rb
+func (r AVRing) Clone() *AVRing {
+	return &r
 }

 func (r AVRing) SubRing(rr *ring.Ring) *AVRing {
@@ -65,19 +64,6 @@ func (r *AVRing) wait() {
 	}
 }

-func (r *AVRing) read() reflect.Value {
-	current := r.Current()
-	for r.Err() == nil && !current.canRead {
-		r.wait()
-	}
-	return reflect.ValueOf(current.Value)
-}
-
-func (r *AVRing) nextRead() reflect.Value {
-	r.MoveNext()
-	return r.read()
-}
-
 func (r *AVRing) CurrentValue() interface{} {
 	return r.Current().Value
 }
@@ -93,6 +79,9 @@ func (r *AVRing) NextRead() (item *AVItem, value interface{}) {
 func (r *AVRing) NextValue() interface{} {
 	return r.Next().Value.(*AVItem).Value
 }
+func (r *AVRing) PreItem() *AVItem {
+	return r.Prev().Value.(*AVItem)
+}
 func (r *AVRing) GetNext() *AVItem {
 	r.MoveNext()
 	return r.Current()
@@ -104,18 +93,3 @@ func (r *AVRing) Read() (item *AVItem, value interface{}) {
 	}
 	return current, current.Value
 }
-
-// ReadLoop 循环读取，采用了反射机制，不适用高性能场景
-// handler入参可以传入回调函数或者channel
-func (r *AVRing) ReadLoop(handler interface{}) {
-	switch t := reflect.ValueOf(handler); t.Kind() {
-	case reflect.Chan:
-		for v := r.read(); r.Err() == nil; v = r.nextRead() {
-			t.Send(v)
-		}
-	case reflect.Func:
-		for args := []reflect.Value{r.read()}; r.Err() == nil; args[0] = r.nextRead() {
-			t.Call(args)
-		}
-	}
-}
--- a/subscriber.go
+++ b/subscriber.go
@@ -82,11 +82,13 @@ func (s *Subscriber) Play(at *AudioTrack, vt *VideoTrack) {
 	case <-extraExit: //可能等不到关键帧就退出了
 		return
 	}
-	vr := vt.SubRing(vt.IDRing) //从关键帧开始读取，首屏秒开
+	vr := vt.SubRing(vt.IDRing)      //从关键帧开始读取，首屏秒开
+	realSt := vt.PreItem().Timestamp // 当前时间戳
 	ar := at.Clone()
 	iv, vp := vr.Read()
 	ia, ap := ar.Read()
-	vst, ast := iv.Timestamp, ia.Timestamp
+	vst := iv.Timestamp
+	chase := true
 	for {
 		select {
 		case <-extraExit:
@@ -96,10 +98,18 @@ func (s *Subscriber) Play(at *AudioTrack, vt *VideoTrack) {
 		default:
 			if ia.Timestamp > iv.Timestamp || ia.Timestamp == 0 {
 				s.OnVideo(iv.Timestamp-vst, vp.(*VideoPack))
+				if chase {
+					if vst < realSt-10 {
+						vst += 10
+					} else {
+						vst = realSt
+						chase = false
+					}
+				}
 				vr.MoveNext()
 				iv, vp = vr.Read()
 			} else {
-				s.OnAudio(ia.Timestamp-ast, ap.(*AudioPack))
+				s.OnAudio(ia.Timestamp-vst, ap.(*AudioPack))
 				ar.MoveNext()
 				ia, ap = ar.Read()
 			}
--- a/video_track.go
+++ b/video_track.go
@@ -384,9 +384,11 @@ func (vt *VideoTrack) Play(onVideo func(uint32, *VideoPack), exit1, exit2 <-chan
 	case <-exit2: //可能等不到关键帧就退出了
 		return
 	}
-	vr := vt.SubRing(vt.IDRing) //从关键帧开始读取，首屏秒开
+	vr := vt.SubRing(vt.IDRing)      //从关键帧开始读取，首屏秒开
+	realSt := vt.PreItem().Timestamp // 当前时间戳
 	item, vp := vr.Read()
-	for startTimestamp := item.Timestamp; ; item, vp = vr.Read() {
+	startTimestamp := item.Timestamp
+	for chase := true; ; item, vp = vr.Read() {
 		select {
 		case <-exit1:
 			return
@@ -394,6 +396,14 @@ func (vt *VideoTrack) Play(onVideo func(uint32, *VideoPack), exit1, exit2 <-chan
 			return
 		default:
 			onVideo(item.Timestamp-startTimestamp, vp.(*VideoPack))
+			if chase {
+				if startTimestamp < realSt-10 {
+					startTimestamp += 10
+				} else {
+					startTimestamp = realSt
+					chase = false
+				}
+			}
 			vr.MoveNext()
 		}
 	}