Added start/end sample numbers

audio/packetizer/adts.go

@@ -6,6 +6,8 @@ import (
 	"io"
 )
 
+const adtsFrameSamples = 1024
+
 type AdtsPacketizer struct {
 	reader  io.Reader
 	samples int64
@@ -21,10 +23,14 @@ func (p *AdtsPacket) KeepMode() KeepMode {
 	return Discard
 }
 
-func (p *AdtsPacket) GetSampleNumber() int64 {
+func (p *AdtsPacket) GetStartSampleNumber() int64 {
 	return p.sampleNumber
 }
 
+func (p *AdtsPacket) GetEndSampleNumber() int64 {
+	return p.sampleNumber + adtsFrameSamples
+}
+
 func (p *AdtsPacket) GetData() []byte {
 	return append(p.header.Encode(), p.data...)
 }
@@ -48,7 +54,7 @@ func (o *AdtsPacketizer) GetPacket() Packet {
 		return nil
 	}
 	packet.sampleNumber = o.samples
-	o.samples += 1024 //always this fixed size per frame
+	o.samples += adtsFrameSamples //always this fixed size per frame
 
 	return packet
 }

audio/packetizer/flac.go

@@ -16,19 +16,24 @@ type FLACPacketizer struct {
 }
 
 type FLACPacket struct {
-	mode         KeepMode
-	sampleNumber int64
-	data         []byte
+	mode            KeepMode
+	sampleNumber    int64
+	endSampleNumber int64
+	data            []byte
 }
 
 func (p *FLACPacket) KeepMode() KeepMode {
 	return p.mode
 }
 
-func (p *FLACPacket) GetSampleNumber() int64 {
+func (p *FLACPacket) GetStartSampleNumber() int64 {
 	return p.sampleNumber
 }
 
+func (p *FLACPacket) GetEndSampleNumber() int64 {
+	return p.endSampleNumber
+}
+
 func (p *FLACPacket) GetData() []byte {
 	return p.data
 }
@@ -68,9 +73,10 @@ func (o *FLACPacketizer) GetPacket() (packet Packet) {
 			return nil
 		}
 		packet = &FLACPacket{
-			mode:         Keep,
-			sampleNumber: 0,
-			data:         o.getBuffer(),
+			mode:            Keep,
+			sampleNumber:    0,
+			endSampleNumber: 0,
+			data:            o.getBuffer(),
 		}
 		return
 	}
@@ -86,9 +92,10 @@ func (o *FLACPacketizer) GetPacket() (packet Packet) {
 		sampleNumber *= int64(frame.BlockSize)
 	}
 	packet = &FLACPacket{
-		mode:         Discard,
-		sampleNumber: sampleNumber,
-		data:         o.getBuffer(),
+		mode:            Discard,
+		sampleNumber:    sampleNumber,
+		endSampleNumber: sampleNumber + int64(frame.Subframes[0].NSamples),
+		data:            o.getBuffer(),
 	}
 
 	return

audio/packetizer/mp3.go

@@ -20,10 +20,14 @@ func (p *Mp3Packet) KeepMode() KeepMode {
 	return Discard
 }
 
-func (p *Mp3Packet) GetSampleNumber() int64 {
+func (p *Mp3Packet) GetStartSampleNumber() int64 {
 	return p.sampleNumber
 }
 
+func (p *Mp3Packet) GetEndSampleNumber() int64 {
+	return p.sampleNumber + int64(p.frame.Samples())
+}
+
 func (p *Mp3Packet) GetData() []byte {
 	return p.frame.Bytes()
 }

audio/packetizer/ogg.go

@@ -35,10 +35,14 @@ func (p *OggPacket) KeepMode() KeepMode {
 	return Discard
 }
 
-func (p *OggPacket) GetSampleNumber() int64 {
+func (p *OggPacket) GetStartSampleNumber() int64 {
 	return p.sampleNumber
 }
 
+func (p *OggPacket) GetEndSampleNumber() int64 {
+	return p.header.AbsoluteGranulePosition
+}
+
 func (p *OggPacket) GetData() []byte {
 	buf := bytes.NewBuffer(make([]byte, 0, 4+1+1+8+4+4+4+1+int(p.header.PageSegments)*(255+1)))
 	binary.Write(buf, binary.LittleEndian, p.header)

audio/packetizer/packetizer.go

@@ -12,7 +12,8 @@ const (
 
 type Packet interface {
 	KeepMode() KeepMode
-	GetSampleNumber() int64
+	GetStartSampleNumber() int64
+	GetEndSampleNumber() int64
 	GetData() []byte
 }