Merged in rtp-ringbuff-bypass (pull request #88)

Rtp ringbuff bypass

Approved-by: Alan Noble <anoble@gmail.com>
Approved-by: kortschak <dan@kortschak.io>

revid/revid.go

@@ -111,6 +111,10 @@ type Revid struct {
 	// destination is the target endpoint.
 	destination []loadSender
 
+	// rtpSender is an unbuffered sender.
+	// It is used to isolate RTP from ring buffer-induced delays.
+	rtpSender *rtpSender
+
 	// bitrate hold the last send bitrate  calculation result.
 	bitrate int
 
@@ -137,6 +141,13 @@ func (p *packer) Write(frame []byte) (int, error) {
 		return len(frame), nil
 	}
 	n, err := p.owner.buffer.Write(frame)
+	// If we have an rtp sender bypass ringbuffer and give straight to sender
+	if p.owner.rtpSender != nil {
+		err = p.owner.rtpSender.send(frame)
+		if err != nil {
+			p.owner.config.Logger.Log(logger.Error, pkg+"rtp send failed with error", "error", err.Error())
+		}
+	}
 	if err != nil {
 		if err == ring.ErrDropped {
 			p.owner.config.Logger.Log(logger.Warning, pkg+"dropped frame", "frame size", len(frame))
@@ -193,7 +204,7 @@ func (r *Revid) reset(config Config) error {
 	}
 
 	n := 1
-	if r.config.Output2 != 0 {
+	if r.config.Output2 != 0 && r.config.Output2 != Rtp {
 		n = 2
 	}
 	r.destination = make([]loadSender, n)
@@ -227,11 +238,10 @@ func (r *Revid) reset(config Config) error {
 			}
 			r.destination[outNo] = s
 		case Rtp:
-			s, err := newRtpSender(r.config.RtpAddress, r.config.Logger.Log, r.config.FrameRate)
+			r.rtpSender, err = newRtpSender(r.config.RtpAddress, r.config.Logger.Log, r.config.FrameRate)
 			if err != nil {
 				return err
 			}
-			r.destination[outNo] = s
 		}
 	}
 

revid/senders.go

@@ -29,6 +29,7 @@ LICENSE
 package revid
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -369,7 +370,6 @@ func (s *udpSender) close() error { return nil }
 // rtpSender implements loadSender for a native udp destination with rtp packetization.
 type rtpSender struct {
 	log     func(lvl int8, msg string, args ...interface{})
-	chunk   *ring.Chunk
 	encoder *rtp.Encoder
 }
 
@@ -385,19 +385,12 @@ func newRtpSender(addr string, log func(lvl int8, msg string, args ...interface{
 	return s, nil
 }
 
-func (s *rtpSender) load(c *ring.Chunk) error {
-	s.chunk = c
-	return nil
-}
-
-func (s *rtpSender) send() error {
-	_, err := s.chunk.WriteTo(s.encoder)
+func (s *rtpSender) send(d []byte) error {
+	var err error
+	if d != nil {
+		_, err = s.encoder.Write(d)
+	} else {
+		err = errors.New("no data to send provided")
+	}
 	return err
 }
-
-func (s *rtpSender) release() {
-	s.chunk.Close()
-	s.chunk = nil
-}
-
-func (s *rtpSender) close() error { return nil }