From d1eb623fd6b655c7633ca7aeff3a5d00556e792b Mon Sep 17 00:00:00 2001
From: Alexey Khit <alexey.khit@gmail.com>
Date: Sun, 20 Aug 2023 21:25:45 +0300
Subject: [PATCH] Add buffer for RTSP output

---
 pkg/rtsp/consumer.go | 60 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 46 insertions(+), 14 deletions(-)

diff --git a/pkg/rtsp/consumer.go b/pkg/rtsp/consumer.go
index a0cc9662..ce9e402b 100644
--- a/pkg/rtsp/consumer.go
+++ b/pkg/rtsp/consumer.go
@@ -1,6 +1,8 @@
 package rtsp
 
 import (
+	"time"
+
 	"github.com/AlexxIT/go2rtc/pkg/aac"
 	"github.com/AlexxIT/go2rtc/pkg/core"
 	"github.com/AlexxIT/go2rtc/pkg/h264"
@@ -8,7 +10,6 @@ import (
 	"github.com/AlexxIT/go2rtc/pkg/mjpeg"
 	"github.com/AlexxIT/go2rtc/pkg/pcm"
 	"github.com/pion/rtp"
-	"time"
 )
 
 func (c *Conn) GetMedias() []*core.Media {
@@ -74,25 +75,55 @@ func (c *Conn) AddTrack(media *core.Media, codec *core.Codec, track *core.Receiv
 }
 
 func (c *Conn) packetWriter(codec *core.Codec, channel, payloadType uint8) core.HandlerFunc {
+	var n int
+	buf := make([]byte, 4096) // 4KB
+
 	handlerFunc := func(packet *rtp.Packet) {
 		if c.state == StateNone {
 			return
 		}
 
-		clone := *packet
-		clone.Header.PayloadType = payloadType
+		clone := rtp.Packet{
+			Header: rtp.Header{
+				Version:        2,
+				Marker:         packet.Marker,
+				PayloadType:    payloadType,
+				SequenceNumber: packet.SequenceNumber,
+				Timestamp:      packet.Timestamp,
+				SSRC:           packet.SSRC,
+			},
+			Payload: packet.Payload,
+		}
 
-		size := clone.MarshalSize()
+		size := 12 + len(packet.Payload)
+
+		if n+4+size > len(buf) {
+			if len(buf) < 1024*1024 {
+				buf = append(buf, make([]byte, len(buf))...)
+			} else {
+				if _, err := c.conn.Write(buf[:n]); err == nil {
+					c.send += n
+				}
+				n = 0
+			}
+		}
 
 		//log.Printf("[RTP] codec: %s, size: %6d, ts: %10d, pt: %2d, ssrc: %d, seq: %d, mark: %v", codec.Name, len(packet.Payload), packet.Timestamp, packet.PayloadType, packet.SSRC, packet.SequenceNumber, packet.Marker)
 
-		data := make([]byte, 4+size)
-		data[0] = '$'
-		data[1] = channel
-		data[2] = byte(size >> 8)
-		data[3] = byte(size)
+		chunk := buf[n:]
+		_ = chunk[4] // bounds
+		chunk[0] = '$'
+		chunk[1] = channel
+		chunk[2] = byte(size >> 8)
+		chunk[3] = byte(size)
 
-		if _, err := clone.MarshalTo(data[4:]); err != nil {
+		if _, err := clone.MarshalTo(chunk[4:]); err != nil {
+			return
+		}
+
+		n += 4 + size
+
+		if !packet.Marker {
 			return
 		}
 
@@ -100,12 +131,13 @@ func (c *Conn) packetWriter(codec *core.Codec, channel, payloadType uint8) core.
 			return
 		}
 
-		n, err := c.conn.Write(data)
-		if err != nil {
-			return
+		//log.Printf("[rtsp] channel:%2d write_size:%6d buffer_size:%6d", channel, n, len(buf))
+
+		if _, err := c.conn.Write(buf[:n]); err == nil {
+			c.send += n
 		}
 
-		c.send += n
+		n = 0
 	}
 
 	if !codec.IsRTP() {