From 5f9788209d0ad50d3183893e43821ec1ec9ab67a Mon Sep 17 00:00:00 2001
From: Alexey Khit <alexey.khit@gmail.com>
Date: Thu, 20 Apr 2023 13:20:52 +0300
Subject: [PATCH] Move MP4 mutex from HTTP to Muxer

---
 cmd/mp4/mp4.go      |  8 +-------
 pkg/mp4/consumer.go | 15 +++++++++++----
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/cmd/mp4/mp4.go b/cmd/mp4/mp4.go
index c0fc343f..825cb647 100644
--- a/cmd/mp4/mp4.go
+++ b/cmd/mp4/mp4.go
@@ -4,7 +4,6 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/AlexxIT/go2rtc/cmd/api"
@@ -110,14 +109,9 @@ func handlerMP4(w http.ResponseWriter, r *http.Request) {
 		Medias:     core.ParseQuery(r.URL.Query()),
 	}
 
-	var mu sync.Mutex
 	cons.Listen(func(msg any) {
 		if data, ok := msg.([]byte); ok {
-			mu.Lock()
-			_, err := w.Write(data)
-			mu.Unlock()
-
-			if err != nil && exit != nil {
+			if _, err := w.Write(data); err != nil && exit != nil {
 				select {
 				case exit <- err:
 				default:
diff --git a/pkg/mp4/consumer.go b/pkg/mp4/consumer.go
index 47555540..a720c8ac 100644
--- a/pkg/mp4/consumer.go
+++ b/pkg/mp4/consumer.go
@@ -7,6 +7,7 @@ import (
 	"github.com/AlexxIT/go2rtc/pkg/h264"
 	"github.com/AlexxIT/go2rtc/pkg/h265"
 	"github.com/pion/rtp"
+	"sync"
 )
 
 type Consumer struct {
@@ -19,6 +20,7 @@ type Consumer struct {
 	senders []*core.Sender
 
 	muxer *Muxer
+	mu    sync.Mutex
 	wait  byte
 
 	send int
@@ -70,10 +72,12 @@ func (c *Consumer) AddTrack(media *core.Media, _ *core.Codec, track *core.Receiv
 				c.wait = waitNone
 			}
 
+			// important to use Mutex because right fragment order
+			c.mu.Lock()
 			buf := c.muxer.Marshal(trackID, packet)
 			c.Fire(buf)
-
 			c.send += len(buf)
+			c.mu.Unlock()
 		}
 
 		if track.Codec.IsRTP() {
@@ -97,10 +101,11 @@ func (c *Consumer) AddTrack(media *core.Media, _ *core.Codec, track *core.Receiv
 				c.wait = waitNone
 			}
 
+			c.mu.Lock()
 			buf := c.muxer.Marshal(trackID, packet)
 			c.Fire(buf)
-
 			c.send += len(buf)
+			c.mu.Unlock()
 		}
 
 		if track.Codec.IsRTP() {
@@ -113,10 +118,11 @@ func (c *Consumer) AddTrack(media *core.Media, _ *core.Codec, track *core.Receiv
 				return
 			}
 
+			c.mu.Lock()
 			buf := c.muxer.Marshal(trackID, packet)
 			c.Fire(buf)
-
 			c.send += len(buf)
+			c.mu.Unlock()
 		}
 
 		if track.Codec.IsRTP() {
@@ -129,10 +135,11 @@ func (c *Consumer) AddTrack(media *core.Media, _ *core.Codec, track *core.Receiv
 				return
 			}
 
+			c.mu.Lock()
 			buf := c.muxer.Marshal(trackID, packet)
 			c.Fire(buf)
-
 			c.send += len(buf)
+			c.mu.Unlock()
 		}
 
 	default: