From d28debabe9691e9ed32a890a19081226ae976096 Mon Sep 17 00:00:00 2001
From: Alexey Khit <alexey.khit@gmail.com>
Date: Mon, 22 Aug 2022 14:44:19 +0300
Subject: [PATCH] Update fix for parsing RTSP SDP

---
 cmd/streams/stream_test.go |  3 ++-
 pkg/rtsp/conn.go           | 46 ++++++++++++++++++++++++--------------
 pkg/streamer/media.go      | 20 -----------------
 3 files changed, 31 insertions(+), 38 deletions(-)

diff --git a/cmd/streams/stream_test.go b/cmd/streams/stream_test.go
index 959e224f..b16ceae4 100644
--- a/cmd/streams/stream_test.go
+++ b/cmd/streams/stream_test.go
@@ -2,6 +2,7 @@ package streams
 
 import (
 	"github.com/AlexxIT/go2rtc/pkg/fake"
+	"github.com/AlexxIT/go2rtc/pkg/rtsp"
 	"github.com/AlexxIT/go2rtc/pkg/streamer"
 	"github.com/stretchr/testify/assert"
 	"testing"
@@ -103,7 +104,7 @@ a=control:streamid=0
 
 func TestRouting(t *testing.T) {
 	prod := &fake.Producer{}
-	prod.Medias, _ = streamer.UnmarshalRTSPSDP([]byte(dahuaSimple))
+	prod.Medias, _ = rtsp.UnmarshalSDP([]byte(dahuaSimple))
 	assert.Len(t, prod.Medias, 3)
 
 	HandleFunc("fake", func(url string) (streamer.Producer, error) {
diff --git a/pkg/rtsp/conn.go b/pkg/rtsp/conn.go
index 9820e385..aa278aea 100644
--- a/pkg/rtsp/conn.go
+++ b/pkg/rtsp/conn.go
@@ -282,13 +282,7 @@ func (c *Conn) Describe() error {
 		}
 	}
 
-	// fix bug in Sonoff camera SDP "o=- 1 1 IN IP4 rom t_rtsplin"
-	// TODO: make some universal fix
-	if i := bytes.Index(res.Body, []byte("rom t_rtsplin")); i > 0 {
-		res.Body[i+3] = '_'
-	}
-
-	c.Medias, err = streamer.UnmarshalRTSPSDP(res.Body)
+	c.Medias, err = UnmarshalSDP(res.Body)
 	if err != nil {
 		return err
 	}
@@ -479,7 +473,7 @@ func (c *Conn) Accept() error {
 				return errors.New("wrong content type")
 			}
 
-			c.Medias, err = streamer.UnmarshalRTSPSDP(req.Body)
+			c.Medias, err = UnmarshalSDP(req.Body)
 			if err != nil {
 				return err
 			}
@@ -728,17 +722,35 @@ type RTCP struct {
 	Packets []rtcp.Packet
 }
 
-func between(s, sub1, sub2 string) (res string, ok1 bool, ok2 bool) {
-	i := strings.Index(s, sub1)
-	if i >= 0 {
-		ok1 = true
-		s = s[i+len(sub1):]
+const sdpHeader = `v=0
+o=- 0 0 IN IP4 0.0.0.0
+s=-
+t=0 0`
+
+func UnmarshalSDP(rawSDP []byte) ([]*streamer.Media, error) {
+	medias, err := streamer.UnmarshalSDP(rawSDP)
+	if err != nil {
+		// fix SDP header for some cameras
+		i := bytes.Index(rawSDP, []byte("\nm="))
+		if i > 0 {
+			rawSDP = append([]byte(sdpHeader), rawSDP[i:]...)
+			medias, err = streamer.UnmarshalSDP(rawSDP)
+		}
+		if err != nil {
+			return nil, err
+		}
 	}
 
-	i = strings.Index(s, sub2)
-	if i >= 0 {
-		return s[:i], ok1, true
+	// fix bug in ONVIF spec
+	// https://www.onvif.org/specs/stream/ONVIF-Streaming-Spec-v241.pdf
+	for _, media := range medias {
+		switch media.Direction {
+		case streamer.DirectionRecvonly, "":
+			media.Direction = streamer.DirectionSendonly
+		case streamer.DirectionSendonly:
+			media.Direction = streamer.DirectionRecvonly
+		}
 	}
 
-	return s, ok1, false
+	return medias, nil
 }
diff --git a/pkg/streamer/media.go b/pkg/streamer/media.go
index 9ac10f48..529236ac 100644
--- a/pkg/streamer/media.go
+++ b/pkg/streamer/media.go
@@ -180,26 +180,6 @@ func UnmarshalSDP(rawSDP []byte) ([]*Media, error) {
 	return medias, nil
 }
 
-func UnmarshalRTSPSDP(rawSDP []byte) ([]*Media, error) {
-	medias, err := UnmarshalSDP(rawSDP)
-	if err != nil {
-		return nil, err
-	}
-
-	// fix bug in ONVIF spec
-	// https://www.onvif.org/specs/stream/ONVIF-Streaming-Spec-v241.pdf
-	for _, media := range medias {
-		switch media.Direction {
-		case DirectionRecvonly, "":
-			media.Direction = DirectionSendonly
-		case DirectionSendonly:
-			media.Direction = DirectionRecvonly
-		}
-	}
-
-	return medias, nil
-}
-
 func MarshalSDP(medias []*Media) ([]byte, error) {
 	sd := &sdp.SessionDescription{}