Fix SDP parsing from cheap Chinese cameras

pkg/rtsp/helpers.go

@@ -5,6 +5,7 @@ import (
 	"github.com/AlexxIT/go2rtc/pkg/streamer"
 	"github.com/pion/rtcp"
 	"net/url"
+	"regexp"
 	"strings"
 )
 
@@ -22,9 +23,12 @@ t=0 0`
 func UnmarshalSDP(rawSDP []byte) ([]*streamer.Media, error) {
 	medias, err := streamer.UnmarshalSDP(rawSDP)
 	if err != nil {
+		// fix multiple `s=` https://github.com/AlexxIT/WebRTC/issues/417
+		re, _ := regexp.Compile("\ns=[^\n]+")
+		rawSDP = re.ReplaceAll(rawSDP, nil)
+
 		// fix SDP header for some cameras
-		i := bytes.Index(rawSDP, []byte("\nm="))
+		if i := bytes.Index(rawSDP, []byte("\nm=")); i > 0 {
-		if i > 0 {
 			rawSDP = append([]byte(sdpHeader), rawSDP[i:]...)
 			medias, err = streamer.UnmarshalSDP(rawSDP)
 		}

pkg/rtsp/rtsp_test.go

@@ -18,3 +18,35 @@ func TestURLParse(t *testing.T) {
 	assert.Empty(t, err)
 	assert.Equal(t, "turret2-cam.lan:554", u.Host)
 }
+
+func TestMultipleSinSDP(t *testing.T) {
+	s := `v=0
+o=- 91674849066 1 IN IP4 192.168.1.123
+s=RtspServer
+i=live
+t=0 0
+a=control:*
+a=range:npt=0-
+m=video 0 RTP/AVP 96
+c=IN IP4 0.0.0.0
+s=RtspServer
+i=live
+a=control:track0
+a=range:npt=0-
+a=rtpmap:96 H264/90000
+a=fmtp:96 packetization-mode=1;profile-level-id=42001E;sprop-parameter-sets=Z0IAHvQCgC3I,aM48gA==
+a=control:track0
+m=audio 0 RTP/AVP 97
+c=IN IP4 0.0.0.0
+s=RtspServer
+i=live
+a=control:track1
+a=range:npt=0-
+a=rtpmap:97 MPEG4-GENERIC/8000/1
+a=fmtp:97 profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1588
+a=control:track1
+`
+	medias, err := UnmarshalSDP([]byte(s))
+	assert.Nil(t, err)
+	assert.NotNil(t, medias)
+}