fix compatibility with some TP-Link cameras (#509) (#510)

pkg/description/media.go

@@ -16,15 +16,19 @@ import (
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 )
 
-var smartRegexp = regexp.MustCompile("^([0-9]+) (.*?)/90000")
+var (
+	smartPayloadTypeRegexp = regexp.MustCompile("^smart/[0-9]/[0-9]+$")
+	smartRtpmapRegexp      = regexp.MustCompile("^([0-9]+) (.+)/[0-9]+$")
+)
 
 func replaceSmartPayloadType(payloadType string, attributes []psdp.Attribute) string {
-	if payloadType == "smart/1/90000" {
+	re1 := smartPayloadTypeRegexp.FindStringSubmatch(payloadType)
+	if re1 != nil {
 		for _, attr := range attributes {
 			if attr.Key == "rtpmap" {
-				sm := smartRegexp.FindStringSubmatch(attr.Value)
+				re2 := smartRtpmapRegexp.FindStringSubmatch(attr.Value)
-				if sm != nil {
+				if re2 != nil {
-					return sm[1]
+					return re2[1]
 				}
 			}
 		}

pkg/description/session_test.go

@@ -550,7 +550,7 @@ var casesSession = []struct {
 		},
 	},
 	{
-		"tp-link",
+		"issue mediamtx/1267 (tp-link)",
 		"v=0\r\n" +
 			"o=- 4158123474391860926 2 IN IP4 127.0.0.1\r\n" +
 			"s=-\r\n" +
@@ -579,6 +579,39 @@ var casesSession = []struct {
 			},
 		},
 	},
+	{
+		"issue gortsplib/509 (tp-link)",
+		"v=0\n" +
+			"o=- 14665860 31787219 1 IN IP4 192.168.1.102\n" +
+			"s=Session streamed by \"TP-LINK RTSP Server\"\n" +
+			"t=0 0\n" +
+			"a=smart_encoder:virtualIFrame=1\n" +
+			"m=application/tp-link 0 RTP/AVP smart/0/25000\n" +
+			"a=rtpmap:95 tp-link/25000\n" +
+			"a=control:track3\n",
+		"v=0\r\n" +
+			"o=- 0 0 IN IP4 127.0.0.1\r\n" +
+			"s=Session streamed by \"TP-LINK RTSP Server\"\r\n" +
+			"c=IN IP4 0.0.0.0\r\n" +
+			"t=0 0\r\n" +
+			"m=application/tp-link 0 RTP/AVP 95\r\n" +
+			"a=control:track3\r\n" +
+			"a=rtpmap:95 tp-link/25000\r\n",
+		Session{
+			Title: `Session streamed by "TP-LINK RTSP Server"`,
+			Medias: []*Media{
+				{
+					Type: "application/tp-link",
+					Formats: []format.Format{&format.Generic{
+						PayloadTyp: 95,
+						RTPMa:      "tp-link/25000",
+						ClockRat:   25000,
+					}},
+					Control: "track3",
+				},
+			},
+		},
+	},
 	{
 		"mercury",
 		"v=0\n" +