Support RFC 3890 (webrtc-rs#489)

* Support RFC 3890

Support RFC 3890 (TIAS) for unmarshaling bandwidth.

* link reference

Author: skyuplam

sdp/src/description/description_test.rs

@@ -402,6 +402,15 @@ m=audio 54400 RTP/SAVPF 0 96\r\n\
 b=X-YZ:128\r\n\
 b=AS:12345\r\n";
 
+const MEDIA_TRANSPORT_BANDWIDTH_SDP: &str = "v=0\r\n\
+o=jdoe 2890844526 2890842807 IN IP4 10.47.16.5\r\n\
+s=SDP Seminar\r\n\
+t=2873397496 2873404696\r\n\
+m=video 51372 RTP/AVP 99\r\n\
+m=audio 54400 RTP/SAVPF 0 96\r\n\
+b=AS:12345\r\n\
+b=TIAS:12345\r\n";
+
 const MEDIA_ENCRYPTION_KEY_SDP: &str = "v=0\r\n\
 o=jdoe 2890844526 2890842807 IN IP4 10.47.16.5\r\n\
 s=SDP Seminar\r\n\
@@ -520,6 +529,11 @@ fn test_round_trip() -> Result<()> {
             Some(MEDIA_DESCRIPTION_OUT_OF_ORDER_SDPACTUAL),
         ),
         ("MediaBandwidth", MEDIA_BANDWIDTH_SDP, None),
+        (
+            "MediaTransportBandwidth",
+            MEDIA_TRANSPORT_BANDWIDTH_SDP,
+            None,
+        ),
         ("MediaEncryptionKey", MEDIA_ENCRYPTION_KEY_SDP, None),
         (
             "MediaEncryptionKeyExtraCRLF",

sdp/src/description/session.rs

@@ -1066,8 +1066,9 @@ fn unmarshal_bandwidth(value: &str) -> Result<Bandwidth> {
         parts[0] = parts[0].trim_start_matches("X-");
     } else {
         // Set according to currently registered with IANA
-        // https://tools.ietf.org/html/rfc4566#section-5.8
-        let i = index_of(parts[0], &["CT", "AS"]);
+        // https://tools.ietf.org/html/rfc4566#section-5.8 and
+        // https://datatracker.ietf.org/doc/html/rfc3890
+        let i = index_of(parts[0], &["CT", "AS", "TIAS"]);
         if i == -1 {
             return Err(Error::SdpInvalidValue(parts[0].to_owned()));
         }