in chime-sdk-signaling-cpp/src/utils/sdp_utils.h [77:83]
static MediaDirection GetDirection(const std::string& str) {
if (str == rec_only) return MediaDirection::kRecvOnly;
if (str == inactive) return MediaDirection::kInactive;
if (str == send_only) return MediaDirection::kSendOnly;
return MediaDirection::kSendRecv;
}