In Reporter.c of Iperf 2.0.3 , the "jitter" designed to follow RFC 1889, Real Time Protocol (RTP):

            // from RFC 1889, Real Time Protocol (RTP) 
            // J = J + ( | D(i-1,i) | - J ) / 16 
            transit = TimeDifference( packet->packetTime, packet->sentTime );
            if ( data->lastTransit != 0.0 ) {
                deltaTransit = transit - data->lastTransit;
                if ( deltaTransit < 0.0 ) {
                    deltaTransit = -deltaTransit;
                }
                stats->jitter += (deltaTransit - stats->jitter) / (16.0);
            }
            data->lastTransit = transit;

so the key is "RFC 1889, Real Time Protocol (RTP)"

ゼロからはじめる! 統計学見るだけノート

宝島社

2018-06-14

Exception in thread "main" java.lang.NoClassDefFoundError: org/bouncycastle/jce/provider/BouncyCastleProvider

java.util.concurrent.ExecutionException: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested targetr

-Djavax.net.ssl.trustStore=C:\Program Files\Java\jdk-21.0.1\lib\security\cacerts

["OK","fdf83a3115ae12c3331acd6390641a2ab075b85bf21a44d7e10ce4d0379b0dc6",true,""]

/**
 * Nostr書き込み処理サンプル。
 */
package nekora.nostr;

import java.io.IOException;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.time.Instant;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;

import org.eclipse.jetty.client.HttpClient;
import org.eclipse.jetty.websocket.api.Callback;
import org.eclipse.jetty.websocket.api.Session;
import org.eclipse.jetty.websocket.api.StatusCode;
import org.eclipse.jetty.websocket.client.WebSocketClient;

import nostr.base.PrivateKey;
import nostr.base.PublicKey;
import nostr.crypto.schnorr.Schnorr;
import nostr.util.NostrUtil;

/**
 * 
 */
public class NostrSendMain {
	//final String RELAY_URL = "wss://relay.nostr.wirednet.jp";
	final String RELAY_URL = "wss://relay-jp.nostr.wirednet.jp";
	final String CONTENT = "初カキコ…ども…from My Java Client";

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		NostrSendMain my = new NostrSendMain();
		my.exec(args);
	}

	private void exec(String[] args) {
		// Use a standard, HTTP/1.1, HttpClient.
		HttpClient httpClient = new HttpClient();

		// Create and start WebSocketClient.
		WebSocketClient webSocketClient = new WebSocketClient(httpClient);
		try {
			webSocketClient.start();
			// The client-side WebSocket EndPoint that
			// receives WebSocket messages from the server.
			MyAutoDemandListenerEndPoint myendp = new MyAutoDemandListenerEndPoint();
			// The server URI to connect to.
			URI serverURI = URI.create(RELAY_URL);

			// クライアントエンドポイントをサーバーに接続.
			CompletableFuture clientSessionPromise = webSocketClient.connect(myendp, serverURI);

			// 接続処理完了を待つ
			// Thread.sleep(1500); // これ要らない気がするので削除してみた

			// セッションを取得
			try (Session session = clientSessionPromise.join()) {
				if (!session.isOpen()) {
					System.err.println("接続できませんでした");
					return;
				}
				System.out.println("接続OK…" + session);

				// Nonstr特化通信
				nostrExec(session);
				System.out.println("Nostrに送信完了");

			} catch (Exception e) {
				throw e;
			}

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			// クローズ
			try {
				webSocketClient.stop();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		System.out.println("すべて完了");
	}

	/**
	 * Nostrリレーサーバと通信 https://zenn.dev/memory_of_snow/articles/1f0ddd964c5f83 参考
	 * 
	 * @param webSocketClient
	 * @param session
	 */
	private void nostrExec(Session session) {
		// テスト用秘密鍵(=アカウント)をランダムに作成。
		PrivateKey secKey = new PrivateKey(Schnorr.generatePrivateKey());
		//PrivateKey secKey = new PrivateKey("アカウント固定する場合はエンコードされた秘密鍵文字列");

		try {
			// 秘密鍵から公開鍵を作成
			PublicKey publicKey = new PublicKey(Schnorr.genPubKey(secKey.getRawData()));
			String publicKeyHex = publicKey.toString();

			System.out.println("SecKey(HEX) = " + secKey);
			System.out.println("publicKey(HEX) = " + publicKey);

			long created_at = Instant.now().getEpochSecond();
			int kind = 1;
			List> tags = new ArrayList<>();

			// id計算に使う要素を集める
			// [0,"公開鍵(HEX)",投稿時間,kind(プレーンテキスト投稿は1),タグ群,"投稿内容"]
			String partsForId = "[0,\"" + publicKeyHex + "\"," + created_at + "," + kind + "," + tags + ",\"" + CONTENT
					+ "\"]";
			byte[] idSourceBytes = partsForId.getBytes(StandardCharsets.UTF_8);
			String id = NostrUtil.bytesToHex(NostrUtil.sha256(idSourceBytes));
			byte[] signedHashedSerializedEvent = Schnorr.sign(NostrUtil.sha256(idSourceBytes), secKey.getRawData(),
					NostrUtil.createRandomByteArray(32));
			String sig = NostrUtil.bytesToHex(signedHashedSerializedEvent);

			// メッセージは["EVENT",{
			// "id":"id",
			// "pubkey":"公開鍵（Hex）",
			// "created_at":作成時間（UnixTimeStamp）,
			// "kind":kind（プレーンテキストは1）,
			// "tags":[],
			// "content":"投稿内容",
			// "sig":"署名"
			// }]
			String message = "[\"EVENT\",{\"id\":\"" + id + "\",\"pubkey\":\"" + publicKeyHex + "\","
					+ "\"created_at\":" + created_at + ",\"kind\":" + kind + ",\"tags\":" + tags + ","
					+ "\"content\":\"" + CONTENT + "\",\"sig\":\"" + sig + "\"}]";

			String displayMessage = message.replace(",", ",\n");
			System.out.println("組み立てたメッセージ：\n" + displayMessage);

			// session.getRemote().sendString(message); // こんなメソッドは無いと言われる
			MySendCallBack calbak = new MySendCallBack(message);
			session.sendText(message, calbak);

			// 受信時間稼ぎ
			Thread.sleep(1500); // これ必要なのか分からないがサンプルに従い残す。

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

package nekora.nostr;

import org.eclipse.jetty.websocket.api.Session;

/**
 * 接続用エンドポイント 以下をコピペ
 * https://eclipse.dev/jetty/documentation/jetty-12/programming-guide/index.html#pg-client-http
 */

public class MyAutoDemandListenerEndPoint implements Session.Listener.AutoDemanding {
	private Session session;

	@Override
	public void onWebSocketOpen(Session session) {
		this.session = session;
		// No need to demand here, because this endpoint is auto-demanding.
	}

	@Override
	public void onWebSocketText(String message) {
		System.out.println("受信メッセージ＝" + message);
		// No need to demand here, because this endpoint is auto-demanding.
	}

}

package nekora.nostr;

import org.eclipse.jetty.websocket.api.Callback;

/**
 * 送信用コールバック
 * https://eclipse.dev/jetty/documentation/jetty-12/programming-guide/index.html#pg-websocket-session-send
 */
public class MySendCallBack implements Callback {
	private String message;

	public MySendCallBack(String message) {
		this.message = message;
	}

	@Override
	public void succeed() {
		System.out.println("テキスト送信成功." + message);
	}

	@Override
	public void fail(Throwable x) {
		// No need to rethrow or close the session.
		System.out.println("テキスト送信失敗." + message + " エラー＝" + x.getMessage());
	}

}

dependency org="org.eclipse.jetty.websocket" name="jetty-websocket-jetty-client" rev="12.0.5"

ノストラダムスの大予言　迫りくる1999年7の月人類滅亡の日 (ノン・ブック)

五島勉

祥伝社

2014-09-05