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精确控制视频播放进度 (YouTube)

精确控制视频播放进度/生成剪辑脚本的工具栏

当前为 2020-04-13 提交的版本，查看 最新版本。

  1. // ==UserScript==
  2. // @name        Precise video playback (YouTube)
  3. // @name:zh-CN  精确控制视频播放进度 (YouTube)
  4. // @description A toolbar to set precise video play time and generate clip script
  5. // @description:zh-CN 精确控制视频播放进度/生成剪辑脚本的工具栏
  6. // @namespace   moe.suisei.pvp.youtube
  7. // @match       https://www.youtube.com/watch*
  8. // @grant       none
  9. // @version     0.5.1
  10. // @author      Outvi V
  11. // ==/UserScript==
  12.  
  13. "use strict";
  14.  
  15. console.log("Precise Video Playback is up");
  16.  
  17. function getVideoId(url) {
  18.   return String(url).match(/v=([^&#]+)/)[1];
  19. }
  20.  
  21. function applyStyle(elem, styles) {
  22.   for (const [key, value] of Object.entries(styles)) {
  23.     elem.style[key] = value;
  24.   }
  25. }
  26.  
  27. function parseTime(str) {
  28.   if (!isNaN(Number(str))) return Number(str);
  29.   let time = str.match(/([0-9]?)?:([0-9]+)(\.([0-9]+))?/);
  30.   if (time === null) return -1;
  31.   let ret =
  32.     Number(time[1] || 0) * 60 + Number(time[2]) + Number(time[4] || 0) * 0.1;
  33.   if (ret == NaN) return -1;
  34.   return ret;
  35. }
  36.  
  37. function generateControl() {
  38.   let app = document.createElement("div");
  39.   let inputFrom = document.createElement("input");
  40.   inputFrom.placeholder = "from time";
  41.   let inputTo = document.createElement("input");
  42.   inputTo.placeholder = "to time";
  43.   let currentTime = document.createElement("span");
  44.   let btn = document.createElement("button");
  45.   let btnStop = document.createElement("button");
  46.   let btnExport = document.createElement("button");
  47.   applyStyle(app, {
  48.     display: "flex",
  49.     alignItems: "center",
  50.     justifyContent: "space-between",
  51.     maxWidth: "700px",
  52.     marginTop: "15px",
  53.     marginLeft: "auto",
  54.     marginRight: "auto",
  55.   });
  56.   applyStyle(currentTime, {
  57.     fontSize: "1.3rem",
  58.   });
  59.   let inputCommonStyle = {
  60.     width: "120px",
  61.   };
  62.   applyStyle(inputFrom, inputCommonStyle);
  63.   applyStyle(inputTo, inputCommonStyle);
  64.   btn.innerText = "Repeat play";
  65.   btnStop.innerText = "Stop";
  66.   btnExport.innerText = "Export";
  67.   app.appendChild(inputFrom);
  68.   app.appendChild(inputTo);
  69.   app.appendChild(currentTime);
  70.   app.appendChild(btn);
  71.   app.appendChild(btnStop);
  72.   app.appendChild(btnExport);
  73.   return {
  74.     app,
  75.     inputFrom,
  76.     inputTo,
  77.     currentTime,
  78.     btn,
  79.     btnStop,
  80.     btnExport,
  81.   };
  82. }
  83.  
  84. async function sleep(time) {
  85.   await new Promise((resolve) => {
  86.     setTimeout(() => {
  87.       resolve();
  88.     }, time);
  89.   });
  90. }
  91.  
  92. async function main() {
  93.   // Player fetching
  94.   console.log("Waiting for the player...");
  95.   let player;
  96.   while (true) {
  97.     player = document.querySelector("ytd-app #player");
  98.     if (player && !player.hidden) break;
  99.     await sleep(500);
  100.   }
  101.   let videoElement = document.querySelector("video");
  102.   if (!videoElement || !player) {
  103.     console.warn("Player not found. Exiting.");
  104.     return;
  105.   }
  106.   console.log("Player detected.");
  107.  
  108.   // Layout
  109.   let control = generateControl();
  110.   console.log(player);
  111.   player.appendChild(control.app);
  112.  
  113.   // States
  114.   let fromValue = 0,
  115.     toValue = 0;
  116.  
  117.   // Initial state update attempt
  118.   let urlTime = window.location.hash.match(
  119.     /#pvp([0-9]+\.?[0-9]?)-([0-9]+\.?[0-9]?)/
  120.   );
  121.   if (urlTime !== null) {
  122.     console.log("Attempting to recover time from URL...");
  123.     control.inputFrom.value = fromValue = Number(urlTime[1]) || 0;
  124.     control.inputTo.value = toValue = Number(urlTime[2]) || 0;
  125.   }
  126.  
  127.   // Current playback time
  128.   function updateCurrentTime() {
  129.     control.currentTime.innerText = Number(videoElement.currentTime).toFixed(2);
  130.     requestAnimationFrame(updateCurrentTime);
  131.   }
  132.   requestAnimationFrame(updateCurrentTime);
  133.  
  134.   // Repeat playback
  135.   function onTimeUpdate() {
  136.     if (videoElement.currentTime >= Number(toValue)) {
  137.       videoElement.currentTime = Number(fromValue);
  138.     }
  139.   }
  140.   control.btn.addEventListener("click", (evt) => {
  141.     evt.preventDefault();
  142.     videoElement.pause();
  143.     videoElement.currentTime = fromValue;
  144.     if (fromValue < toValue) {
  145.       videoElement.play();
  146.       videoElement.addEventListener("timeupdate", onTimeUpdate);
  147.     } else {
  148.       videoElement.removeEventListener("timeupdate", onTimeUpdate);
  149.     }
  150.   });
  151.   control.btnStop.addEventListener("click", (evt) => {
  152.     evt.preventDefault();
  153.     videoElement.removeEventListener("timeupdate", onTimeUpdate);
  154.     videoElement.pause();
  155.   });
  156.  
  157.   // Start/end time setting
  158.   function updateURL() {
  159.     history.pushState(null, null, `#pvp${fromValue}-${toValue}`);
  160.   }
  161.   control.inputFrom.addEventListener("change", () => {
  162.     let input = control.inputFrom.value;
  163.     if (input === "") {
  164.       fromValue = 0;
  165.       control.inputFrom.placeholder = "from 0";
  166.       return;
  167.     }
  168.     let time = parseTime(input);
  169.     if (time == -1) {
  170.       control.btn.disabled = true;
  171.       return;
  172.     }
  173.     control.btn.disabled = false;
  174.     fromValue = time;
  175.     updateURL();
  176.   });
  177.   control.inputTo.addEventListener("change", () => {
  178.     let input = control.inputTo.value;
  179.     if (input === "") {
  180.       toValue = videoElement.duration || 0;
  181.       control.inputTo.placeholder = `to ${toValue.toFixed(2)}`;
  182.       return;
  183.     }
  184.     let time = parseTime(input);
  185.     if (time == -1) {
  186.       control.btn.disabled = true;
  187.       return;
  188.     }
  189.     control.btn.disabled = false;
  190.     toValue = time;
  191.     updateURL();
  192.   });
  193.  
  194.   // Button export
  195.   control.btnExport.addEventListener("click", (evt) => {
  196.     evt.preventDefault();
  197.     let videoId = getVideoId(window.location);
  198.     alert(`ffmpeg -i $(youtube-dl -f bestaudio -g "https://www.youtube.com/watch?v=${videoId}") \
  199. -ss ${fromValue} \
  200. -to ${toValue} \
  201. -acodec libmp3lame \
  202. -ab 192k \
  203. -af loudnorm=I=-16:TP=-2:LRA=11 \
  204. output-${videoId}-${fromValue}-${toValue}.mp3`);
  205.   });
  206. }
  207.  
  208. main();