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Facebook video downloader

Download any video on Facebook (post/chat/comment)

Aby zainstalować ten skrypt, wymagana jest instalacje jednego z następujących rozszerzeń: Tampermonkey, Greasemonkey lub Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

Aby zainstalować ten skrypt, wymagana jest instalacje jednego z następujących rozszerzeń: Tampermonkey, Violentmonkey.

Aby zainstalować ten skrypt, wymagana będzie instalacja rozszerzenia Tampermonkey lub Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

Aby zainstalować ten skrypt, musisz zainstalować rozszerzenie menedżera skryptów użytkownika.

(Mam już menedżera skryptów użytkownika, pozwól mi to zainstalować!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

Będziesz musiał zainstalować rozszerzenie menedżera stylów użytkownika, aby zainstalować ten styl.

Będziesz musiał zainstalować rozszerzenie menedżera stylów użytkownika, aby zainstalować ten styl.

Musisz zainstalować rozszerzenie menedżera stylów użytkownika, aby zainstalować ten styl.

(Mam już menedżera stylów użytkownika, pozwól mi to zainstalować!)

// ==UserScript==
// @name        Facebook video downloader
// @icon        https://www.facebook.com/favicon.ico
// @namespace   Violentmonkey Scripts
// @match       https://www.facebook.com/*
// @match       https://web.facebook.com/*
// @grant       GM_registerMenuCommand
// @version     1.4
// @author      https://github.com/HoangTran0410
// @description Download any video on Facebook (post/chat/comment)
// @license MIT
// ==/UserScript==

(() => {
  function getOverlapScore(el) {
    var rect = el.getBoundingClientRect();
    return (
      Math.min(
        rect.bottom,
        window.innerHeight || document.documentElement.clientHeight
      ) - Math.max(0, rect.top)
    );
  }

  function getVideoIdFromVideoElement(videoEle) {
    try {
      let key = "";
      for (let k in videoEle.parentElement) {
        if (k.startsWith("__reactProps")) {
          key = k;
          break;
        }
      }
      const props = videoEle.parentElement[key].children.props;
      return props.videoFBID || props.coreVideoPlayerMetaData?.videoFBID;
    } catch (e) {
      console.log("ERROR on get videoFBID: ", e);
      return null;
    }
  }

  async function getWatchingVideoId() {
    let allVideos = Array.from(document.querySelectorAll("video"));
    let result = [];

    for (let video of allVideos) {
      let videoId = getVideoIdFromVideoElement(video);
      if (videoId) {
        result.push({
          videoId,
          overlapScore: getOverlapScore(video),
          playing: !!(
            video.currentTime > 0 &&
            !video.paused &&
            !video.ended &&
            video.readyState > 2
          ),
        });
      }
    }

    // if there is playing video => return that
    let playingVideo = result.find((_) => _.playing);
    if (playingVideo) return [playingVideo.videoId];

    // else return all videos in-viewport
    return result
      .filter((_) => _.videoId && (_.overlapScore > 0 || _.playing))
      .sort((a, b) => b.overlapScore - a.overlapScore)
      .map((_) => _.videoId);
  }

  async function getVideoUrlFromVideoId(videoId) {
    let dtsg = await getDtsg();
    try {
      return await getLinkFbVideo2(videoId, dtsg);
    } catch (e) {
      return await getLinkFbVideo1(videoId, dtsg);
    }
  }

  async function getLinkFbVideo2(videoId, dtsg) {
    let res = await fetch(
      "https://www.facebook.com/video/video_data_async/?video_id=" + videoId,
      {
        method: "POST",
        headers: { "content-type": "application/x-www-form-urlencoded" },
        body: stringifyVariables({
          __a: "1",
          fb_dtsg: dtsg,
        }),
      }
    );

    let text = await res.text();
    text = text.replace("for (;;);", "");
    let json = JSON.parse(text);

    const { hd_src, hd_src_no_ratelimit, sd_src, sd_src_no_ratelimit } =
      json?.payload || {};

    return hd_src_no_ratelimit || hd_src || sd_src_no_ratelimit || sd_src;
  }

  async function getLinkFbVideo1(videoId, dtsg) {
    let res = await fetchGraphQl("5279476072161634", {
      UFI2CommentsProvider_commentsKey: "CometTahoeSidePaneQuery",
      caller: "CHANNEL_VIEW_FROM_PAGE_TIMELINE",
      displayCommentsContextEnableComment: null,
      displayCommentsContextIsAdPreview: null,
      displayCommentsContextIsAggregatedShare: null,
      displayCommentsContextIsStorySet: null,
      displayCommentsFeedbackContext: null,
      feedbackSource: 41,
      feedLocation: "TAHOE",
      focusCommentID: null,
      privacySelectorRenderLocation: "COMET_STREAM",
      renderLocation: "video_channel",
      scale: 1,
      streamChainingSection: !1,
      useDefaultActor: !1,
      videoChainingContext: null,
      videoID: videoId,
    }, dtsg);
    let text = await res.text();

    let a = JSON.parse(text.split("\n")[0]),
      link = a.data.video.playable_url_quality_hd || a.data.video.playable_url;

    return link;
  }

  function fetchGraphQl(doc_id, variables, dtsg) {
    return fetch("https://www.facebook.com/api/graphql/", {
      method: "POST",
      headers: {
        "content-type": "application/x-www-form-urlencoded",
      },
      body: stringifyVariables({
        doc_id: doc_id,
        variables: JSON.stringify(variables),
        fb_dtsg: dtsg,
        server_timestamps: !0,
      }),
    });
  }

  function stringifyVariables(d, e) {
    let f = [],
      a;
    for (a in d)
      if (d.hasOwnProperty(a)) {
        let g = e ? e + "[" + a + "]" : a,
          b = d[a];
        f.push(
          null !== b && "object" == typeof b
            ? stringifyVariables(b, g)
            : encodeURIComponent(g) + "=" + encodeURIComponent(b)
        );
      }
    return f.join("&");
  }

  async function getDtsg() {
    return require("DTSGInitialData").token;
  }

  function downloadURL(url, name) {
    var link = document.createElement("a");
    link.target = "_blank";
    link.download = name;
    link.href = url;
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
  }

  async function downloadWatchingVideo() {
    try {
      let listVideoId = await getWatchingVideoId();
      if (!listVideoId?.length > 0) throw Error("No video found in the page");

      console.log(listVideoId)

      for (let videoId of listVideoId) {
        let videoUrl = await getVideoUrlFromVideoId(videoId);
        if (videoUrl) downloadURL(videoUrl, "fb_video.mp4");
      }
    } catch (e) {
      alert("ERROR: " + e);
    }
  }

  function resisterMenuCommand() {
    GM_registerMenuCommand("Download watching video", downloadWatchingVideo);
  }

  resisterMenuCommand();
})();