YouTube EXPERIMENT_FLAGS Tamer

Adjust EXPERIMENT_FLAGS

Pada tanggal 20 Agustus 2023. Lihat %(latest_version_link).

// ==UserScript==
// @name        YouTube EXPERIMENT_FLAGS Tamer
// @namespace   UserScripts
// @match       https://www.youtube.com/*
// @version     1.0.2
// @license     MIT
// @author      CY Fung
// @icon        https://github.com/cyfung1031/userscript-supports/raw/main/icons/yt-engine.png
// @description Adjust EXPERIMENT_FLAGS
// @grant       none
// @unwrap
// @run-at      document-start
// @allFrames   true
// @inject-into page
// ==/UserScript==

((__CONTEXT__) => {

  // Purpose 1: Remove Obsolete Flags
  // Purpose 2: Remove Flags bring no visual difference
  // Purpose 3: Enable Flags bring performance boost

  const DISABLE_CINEMATICS = false; // standard design
  const NO_SerializedExperiment = true;
  const KEEP_PLAYER_QUALITY_STICKY = true; // see https://greasyfork.org/scripts/471033/
  const DISABLE_serializedExperimentIds = true;
  const DISABLE_serializedExperimentFlags = true;
  const IGNORE_VIDEO_SOURCE_RELATED = true;
  const NO_REFRESH = true;
  const ENABLE_MINOR_CHAT_FEATURE_UPGRADE = true;
  const ENABLE_EMOJI_PICKER_NEW_STYLE = false;
  const ENABLE_BADGE_STYLE = false;

  const ENABLE_EXPERIMENT_FLAGS_MAINTAIN_STABLE_LIST = {
    defaultValue: true, // performance boost
    useExternal: () => typeof localStorage.EXPERIMENT_FLAGS_MAINTAIN_STABLE_LIST !== 'undefined',
    externalValue: () => (+localStorage.EXPERIMENT_FLAGS_MAINTAIN_STABLE_LIST ? true : false)
  };
  const ENABLE_EXPERIMENT_FLAGS_MAINTAIN_REUSE_COMPONENTS = {
    defaultValue: true, // not sure
    useExternal: () => typeof localStorage.EXPERIMENT_FLAGS_MAINTAIN_REUSE_COMPONENTS !== 'undefined',
    externalValue: () => (+localStorage.EXPERIMENT_FLAGS_MAINTAIN_REUSE_COMPONENTS ? true : false)
  };
  const ENABLE_EXPERIMENT_FLAGS_DEFER_DETACH = {
    defaultValue: true, // not sure
    useExternal: () => typeof localStorage.ENABLE_EXPERIMENT_FLAGS_DEFER_DETACH !== 'undefined',
    externalValue: () => (+localStorage.ENABLE_EXPERIMENT_FLAGS_DEFER_DETACH ? true : false)
  };

  const ALLOW_ALL_LIVE_CHATS_FLAGS = false;

  const USE_MAINTAIN_STABLE_LIST_ONLY_WHEN_KS_FLAG_IS_SET = false;



  // TBC
  // kevlar_tuner_should_always_use_device_pixel_ratio
  // kevlar_tuner_should_clamp_device_pixel_ratio
  // kevlar_tuner_clamp_device_pixel_ratio
  // kevlar_tuner_should_use_thumbnail_factor
  // kevlar_tuner_thumbnail_factor
  // kevlar_tuner_min_thumbnail_quality
  // kevlar_tuner_max_thumbnail_quality

  // kevlar_tuner_should_test_visibility_time_between_jobs
  // kevlar_tuner_visibility_time_between_jobs_ms

  // kevlar_tuner_default_comments_delay
  // kevlar_tuner_run_default_comments_delay

  let settled = null;
  // cinematic feature is no longer an experimential feature.
  // It has been officially implemented.
  // To disable cinematics, the user shall use other userscripts or just turn off the option in the video options.

  const getSettingValue = (fm) => fm.useExternal() ? fm.externalValue() : fm.defaultValue;

  const win = this instanceof Window ? this : window;

  // Create a unique key for the script and check if it is already running
  const hkey_script = 'jmimcvowrlzl';
  if (win[hkey_script]) throw new Error('Duplicated Userscript Calling'); // avoid duplicated scripting
  win[hkey_script] = true;

  /** @type {globalThis.PromiseConstructor} */
  const Promise = ((async () => { })()).constructor;

  let isMainWindow = false;
  let mzFlagDetected1 = new Set();
  let mzFlagDetected2 = new Set();
  let zPlayerKevlar = false;
  try {
    isMainWindow = window.document === window.top.document
  } catch (e) { }

  function fixSerializedExperiment(conf) {

    const supportAV1 = window.MediaSource.isTypeSupported('video/webm; codecs=av01.0.05M.08');
    const supportVP9 = window.MediaSource.isTypeSupported('video/webm; codecs=vp09.01.20.08.01.01.01.01.00');

    if (DISABLE_serializedExperimentIds && typeof conf.serializedExperimentIds === 'string') {
      let ids = conf.serializedExperimentIds.split(',');
      let newIds = [];
      for (const id of ids) {
        let keep = false;
        if (keep) {
          newIds.push(id);
        }
      }
      conf.serializedExperimentIds = newIds.join(',');
    }

    const mez = (mRes)=>{

      mRes.set('html5_disable_low_pipeline', 'false');
      mRes.set('html5_min_startup_buffered_ad_media_duration_secs', '0')

      if (supportAV1 === false && localStorage['yt-player-av1-pref'] === '-1') {

        mRes.set('html5_disable_av1', 'true');
        mRes.set('html5_disable_av1_hdr', 'true');
        mRes.set('html5_prefer_hbr_vp9_over_av1', 'true');



      } else if (supportAV1 === true && supportVP9 === true && localStorage['yt-player-av1-pref'] === '8192') {

        mRes.set('html5_disable_av1', 'false');
        mRes.set('html5_disable_av1_hdr', 'false');
        mRes.set('html5_prefer_hbr_vp9_over_av1', 'false');
      }


      // html5_perf_cap_override_sticky = true;
      // html5_perserve_av1_perf_cap = true;


      mRes.set('html5_enable_server_format_filter', 'true')
      mRes.set('html5_use_ump', 'true')

      mRes.set('html5_live_defrag_only_h264_playbacks', 'true')
      mRes.set('html5_live_defrag_only_h264_formats', 'true')

      mRes.set('html5_disable_protected_hdr', 'false')
      mRes.set('html5_disable_vp9_encrypted', 'false')
      mRes.set('html5_ignore_h264_framerate_cap', 'true')

      mRes.set('html5_allow_asmjs', 'true')
      mRes.set('html5_defer_modules_on_ads_only', 'true')
      mRes.set('html5_use_drm_retry', 'true')
      mRes.set('html5_delta_encode_fexp', 'true')
      mRes.set('html5_only_send_cas_health_pings', 'true')

      mRes.set('html5_modify_caption_vss_logging', 'true')
      mRes.set('html5_allow_zero_duration_ads_on_timeline', 'true')
      mRes.set('html5_reset_daistate_on_audio_codec_change', 'true')
      mRes.set('html5_enable_safari_fairplay', 'true')

      mRes.set('html5_safari_fairplay_ignore_hdcp', 'true')

      mRes.set('html5_enable_vp9_fairplay', 'true')
      mRes.set('html5_eme_loader_sync', 'true')

      mRes.set('html5_enable_same_language_id_matching', 'true');
      mRes.set('html5_enable_new_hvc_enc', 'true')
      mRes.set('html5_enable_ssap', 'true')
      mRes.set('html5_enable_short_gapless', 'true')
      mRes.set('html5_enable_aac51', 'true')
      mRes.set('html5_enable_ssap_entity_id', 'true')

      mRes.set('html5_high_res_logging_always', 'true')
      mRes.set('html5_local_playsinline', 'true')
      mRes.set('html5_disable_media_element_loop_on_tv', 'true')
      mRes.set('html5_native_audio_track_switching', 'true')

      mRes.set('html5_format_hybridization', 'true')
      mRes.set('html5_disable_encrypted_vp9_live_non_2k_4k', 'false')

      mRes.set('html5_default_ad_gain', 'false')
      mRes.set('html5_use_sabr_requests_for_debugging', 'false')
      mRes.set('html5_enable_sabr_live_streaming_xhr', 'true')
      mRes.set('html5_sabr_live_ultra_low_latency', 'true')

      mRes.set('html5_sabr_live_low_latency', 'true')
      mRes.set('html5_sabr_live', 'true')
      mRes.set('html5_sabr_post_live', 'true')
      mRes.set('html5_sabr_premiere', 'true')

      mRes.set('html5_enable_sabr_live_streaming_xhr', 'true')
      mRes.set('html5_enable_sabr_live_non_streaming_xhr', 'true')



      mRes.set('html5_enable_subsegment_readahead_v3', 'true')
      mRes.set('html5_ultra_low_latency_subsegment_readahead', 'true')
      mRes.set('html5_disable_move_pssh_to_moov', 'true')



      mRes.set('html5_modern_vp9_mime_type', 'true')






    }

    const qrz = (mRes)=>{

      const res = [];
      mRes.forEach((value, key) => {
        res.push(`${key}=${value}`);
      });
      return res.join('&');
    }

    if (DISABLE_serializedExperimentFlags && typeof conf.serializedExperimentFlags === 'string') {
      const fg = conf.serializedExperimentFlags;
      const rx = /(^|&)(\w+)=([^=&|\s\{\}\[\]\(\)?]*)/g;

      const mRes = new Map();
      for (let m; m = rx.exec(fg);) {
        let key = m[2];
        let value = m[3];
        let keep = false;


        if (IGNORE_VIDEO_SOURCE_RELATED && key.indexOf('html5_') >= 0) {


          if (key === 'html5_live_use_alternate_bandwidth_window_sizes') {
            keep = true;
          }
          else if (key === 'html5_live_ultra_low_latency_bandwidth_window') {
            keep = true;
          }
          else if (key === 'html5_live_low_latency_bandwidth_window') {
            keep = true;
          }
          else if (key === 'html5_live_normal_latency_bandwidth_window') {
            keep = true;
          } else if (key === 'html5_skip_slow_ad_delay_ms') {
            keep = true;
            if (typeof value === 'string' && +value > 2) {
              keep = true;
              if (+value > 4) value = '4';
            } else {
              keep = false;
            }
          } else if (key === 'html5_player_preload_ad_fix') {
            keep = true;
          } else if (key.includes('_ad_') || key.includes('_ads_')) {
            keep = false;
          } else if (key === 'html5_ssdai_adfetch_dynamic_timeout_ms') {
            keep = false;
          } else if (key === 'html5_log_ssdai_fallback_ads' || key === 'html5_deprecate_adservice') {
            keep = false;
          } else {
            if (!key.includes('deprecat')) keep = true;
          }


        } else if (IGNORE_VIDEO_SOURCE_RELATED && key.indexOf('h5_') >= 0) {
          if (key.startsWith('enable_h5_player_ad_block_')) keep = false;
          else if (key === 'fix_h5_toggle_button_a11y') keep = true;
          else if (key === 'h5_companion_enable_adcpn_macro_substitution_for_click_pings') keep = false;
          else if (key === 'h5_enable_generic_error_logging_event') keep = false;
          else if (key === 'h5_enable_unified_csi_preroll') keep = true;
          else if (key === 'h5_reset_cache_and_filter_before_update_masthead') keep = true;
          else if (key === 'web_player_enable_premium_hbr_in_h5_api') keep = true;
          else {
            if (!key.includes('deprecat')) keep = true;
          }
        }

        // if(key.includes('sticky')){

        // console.log(5599,key)
        // }

        if (key.includes('_timeout') && typeof value === 'string') {
          const valur = (value, k) => {
            if (+value === 0) value = k;
            else if (+value > +k) value = k;
            return value;
          }
          if (key === 'check_navigator_accuracy_timeout_ms') {
            value = valur(value, '4');
            keep = true;
          } else if (key === 'html5_ad_timeout_ms') {
            value = valur(value, '4');
            keep = true;
          } else if (key === 'html5_ads_preroll_lock_timeout_delay_ms') {
            // value = valur(value, '4');
            // keep = true;
            keep = false;
          } else if (key === 'html5_slow_start_timeout_delay_ms') {
            value = valur(value, '4');
            keep = true;
          } else if (key === 'variable_buffer_timeout_ms') {
            // value = valur(value, '4');
            // keep = true;
            keep = false;
          } else {
            if (+value > 3000) value = '3000';
            keep = true;
          }
        }


        if (KEEP_PLAYER_QUALITY_STICKY && key.includes('_sticky')) {


          if (key === 'html5_onesie_sticky_server_side') {
            keep = false;

          } else if (key === 'html5_perf_cap_override_sticky') {
            keep = true;

          } else if (key === 'html5_ustreamer_cap_override_sticky') {
            keep = true;


          } else if (key === 'html5_exponential_memory_for_sticky') {
            keep = true;

          } else {
            keep = true;

          }

        }


        if (key === 'html5_streaming_xhr_time_based_consolidation_ms') keep = true;
        if (key === 'html5_bypass_contention_secs') keep = true;

        if (key === 'vp9_drm_live') keep = true;
        if (key === 'html5_log_rebuffer_reason') keep = false;
        if (key === 'html5_enable_audio_track_log') keep = false;

        if (key.startsWith('h5_expr_')) {
          // by userscript
          keep = true;
        } else if (key.includes('deprecat')) {
          keep = false;
        }

        if (key === 'html5_safari_desktop_eme_min_version') keep = true;

        if (key === 'html5_disable_av1') keep = true;
        if (key === 'html5_disable_av1_hdr') keep = true;
        if (key === 'html5_disable_hfr_when_vp9_encrypted_2k4k_unsupported') keep = true;
        if (key === 'html5_account_onesie_format_selection_during_format_filter') keep = true;
        if (key === 'html5_prefer_hbr_vp9_over_av1') keep = true;

        if (!DISABLE_CINEMATICS && key === 'web_cinematic_watch_settings') {
          keep = true;
        }
        if (keep) mRes.set(key, value);
      }

      mez(mRes);

      conf.serializedExperimentFlags = qrz(mRes);

    }

  }

  const all_live_chat_flags = `live_chat_banner_expansion_fix
  live_chat_enable_mod_view
  live_chat_enable_qna_banner_overflow_menu_actions
  live_chat_enable_qna_channel
  live_chat_enable_send_button_in_slow_mode
  live_chat_filter_emoji_suggestions
  live_chat_increased_min_height
  live_chat_over_playlist
  live_chat_web_enable_command_handler
  live_chat_web_use_emoji_manager_singleton
  live_chat_whole_message_clickable`.trim().split(/\s+/)

  const hLooper = ((fn) => {

    let nativeFnLoaded = false;
    let kc1 = 0;

    const setIntervalW = setInterval;
    const clearIntervalW = clearInterval;
    let microDisconnectFn = null;
    let fStopLooper = false;
    const looperFn = () => {
      if (fStopLooper) return;

      let config_ = null;
      let EXPERIMENT_FLAGS = null;
      try {
        config_ = yt.config_ || ytcfg.data_;
      } catch (e) { }
      if (!config_) return;
      EXPERIMENT_FLAGS = config_.EXPERIMENT_FLAGS || 0;

      if (EXPERIMENT_FLAGS) {


        if (!settled) {
          settled = {
            use_maintain_stable_list: getSettingValue(ENABLE_EXPERIMENT_FLAGS_MAINTAIN_STABLE_LIST),
            use_maintain_reuse_components: getSettingValue(ENABLE_EXPERIMENT_FLAGS_MAINTAIN_REUSE_COMPONENTS),
            use_defer_detach: getSettingValue(ENABLE_EXPERIMENT_FLAGS_DEFER_DETACH),
          }
          if (settled.use_maintain_stable_list) Promise.resolve().then(() => console.debug("use_maintain_stable_list"));
          if (settled.use_maintain_reuse_components) Promise.resolve().then(() => console.debug("use_maintain_reuse_components"));
          if (settled.use_defer_detach) Promise.resolve().then(() => console.debug("use_defer_detach"));
        }

        fn(config_);
      }

      if (EXPERIMENT_FLAGS && microDisconnectFn) {


        let isYtLoaded = false;
        try {
          isYtLoaded = typeof ytcfg.set === 'function';
        } catch (e) { }
        if (isYtLoaded) {
          microDisconnectFn();
        }

      }

      const playerKevlar = (config_.WEB_PLAYER_CONTEXT_CONFIGS || 0).WEB_PLAYER_CONTEXT_CONFIG_ID_KEVLAR_WATCH || 0;


      if (playerKevlar && !zPlayerKevlar) {
        zPlayerKevlar = true;

        if (NO_SerializedExperiment && typeof playerKevlar.serializedExperimentFlags === 'string' && typeof playerKevlar.serializedExperimentIds === 'string') {
          fixSerializedExperiment(playerKevlar);
        }


      }



    };

    const controller = {
      start() {
        kc1 = setIntervalW(looperFn, 1);
        (async () => {
          while (true && !nativeFnLoaded) {
            looperFn();
            if (fStopLooper) break;
            await (new Promise(requestAnimationFrame));
          }
        })();
        looperFn();
      },
      /**
       *
       * @param {Window} __CONTEXT__
       */
      setupForCleanContext(__CONTEXT__) {

        const { requestAnimationFrame, setInterval, clearInterval, setTimeout, clearTimeout } = __CONTEXT__;

        (async () => {
          while (true) {
            looperFn();
            if (fStopLooper) break;
            await (new Promise(requestAnimationFrame));
          }
        })();

        let kc2 = setInterval(looperFn, 1);

        const marcoDisconnectFn = () => {
          if (fStopLooper) return;
          Promise.resolve().then(() => {
            if (kc1 || kc2) {
              kc1 && clearIntervalW(kc1); kc1 = 0;
              kc2 && clearInterval(kc2); kc2 = 0;
              looperFn();
            }
            fStopLooper = true;
          });
          document.removeEventListener('yt-page-data-fetched', marcoDisconnectFn, false);
          document.removeEventListener('yt-navigate-finish', marcoDisconnectFn, false);
          document.removeEventListener('spfdone', marcoDisconnectFn, false);
        };
        document.addEventListener('yt-page-data-fetched', marcoDisconnectFn, false);
        document.addEventListener('yt-navigate-finish', marcoDisconnectFn, false);
        document.addEventListener('spfdone', marcoDisconnectFn, false);


        function onReady() {
          if (!fStopLooper) {
            setTimeout(() => {
              !fStopLooper && marcoDisconnectFn();
            }, 1000);
          }
        }

        Promise.resolve().then(() => {
          if (document.readyState !== 'loading') {
            onReady();
          } else {
            window.addEventListener("DOMContentLoaded", onReady, false);
          }
        });

        nativeFnLoaded = true;

        microDisconnectFn = () => Promise.resolve(marcoDisconnectFn).then(setTimeout);

      }
    };

    return controller;
  })((config_) => {

    if (!config_.EXPERIMENT_FLAGS) return;


    const { use_maintain_stable_list, use_maintain_reuse_components, use_defer_detach } = settled;

    // i don't know why it requires to be extracted function.
    const mex = (EXPERIMENT_FLAGS, mzFlagDetected, fEntries) => {

      for (const [key, value] of fEntries) {


        if (value === true) {
          // if(key.indexOf('modern')>=0 || key.indexOf('enable')>=0 || key.indexOf('theme')>=0 || key.indexOf('skip')>=0  || key.indexOf('ui')>=0 || key.indexOf('observer')>=0 || key.indexOf('polymer')>=0 )continue;

          if (mzFlagDetected.has(key)) continue;
          mzFlagDetected.add(key);
          const kl = key.length;
          const kl7 = kl % 7;
          const kl5 = kl % 5;
          const kl3 = kl % 3;
          const kl2 = kl % 2;

          if (!DISABLE_CINEMATICS) {

            // web_watch_cinematics_disabled_by_default
            // web_watch_cinematics_preferred_reduced_motion_default_disabled

            if (key === 'kevlar_measure_ambient_mode_idle' || key === 'kevlar_watch_cinematics_invisible' || key === 'web_cinematic_theater_mode' || key === 'web_cinematic_fullscreen') {
              continue;
            }


            let cineKey = key === 'enable_cinematic_blur_desktop_loading' ? 1
              : key === 'kevlar_watch_cinematics' ? 2
                : key === 'web_cinematic_masthead' ? 3
                  : key === 'web_watch_cinematics_preferred_reduced_motion_default_disabled' ? 4 : 0;
            if (cineKey > 0) {
              return;
            }
          }

          if (key.indexOf('html5_') === 0) {


            if (IGNORE_VIDEO_SOURCE_RELATED) {
              continue;
            }

            // if(IGNORE_VIDEO_SOURCE_RELATED){
            //   if(key ==='html5_enable_vp9_fairplay') continue;
            //   if(key ==='html5_disable_av1_hdr') continue;
            //   if(key ==='html5_disable_hfr_when_vp9_encrypted_2k4k_unsupported') continue;
            //   if(key ==='html5_account_onesie_format_selection_during_format_filter') continue;
            //   if(key ==='html5_prefer_hbr_vp9_over_av1') continue;
            // }

          } else if (key.indexOf('kevlar_') === 0) {



            if (kl7 === 2 && kl5 === 2 && kl2 === 1 && kl3 === 1) {
              if (key === 'kevlar_rendererstamper_event_listener') continue; // https://github.com/cyfung1031/userscript-supports/issues/11
            }

            if (kl === 22) {
              // kevlar_enable_up_arrow - no use
              // kevlar_help_use_locale - might use
              // kevlar_refresh_gesture - might use
              // kevlar_smart_downloads - might use
              // kevlar_thumbnail_fluid
              // kevlar_ytb_live_badges

              if (key === 'kevlar_ytb_live_badges') continue;

            }


            // if (!use_maintain_stable_list) {

            if (key === 'kevlar_tuner_should_test_maintain_stable_list') continue;
            if (key === 'kevlar_should_maintain_stable_list') continue;
            if (key === 'kevlar_tuner_should_maintain_stable_list') continue; // fallback
            // }
            // if (!use_maintain_reuse_components) {

            if (key === 'kevlar_tuner_should_test_reuse_components') continue;
            if (key === 'kevlar_tuner_should_reuse_components') continue;
            if (key === 'kevlar_should_reuse_components') continue; // fallback
            // }

            if (key === 'kevlar_tuner_should_defer_detach') continue;

            if (kl7 === 5 && kl5 == 4 && kl2 === 1 && kl3 === 1) {
              if (key === 'kevlar_system_icons') continue;
            }

            // if(key==='kevlar_prefetch_data_augments_network_data') continue;

            if (kl7 === 6 && kl5 === 0 && kl3 === 2 && kl2 === 0) { // home page / watch page icons

              if (key === 'kevlar_three_dot_ink') continue;
              if (key === 'kevlar_use_wil_icons') continue;
              if (key === 'kevlar_home_skeleton') continue;
            }

            if (kl7 === 4 && kl5 === 0 && kl3 === 1 && kl2 === 1) {

              if (key === 'kevlar_fluid_touch_scroll') continue;
              if (key === 'kevlar_watch_color_update') continue;
              if (key === 'kevlar_use_vimio_behavior') continue; // home page - channel icon

            }

            if (kl3 === 2 && kl5 === 4 && kl2 < 2) {  // collapsed meta
              // no teaser, use latest collapsed meta design
              if (key === 'kevlar_structured_description_content_inline') continue;
              if (key === 'kevlar_watch_metadata_refresh') continue;

            }


            if (kl5 === 3 && kl3 === 1 && kl2 === 0) {

              if (key === 'kevlar_watch_js_panel_height') continue; // affect Tabview Youtube


            }


          } else {


            if (ALLOW_ALL_LIVE_CHATS_FLAGS && all_live_chat_flags.indexOf(key) >= 0) {
              continue;
              /*
               *
              live_chat_banner_expansion_fix
              live_chat_enable_mod_view
              live_chat_enable_qna_banner_overflow_menu_actions
              live_chat_enable_qna_channel
              live_chat_enable_send_button_in_slow_mode
              live_chat_filter_emoji_suggestions
              live_chat_increased_min_height
              live_chat_over_playlist
              live_chat_web_enable_command_handler
              live_chat_web_use_emoji_manager_singleton
              live_chat_whole_message_clickable

              */
            }

            if (kl7 === 1 && kl5 === 1 && kl2 === 0 && kl3 === 0) {
              if (key === 'live_chat_web_enable_command_handler') continue;

            }
            if (kl7 === 1 && kl5 === 4 && kl3 === 2 && kl2 === 1) {

              if (key === 'shorts_desktop_watch_while_p2') continue;
            }

            if (key === 'web_button_rework') continue;

            if (kl7 === 3 && kl5 == 1 && kl2 === 1 && kl3 === 1) {
              if (key === 'web_darker_dark_theme_live_chat') continue;
            }

            if (kl5 === 1 && kl3 === 0 && kl2 === 1 && kl7 === 0) {
              if (key === 'web_darker_dark_theme') return; // it also affect cinemtaics
            }

            if (kl3 === 0 && kl5 === 2) {  // modern menu

              if (key === 'web_button_rework_with_live') continue;
              if (key === 'web_fix_fine_scrubbing_drag') continue;
            }


            if (kl3 === 1 && kl5 === 4 && kl2 === 1) {  // full screen -buggy
              if (key === 'external_fullscreen') continue;
            }

            if (kl3 === 0 && kl5 === 3 && kl2 === 0) { // minimize menu
              if (key === 'web_modern_buttons') continue;
              if (key === 'web_modern_dialogs') continue;

            }

            if (kl3 === 1 && kl5 === 0 && kl7 === 5 && kl2 === 0) { // Tabview Youtube - multiline transcript
              if (key === 'enable_mixed_direction_formatted_strings') continue;
            }

            if(key ==='enable_unknown_lact_fix_on_html5') continue;

          }

          if(key==='live_chat_chunk_across_update_interval') continue;

          if (key === 'enable_native_live_chat_on_kevlar') continue;

          if (key === 'live_chat_author_name_color_usernames') continue;
          if (key === 'live_chat_seed_color_usernames') continue;
          if (key === 'live_chat_colored_usernames') continue;
          if (key === 'live_chat_simple_color_usernames') continue;
          if (key === 'web_button_rework_with_live') continue;
          if (key === 'live_chat_hide_avatars') continue;
          if (key === 'live_chat_enable_qna_replay') continue;
          if (key === 'live_chat_aggregation') continue;
          if (key === 'live_chat_web_use_emoji_manager_singleton') continue;
          if (key === 'enable_docked_chat_messages') continue;
          if (key === 'live_chat_taller_emoji_picker') continue;
          if (key === 'live_chat_emoji_picker_restyle') continue;
          if (key === 'live_chat_emoji_picker_restyle_remain_open_on_send') continue;
          if (key === 'live_chat_web_input_update') continue;
          if (key === 'live_chat_enable_send_button_in_slow_mode') continue;

          if (key === 'kevlar_watch_metadata_refresh_no_old_primary_data') continue;
          if (key === 'kevlar_watch_metadata_refresh_no_old_secondary_data') continue;
          if (key === 'enable_web_cosmetic_refresh_hashtag_page') continue;
          if (key === 'kevlar_watch_metadata_refresh_description_lines') continue;




          if(key==='enable_service_ajax_csn') continue;

          if(key==='kevlar_use_vimio_behavior')continue;

          if(key==='web_use_cache_for_image_fallback') continue;
          if(key==='kevlar_woffle_fallback_image')continue;
          if(key==='yt_img_shadow_trigger_show_on_visible') continue;
          if(key==='kevlar_thumbnail_bg') continue;
          if(key==='web_rounded_thumbnails')continue;



          if(key==='kevlar_rendererstamper_event_listener') continue;

          if(key==='dialog_behavior_no_tap_killswitch')continue;

          if(key==='handle_service_request_actions') continue;

          if(key === 'live_chat_whole_message_clickable') continue;

          if(key === 'live_chat_require_space_for_autocomplete_emoji') continue;

          if(key==='kevlar_keyboard_button_focus') continue;

          if(key==='live_chat_emoji_picker_toggle_state')continue;
          if(key==='super_sticker_emoji_picker_category_button_icon_filled')continue;
          if(key==='enable_super_chat_buy_flow_revamp_web') continue;


          if(key==='web_modern_buttons') continue;

          
          if(key==='web_modern_dialogs') continue;
          if(key==='live_chat_disable_chat_feed_animation') continue;
          if(key==='live_chat_overflow_hide_chat') continue;
          if(key==='web_darker_dark_theme_live_chat')continue;
          if(key==='live_chat_channel_activity')continue;
          if(key==='live_chat_emoji_picker_restyle_remain_open_on_click_to_input_area')continue;
          if(key==='live_chat_top_chat_sampling_enabled') continue;

          if(key==='live_chat_enable_mod_view')continue;
          if(key==='live_chat_web_enable_command_handler_action_handling')continue;
          if(key==='web_modern_dialogs')continue;
          if(key==='web_modern_dialog_layout')continue;
          if(key==='web_modern_typography')continue;

          if(key==='kevlar_disable_component_resizing_support') continue;
          if(key==='web_rounded_thumbnails') continue;
          if(key==='enable_quiz_desktop_animation')continue;
          if(key==='kevlar_thumbnail_fluid')continue;
          if(key==='web_enable_playlist_video_lockup_equalizer')continue;
          if(key==='web_modern_collections_v2') continue;
          if(key==='animated_live_badge_icon') continue;
          if(key==='use_color_palettes_modern_collections_v2') continue;
          if(key==='web_amsterdam_post_mvp_playlists')continue;
          if(key==='enable_desktop_search_bigger_thumbs')continue;
          if(key==='web_animated_actions') continue;
          if(key==='mweb_animated_actions') continue;
          if(key==='enable_desktop_amsterdam_info_panels') continue;

          if(key==='kevlar_modern_sd')continue;
          if(key==='problem_walkthrough_sd')continue;
          if(key==='polymer_video_renderer_defer_menu')continue;


          if(key==='enable_html5_teal_ad_badge') continue;
          if(key==='kevlar_ytb_live_badges') continue;
          if(key==='live_chat_enable_new_moderator_badge') continue;
          if(key==='live_chat_prepend_badges') continue;
          if(key==='live_chat_bold_color_usernames') continue;
          if(key==='render_custom_emojis_as_small_images') continue;

          if(key==='web_enable_dynamic_metadata') continue;


          
          // console.log(key)
          EXPERIMENT_FLAGS[key] = false;
        }
      }
    }

    const mey = (EXPERIMENT_FLAGS, mzFlagDetected) => {


      
      EXPERIMENT_FLAGS.defer_menus = true;
      EXPERIMENT_FLAGS.defer_overlays = true;
      EXPERIMENT_FLAGS.faster_load_overlay = true;
      EXPERIMENT_FLAGS.disable_moving_thumbs_handling = true;
      EXPERIMENT_FLAGS.polymer_video_renderer_defer_menu = true;
      EXPERIMENT_FLAGS.web_announce_stop_seeing_this_ad_text_a11y_bugfix = true;

      EXPERIMENT_FLAGS.disable_chips_intersection_observer = true;

      EXPERIMENT_FLAGS.live_chat_top_chat_sampling_enabled = true;

      EXPERIMENT_FLAGS.kevlar_dropdown_fix = true;

      EXPERIMENT_FLAGS.debug_forward_web_query_parameters = false;
      EXPERIMENT_FLAGS.cancel_pending_navs =true;
      EXPERIMENT_FLAGS.web_no_lock_on_touchstart_killswitch = false;
      


      // EXPERIMENT_FLAGS.live_chat_author_name_color_usernames = true;
      // EXPERIMENT_FLAGS.live_chat_seed_color_usernames = true;
      // EXPERIMENT_FLAGS.live_chat_colored_usernames = true;
      // EXPERIMENT_FLAGS.live_chat_simple_color_usernames = true;
      // live_chat_hide_avatars
      if(ENABLE_MINOR_CHAT_FEATURE_UPGRADE){

        
        
        // EXPERIMENT_FLAGS.mweb_wiz_skip_render = true;
        // EXPERIMENT_FLAGS.kevlar_wiz_prototype_enable_all_components= true;
        // EXPERIMENT_FLAGS.kevlar_wiz_enable_on_demand_alternative_components= true;

        EXPERIMENT_FLAGS.web_enable_dynamic_metadata = true;

        EXPERIMENT_FLAGS.web_supports_animations_api = true;
        EXPERIMENT_FLAGS.smartimation_background = true;
        EXPERIMENT_FLAGS.register_web_smartimations_component = true;

        EXPERIMENT_FLAGS.enable_native_live_chat_on_kevlar = true;

        EXPERIMENT_FLAGS.live_chat_enable_qna_replay = true;
        EXPERIMENT_FLAGS.live_chat_aggregation = true;
        EXPERIMENT_FLAGS.live_chat_web_use_emoji_manager_singleton = true;
        // EXPERIMENT_FLAGS.enable_docked_chat_messages = true;

        EXPERIMENT_FLAGS.live_chat_mention_regex_update = true;

      }

      // EXPERIMENT_FLAGS.live_chat_taller_emoji_picker = true;
      // EXPERIMENT_FLAGS.live_chat_web_input_update = true;

      if(ENABLE_EMOJI_PICKER_NEW_STYLE){

        EXPERIMENT_FLAGS.live_chat_emoji_picker_restyle = true;
        EXPERIMENT_FLAGS.live_chat_emoji_picker_restyle_remain_open_on_send = true;
        EXPERIMENT_FLAGS.live_chat_taller_emoji_picker = false;

      }

      if(ENABLE_BADGE_STYLE) {
        
        EXPERIMENT_FLAGS.enable_html5_teal_ad_badge = true;
        EXPERIMENT_FLAGS.kevlar_ytb_live_badges = true;
        EXPERIMENT_FLAGS.live_chat_enable_new_moderator_badge = true;
        EXPERIMENT_FLAGS.live_chat_prepend_badges=true;

        EXPERIMENT_FLAGS.live_chat_bold_color_usernames =true;
        EXPERIMENT_FLAGS.render_custom_emojis_as_small_images =true;
        
        
      }

      // EXPERIMENT_FLAGS.kevlar_wiz_prototype_enable_all_components = true;


      EXPERIMENT_FLAGS.html5_allow_asmjs = true;
      EXPERIMENT_FLAGS.html5_honor_caption_availabilities_in_audio_track = true;
      EXPERIMENT_FLAGS.web_player_hide_nitrate_promo_tooltip = true;
      EXPERIMENT_FLAGS.html5_enable_vod_slar_with_notify_pacf = true;
      EXPERIMENT_FLAGS.html5_recognize_predict_start_cue_point = true;
      EXPERIMENT_FLAGS.enable_player_logging_lr_home_infeed_ads = false;

      EXPERIMENT_FLAGS.log_gel_compression_latency = true;
      EXPERIMENT_FLAGS.log_gel_compression_latency_lr = true;
      EXPERIMENT_FLAGS.log_jspb_serialize_latency = true;

      if (NO_REFRESH) {

        EXPERIMENT_FLAGS.kevlar_watch_metadata_refresh_standardized_body_typography = false;
        EXPERIMENT_FLAGS.kevlar_refresh_gesture = false;


      }

      // EXPERIMENT_FLAGS.kevlar_watch_metadata_refresh_no_old_primary_data = true;
      // EXPERIMENT_FLAGS.kevlar_watch_metadata_refresh_no_old_secondary_data = true;
      // EXPERIMENT_FLAGS.enable_web_cosmetic_refresh_hashtag_page = true;
      // EXPERIMENT_FLAGS.kevlar_watch_metadata_refresh_description_lines = true;




      EXPERIMENT_FLAGS.desktop_delay_player_resizing = false;
      EXPERIMENT_FLAGS.web_animated_like = false;
      EXPERIMENT_FLAGS.web_animated_like_lazy_load = false;

      if (use_maintain_stable_list) {
        if (USE_MAINTAIN_STABLE_LIST_ONLY_WHEN_KS_FLAG_IS_SET ? EXPERIMENT_FLAGS.kevlar_should_maintain_stable_list === true : true) {
          EXPERIMENT_FLAGS.kevlar_tuner_should_test_maintain_stable_list = true;
          EXPERIMENT_FLAGS.kevlar_should_maintain_stable_list = true;
          EXPERIMENT_FLAGS.kevlar_tuner_should_maintain_stable_list = true; // fallback
        }
      }

      if (use_maintain_reuse_components) {
        EXPERIMENT_FLAGS.kevlar_tuner_should_test_reuse_components = true;
        EXPERIMENT_FLAGS.kevlar_tuner_should_reuse_components = true;
        EXPERIMENT_FLAGS.kevlar_should_reuse_components = true; // fallback
      }

      if (use_defer_detach) {
        EXPERIMENT_FLAGS.kevlar_tuner_should_defer_detach = true;
      }

      // EXPERIMENT_FLAGS.kevlar_prefetch_data_augments_network_data = true; // TBC

      EXPERIMENT_FLAGS.kevlar_clear_non_displayable_url_params = true;
      EXPERIMENT_FLAGS.kevlar_clear_duplicate_pref_cookie = true;
      // EXPERIMENT_FLAGS.kevlar_unified_player_clear_watch_next_killswitch = true;
      EXPERIMENT_FLAGS.kevlar_player_playlist_use_local_index = true;
      // EXPERIMENT_FLAGS.kevlar_non_watch_unified_player = true;
      // EXPERIMENT_FLAGS.kevlar_player_update_killswitch = true;

      EXPERIMENT_FLAGS.web_secure_pref_cookie_killswitch = true;
      EXPERIMENT_FLAGS.ytidb_clear_optimizations_killswitch = true;
      // EXPERIMENT_FLAGS.defer_overlays = true;


    }
    const setterFn = (EXPERIMENT_FLAGS, mzFlagDetected) => {

      const fEntries = Object.entries(EXPERIMENT_FLAGS);
      mex(EXPERIMENT_FLAGS, mzFlagDetected, fEntries);
      mey(EXPERIMENT_FLAGS, mzFlagDetected);

    };

    setterFn(config_.EXPERIMENT_FLAGS, mzFlagDetected1);

    if (config_.EXPERIMENTS_FORCED_FLAGS) setterFn(config_.EXPERIMENTS_FORCED_FLAGS, mzFlagDetected2);


  });

  hLooper.start();


  const cleanContext = async (win) => {
    const waitFn = requestAnimationFrame; // shall have been binded to window
    try {
      let mx = 16; // MAX TRIAL
      const frameId = 'vanillajs-iframe-v1'
      let frame = document.getElementById(frameId);
      let removeIframeFn = null;
      if (!frame) {
        frame = document.createElement('iframe');
        frame.id = 'vanillajs-iframe-v1';
        frame.sandbox = 'allow-same-origin'; // script cannot be run inside iframe but API can be obtained from iframe
        let n = document.createElement('noscript'); // wrap into NOSCRPIT to avoid reflow (layouting)
        n.appendChild(frame);
        while (!document.documentElement && mx-- > 0) await new Promise(waitFn); // requestAnimationFrame here could get modified by YouTube engine
        const root = document.documentElement;
        root.appendChild(n); // throw error if root is null due to exceeding MAX TRIAL
        removeIframeFn = (setTimeout) => {
          const removeIframeOnDocumentReady = (e) => {
            e && win.removeEventListener("DOMContentLoaded", removeIframeOnDocumentReady, false);
            win = null;
            setTimeout(() => {
              n.remove();
              n = null;
            }, 200);
          }
          if (document.readyState !== 'loading') {
            removeIframeOnDocumentReady();
          } else {
            win.addEventListener("DOMContentLoaded", removeIframeOnDocumentReady, false);
          }
        }
      }
      while (!frame.contentWindow && mx-- > 0) await new Promise(waitFn);
      const fc = frame.contentWindow;
      if (!fc) throw "window is not found."; // throw error if root is null due to exceeding MAX TRIAL
      const { requestAnimationFrame, setInterval, setTimeout, clearInterval, clearTimeout } = fc;
      const res = { requestAnimationFrame, setInterval, setTimeout, clearInterval, clearTimeout };
      for (let k in res) res[k] = res[k].bind(win); // necessary
      if (removeIframeFn) Promise.resolve(res.setTimeout).then(removeIframeFn);
      return res;
    } catch (e) {
      console.warn(e);
      return null;
    }
  };

  cleanContext(win).then(__CONTEXT__ => {

    const { requestAnimationFrame, setInterval, clearInterval, setTimeout, clearTimeout } = __CONTEXT__;

    hLooper.setupForCleanContext(__CONTEXT__)

  });


  if (isMainWindow) {

    console.groupCollapsed(
      "%cYouTube EXPERIMENT_FLAGS Tamer",
      "background-color: #EDE43B ; color: #000 ; font-weight: bold ; padding: 4px ;"
    );

    console.log("Script is loaded.");
    console.log("This might affect the new features when YouTube rolls them out to general users.");
    console.log("If you found any issue in using YouTube, please disable this script to check whether the issue is due to this script or not.");

    console.groupEnd();

  }

})(null);