yt-dlp 開發筆記 @ Python3, macOS 13.2.1

yt-dlp 是知名的網路影音網站研究的專案，內含不少各大網站的爬蟲技術。若某個服務失效想要貢獻的話，可這樣操作，邊改 code 變測試：

% git clone https://github.com/yt-dlp/yt-dlp.git

% cd yt-dlp

% python3 yt_dlp/__main__.py 'URL' --skip-download -j

以 2023/08/31 即將關站的 Xuite 為例，從 github.com/yt-dlp/yt-dlp/tree/master/yt_dlp/extractor/xuite.py 找一則 unit test 來跑：

% python3 yt_dlp/__main__.py 'http://vlog.xuite.net/embed/cE1xbENoLTI3NDQ3MzM2LmZsdg==?ar=0&as=0' -f mp4 --skip-download -j | jq '' | tail -n 25

  "format_id": "720",

  "height": 720,

  "protocol": "http",

  "resolution": "720p",

  "dynamic_range": "SDR",

  "aspect_ratio": null,

  "http_headers": {

    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.50 Safari/537.36",

    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",

    "Accept-Language": "en-us,en;q=0.5",

    "Sec-Fetch-Mode": "navigate"

  },

  "video_ext": "mp4",

  "audio_ext": "none",

  "format": "720 - 720p",

  "_filename": "男女平權只是口號？專家解釋約會時男生是否該幫女生付錢 (中字) [27447336].mp4",

  "filename": "男女平權只是口號？專家解釋約會時男生是否該幫女生付錢 (中字) [27447336].mp4",

  "_type": "video",

  "_version": {

    "version": "2023.03.04",

    "current_git_head": "b423b6a48",

    "release_git_head": "392389b7df7b818f794b231f14dc396d4875fbad",

    "repository": "yt-dlp/yt-dlp"

  }

}

至於，若要貢獻給 yt-dlp 社群，可以仿其架構，挑一個 extractor 來模仿，過程要繼承 InfoExtractor 來做事，例如實作 _VALID_URL 和 _real_extract(self, url) 等等，可以挑幾個實作沒那麼複雜的網站研究一下流程：

• github.com/yt-dlp/yt-dlp/tree/master/yt_dlp/extractor/xuite.py
• github.com/yt-dlp/yt-dlp/tree/master/yt_dlp/extractor/udn.py
• github.com/yt-dlp/yt-dlp/tree/master/yt_dlp/extractor/imgur.py
• github.com/yt-dlp/yt-dlp/tree/master/yt_dlp/extractor/sohu.py

Javascript 開發筆記 - 使用 Yuotube Player API for iframe Embeds 將 videos 串成 playlist

透過 Youtube Player API 可以動態把一堆 Youtube video 串成一個 playlist 來播放。網路上不少範例，但很少看到處理多則 video 的方式，有也是一則 video 搭配一個 player 架構，摸了一下終於搞懂其設計架構，片段程式碼：

<div id="player"></div>
<script>
var player;
var videos = ['LzHFD1sEqpE', 'iV8JDbtXZm4', '-sjfQWGkGF4'];
(function() {
if (videos.length) {
var tag = document.createElement('script');
tag.onload = function() {
YT.ready(function() {
player = new YT.Player('player', {
playerVars: {
playlist: videos.join(","),
}
});
});
}
tag.src = "https://www.youtube.com/iframe_api";
var firstScriptTag = document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
}
})();
</script>

更多資訊請參考：https://developers.google.com/youtube/iframe_api_reference