1) Provide User-Agent to YT-DLP (if any).

2) Try to extract cookies from web browser if no cookies are provided.

plugin/manifest.json

@@ -2,7 +2,7 @@
   "uuid": "elephant",
   "name": "Elephant",
   "description": "Provides support for downloading videos from various sites.",
-  "version": "1.1.20",
+  "version": "1.1.21",
   "icon": "icon.svg",
   "mediaParser": true,
   "mediaListParser": true,

plugin/msabstractparser.js

@@ -1,3 +1,5 @@
+var g_browsers = Object.create(null);
+
 var msAbstractParser = (function()
 {
     function MsAbstractParser()
@@ -10,10 +12,19 @@ var msAbstractParser = (function()
         {
             console.log("parsing...");
 
-            var args = [];
-			var tmpCookies;
+            let args = [];
+            let tmpCookies;
+            let systemUserAgent;
+            let systemBrowser;
+
+            try
+            {
+                systemUserAgent = qtJsSystem.defaultUserAgent;
+                systemBrowser = qtJsSystem.defaultWebBrowser;
+            }
+            catch(e) {}
 
-            var proxyUrl = qtJsNetworkProxyMgr.proxyForUrl(obj.url).url();
+            let proxyUrl = qtJsNetworkProxyMgr.proxyForUrl(obj.url).url();
             if (proxyUrl)
             {
                 proxyUrl = proxyUrl.replace(/^https:\/\//i, 'http://'); // FDM bug workaround
@@ -23,11 +34,31 @@ var msAbstractParser = (function()
             args.push("-J", "--flat-playlist", "--no-warnings", "--compat-options", "no-youtube-unavailable-videos");
 
             if (obj.cookies && obj.cookies.length)
-			{
-				tmpCookies = qtJsTools.createTmpFile("request_" + obj.requestId + "_cookies");
-				if (tmpCookies && tmpCookies.writeText(cookiesToNetscapeText(obj.cookies)))
-					args.push("--cookies", tmpCookies.path);
-			}
+            {
+                tmpCookies = qtJsTools.createTmpFile("request_" + obj.requestId + "_cookies");
+                if (tmpCookies && tmpCookies.writeText(cookiesToNetscapeText(obj.cookies)))
+                    args.push("--cookies", tmpCookies.path);
+            }
+            else
+            {
+                let browser = obj.browser || systemBrowser;
+                if (browser)
+                {
+                    if (!(browser in g_browsers))
+                    {
+                        return this.checkBrowser(obj.requestId, obj.interactive, browser)
+                            .then(() => this.parse(obj, customArgs));
+                    }
+                    else if (g_browsers[browser])
+                    {
+                        args.push('--cookies-from-browser', browser);
+                    }
+                }
+            }
+
+            let userAgent = obj.userAgent || systemUserAgent;
+            if (userAgent)
+                args.push('--user-agent', userAgent);
 
             if (customArgs.length)
                 args = args.concat(customArgs);
@@ -80,10 +111,43 @@ var msAbstractParser = (function()
             return /^https?:\/\//.test(obj.url);
         },
 
-	overrideUrlPolicy: function(url)
-	{
-	    return true;
-	}
+        overrideUrlPolicy: function(url)
+        {
+            return true;
+        },
+
+        checkBrowser: function(requestId, interactive, browser)
+        {
+            console.log("Checking browser support (", browser, ")...");
+
+            return launchPythonScript(requestId, interactive, "yt-dlp/yt_dlp/__main__.py", ['--cookies-from-browser', browser, 'e692ec362191442c960a761ac6b84878://test.test'])
+            .then(function(obj)
+            {
+                console.log("Python result: ", obj.output);
+
+                return new Promise(function (resolve, reject)
+                {
+                    var output = obj.output.trim();
+                    if (!output)
+                    {
+                        reject({
+                                   error: "Parse error",
+                                   isParseError: false
+                               });
+                    }
+                    else
+                    {
+                        let isSupported = /"e692ec362191442c960a761ac6b84878"/.test(output);
+
+                        console.log(browser, " supported: ", isSupported);
+
+                        g_browsers[browser] = isSupported;
+
+                        resolve();
+                    }
+                });
+            });
+        }
     };
 
     return new MsAbstractParser();