YT: support live HLS videos

src/youtube.js

@@ -319,6 +319,10 @@ var YouTubeClient = GObject.registerClass({
             codec: 'h264',
             type: settings.get_string('yt-quality-type'),
         };
+
+        uri = this.getHLSUri(info, itagOpts);
+
+        if(!uri) {
             const dashInfo = await this.getDashInfoAsync(info, itagOpts).catch(debug);
 
             if(dashInfo) {
@@ -338,6 +342,7 @@ var YouTubeClient = GObject.registerClass({
                     debug('got dash file');
                 }
             }
+        }
 
         if(!uri)
             uri = this.getBestCombinedUri(info, itagOpts);
@@ -437,6 +442,27 @@ var YouTubeClient = GObject.registerClass({
         };
     }
 
+    getHLSUri(info, itagOpts)
+    {
+        const isLive = info.videoDetails.isLiveContent;
+        debug(`video is live: ${isLive}`);
+
+        /* YouTube only uses HLS for live content */
+        if(!isLive)
+            return null;
+
+        const hlsUri = info.streamingData.hlsManifestUrl;
+        if(!hlsUri) {
+            debug(new Error('no HLS manifest URL'));
+            return null;
+        }
+
+        /* TODO: download manifest and select best resolution
+         * for monitor when adaptive streaming is disabled */
+
+        return hlsUri;
+    }
+
     getBestCombinedUri(info, itagOpts)
     {
         debug(`obtaining best combined URL for resolution: ${itagOpts.width}x${itagOpts.height}`);
@@ -708,14 +734,21 @@ var YouTubeClient = GObject.registerClass({
 
     _getIsCipher(data)
     {
-        /* Check only first best combined,
-         * AFAIK there are no videos without it */
-        if(data.formats[0].url)
+        const stream = (data.formats.length)
+            ? data.formats[0]
+            : data.adaptiveFormats[0];
+
+        if(!stream) {
+            debug(new Error('no streams'));
+            return false;
+        }
+
+        if(stream.url)
             return false;
 
         if(
-            data.formats[0].signatureCipher
-            || data.formats[0].cipher
+            stream.signatureCipher
+            || stream.cipher
         )
             return true;