allow ":" or "=" inside metadata value

Author: aidenlx

src/vtt/vtt-parser.ts

@@ -115,8 +115,13 @@ export class VTTParser implements CaptionsParser {
   protected _parseHeader(line: string, lineCount: number) {
     if (lineCount > 1) {
       if (SETTING_SEP_RE.test(line)) {
-        const [key, value] = line.split(SETTING_SEP_RE);
-        if (key) this._metadata[key] = (value || '').replace(SPACE_RE, '');
+        const separatorIndex = line.indexOf(SETTING_SEP_RE);
+        if (separatorIndex !== -1) {
+          const key = line.substring(0, separatorIndex);
+          const value = line.substring(separatorIndex + SETTING_SEP_RE.length);
+          this._metadata[key] = (value || '').trim()
+        }
+        if (key) 
       }
     } else if (line.startsWith(HEADER_MAGIC)) {
       this._block = VTTBlock.Header;