json - NSInvalidArgumentException'、理由: 'JSON 書き込みの型が無効です (Sound)

Question

//ダブをデータベースに保存

NSDictionary * dict = [NSDictionary dictionaryWithObjectsAndKeys:[DubsUtils dubUrlFromPath:trimmedDubPath], @"url", _sound, @"sound", nil];

if([NSJSONSerialization isValidJSONObject:dict])
{
    NSLog(@"Valid ... %@", dict);
    NSError *err;
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:&err];
    NSLog(@"Done .. err : %@ Data : %@",err,jsonData);


    PFObject *data = [PFObject objectWithClassName:@"DubsData"];
    data[@"dubs"] = dict;

    [data saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
        if (succeeded) {
            // The object has been saved.
            NSLog(@"New dub uploaded...");
        } else {
            NSLog(@"New dub Problem uploaded...");
            // There was a problem, check error.description
        }
    }];

}
else
    NSLog(@"Not Valid ... \n Detail : %@ \n data : ",dict);

O/P : Not Valid ... Detail : { sound = "sound : Hilarious Dolphin - url : dolphin.mp3 - category : Category n\U00b02 - name : Local Category 2 - lang : en"; url = "LMHFuxhDfUb9i2tm0Qryn67eZ4kH6n.mov"; }

この dict var オブジェクトを解析サーバーに保存したい