title: Why can only download the first episode video on bilibili with youtube-dl?
body: <p>I can download the first episode of a series.</p>
  
  <pre><code> yutube-dl  https://www.bilibili.com/video/av90163846?p=1 
  </code></pre>
  
  <p>Now I want to download all episodes of the series.</p>
  
  <pre><code>for i in $(seq  1  55)
  do
      yutube-dl  https://www.bilibili.com/video/av90163846?p=$i
  done  
  </code></pre>
  
  <p>All other episodes except the first can't be downloaded ,both of them contains same error info such as below:</p>
  
  <pre><code>[BiliBili] 90163846: Downloading webpage
  [BiliBili] 90163846: Downloading video info page
  [download] 【合集300集全】地道美音 美国中小学教学 自然科学 社会常识-90163846.flv has already been downloaded
  </code></pre>
  
  <p>Please have a try and check what happens,how to fix then?<br>
  @Christos Lytras,strange thing happen with your code:</p>
  
  <pre><code>for i in $(seq  1  55)
  do
      youtube-dl https://www.bilibili.com/video/av90163846?p=$i -o "%(title)s-%(id)s-$i.%(ext)s"
  done
  </code></pre>
  
  <p>It surely can download video on bilibili,but all of downloaded video have different name and same content,all the content are the same as the first episode,have a try and check ,you will find that fact.</p>