As you may know, you can download youtube video using http://vrank.org/. The advantage of http://vrank.org/ over http://ytconv.net/ is that vrank allow you to download the video in their original format supplied by youtube. The one we will discuss is about DASH video and DASH audio formats. They are high quality video and audio formats but it has drawback: when you download a video in DASH video format you can’t hear any sound AND when you download in DASH audio format, you can’t see any video (obviously!).
Why? Well, the simple answer is: google/youtube separate the video into two stream: video and audio. So, when you are streaming a youtube video (using browser) in high quality format (720p and up), you actually download/stream from two different files.
Now, how can you play these two files (DASH video and DASH audio) at the same time? We will use VLC to do this!
- Let’s assume you already downloaded the two files (DASH audio and video)
- Open VLC
- Access Menu: Media –> Open Multiple Files…
- A new empty “Open Media” window will be opened, click on that “Add” button then browse and select your first file (could be DASH video or DASH audio file, not in particular order)
- Check/click/activate “Show more options” checkbox
- Check/click/activate “Play another media synchronously …” then click on “Browse…” button
- A new empty “Open Media” window will be opened. Click “Add“, browse to your second files (either DASH audio or DASH video depended on your first opened file). Then click “Select” button (the button will become active/clickable after you choose your second file), this second “Open Media” window will be automatically closed.
- Now, you’ll have the two files chosen and listed on the first “Open Media” window. You may click “Play” button.
VLC will play those two files synchronously, you may check it via VLC menu: Tools –> Codec Information, there will be two stream played together.