Repository: youtube-dl
Issue: [Viki] doesn't return episode number or any of the series output template
Labels: geo-restricted



### Make sure you are using the *latest* version: run `youtube-dl --version` and ensure your version is *2018.09.01*. If it's not, read [this FAQ entry](https://github.com/rg3/youtube-dl/blob/master/README.md#how-do-i-update-youtube-dl) and update. Issues with outdated version will be rejected.
- [x] I've **verified** and **I assure** that I'm running youtube-dl **2018.09.01**

### Before submitting an *issue* make sure you have:
- [x] At least skimmed through the [README](https://github.com/rg3/youtube-dl/blob/master/README.md), **most notably** the [FAQ](https://github.com/rg3/youtube-dl#faq) and [BUGS](https://github.com/rg3/youtube-dl#bugs) sections
- [x] [Searched](https://github.com/rg3/youtube-dl/search?type=Issues) the bugtracker for similar issues including closed ones
- [x] Checked that provided video/audio/playlist URLs (if any) are alive and playable in a browser

### What is the purpose of your *issue*?
- [x] Feature request (request for a new functionality)
- [ ] Bug report (encountered problems with youtube-dl)
- [ ] Site support request (request for adding support for a new site)
- [ ] Question
- [ ] Other

---



```
~/Downloads/youtube-dl -o '%(episode_number)s.%(ext)s' 'https://www.viki.com/videos/1033597v-my-love-from-the-star-epilogue-episode-22' -v        [debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-o', u'%(episode_number)s.%(ext)s', u'https://www.viki.com/videos/1033597v-my-love-from-the-star-epilogue-episode-22', u'-v']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2018.09.01
[debug] Python version 2.7.13 (CPython) - Linux-4.9.0-3-amd64-x86_64-with-debian-9.1
[debug] exe versions: ffmpeg 3.2.7-1, ffprobe 3.2.7-1
[debug] Proxy map: {}
[viki] 1033597v: Downloading video JSON
[viki] 1033597v: Downloading video streams JSON
[debug] Default format spec: bestvideo+bestaudio/best
[debug] Invoking downloader on u'https://v4.viki.io/1033597v/1033597v_high_480p_1403051005.mp4?e=1535950501&h=ccaabefd815378cd29ddd877e2ce3cb7'
[download] Destination: NA.mp4
[download] 100% of 12.95MiB in 00:00

```

---

As you can see instead of returning **Episode number** it returns **NA**

I did skim through the code once there was no mention on returning this or any of the filename commands mentioned in the homepage in the output template section 
```
Available for the video that is an episode of some series or programme:

series (string): Title of the series or programme the video episode belongs to
season (string): Title of the season the video episode belongs to
season_number (numeric): Number of the season the video episode belongs to
season_id (string): Id of the season the video episode belongs to
episode (string): Title of the video episode
episode_number (numeric): Number of the video episode within a season
episode_id (string): Id of the video episode
```
Though i can read it and understand whats missing unfortunately i'm not good enough to write the code to add this!