Repository: youtube-dl
Issue: Retrieve JSON data in unicode (Encoding UTF-8) 
Labels: request

- [x] Bug report (encountered problems with youtube-dl)
- [ ] Site support request (request for adding support for a new site)
- [x] Feature request (request for a new functionality)
- [x] Question
- [ ] Other
===================================================


I need JSON data containing unicode (utf-8) from Youtube-dl, sadly it couldn't retrieve JSON data from YouTube video in UTF-8 (?). 

Trying to print JSON info with `-j, --dump-json` or `-J, --dump-single-json` , `--print-json` and or wrote directly into JSON file  with `--write-info-json`. All results were printed in non unicode data string like originally of video source.  

The paramaters which were used with/out  `--encoding utf-8`

```youtube-dl --write-info-json  --encoding utf-8 -f mp4 -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=0alnhFO1B7Y -v```

```youtube-dl -j  --encoding utf-8 -f mp4 -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=0alnhFO1B7Y -v```

```youtube-dl -J  --encoding utf-8 -f mp4 -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=0alnhFO1B7Y -v```

```youtube-dl --print-json   --encoding utf-8 -f mp4 -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=0alnhFO1B7Y -v```

**The log output:**
```
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--write-info-json', '--encoding', 'utf-8', '-f', 'mp4', '-o', '%(title)s.%(ext)s', 'https://www.youtube.com/watch?v=0alnhFO1B7Y', '-v']
[debug] Encodings: locale cp1252, fs mbcs, out cp1252, pref utf-8
[debug] youtube-dl version 2017.01.10
[debug] Python version 3.4.4 - Windows-10-10.0.14393
[debug] exe versions: ffmpeg N-82966-g6993bb4, ffprobe N-82966-g6993bb4
[debug] Proxy map: {}
[youtube] 0alnhFO1B7Y: Downloading webpage
[youtube] 0alnhFO1B7Y: Downloading video info webpage
[youtube] 0alnhFO1B7Y: Extracting video information
[youtube] 0alnhFO1B7Y: Downloading MPD manifest
[info] Writing video description metadata as JSON to: 香港麥當勞42年歷史大盤點.info.json
[debug] Invoking downloader on 'https://r4---sn-npoeen7k.googlevideo.com/videoplayback?signature=9CF8920347BA9578C4C6C1909BF07083928118A5.C4840C9CB5EE1D0233179DF1EBB58DBF74095DD8&initcwndbps=6973750&mime=video%2Fmp4&key=yt6&ei=yiJ4WKbGGcugoQOQprzACg&upn=-mYp2oMPHqQ&expire=1484289834&dur=105.581&lmt=1484189129530128&clen=8002642&gir=yes&nh=IgpwcjAyLnNpbjExKg03NC4xMjUuNTEuMTcz&ratebypass=yes&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cnh%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cupn%2Cexpire&requiressl=yes&itag=18&source=youtube&id=o-AOL2Ym3gKDUBTYFiGyLZ6ipSYhPAoMG_7kFGBFNI5-ti&pl=18&ms=au&mt=1484268048&mv=m&mm=31&ip=128.199.217.235&mn=sn-npoeen7k&ipbits=0'
[download] Destination: 香港麥當勞42年歷史大盤點.mp4
[download] 100% of 7.63MiB
```
Below is log of JSON data (this is only a part of full logs - but it represent the essential of this issue) as JSON data contains a huge string data. 
For example: Title, tags and descriptions :

```
"title": "\u9999\u6e2f\u9ea5\u7576\u52de42\u5e74\u6b77\u53f2\u5927\u76e4\u9ede", "url": "https://r4---sn-npoeen7k.googlevideo.com/videoplayback?nh=IgpwcjAyLnNpbjExKg03NC4xMjUuNTEuMTcz&mm=31&mime=video%2Fmp4&pl=18&itag=18&mv=m&mt=1484268354&ms=au&ei=iiN4WN3qBc-XoQOAkrCgAQ&requiressl=yes&gir=yes&ratebypass=yes&mn=sn-npoeen7k&clen=8002642&initcwndbps=6792500&source=youtube&id=o-AGC0tYRBdONrnPr4dLWQi5RZD33w4-n6WvsXmWUoX6-W&lmt=1484189129530128&key=yt6&ip=128.199.217.235&expire=1484290026&dur=105.581&upn=1lnlrUcKnCg&signature=D656C1E342F3EFA9F3C8D5DE181169801D2B52F9.17D6C35911182083504F92FEDE78E6010D62E3B6&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cnh%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cupn%2Cexpire&ipbits=0", "categories": ["News & Politics"], "duration": 106, "uploader": "\u860b\u679c\u52d5\u65b0\u805e HK Apple Daily", "uploader_id": "appleactionews", "subtitles": {}, "format": "18 - 640x360 (medium)", "abr": 96, "ext": "mp4", "upload_date": "20170110", "thumbnail": "https://i.ytimg.com/vi/0alnhFO1B7Y/hqdefault.jpg", "formats": [{"height": null, "format_note": "DASH audio", "tbr": 57, "fps": null, "vcodec": "none", "url": 
```

```
 "description": "\u3010\u672c\u5831\u8a0a\u3011\u9ea5\u7576\u52de\u9003\u4e0d\u904e\u67d3\u7d05\u547d\u904b\uff0c\u6e2f\u4eba\u559c\u6b61\u53eb\u9ea5\u7576\u52de\u505a\u300c\u8001\u9ea5\u300d\u3001\u300c\u9ea5\u8a18\u300d\uff0c\u5168\u56e0\u9ea5\u7576\u52de\u5df2\u966a\u4f34\u6e2f\u4eba\u903e42\u500b\u5e74\u982d\uff0c\u9ea5\u7576\u52de\u53d4\u53d4\u3001\u958b\u751f\u65e5\u6703\u7b49\u96c6\u9ad4\u56de\u61b6\u6df1\u5165\u6c11\u5fc3\uff0c\u9ea5\u7576\u52de\u66fe\u63a8\u63db\u8cfc\u53f2\u8afe\u6bd4\u516c\u4ed4\u6380\u5168\u57ce\u6392\u968a\u71b1\u6f6e\uff0c\u4ea6\u5920\u7d93\u5178\u3002\n\n\u860b\u679c\u65e5\u5831\uff1ahttp://hk.apple.nextmedia.com\n\u5373like\u860b\u679cfb\uff1ahttp://www.facebook.com/hk.nextmedia\niPhone App\uff1ahttp://bit.ly/AppleDailyApp-iPhone\nAndroid App\uff1ahttp://bit.ly/AppleDailyApp-Android", "http_headers": {"Accept-Language": "en-us,en;q=0.5", "Accept-Encoding": "gzip, deflate", "Accept-Charset": "ISO-8859-1,utf-8;q=0.7,*;q=0.7", "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8", "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20150101 Firefox/47.0 (Chrome)"}, "start_time": null, "player_url": null, "playlist_index": null, "like_count": 490, "protocol": "https", "format_id": "18"}
```

```
{"tags": ["\u860b\u679c\u52d5\u65b0\u805e", "\u860b\u679c\u65e5\u5831", "appledaily", "Apple Daily(Newspaper)", "Hong Kong", "news", "\u52d5\u65b0\u805e", "\u65b0\u805e", "hk", "\u9999\u6e2f"], "uploader_url": "http://www.youtube.com/user/appleactionews", "license": "Standard YouTube License", "age_limit": 0, "resolution": "640x360", "id": "0alnhFO1B7Y",
```