Repository: youtube-dl
Issue: Set constant bitrate for audio only
Labels: request

## Please follow the guide below
- You will be asked some questions and requested to provide some information, please read them **carefully** and answer honestly
- Put an `x` into all the boxes [ ] relevant to your _issue_ (like that [x])
- Use _Preview_ tab to see how your issue will actually look like

---
### Make sure you are using the _latest_ version: run `youtube-dl --version` and ensure your version is _2016.10.25_. 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 Issues with outdated version will be rejected.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 **2016.10.25**
### Before submitting an _issue_ make sure you have:
- [x] At least skimmed through [README](https://github.com/rg3/youtube-dl/blob/master/README.md) and **most notably** [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
### What is the purpose of your _issue_?
- [ ] 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)
- [ ] Question
- [ ] Other

---
### The following sections concretize particular purposed issues, you can erase any section (the contents between triple ---) not applicable to your _issue_

---
### If the purpose of this _issue_ is a _bug report_, _site support request_ or you are not completely sure provide the full verbose output as follows:

Add `-v` flag to **your command line** you run youtube-dl with, copy the **whole** output and insert it here. It should look similar to one below (replace it with **your** log inserted between triple ```):

```
$ youtube-dl -v --audio-format mp3 --audio-quality 0 -x https://www.youtube.com/watch?v=Zej2OYAYDKY
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'-v', u'--audio-format', u'mp3', u'--audio-quality', u'0', u'-x', u'https://www.youtube.com/watch?v=Zej2OYAYDKY']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2016.10.25
[debug] Python version 2.7.12+ - Linux-4.8.0-26-generic-x86_64-with-Ubuntu-16.10-yakkety
[debug] exe versions: avconv 3.0.2-1ubuntu3, avprobe 3.0.2-1ubuntu3, ffmpeg 3.0.2-1ubuntu3, ffprobe 3.0.2-1ubuntu3, rtmpdump 2.4
[debug] Proxy map: {}
[youtube] Zej2OYAYDKY: Downloading webpage
[youtube] Zej2OYAYDKY: Downloading video info webpage
[youtube] Zej2OYAYDKY: Extracting video information
[youtube] {43} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {18} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {36} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {17} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {135} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {244} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {134} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {243} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {133} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {242} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {160} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {278} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {140} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {171} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {249} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {250} signature length 40.41, html5 player en_US-vflEz7zqU
[youtube] {251} signature length 40.41, html5 player en_US-vflEz7zqU
[debug] Invoking downloader on u'https://r3---sn-5hnednlr.googlevideo.com/videoplayback?gir=yes&nh=IgpwcjAzLmFtczE2Kg03Mi4xNC4yMDMuMTcx&expire=1477453920&requiressl=yes&keepalive=yes&pl=14&itag=251&key=yt6&mime=audio%2Fwebm&clen=8257189&ipbits=0&lmt=1410678477611640&mn=sn-5hnednlr&source=youtube&mm=31&upn=-hkb07XNYT8&dur=408.801&ms=au&mv=m&mt=1477432256&ip=87.212.130.235&ei=ANQPWMvzA4KeWbnxgOgD&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Ckeepalive%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cnh%2Cpl%2Crequiressl%2Csource%2Cupn%2Cexpire&id=o-AFeb2NMRbtc7nN0U5EEAhMfbUgpQ2NPFrnfjU4lKkRqe&initcwndbps=961250&signature=E3A9BB14B3495241E815FF78AFEF3EC48380D3D5.867C238DA23F4074A854ED34F1AF384F4E0EC8A5&ratebypass=yes'
```

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### If the purpose of this _issue_ is a _site support request_ please provide all kinds of example URLs support for which should be included (replace following example URLs by **yours**):
- Single video: https://www.youtube.com/watch?v=BaW_jenozKc
- Single video: https://youtu.be/BaW_jenozKc
- Playlist: https://www.youtube.com/playlist?list=PL4lCao7KL_QFVb7Iudeipvc2BCavECqzc

---
### Description of your _issue_, suggested solution and other information

Explanation of your _issue_ in arbitrary form goes here. Please make sure the [description is worded well enough to be understood](https://github.com/rg3/youtube-dl#is-the-description-of-the-issue-itself-sufficient). Provide as much context and examples as possible.
If work on your _issue_ requires account credentials please provide them or explain how one can obtain them.

Please offer options to force constant bitrate for audio only download. Some dj applicatoins work better with CBR than VBR.