Downloading only Audio from Youtube

Here is a recent article in webupd8.org that explains how to use youtube-dl to directly download audio instead of first downloading video+audio and then extracting audio using -x. Unfortunately, the search facility that Maythux asked for here isn't offered. But it is still worth a look:
Video Downloader youtube-dl Gets Support For Separate Audio And Video YouTube DASH Streams

Basically, download the latest version of youtube-dl from source or from the ppa offered in the link above but not from the Software Center.

Then, if you already have the video link ...

Run, as example:

youtube-dl -F http://www.youtube.com/watch?v=HRIF4_WzU1w

This will list the various download formats available for this url (audio and video).

$ youtube-dl -F http://www.youtube.com/watch?v=HRIF4_WzU1w
[youtube] Setting language
[youtube] HRIF4_WzU1w: Downloading webpage
[youtube] HRIF4_WzU1w: Downloading video info webpage
[youtube] HRIF4_WzU1w: Extracting video information
[info] Available formats for HRIF4_WzU1w:
format code extension resolution  note 
171         webm      audio only  DASH webm audio , audio@ 48k (worst)
140         m4a       audio only  DASH audio , audio@128k
160         mp4       192p        DASH video 
133         mp4       240p        DASH video 
134         mp4       360p        DASH video 
135         mp4       480p        DASH video 
17          3gp       176x144     
36          3gp       320x240     
5           flv       400x240     
43          webm      640x360     
18          mp4       640x360     (best)

Now, choose desired audio format. I went for 140

Run:

youtube-dl -f 140 http://www.youtube.com/watch?v=HRIF4_WzU1w

$ youtube-dl -f 140 http://www.youtube.com/watch?v=HRIF4_WzU1w
[youtube] Setting language
[youtube] HRIF4_WzU1w: Downloading webpage
[youtube] HRIF4_WzU1w: Downloading video info webpage
[youtube] HRIF4_WzU1w: Extracting video information
[download] Destination: Martin Luther King - I Have a Dream on August 28, 1963 [Sous-titres & Subtitles] [FULL SPEECH]-HRIF4_WzU1w.m4a
[download] 100% of 15.19MiB in 00:04

That's it.

Taken from <http://askubuntu.com/questions/423508/can-i-directly-download-audio-using-youtube-dl>

Introduction

This blog is meant to keep an online account of things that I keep telling to myself that I should be doing, but probably might be following or not. The idea is also to see if it is useful to anybody else there, in which case I would be extremely happy.

Disclaimer:
1) This doesnt intend to be preachy though it might sound so.
2) The thoughts are purely subjective and I do not intend to pick up a debate/argument. If you do not like some point, please ignore it and move on.
3) Some might be redundant. I am sorry about that. 
4) I myself might not have been following perfectly all the mentioned points. I just try to.


So without much ado, here it goes.

• If someone asks me on what is one golden rule to lead life happily, I would say this is the golden rule 
• "There is NO single golden rule to live life happily"  

•  Honesty is the best policy. 
• Speak truth at all times as much as possible.
• Your conscience becomes lighter and you feel less guilty.
• You dont need to remember if you are telling the truth.

•  All are equal and unique in this world. No one is lesser or greater than anyone else in this world. 
• Believe that whatever one suffers or enjoys is only result of his own actions only. Quoting Kaniyan poongundranaar a tamil poet here, 
• "தீதும் நன்றும் பிறர் தர வாரா". 

• Happiness is a choice. Always choose to be happy. Takes a lot of practice, but achievable.
• Sadness and anger are unwanted emotions. They serve no purpose. If at all anything they do, they only worsen the situations. So no point in being angry or sad or for that matter have any negative emotions.
• Sound body is sound mind. So, take great care of your own health. It will tremendously improve your concentration on other things and ability to think calmly and clearly. 
• Be positive always. Try to look at any particular situation with a positive outlook. 

                                            (To be continued...)