Ios – How to stream only the sound of a video from YouTube?

audioiosobjective-cstreamyoutube

I would like to stream only sound from youtube. I need this for IOS but others can be ok. I have searched on stackoverflow but I couldn't find. Because I don't want to use another software, I want to directly stream only sound of youtube video by code. Also It should work on background.

Best Solution

Flashgot (for Firefox) has a way to download only the audio of a Youtube video. It exposes links to the audio that looks like this:

https://r3---sn-p5qlsu7d.googlevideo.com/videoplayback?id=887ce37c617a3225&itag=141&source=youtube&requiressl=yes&gcr=ca&ratebypass=yes&mime=audio%2Fmp4&gir=yes&clen=4012348&lmt=1409362978343745&dur=125.828&signature=0A00B9B16BB6EF3192DF33EEF9B2AB67F66F501F.0B649D407144B914A7CC7BE00E795B5BD1B9D932&upn=VFAbXgDGSU8&key=cms1&fexp=900718%2C924231%2C924637%2C927622%2C930809%2C931354%2C932404%2C9405454%2C941004%2C943917%2C945066%2C947209%2C947218%2C948124%2C952302%2C952605%2C952901%2C955301%2C957103%2C957105%2C957201&sver=3&ip=24.235.37.181&ipbits=0&expire=1419930614&sparams=clen,dur,expire,gcr,gir,id,ip,ipbits,itag,lmt,mime,mm,ms,mv,ratebypass,requiressl,source&cmbypass=yes&req_id=3eb2c618c54ca3ee&redirect_counter=2&cms_redirect=yes&mm=26&ms=tsu&mt=1419909012&mv=m

OK, so that is a very big link. This is the same link dissected into pieces:

https://r3---sn-p5qlsu7d.googlevideo.com/videoplayback?id=887ce37c617a3225
&itag=141
&source=youtube
&requiressl=yes
&gcr=ca
&ratebypass=yes
&mime=audio/mp4 #Here's where audio only is specified.
&gir=yes
&clen=4012348
&lmt=1409362978343745
&dur=125.828
&signature=0A00B9B16BB6EF3192DF33EEF9B2AB67F66F501F.0B649D407144B914A7CC7BE00E795B5BD1B9D932
&upn=VFAbXgDGSU8
&key=cms1
&fexp=900718,924231,924637,927622,930809,931354,932404,9405454,941004,943917,945066,947209,947218,948124,952302,952605,952901,955301,957103,957105,957201
&sver=3
&ip=24.235.37.181 #Oh, look. My IP address.
&ipbits=0
&expire=1419930614
&sparams=clen,dur,expire,gcr,gir,id,ip,ipbits,itag,lmt,mime,mm,ms,mv,ratebypass,requiressl,source
&cmbypass=yes
&req_id=3eb2c618c54ca3ee
&redirect_counter=2
&cms_redirect=yes
&mm=26
&ms=tsu
&mt=1419909012
&mv=m

Very interesting. This enables Flashgot to download only the audio and skip the video, thus saving bandwidth. I'm missing details, like how Flashgot created this link, but if Flashgot has a way to do it, it stands to reason that other HTTP clients could do it too.