Don't load audio if there is no URI for it in manifest

[FeniXenAaaa]

Environment

• [x ] The stream has correct Access-Control-Allow-Origin headers (CORS)
• There are no network errors such as 404s in the browser console when trying to play the stream
• The issue observed is not already reported by searching on Github under https://github.com/dailymotion/hls.js/issues
• The issue occurs in the latest reference client on http://dailymotion.github.io/hls.js/demo and not just on my page
• Hls.js version: 0.6.2-1
• Browser name/version: Any
• OS name/version: Any

Steps to reproduce

1. Use any manifest with audio track defined like that (no URI):

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="English - Spoken Language",LANGUAGE="EN",AUTOSELECT=YES,DEFAULT=YES

Actual behavior

xhr-loader.js trying to load the resource with empty URL. As a result, the URL equals to current page:

http://currentsite.com/...

This raises the error in loadsuccess function of playlist-loader.js and as a result attempt to recover in HLS what increases the loading time. I think it makes sense to catch such situations and to load resources if the URL is blank.

Console output

trigger @   hls.js:142
loaderror   @   playlist-loader.js:389
loadend @   xhr-loader.js:115

[roquez]

I encountered the same problem. Here is an example stream url where the issue happens:
http://content.uplynk.com/ext/d874124ecca24c88a3c9575e78686acf/10065013.m3u8

Player is not reacting until all segments are downloaded. Then it starts playing without audio. On Microsoft Edge it doesn't play at all.

Demo page shows the following error:
error while parsing manifest:no EXTM3U delimiter,network error ...

[mangui]

this should be related to these lines
https://github.com/dailymotion/hls.js/blob/master/src/loader/playlist-loader.js#L367-L369
if you remove them it should work fine.
they were introduced in dailymotion@c965973
to support https://github.com/dailymotion/hls.js/issues/585
basically in case #EXT-X-MEDIA:TYPE=AUDIO is found, with no URL attribute, we should not add a default main audio track

[FeniXenAaaa]

@mangui Just to clarify, this should be fixed from hls.js side, right?

[mangui]

Yes

[mangui]

plz recheck your streams on demo page, issue should be fixed

[FeniXenAaaa]

@mangui yes, fixed. Thank you very much!

[roquez]

Thanks!