Bug 160959

Summary: Audio HLS + WebVTT player error
Product: WebKit Reporter: Francesco <francesco.dambrosio>
Component: MediaAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Critical CC: eric.carlson, francesco.dambrosio, jer.noble, jonlee
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Mac   
OS: OS X 10.11   
Attachments:
Description Flags
player error none

Description Francesco 2016-08-18 08:56:53 PDT 
Created attachment 286370 [details]
player error

We have a problem with audio files streamed by Wowza 4 using HLS protocol, when we add VTT file. It doesn't works with Safari on Mac and iOS. 
The file is an .m4a with aac codec. 

1. create html page with video tag, add HLS with m4a source
2. add crossorigin="anonymous" properties
3. add track tag with vtt file
demo: http://www.fdambrosio.net/test/player7/safari-bug.html

We expect that it play audio with subtitles control button but player return "error" message, don't play audio and don't show subtitles. There's no error on Safari Console. 

Tested with: 
latest webKit release (11601.6.17, r204592) and Safari 9.1.1 on OSX 10.11.5
Safari on iOS 9.3.4 (iPhone 5S / iPhone6S)

Note: there's no issue using HLS stream with mp4 video file and vtt. Problem occurs only with audio HLS stream.
Comment 1 Eric Carlson 2016-08-18 12:51:01 PDT 
<rdar://problem/25980997>