Bug 255499

Summary: subtitles remain on Safari when playing live content
Product: WebKit Reporter: valletgood
Component: MediaAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: jer.noble, karlcow, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: All   
OS: iOS 15   
Attachments:
Description Flags
Subtitle data received from the server.
none
Subtitle data confirmed through textTracks. none

Description valletgood 2023-04-16 17:02:06 PDT 
When playing HLS live content in Safari, the subtitles continue to be displayed and are not disappearing. When checking the activeCues through the Web API textTracks, it was found that some cues have an endTime of Infinity. When playing the same live content in Chrome, the issue does not occur. What is the reason for assigning the value of Infinity to endTime when processing the received startTime and endTime of the subtitles from the server in Safari?
Comment 1 Karl Dubost 2023-04-16 18:00:50 PDT 
valletgood,
thanks for the report. Would you have a test case or a website where this is breaking?
Comment 2 valletgood 2023-04-17 16:53:26 PDT 
Created attachment 465949 [details]
Subtitle data received from the server.
Comment 3 valletgood 2023-04-17 16:54:28 PDT 
Created attachment 465950 [details]
Subtitle data confirmed through textTracks.
Comment 4 valletgood 2023-04-17 16:55:13 PDT 
(In reply to Karl Dubost from comment #1)
> valletgood,
> thanks for the report. Would you have a test case or a website where this is
> breaking?

We cannot provide our website because live content streaming is currently not available. However, we will upload a screenshot that we tested before. The subtitle data of the live content received from the server contains values for "begin" and "end". However, when we checked the subtitle data using the Web API "textTracks" in Safari, the "endTime" value was set to "Infinity", and the subtitles continued to display without disappearing. Please check attachment 465949 [details] and attachment 465950 [details]
Comment 5 Radar WebKit Bug Importer 2023-04-25 09:04:05 PDT 
<rdar://problem/108506607>