Closed Bug 1703444 Opened 1 year ago Closed 1 year ago

[webvtt] NOTE as subtitle in Firefox 87.0

Categories

(Core :: Audio/Video: Playback, defect, P3)

Firefox 87
defect

Tracking

()

RESOLVED FIXED
89 Branch
Tracking Status
firefox89 --- fixed

People

(Reporter: github, Assigned: alwu, NeedInfo)

References

(Blocks 1 open bug)

Details

Attachments

(2 files)

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

  1. Create a vtt file with this subtitle:
    00:00.000 --> 00:02.000
    NOTE A
  2. Put it in a "track" element and start a video with this subtitle file.

Actual results:

Firefox 87 doesn't show a subtitle.

Expected results:

Firefox should show "NOTE A" as subtitle.
Chromium 89.0 shows this.
Also see here: https://stackoverflow.com/questions/66903928/webvtt-escape-note-in-subtitle-for-firefox-87-0

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: Playback' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Component: Untriaged → Audio/Video: Playback
Product: Firefox → Core

Thanks for the bug report!

Per https://www.w3.org/TR/webvtt1/#introduction-comments

Comments are just blocks that are preceded by a blank line

So, it does seem like Firefox should render a line starting with NOTE when it's in a cue position like the example.

As a workaround, you can precede the NOTE with a space, and Firefox appears to render it.

Blocks: webvtt
Severity: -- → S3
Flags: needinfo?(alwu)
Priority: -- → P3

Yes, this is Firefox bug, currently we would skip all line starting with NOTE [1] and we should handle the NOTE in a better way.

[1] https://searchfox.org/mozilla-central/rev/62135a96327f42fd1ccf8a04feb62be04b102195/dom/media/webvtt/vtt.jsm#1372-1374

Assignee: nobody → alwu
Flags: needinfo?(alwu)

Depends on D111300

Pushed by alwu@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/b5a9076a78b5
part1 : comment block should be preceded by a blank line. r=jbauman
https://hg.mozilla.org/integration/autoland/rev/200e93289ab1
part2 : add more debug log. r=jbauman
Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/28419 for changes under testing/web-platform/tests
Upstream PR was closed without merging
Pushed by alwu@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/a3a331a5c7bf
part1 : comment block should be preceded by a blank line. r=jbauman
https://hg.mozilla.org/integration/autoland/rev/9e7725587bbf
part2 : add more debug log. r=jbauman
Status: UNCONFIRMED → RESOLVED
Closed: 1 year ago
Resolution: --- → FIXED
Target Milestone: --- → 89 Branch
Upstream PR merged by moz-wptsync-bot
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