886748 - Ensure <track> captions are visible for <audio>

Status: RESOLVED INVALID

(Core :: Audio/Video, defect)

Description

[Mardeg]

Attachment: WebVTT file for <track> in testcase

Currently on trunk with about:config?filter=media.webvtt.enabled set to true the text of a WebVTT <track> file cannot be seen for <audio>

Steps to Reproduce:
1. Load the testcase
2. Play the audio

Expected Results:
Captions shown.

Actual Results:
Captions don't appear.

Comment 1

[Mardeg]

Attachment: Ogg audio for testcase

Comment 2

[Mardeg]

Attachment: testcase

Comment 3

[Ralph Giles (:rillian)]

Currently the spec disallows this.

http://dev.w3.org/html5/webvtt/#dfn-rules-for-updating-the-display-of-webvtt-text-tracks (step 1 is to abort if it's an audio element)

I don't particularly agree with that, but it is a little weird since it only makes sense to render cues if there's ui displayed, which is conditional on 'controls'.

Please file a bug with the TextTracks Community Group's WebVTT component at https://www.w3.org/Bugs/Public to consider changing the spec, and cross-link with this bug.

As work-arounds, you can use a <video> element instead; it will still pay with just an audio file as the source. The text track API is also still functional with the <audio> element, so you can pull out the cues and render them with script if you want.

Comment 4

[Mardeg]

The spec change won't happen, resolving per https://www.w3.org/Bugs/Public/show_bug.cgi?id=22458#c3

Comment 5

[Caitlin Potter (:caitp)]

the nerds have spoken

Comment 6

[Mardeg]

Attachment: Workaround .vtt file for Firefox 29

Comment 7

[Mardeg]

Attachment: Workaround .vtt file for Firefox 31

Comment 8

[Mardeg]

Attachment: Testcase of audio file in <video> with WebVTT tracks

(In reply to Ralph Giles (:rillian) from comment #3)
> As work-arounds, you can use a <video> element instead;
Back when you said this, I remember testing that and it was working fine but I don't think there are any tests written, because it seems to have regressed since.

Now all captions are rendered hidden behind the video controls, and the workarounds to see them are to hack different Cue settings directly into the .vtt file. Should this be filed as a new bug?

Comment 9

[Mardeg]

Attachment: Testcase of audio file in <video> with WebVTT tracks

Previous testcase didn't load the .vtt files, trying with bug886748. as a subdomain.

Comment 10

[Mardeg]

Attachment: Testcase of audio file in <video> with WebVTT tracks

Mispaste in previous attachment.

Comment 11

[Mardeg]

Filed bug 992664

Comment 12

[Carlos Araya]

The two bugs are not the same issue. 

I should be able to caption an <audio> element

Has the audio issue been resolved or otherwise explained why it was marked as invalid

Comment 13

[Carlos Araya]

Saw the explanation above. It should still be made clear why the bug was marked as invalid as we don't always see the full thread of the issue.

Comment 14

[Rick Eyre (:reyre)]

(In reply to Carlos Araya from comment #13)
> Saw the explanation above. It should still be made clear why the bug was
> marked as invalid as we don't always see the full thread of the issue.

Hope this makes it more clear. The rules for rendering WebVTT subtitles explicitly state that if it is an Audio Element they should not be displayed. See http://dev.w3.org/html5/webvtt/#processing-model step 1.

If you'd like to get this changed feel free to file a bug on the spec or shoot an email to the community text tracks mailing list.