179237 2017-11-03 03:45:24 -0700 Automatic linebreaking of WebVTT subtitles is not supported 2023-10-25 09:20:50 -0700 1 1 1 Unclassified WebKit Media WebKit Nightly Build Unspecified Unspecified NEW https://bugs.webkit.org/show_bug.cgi?id=179370 http://wpt.live/html/semantics/embedded-content/media-elements/track/track-element/track-webvtt-non-snap-to-lines.html WPTImpact P2 Normal --- 1 fred.wang webkit-unassigned ahmad.saleem792 eric.carlson fred.wang jer.noble oldest_to_newest 1367870 0 fred.wang 2017-11-03 03:45:24 -0700 From the spec: https://w3c.github.io/webvtt/#introduction-multiple-lines "Line breaks in cues are honored. User agents will also insert extra line breaks if necessary to fit the cue in the cue’s width. In general, therefore, authors are encouraged to write cues all on one line except when a line break is definitely necessary." This page uses the example from the specification: https://people.igalia.com/fwang/webvtt-tests/subtitle-linebreaking.html Linebreaking happens for the long (third) subtitle in Gecko, but not in WebKit. I tried both WebKitGTK+/Linux and Safari/macOS. 1368969 1 326204 fred.wang 2017-11-07 03:47:45 -0800 Created attachment 326204 WIP Patch I had reported this to Chromium and they reply it is fixed (see https://bugs.chromium.org/p/chromium/issues/detail?id=781186). The attached patch is based on https://chromium.googlesource.com/chromium/src.git/+/e6b16d301f0da8a22bfba7ab5997771af0459cf5%5E!/#F2 and removes a feature that is no longer in the WebVTT spec. It turns out to fix the linebreaking issue. I also opened bug 179370 to import the WebVTT tests. 1987432 2 ahmad.saleem792 2023-10-25 09:13:53 -0700 All browsers are failing WPT test linked in the URL (removed the standard link URL since it is in Comment 0). Added 'WPTImpact' tag for future tracking. 1987433 3 ahmad.saleem792 2023-10-25 09:20:50 -0700 We still have this code but in different shape here: https://searchfox.org/wubkat/source/Source/WebCore/html/track/VTTCue.cpp#261 if (!cue->snapToLines()) { setInlineStyleProperty(CSSPropertyWhiteSpaceCollapse, CSSValuePreserve); setInlineStyleProperty(CSSPropertyTextWrapMode, CSSValueNowrap); } 326204 2017-11-07 03:47:45 -0800 2017-11-07 03:47:45 -0800 WIP Patch 179237.patch text/plain 1449 fred.wang ZGlmZiAtLWdpdCBhL1NvdXJjZS9XZWJDb3JlL2h0bWwvdHJhY2svVlRUQ3VlLmNwcCBiL1NvdXJj ZS9XZWJDb3JlL2h0bWwvdHJhY2svVlRUQ3VlLmNwcAppbmRleCAyMWVhNjY0ZTViYy4uZGNiOGIx ZTIwZGMgMTAwNjQ0Ci0tLSBhL1NvdXJjZS9XZWJDb3JlL2h0bWwvdHJhY2svVlRUQ3VlLmNwcAor KysgYi9Tb3VyY2UvV2ViQ29yZS9odG1sL3RyYWNrL1ZUVEN1ZS5jcHAKQEAgLTIwNSwyMyArMjA1 LDYgQEAgdm9pZCBWVFRDdWVCb3g6OmFwcGx5Q1NTUHJvcGVydGllcyhjb25zdCBJbnRTaXplJiB2 aWRlb1NpemUpCiAgICAgLy8gd2hvc2UgZmlyc3QgY2VsbCBpcyB0aGUgdmFsdWUgb2YgdGhlIGNv cnJlc3BvbmRpbmcgY3VlJ3MgdGV4dCB0cmFjayBjdWUKICAgICAvLyBhbGlnbm1lbnQ6CiAgICAg c2V0SW5saW5lU3R5bGVQcm9wZXJ0eShDU1NQcm9wZXJ0eVRleHRBbGlnbiwgbV9jdWUuZ2V0Q1NT QWxpZ25tZW50KCkpOwotICAgIAotICAgIGlmICghbV9jdWUuc25hcFRvTGluZXMoKSkgewotICAg ICAgICAvLyAxMC4xMy4xIFNldCB1cCB4IGFuZCB5OgotICAgICAgICAvLyBOb3RlOiB4IGFuZCB5 IGFyZSBzZXQgdGhyb3VnaCB0aGUgQ1NTIGxlZnQgYW5kIHRvcCBhYm92ZS4KLQotICAgICAgICAv LyAxMC4xMy4yIFBvc2l0aW9uIHRoZSBib3hlcyBpbiBib3hlcyBzdWNoIHRoYXQgdGhlIHBvaW50 IHglIGFsb25nIHRoZQotICAgICAgICAvLyB3aWR0aCBvZiB0aGUgYm91bmRpbmcgYm94IG9mIHRo ZSBib3hlcyBpbiBib3hlcyBpcyB4JSBvZiB0aGUgd2F5Ci0gICAgICAgIC8vIGFjcm9zcyB0aGUg d2lkdGggb2YgdGhlIHZpZGVvJ3MgcmVuZGVyaW5nIGFyZWEsIGFuZCB0aGUgcG9pbnQgeSUKLSAg ICAgICAgLy8gYWxvbmcgdGhlIGhlaWdodCBvZiB0aGUgYm91bmRpbmcgYm94IG9mIHRoZSBib3hl cyBpbiBib3hlcyBpcyB5JQotICAgICAgICAvLyBvZiB0aGUgd2F5IGFjcm9zcyB0aGUgaGVpZ2h0 IG9mIHRoZSB2aWRlbydzIHJlbmRlcmluZyBhcmVhLCB3aGlsZQotICAgICAgICAvLyBtYWludGFp bmluZyB0aGUgcmVsYXRpdmUgcG9zaXRpb25zIG9mIHRoZSBib3hlcyBpbiBib3hlcyB0byBlYWNo Ci0gICAgICAgIC8vIG90aGVyLgotICAgICAgICBzZXRJbmxpbmVTdHlsZVByb3BlcnR5KENTU1By b3BlcnR5VHJhbnNmb3JtLAotICAgICAgICAgICAgU3RyaW5nOjpmb3JtYXQoInRyYW5zbGF0ZSgt JS4yZiUlLCAtJS4yZiUlKSIsIHBvc2l0aW9uLmZpcnN0LCBwb3NpdGlvbi5zZWNvbmQpKTsKLQot ICAgICAgICBzZXRJbmxpbmVTdHlsZVByb3BlcnR5KENTU1Byb3BlcnR5V2hpdGVTcGFjZSwgQ1NT VmFsdWVQcmUpOwotICAgIH0KIAogICAgIC8vIE1ha2Ugc3VyZSBzaGFkb3cgb3Igc3Ryb2tlIGlz IG5vdCBjbGlwcGVkLgogICAgIHNldElubGluZVN0eWxlUHJvcGVydHkoQ1NTUHJvcGVydHlPdmVy ZmxvdywgQ1NTVmFsdWVWaXNpYmxlKTsK