- From: Pierre-Anthony Lemieux <pal@sandflow.com>
- Date: Fri, 30 Mar 2018 08:19:38 -0700
- To: W3C WAI Accessible Platform Architectures <public-apa@w3.org>
- Cc: TTWG <public-tt@w3.org>
Hi all, FYI. Per our February 28 call and having seen not further discussions, I plan to merge the following two pull requests: https://github.com/w3c/imsc/pull/339 https://github.com/w3c/imsc/pull/326 and close the following issues: https://github.com/w3c/imsc/issues/321 https://github.com/w3c/imsc/issues/320 https://github.com/w3c/imsc/issues/319 https://github.com/w3c/imsc/issues/318 https://github.com/w3c/imsc/issues/317 https://github.com/w3c/imsc/issues/316 https://github.com/w3c/imsc/issues/315 on Tuesday COB. Best, - Pierre On Wed, Feb 28, 2018 at 10:18 AM, Janina Sajka <janina@rednote.net> wrote: > Colleagues: > > Minutes from the joint teleconference with APA and TimedText of 28 February > are provided below as text. They're available as hypertext at: > > https://www.w3.org/2018/02/28-apa-minutes.html > > Our thanks to the timeText folks for a very helpful and productive conversation! > > Janina > > <Begin Minutes> > > W3C > > - DRAFT - > > Accessible Platform Architectures Working Group Teleconference > > 28 Feb 2018 > > Attendees > > Present > janina, Joanmarie_Diggs, JF, pal, IanPouncey, Nigel, Becka11y, MichaelC, marisa_demeglio > > Regrets > Leonie, Gottfried, david_singer > > Chair > janina > > Scribe > jasonjgw > > Contents > > * Topics > 1. Agenda Overview; Introductions go around > 2. APA Captioning Comments -- Discussion with TTML and WebVTT > 3. Styling Concerns > * Summary of Action Items > * Summary of Resolutions > __________________________________________________________________________________________________________________ > > present_ > > <janina> scribe: jasonjgw > > Agenda Overview; Introductions go around > > Janina: the main agendum is to discuss issues presented to TTML and WebVTT, and attempt to move closer to resolution > than has been achieved via e-mail. > ... beyond that conversation, the usual agenda apply. > > Nigel: notes that he chairs the TTML work and that WebVTT is separate. Nigel notes issues with timing requirements for > captions/subtitles. > > <janina> We can add Styling below the Captioning issue as a topic > > Styling issues with captions and CSS. > > JF: there are cofnlicting user needs and conflicting understandings of what we need and the optimal user experience. > ... he is concerned that there be nothing in the caption-related specs that prevents users from resizing/presenting the > caption differently according to their needs. > > Janina: would like to continue collecting topics before entering into the details. Styling issues have been identified. > > Participants introduce themselves. > > APA Captioning Comments -- Discussion with TTML and WebVTT > > <JF> examploe here: http://john.foliot.ca/demos/captions.png > > Janina proposes that APA concerns could be easily addressed. Normative changes don't appear to be necessary and an > explanatory note (clarifying that the author's supplied presentation of captions isn't set in stone) may be sufficient. > > <JF> in practice here: https://www.3playmedia.com/solutions/features/integrations/brightcove-integration/ > > Janina: anyone who needs significant magnification of captions is likely to ahve a strategy for dealing with the > consequences of doing so. > ... there are important, but marginal, use cases: user needs supersede default authoring decisions - the author > proposes, the user disposes. Most consumers will receive what the author has created, but there are edge cases. JF has > offered an example of a tool demonstrating such cases. > > Nigel: TTML allows the author to define presentaton of captions, but it is open to implementations to present captions > otherwise than as the author has requested. He notes that users can enlarge the entire video or present it on a larger > display. > > <JF> https://www.w3.org/WAI/PF/media-a11y-reqs/ > > JF: He notes the concern that captions could completely obscure the content in the viewport. Media Accessibility User > Requirements discussions envisage possible reliance on a second screen that presents the video in parallel with the > primary display, but with the captions enlarged. He argues that preserving visibility of video content in the viewport > isn't a critical requirement. > > <JF> http://john.foliot.ca/demos/captions.png > > <JF> https://www.3playmedia.com/solutions/features/integrations/brightcove-integration/ > > JF: refers to a caption increased to 400%, achievable (with other modifications) by adjusting options in the video > player. > > WebVTT and TTML should not specify anything that frustrates these user adjustments. > > Janina proposes an accessibility impact statement that could note the issues. > > Nigel notes that the user needs to be able to obtain equivalents of both the audio track and the video track in order > to understand the program content. > > For example, the user needs to be able to see that there's something important in the video while reading captions. > > <JF> clarification around the 2/3 viewport: I have been told this anecdotally > > pal: there's nothing in the TTML spec that prevents the viewing system from transforming the video itself or the > caption text. > > Presentation systems can display teh timed text on a separate device, increase the size, etc. It isn't clear that any > changes are needed. > > Andreas: it's a question of responsibility - of where the customization task should be handled. There is no layer to > negotiate subtitle customizations. > > Typically the customizations are performed by the application. > > JF: part of the cdore concern is wehre the customization happens and who/what is responsible. While agreeing with Nigel > that the video and audio complement each other to comprise the entire presentation, there are users who need to access > it in ways that don't respect this totality (e.g., viewing the video more than once). > > He reiterates the question of who's responsible for customizations and how they will occur. > > Janina: doesn't notice any substantive disagreement - timed text specialist appear to acknowledge the principle that > users may need to customize the timed text to ensure it's usable by them. > > Janina would expect users requiring significant enlargement to have strategies for working with it (additional > monitors, large displays, etc.). > > Janina: perhaps we need to focus on the particular language in the TTML spec which may appear to be inconsistent with > this principle (of users being able to adjust the presentation as needed for accessibility purposes). > > Janina suggests focusing on this specific language and that an accessibility impact statement may be appropriate. > > Responding to a question, John states that he can't find any specific language in the specification, and that the > concern arises from comments received in response to the horizontal review. He wishes it to be clarified that the use > cases under consideration are matters that we want to support. > > JF: notes that technologies often arise for review by APA without sufficient documentation of their intent. > ... suggests we need clarification that nothing prevents, for example, increasing caption size to 400%. > > <JF> @Pierre: https://www.w3.org/WAI/PF/media-a11y-reqs/ > > : Establishing authoring guidelines for various territories and\/or languages is outside the core of the format spec, > while being valuable to application implementors. > > Nigel: notes difficulties that arise with changing captions over time if not all of the text is simultaneously visible > due to extreme enlargement. > > He notes that timed text is different from an HTML page that can be scrolled. > > Unbounded zooming results in the user's missing out on content. > > Michael: there's a challenge in that although the spec may not prevent zooming, the UA developers might not think to > support it. We need user agent implementation guidance. > ... agrees with Nigel taht there's a level of magnification that becomes infeasible for the user, and hence we tend to > require it to be supported up to a specified level (400%, for example). > > JF: no WCAG requirement to support zooming of captions. He agrees that authoring guidance is important. > ... MAUR provides some guidance that can be drawn upon. > > Michael: WCAG didn't require support for caption enlargement as this wasn't supported by user agents when the WCAG 2.0 > Recommendation was published. In the present context we anticipate future requirements. > > Responding to a question about whether MAUR has been found consistent with regulatory requirements (e.g., related to > captions), JF notes the expertise of caption and media-related developers who contributed to the process. It hasn't > been checked for consistency with regulatory requirements; it reflects user requirements as identified by the W3C. > > <pal> https://www.w3.org/TR/media-accessibility-reqs/ > > JF agrees with the proposition that an informative note citing this MAUR document would improve the caption-related > specifications. > > <pal> https://github.com/w3c/imsc/issues/316 > > There's discussion of identifying the GitHub issue to which proposing a link to the MAUR document would resolve. > > JF suggests it should be #316. > > Summarizing, Janina suggests that a response proposing a non-normative note citing the MAUR would address the issues > raised. > > Styling Concerns > > <nigel> https://www.w3.org/wiki/TimedText/CSSRequirements > > Nigel: work has been done to identify which styling features important to captions are supported in CSS. > ... there are some desired features that are difficult to map to CSS. > > Nigel suggests taht more work needs to be done to develop specific proposals to address these issues. > > <pal> Below are some of the issues filed against CSS: > > <pal> https://github.com/w3c/csswg-drafts/issues/1975 > > <pal> https://github.com/w3c/csswg-drafts/issues/1974 > > <pal> https://github.com/w3c/csswg-drafts/issues/1973 > > Ian: from the CSS accessibility Task Force point of view, we should identify wehther the issues pertain to > accessibility. > > <nigel> https://w3c.github.io/ttml2/index.html#style-attribute-derivation > > He favours technology-agnostic requriements with technology-specific techniques, and there may be use cases on the > accessibility side for some of the desired styling features for captions (with CSS as the technology for which > techniques are needed). > > Nigel notes the work documented on the wiki. > > Nigel notes that examples were presented to the CSS WG. > > Janina: we've made good progress. There appears to be a way forward arising from the meeting. Minutes will be posted to > both working groups if this is acceptable. > > Janina notes likely future topics to be jointly taken up. > > There's an invitation for TTML WG participants who may be interested to join the CSS accessibility task force. > > Janina will establish whether the conclusions reached at the meeting sufficiently address the open GitHub issues. > > <pal> See slides 8-11 at https://drive.google.com/open?id=0B_OQLEGiaO-RamRTam5Edkc1cXc > > Summary of Action Items > > Summary of Resolutions > > [End of minutes] > __________________________________________________________________________________________________________________ > > Present: janina Joanmarie_Diggs JF pal IanPouncey Nigel Becka11y MichaelC marisa_demeglio > Regrets: Leonie Gottfried david_singer > Found Scribe: jasonjgw > Found Date: 28 Feb 2018 > > > -- > > Janina Sajka > > Linux Foundation Fellow > Executive Chair, Accessibility Workgroup: http://a11y.org > > The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI) > Chair, Accessible Platform Architectures http://www.w3.org/wai/apa > >
Received on Friday, 30 March 2018 15:20:27 UTC