A study of accessibility requirements for media players on the Web
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Authors: Lourdes Moreno, María González, Paloma Martínez, Ana Iglesias HCII 2011: 14th International Conference on Human-Computer Interaction. 6th International Conference on Universal Access in Human-Computer Interaction, (July 2011, Orlando, Florida, USA). Springer Computer Science Editorial, Volumen: LNCS 6765 , Páginas: 249-257. A study of accessibility requirements for media players on the Web
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A study of accessibility requirements for media players on the Web
- 1. A study of accessibility requirements for media players on the Web María González Lourdes Moreno, María González, Paloma Martínez and Ana Iglesias LaBDA Group, Computer Science Department Universidad Carlos III de Madrid,, Spain {lmoreno, mgonza1, pmf, aiglesia}@inf.uc3m.es HCI International 2011 9-14 July 2011, Hilton Orlando Bonnet Creek, Orlando, Florida, USA
- 2. Contents • Motivation • Background • Proposal and evaluation • Conclusions and future works María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 3. Motivation • Great increase of multimedia contents on the Web. • Multimedia content has more accessibility barriers than other contents. We are usually focused on providing accessible multimedia contents, but… Do the players support them? María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 4. Introduction • Multimedia content must be accessible according to WCAG 2.0 (Web Content Accessibility Guidelines) [1]. • Provide caption, audio-description, … • Media players should allow: • Play delivered accessible multimedia content. • A successful user-video interaction. • Media players should be developed according to: • UAAG (User Agent Accessibility Guidelines) [2]. • ISO 9241-171:2008 [3]. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 5. Background (I) • UAAG: – Current versions of UAAG: • UAAG 1.0 Recommendation [4]. • UAAG 2.0 Working Draft [5]. • Media players: – Standalone players more accessible. – Embedded players Flash is one of the most used format. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 6. Background (II) • Most of videos on-line are delivered via Flash [6] because: – High-fidelity audio. – High-resolution video. • HTML5 [7]: – Do not need plug-ins – Labels: <video> and <audio>. – Waiting for support for caption and audio description. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 7. Background (III) • In short: – Accessibility requirements in media players. – Observatory: media players are still inaccessible. – Lack of knowledge. – Lack of guidelines and documentation. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 8. Proposal • An agile evaluation method based on UAAG 2.0 to check accessibility requirements in Web media players. • Study case using the agile method. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 9. Accessibility Evaluation Method (I) Development 1º Step: Distinguish which guidelines from UAAG 2.0 are related to media players. 2º Step: Group the guidelines and set an order to follow them => agile evaluation method. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain UAAG UAAG for players Make the evaluation
- 10. Accessibility Evaluation Method (II) María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain • Number of guidelines by conformance levels Level “A” Level “AA” Level “AAA” Undetermined in Working Draft UAAG 2.0 76 29 14 6 Selection guidelines for media players 36 20 9 4
- 11. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain Group Accessibility issue Guidelines (G) and Success Criteria (sc) G1 Alternative content G: 3.1 G2 Highlighting sc: 3.5.1 G3 Text configuration and alternative views sc: 3.6.1 3.12.2, 3.12.3 G4 Volume configuration G: 3.7 G5 Synthesized speech configuration G: 3.8 G6 Viewports sc: 3.10.4 G7 Focus sc: 3.11.3, 3.11.4, 3.11.6, 3.11.7, 3.11.8, 3.11.10, 3.11.11 sc: 5.4.2 G8 Keyboard access and navigation sc: 3.11.9, 4.1.1, 4.1.3, 4.1.4, 4.1.6, 4.1.7, 4.1.8, 4.1.9, 4.1.10, 4.1.11, 4.1.12, 4.7.5, 4.7.6, 4.7.7 G9 Preferences G: 4.5 G10 Text search G: 4.6 G11 Toolbar configuration G: 4.8 G12 Control of content that may reduce accessibility 4.9.2, 4.9.5, 4.9.6, 4.9.6, 4.9.7, 4.9.8, 4.9.9, 4.9.10, 4.9.11 G13 Unnecessary message G: 5.1 G14 Documentation of accessibility features G: 5.3
- 12. Study case using the agile method (I) • Select three embedded media players to evaluate them: – Youtube. – CCPlayer. – BBC iPlayer. • Evaluate the fourteen groups about media players. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 13. • Identify presence of alternative content (sc 3.1.1). BBC iPlayer María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 14. • Identify presence of alternative content (sc 3.1.1). María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 15. • Configure text (sc 3.6.1). YouTube Media Player María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 16. • Configure text (sc 3.6.1). María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 17. • Present direct commands in rendered content (sc 4.1.6). CCPlayer María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 18. • Find (sc 4.6.1). CCPlayer María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 19. Discussion (I) • Results: Level “A” Level “AA” Level “AAA” YouTube 66.67% 25% 0% BBC iPlayer 63.89% 20% 0% CCPlayer 75% 45% 11.11% María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 20. Discussion (II) • CCPlayer The best results in all of the conformance levels. – Accessibility features’ documents, commands’ menu, search, etc. – Compatible with screen readers – Audio description examples have not been found. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 21. Discussion (III) • YouTube: − Provides subtitles. − Some videos have embedded audio description. − Problems: • Difficulty operating player control not accessible by the keyboard. • Screen readers do not always distinguish the function of controls implemented in Flash. • Some of screen readers cannot access controls at all. − There are complementary technological solutions [9][10][11][12][13]and beta version about accessibility features. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 22. Discussion (IV) • BBC iPlayer: – Besides the subtitles, BBC includes 25 hours with audio description per week. – Does not allow to turn on or turn off the audio description signal. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 23. Conclusions • In this work, we include: – An agile method with in depth documentation about it. – An evaluation of three players – Results of the evaluation. • Answering the question Do the players support accessible multimedia content? At the moment the answer is: NO María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 24. Future work • Develop basic guidelines for professionals who want to embed video players on their Web sites [14]. • Define the required controls for accessible media player on the Web [14]. • Study of UAAG 2.0, coming recommendation. • Study of HTML 5 support for accessible media players on the Web [15]. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 25. References [1] W3C, WAI, Web Content Accessibility Guidelines (WCAG), 2010, http://www.w3.org/WAI/intro/wcag.php [2] W3C, WAI, User Agent Accessibility Guidelines (UAAG), 2010, http://www.w3.org/WAI/intro/uaag.php [3] ISO, International Organization for Standardization, 2008, http://www.iso.org [4] W3C, User Agent Accessibility Guidelines 1.0, 2002, http://www.w3.org/TR/WAI-USERAGENT/ [5] W3C, User Agent Accessibility Guidelines 2.0, 2010, http://www.w3.org/TR/UAAG20/ [6] ADOBE, Flash Player penetration. Flash content reaches 99% of Internet viewers, , Millward Brown survey, conducted December 2010 http://www.adobe.com/products/player_census/flashplayer/ [7] W3C, HTML5, A vocabulary and associated APIs for HTML and XHTML, http://www.w3.org/TR/2009/WD-html5-20090423/ [8] Lourdes Moreno, María González-García, Paloma Martínez, Ana Iglesias, (2011). A study of accessibility requirements for media players on the Web, 14th International Conference on Human-Computer Interaction (HCII 2011). 6th International Conference on Universal Access in Human-Computer Interaction, Orlando, Florida, USA, July, 2011, Volumen: In press. [9] OSU Web Accessibility Center’s, Captioning YouTube and Providing Accessible Controls, http://wac.osu.edu/examples/YouTube-player-controls/ [10] Christian Heilmann’s Accessible Easy YouTube http://icant.co.uk/easy-YouTube/ [11] Accessible YouTube player controls (vision australia) http://www.visionaustralia.org/info.aspx?page=2260 [12] YouTubeCC, http://www.YouTubecc.com/ [13] CaptionTube http://captiontube.appspot.com/ [14] María González-García, Lourdes Moreno, Paloma Martínez, Ana Iglesias, (2011). Web accessibility requirements for media players, INTERACT 2011. 13th IFIP TC13 Conference on Human-Computer Interaction, Lisboa, Portugal, September, 2011, LNCS, Springer, Volumen: In press. [15] Lourdes Moreno, Paloma Martínez, Ana Iglesias, María González-García, (2011). HTML5 support for an accessible user-video-interaction on the Web, INTERACT 2011. 13th IFIP TC13 Conference on Human-Computer Interaction, Lisboa, Portugal, September, 2011, LNCS, Springer, Volumen: In press. María González, ‘A study of accessibility requirements for media players on the Web’ , Universidad Carlos III de Madrid, Spain
- 26. ‘‘A study of accessibility requirements for media players on the Web’’ María González mgonza1@inf.uc3m.es Thank you for your attention
Hinweis der Redaktion
- Good afternoon. My name is María González and I’m going to talk about ‘A study of accessibility requirements for media players on the Web’ that has been accomplished at Carlos III University of Madrid.
- As you can see, our presentation is divided in these points.
- What has motivated us is that multimedia content has more accessibility barriers than other contents in spite of being increased every day.
- To pass those barriers, multimedia content must be accessible according to standards like Web Content Accessibility Guidelines (WCAG) 2.0 that in its guideline 1.2 set that user agent has to provided synchronized alternatives such as captions, audio description and transcriptions. That means, that user agents in general and media players in particular have to support these requirements, so they should allow to play delivered accessible multimedia content and therefore a positive user-video interaction. In order to get those points, media players have been developed according to (User Agent Accessibility Guidelines) UAAG of Web Accessibility Initiative (WAI) and international standards like International Standard Organization (ISO) that is related to software accessibility.
- If we focus on the standard under study, we have the UAAG 1.0 that is a recommendation since 2002, but to this study we follow the UAGG 2.0, although is still a working draft, is the version that we have used because it supports WCAG 2.0. By an overview of the kind of media players that we can find on the Web, we distinguish two groups. On one hand media players that do not open any application to see them, these media players have more controls and they are more accessible, however on the other hand we have others that are more usable because they do not have to open a software, being one of the most used formats Flash.
- It’s because Flash has an excellent compression system that can deliver high-fidelity audio and high-resolution video without taxing bandwidth. Flash does not play in some platforms, leading to an incompatibility of formats among platforms, in this situation the new standard HTML5, that is still a working draft, seems to provide an universal solution, for instance, it takes advantage of the fact that it provides two labels, video and audio, that do not need plug-ins, but it does not support subtitles and audio description yet.
- In conclusion to this point, it is necessary to satisfy accessibility requirements in media players, because they are still inaccessible and there are a lack of knowledge, guidelines and documentation.
- Due to the above, we propose an agile method based on UAAG 2.0 to check accessibility requirements for media players and a study case using the agile method.
- We need two steps to develop the agile method. First of all, we distinguish which guidelines from UAAG 2.0 are related to media players. After that, we group these guidelines according to accessibility features and set an order to follow them.
- After distinguishing the guidelines, we obtain the results shown in this slide. As we can see the guidelines are divided depending on its conformance level.
- In the following slide we show the fourteen groups, I’m sorry for the size, bus this tablet is in the paper. These groups are applied in the sequential order that is shown in the table.
- If we pass to the study case, first of all, we selected three media players, YouTube because it is the most used media player on the Web, CCPlayer that belong National Centre for Accessible Media (NCAM) and BBC iPlayer that belong BBC. After selecting them, we evaluate the fourteen groups about them. Due to the time, I am only going to show four relevant examples of these groups.
- The first one, Identify presence of alternative content, the success criteria are satisfied by all the media players. All of the media players have a button that allows enable or disable the captions.
- The second example is Configure text. This screenshot shows a text configuration menu that allows configure the captions that appears during the play. These success criteria are only satisfied by YouTube Video Player.
- The third example, Present direct commands in rendered content, is only satisfied by CCPlayer. This media player has a command menu to know different keyboard shortcuts.
- The last example, Find, is only satisfied by CCPlayer too. In this case, media player has to provide a menu to find text within the captions during the play.
- After the evaluation process, we obtain the following results: The conformance level A is exceeded by all media players in more than fifty percen. The rest of the levels do not get the fifty percen. As we can see, CCPlayer obtain the best results in all of the conformance levels, whereas YouTube and BBC iPlayer do not satisfy any guideline belong conformance level AAA.
- As we said, CCPlayers obtain the best results and it’s due to it has accessibility features’ documents, commands’ menu, search, it’s compatible with screen readers but i have not found any example with audio description.
- On the other hand, YouTube provides subtitles and there are some audio description examples, but these examples do not afford to turn off the audio description as the audio description is embedded in the video. Although the most of videos on-line are played by YouTube Media Player, it has different problems such as screen readers do not always distinguish the function of controls implemented in Flash and difficulty operating player control that cannot be accessible by keyboard. Although I do not have time to comment it, there are some works where authors are developing complementary technological solutions and there is also a beta version about accessibility features. The references of these works are shown here and in the paper.
- At last, BBC iPlayer provides subtitles and 25 hours with audio description per week, although this audio description is also embedded, so we cannot enable or disable it.
- To summarize, nowadays the access and the accessibility of media players are more and more important, owing to the fact, we have wanted to develop an agile method to evaluate accessibility features, an evaluation and the results of that evaluations. So, after this work, we can say that media players are not enough accessible now.
- Before finishing the presentation, I want to tell us that in our research group we continue working in some proposal: Develop basic guidelines for professionals who want to embed video players on their Web sites. Define the required controls for accessible media player on the Web. Study of UAAG 2.0, coming recommendation. Study of HTML 5 support for accessible media players on the Web. Some of these proposals have been accepted at INTERACT Conference that is going to celebrate in Lisbon in September.