Proposed Annex G for TV - for the revision of EN 301 549 from Digital Europe
Digital Europe submitted the document HF_23_090020_Proposed_Annex_G_for_TV_-_for_the_revision_of_EN_301_549.docx during the HF#90 meeting of ETSI TC HF.
This will be considered as part of the update of EN 301 549 to support the European Accessibility Act.
Quoting Digital Europe's submission below:
The following document is a technical input to support ETSI in their standards review process within the framework of the EAA standardisation request mandate. DIGITALEUROPE proposes that the following new Annex is added to the document.
Proposed Annex G (informative):
G1. General information for TV accessibility
Annex G describes the application of EN 301549 in relation to Television products and to understand how accessibility is applied.
A Television is defined as being a digital device having an integrated tuner and full screen display with visible diagonal greater than 30cm1 and receives electrical broadcast signals which it decodes and renders to present video and audio to a user.
A Television (TV) can be categorized into two types: A TV, that cannot be connected to the internet or has restricted connectivity, and its menu and feature set typically cannot be updated by the user. Hardware and software generally do not change.
A Smart TV, a subcategory of a TV, often referred to as a connected TV, that includes the convergence of computer and internet technologies. The primary purpose of the television remains the same, whilst the set can include connected features such as web browsers, apps, media players etc. These extra features make it possible for settings, menus and features to be customized beyond the default condition. Hardware generally does not change but software is expected to change.
From herein, the term TV encapsulates both categories.
NOTE 1: A TV is not assistive technology in itself as per the definition of assistive technology in chapter 3 of this document.
NOTE 2: Broadcast Video or Audio content (for example, containing audio descriptions, subtitling, rapid flashing images, animations or colors) that are received from external sources is out of control of the TV and therefore out of scope.
NOTE 3: To ensure safety and correct installation, notwithstanding non-ICT information related to products (i.e., Packaging or printed materials), a TVs accessibility conformance is deemed to start after the TV has completed initial user software set-up.
NOTE 4: Where a consumer TV is used in a domestic setting, the accessibility features are intended for personal use and supporting a single user.
G.2 Scope of TV
As per Art 2 (Scope) of the EAA directive, a TV only falls within the following scope definition: (d) consumer terminal equipment with interactive computing capability, used for accessing audiovisual media services.
NOTE: The scope definitions apply to the TVs primary functions specified in G.4
G.3 Open or Closed functionality
With reference to Chapter 3.1 Terms, this section aims to further clarify how the definitions of Open and Closed functionality apply to a TV.
- For the purpose of EN301549 a TV and its primary functions are considered as CLOSED functionality because:
- The primary function of a Television is the presentation of audio, video, broadcast and broadband related content and services.
- Such TV content usually has content or digital rights management (DRM) restrictions that prevent the TV display content from being exported to other devices due to commercial reasons, to prevent piracy and to respect the content holders’ rights and distribution agreements.
- From the TV, data and AV signals cannot be exported.
- While a TV classification is primarily CLOSED, there may be some instances on a case-by-case basis whereby an OPEN classification could apply (i.e. Keyboard connection, Switch Access, Remote control codes)
- If Open classification is selected, it should be clear as to the interface / signals that are provided from the TV to the external assistive technology.
The Closed functionality definition means that the TV itself would need to provide the required Accessibility feature support in principle.
- TVs are traditionally devices that provide built in Accessibility support directly, without the need to connect additional peripheral equipment.
- Although apps can be downloaded, primary European Television accessibility functions cannot be downloaded and are integral to the TV.
- The TV manufacturer is not responsible for any third-party software that is installed onto the TV by the user which does not conform to the requirements.
G.4 TV primary functions:
As TVs continue to evolve and to guarantee performance, this annex clarifies the TVs primary purpose and scope of this document. When accessibility of a TV is considered, the following set of minimum functions must be supported.
- Power On/Off: Function that allows the user to turn the device on or off.
- Volume Adjust and Mute: Function that allows the user to adjust the volume and to mute or un-mute the volume.
- Channel/Program Selection: Function that allows the user to select channels and programs (e.g., via physical numeric or channel up/channel down buttons or via on-screen guides and menus).
- Display Channel/Program Information: Function that allows the user to display channel or program information.
- Configuration–Setup: Function that allows the user to access and change configuration or setup options (e.g., configuration of video display and audio settings, selection of preferred language for on-screen guides or menus, etc.).
- Configuration–Subtitle Control: Function that allows the user to enable or disable the display of closed captioning. (Or Subtitle Control).
- Configuration–Subtitle Options: Function that allows the user to modify the display of closed caption data (e.g., configuration of the font size, font colour, background colour, opacity, etc.). (Or Subtitle Options).
- Configuration–Audio Description Control or Video Description: Function that allows the user to enable or disable the output of audio description (i.e., allows the user to change from the main audio to the secondary audio stream that contains audio description and from the secondary audio stream back to the main audio).
- Display Configuration Info: Function that allows the user to display how user preferences are currently configured.
- Playback Functions: Function that allows the user to control playback functions (e.g., pause, play, rewind, fast forward, stop, and record).
- Input Selection: Function that allows the user to select their preferred input source. Source: Annex J – FCC user interface rules, IEC62944 Audio, video and multimedia systems and equipment - Digital television accessibility – Functional specifications.
G.5 TV Software
G.5.1 TV software
TV software must conform to the accessibility requirements after initial setup. This includes pre-installed software.
Software updates are often deployed to fix bugs and introduce feature upgrades including enhancements to the accessibility functionality beyond the manufactured specification.
A TV can periodically receive a software update via a number of methods including:
- Via a service center
- Software contents contained on physical storage media
- Software downloaded & installed directly by the TV
The table below clarifies where responsibility for conformance lies:
Scenario | Manufacturer | 3rd party SW vendor | |
---|---|---|---|
1 | TV firmware updates which include 3rd party approved software, is released by the Manufacturer to update the TV | Liable | Must provide declaration of conformity |
2 | TV reset to Factory default (sold) condition | Liable | No liability (Note: declaration of conformity would have already been provided) |
3 | 3rd party approved software pre-installed at delivery | Liable. Declarations of conformity must be obtained from 3rd party vendor | Must provide declaration of conformity |
4 | Soft link in TV and 3rd parties software is downloaded | No liability | Liable |
5 | 3rd party non approved software is downloaded from a repository e.g., an app store | No liability | Liable |
6 | Background updates occur to 3rd party approved software | No liability | Liable |
7 | User installs own 3rd party software | No liability | No liability |
Approved software: Software that has been provided by the TV manufacturer
3rd Party Software: An Application which is supplied as already installed at the point of sale/purchase
Downloaded Software: An Application which the User has downloaded and installed from that devices Application store or other source.
Pre-installed Software: Provided by the manufacturer as part of the TV functionality
Firmware: Intended software including Operating Systems, provided by the TV manufacturer as an essential part of the functionality, without which the product wouldn’t work as specified
Soft link: Also known as a ‘stub’, typically a text, icon or appearing as pre-installed software, which after the user knowingly selects, software is downloaded and installed
G.5.2 Platform Software Systems and Apps
TVs can be manufactured with an Operating System (OS), as a ‘Platform’ with the possibility to allow OS vendors, App providers, or users to develop, update, download, install, delete, modify and create software applications (apps).
A TVs software can provide an indeterminate amount of common software APIs to other software applications in order to achieve accessibility. How capabilities and APIs are defined, determined and used, is out of scope of this document.
G.5.4 TV & non-web software
The Web Content Accessibility Guidelines (WCAG) is intended for web browser-based content and usage of mobile web applications. Those guidelines have been extended to include other products. A TV is non-web software. Sections 9, 10 and 11 apply. The following link gives guidance on applying WCAG 2.0 to Non-Web software.
https://www.w3.org/WAI/standards-guidelines/wcag/non-web-ict/
G.6 TV Accessibility Features
A TV is not limited to but can support connectivity such as Bluetooth, Wi-Fi or inductive loops to enhance the availability of accessibility features.
The primary responsibility for the accessibility of Services including adequate quality for accurate display and synchronized with sound and video delivered to a TV lies with the service provider.
G.6.1 Audio Description
Audio Description or Spoken Subtitles can be contained in an audio track which a TV receives. The TV has no control over the contents of the AD track, therefore has no responsibility for ensuring correlation with video or for ensuring a correct narrative that describes the scene.
G.6.2 Subtitles / Closed Captions
Subtitles in Europe are typically received by the TV as bitmap images which the TV renders on screen. The TV therefore has no control as to the contents of the subtitles or the prescribed placement of the subtitles on screen.
There is no requirement for subtitle text to be parsed by a built-in Text To Speech synthesizer as Spoken Subtitles are delivered as a separate audio track.
G.6.3 Text To Speech
Text To Speech synthesizers built into a TV are reliant on text strings being parsed by it. A TV will not be able to provide speech output if the text is not available in a recognized format.
G.6.4 Sign language
Support for sign language is typically provided in the broadcast stream so the TV does not have control over it.
G.6.5 EPGs
EPG receivers/TVs should include the following accessibility features:
- Render text needed for EPG navigation and the provision of information on channels and programs included in the EPG as speech;
- Adjust the display of EPG information so that it can magnified, or the text enlarged; and
- Select a ‘high contrast’ display.
G.6.6 Interactive services
Interactive services such as HbbTV can introduce support for accessibility however a TVs role within the protocol and transaction could be limited as it will not be able to control elements of the interaction. Two-way voice or video communication is not a primary function of a TV.
G.7 TV language support
TV language support is to be considered as a localization or policy issue and not an accessibility feature.
The accuracy of the translation is subjective and dependent on the translator used.
After a TV enters a market, political, commercial and industry movements can occur that may impact language preferences which the manufacturer will have no control over.
The number of on-screen languages implemented in a TV does not necessarily equate to market boundaries as language support is not defined by geographic borders.
OSD language
A single TV model is typically manufactured to support a particular region or a number of countries. Many text strings can be hard coded into a TV, all of which will need to be translated individually for each language supported. Therefore, on screen display language support is implemented only for the targeted market to eliminate unnecessary system overhead and cost.
Text To Speech language
Support for TTS in a TV is facilitated by the integration of software ‘TTS libraries’ which enables support for a particular language. TTS libraries are typically sourced from vendors which support the TV platform so the availability of TTS languages can vary depending on platform. Therefore, a minimum of 7 languages should be supported by the TV speech synthesizer to include English, French, German, Italian, Spanish, Polish and Dutch. It is possible the TV software can be updated with additional libraries when they are available, to provide coverage for more languages.
A TVs speech output must conform to the necessary testing set out in Annex C to achieve conformance. Subtitles are usually broadcast as images in Europe. If a text version of subtitles exists, the text will not be passed to the speech synthesizer.
G.8 Resolution & Frame Rate
TV may meet the resolution and frame rate requirements set out in 6.5.2 and 6.5.3, but two-way video communication if supported may be limited to lower resolution based on the user's internet connection, the communication service's server capabilities, etc.
G.9 Remote Controls
As most Remote Controls can be used to enter characters into a TV application (e.g. to search for whether a specific film can be viewed) they are operating as keyboards as they are generating keystroke input, therefore can be considered as keyboards in the context of Clause 5.1.6 “Operation without keyboard interface”.
G.10 Conformance
Where there is no test case defined in appendix C ‘Determination of conformance’ for a functional requirement of a TV, the requirement is informative only.
Televisions are complex devices with 1000s of lines of code. If a bug is detected, TV manufacturers will abide by best efforts to find the root cause or provide a workaround to rectify the issue as soon as possible.
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Source: Universal Service Directive 2009/136 (Council of 25 November 2009 amending Directive 2002/22/EC ). Annex VI article 2. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2009:337:0011:0036:En:PDF
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