DVB-DASH and EBU-TT-D support in AWS Elemental MediaPackage

Introducing new functionality in Amazon Web Services (AWS) Elemental MediaPackage v2 for DVB-DASH and EBU-TT-D support. These standards, working together, are particularly important because they form the backbone of modern European broadcast streaming. They help ensure high-quality, accessible content delivery, while maintaining professional broadcast standards in the streaming era.

DVB-DASH

DVB-DASH (Digital Video Broadcasting-Dynamic Adaptive Streaming over HTTP) is a specification for delivery of live and on-demand video over the open internet. It builds on MPEG-DASH, which was the first internationally standardized adaptive bitrate HTTP-based streaming solution. To improve interoperability and facilitate implementation, additional constraints and requirements are defined in DVB-DASH.

DVB-DASH is not a country-specific standard, but rather a technology used within the broader DVB framework. It is primarily adopted in Europe especially within the context of HbbTV (Hybrid Broadcast Broadband TV). DVB-DASH is incorporated into HbbTV specifications, enabling the combination of broadcast and broadband services in connected devices. Many devices in Europe already support the DVB-DASH profile.

One example of DVB-DASH standard adaption is the Freely platform. Freely is a British free-to-air IPTV (Internet Protocol television) service launched in 2024 by Everyone TV, a joint venture between the country’s public broadcasters BBC, ITV, Channel 4, and Channel 5. Freely is part of the Broadcast to IP initiative so audiences can watch live and on-demand content all in one place for free, without the need for a dish or antenna.

Many other European countries have similar free streaming services provided by their state-owned broadcasters that utilize the DVB-DASH protocol. Some examples include: RaiPlay (Italy), Arte.tv (France/Germany), and Mediaset Infinity (Italy).

EBU-TT-D

EBU-TT-D (European Broadcasting Union-Timed Text-Distribution) is a subtitle distribution format developed by the European Broadcasting Union (EBU). It provides a flexible way to style and position subtitles, including support for responsive design. This means subtitles can adapt their appearance to different screen sizes.

EBU-TT-D is designed for online distribution, in particular for streaming video over IP networks using DVB-DASH. EBU-TT-D, while based on TTML (Timed Text Markup Language), is a simplified profile. This makes it easier for clients to handle, as opposed to full TTML and SMPTE-TT (Society of Motion Picture and Television Engineers), which are more complex. Other subtitle formats such as SRT, WebVTT, and SCC are more general-purpose or are used in different contexts.

Several European countries have adopted the EBU-TT-D standard for subtitles, including Germany, Spain, and Portugal. The Freely platform in UK mandates EBU-TT-D format for all players who want to participate.

AWS Elemental MediaPackage

AWS Elemental MediaPackage (MediaPackage) is a just-in-time video packaging and origination service available from AWS. With MediaPackage, you can deliver highly secure, scalable, and reliable video streams to a wide variety of playback devices and content delivery networks (CDNs).

MediaPackage makes it quicker to implement popular DVR features, such as start over, pause, and rewind. MediaPackage offers a broadcast-grade viewing experience for viewers, while you have the flexibility to control and protect your content. Your content will be protected with comprehensive support for digital rights management (DRM). Additionally, the built-in resiliency and scalability of MediaPackage means that you have the right number of resources at the right time, with no manual intervention required.

DVB-DASH and EBU-TT-D support in MediaPackage v2

DVB-DASH and EBU-TT-D support was added to MediaPackage v2 in June 2025.

EDU-TT-D settings will be available for you automatically for DASH manifest section in endpoint configuration of your channel. If you need more details on how to configure your channels in MediaPackage please check our user guide.

You will have options to select between IMSC-1 and EBU-TT-D.

Figure 1: Subtitle options selection for MediaPackage DASH manifest.

We discussed EBU-TT-D a bit previously. IMSC-1 (Internet Media Subtitles and Captions) is a TTML profile format adopted by several organizations and projects across the globe. This includes the Advanced Television Systems Committee (ATSC) and the Society of Motion Picture and Television Engineers (SMPTE). It’s a key component of ATSC 3.0, a next-generation television broadcasting standard. IMSC-1 is also used in various profiles and extensions within the television industry, including the EBU, DVB, HbbTV, and MPEG-CMAF (MPEG-Common Media Application Format).

If you select EBU-TT-D, it will show up in AdaptationSet in a Media Presentation Description (mpd) manifest file as an application content type with stpp codec type. Following is an example of what you can expect in your mpd manifest from a signaling perspective:

    <AdaptationSet id="925008406" contentType="application" mimeType="application/mp4" segmentAlignment="true" startWithSAP="1" bitstreamSwitching="true" codecs="stpp" lang="en">

If you use AWS Elemental MediaLive as an upstream encoder, you can configure accessibility tags for your subtitles that MediaPackage will recognize and present it with the following signalling in an output mpd manifest file:

<Accessibility schemeIdUri="urn:tva:metadata:cs:AudioPurposeCS:2007" value="7"/>

To enable the DVB feature sets, during channel creation in the AWS Management Console you need to select CMAF for the input type as the ingest protocol.

Figure 2: Ingest options selection for MediaPackage channel.

You can configure the DVB profile on the desired DASH manifest when you create/configure your endpoint.

Figure 3: DVB-DASH profile configuration for MediaPackage DASH manifest.

While the DVB profile information will be present as XML attributes on the MPD element, the MPD@suggestedPresentationDelay data will not be present in the manifest:

<MPD id="123" profiles="urn:dvb:dash:profil
e:dvb-dash:2014,urn:dvb:dash:profile:dvb-dash:isoff-ext-live:2014" ...>

UTC timing mode shows up as an XML element at the MPD level:

<MPD id="123" profiles="urn:dvb:dash:profile:dvb-dash:2014,urn:dvb:dash:profile:dvb-dash:isoff-ext-live:2014" ...>
...
  <UTCTiming schemeIdUri="urn:mpeg:dash:utc:http-xsdate:2014" value="https://example.com/iso"/>#

As part of this release, MediaPackage now has the ability to configure DASH base URLs.

Figure 4: Base URLs configuration for MediaPackage DASH manifest.

BaseURL, dvb:weight and dvb:priority will show up as XML attributes in output MPD manifest:

<BaseURL serviceLocation="A" dvb:priority="1" dvb:weight="3"> https://example.com/</BaseURL>

Additionally, you can configure font settings for captions as well as error metrics.

Figure 5: DVB DASH settings for MediaPackage DASH manifest.

DVB Error Metrics will show up as an MPD level element set:

<MPD id="123" profiles="urn:dvb:dash:profile:dvb-dash:2014,urn:dvb:dash:profile:dvb-dash:isoff-ext-live:2014" ...>
...
  <Metrics metrics="DVBErrors">
    <Reporting schemeIdUri="urn:dvb:dash:reporting:2014" value="1" dvb:reportingUrl="https://dvb.org" dvb:probability="500"/>
  </Metrics>

</MPD>

The DVB font download information is output as an AdaptationSet level SupplementalProperty XML element:

<SupplementalProperty schemeIdUri="urn:dvb:dash:fontdownload:2014" value="1" dvb:url="https://test.sample.com/fonts/test.woff" dvb:mimeType="application/font-woff" dvb:fontFamily="Test"/>

Conclusion

With the strategic additions of DVB-DASH and EBU-TT-D functionality, AWS Elemental MediaPackage has significantly broadened its global reach and application scope. This enhanced capability enables MediaPackage to be deployed in a much wider range of applications and geographical markets. Particularly, it can now be deployed in European countries and other regions where DVB-DASH support is not just preferred, but legally mandated for delivering live video content to consumers.

The new features represent a crucial advancement for broadcasters and content providers who need to comply with regional broadcasting standards and regulations. DVB-DASH support ensures compatibility with European digital television standards, while EBU-TT-D provides standardized subtitle and caption delivery that meets accessibility requirements across different European markets.

With this expansion organizations can leverage AWS cloud-native video infrastructure while maintaining full compliance with local broadcasting regulations. Now they can reach broader audiences and enter new markets which were previously inaccessible due to technical standard requirements.

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Further reading

• AWS Skill Builder Lesson: Media Services Learning Plan
• AWS Media Services Resources
• Back to basics: HTTP video streaming
• Packager settings fields