Providing more than 7 billion devices worldwide with excellent audio quality, HE-AAC has become one of the most important enabling technologies for state-of-the-art multimedia systems and is also the established codec for streaming and broadcasting. Fraunhofer IIS conducted the workshop “Audio Codec Technology for Digital TV Broadcasting in India” in order to encourage a deeper understanding of audio coding in general and, in particular, of HE-AAC. The event, supported by Broadcast Engineering Consultants India Limited (BECIL) and the Institution of Electronics and Telecommunication Engineers (IETE), attracted 75 senior engineering executives drawn from different sectors across the Indian broadcasting industry. Attendees included personnel from public radio and TV broadcasters, standards institutions, DTH broadcasters, product manufacturers, cable operators, project engineers and systems integrators.
HE-AAC – audio codec of choice for broadcast and streaming
Following a general introduction into audio coding and the various related options, the workshop focused on HE-AAC, the predominant audio codec in most state-of-the-art broadcast and streaming systems worldwide. The codec is not unknown to Indian broadcast services as the country is already using this technology for digital radio broadcasting, but in fact this is just one of its many applications worldwide. Most digital radio standards, including DAB+ and DRM (Digital Radio Mondiale), have adopted HE-AAC and digital TV services across the globe trust the codec’s efficiency. It is part of the DVB toolbox, as well as the ISDB-T standard for South America, and is in use in several European, South American, African and Asian countries. As a result, the majority of HD-capable TV receivers being sold today support HE-AAC. In addition, all major broadcast encoder manufacturers incorporated HE-AAC into their devices long ago. Thanks to this widespread adoption HE-AAC can easily be integrated into existing production and distribution chains without much effort.
Hands-on demonstrations illustrate HE-AAC’s features
During the workshop, Fraunhofer IIS presenters explained the challenges of meeting the requirements for audio services in digital TV and the advantages of using HE-AAC for this purpose. Among these are the numerous possible channel configurations, from mono to 48 channels, loudness control enabled by metadata support, and an audio description service.
Subsequently, a series of hands-on demonstrations further explored the feature-sets of Fraunhofer’s latest audio technologies and included a presentation on achieving bit rate savings with HE-AAC. New types of services for enhancing the audience experience such as Dialogue Enhancement were also highlighted. Dialogue Enhancement enables TV audience members to adjust the program’s audio mix to match their personal preferences and enables increased speech intelligibility of dialogue and commentary. Several HE-AAC audio tracks were played back at various bit rates to provide examples of how the codec delivers superior audio quality at different bit rates, making it the codec of choice for adaptive streaming standards such as DASH where glitch-less bit rate switching is essential.
The latest software development, Fraunhofer Cingo, was also showcased. The software-based mobile surround sound technology has already been adopted by Google for its Nexus family of devices. Cingo enables the playback of surround content over the stereo speakers of the mobile device or regular headphones. To provide its customers with the necessary surround content, Google selected HE-AAC multichannel for its Google Play Movies.
Fraunhofer IIS very much appreciates the enthusiasm expressed by the Indian broadcasting industry in its technologies, as well as the support it received from BECIL and IETE.