From silence to symphony

Dolby Atmos on Cirrus Logic CS498xx

From silence to symphony

Dolby Atmos on Cirrus Logic CS498xx

Throughout the years, RT-RK has humbly emerged as a prominent provider of DSP applications and comprehensive system support for state-of-the-art audio technologies in home theater systems. Leveraging the power of Cirrus Logic’s high-performance CS498xx chip family, we offer an extensive array of cutting-edge audio technology solutions. Among these groundbreaking offerings stands Dolby Atmos, an industry-leading surround sound technology that redefines the audio experience. In this article, we investigate this extraordinary technology, uncovering its captivating immersive capabilities and shedding light on how we seamlessly integrate it into home theater systems for some of the world’s premier manufacturers.

Whether you’re at the cinema, in the comfort of your own home, or on the go with your mobile device, this revolutionary surround sound system transports you into a world of realistic, deep, and vivid immersive soundscapes. What sets Dolby Atmos apart is its ability to achieve accurate spatial reproduction of audio, regardless of speaker configuration, offering unparalleled diversity and flexibility for audio systems. By adopting a 3D object-based approach, each sound is treated as a separate entity, from a gentle whisper to a thunderous roar, with metadata carrying precise data, coordinates, movement, and volume. As you indulge in Dolby Atmos content, the Object Audio Renderer seamlessly combines and positions these sound objects according to your specific speaker layout, creating a truly captivating listening experience.

Dolby Atmos audio format reaches listeners through a variety of audio codecs, each offering distinct advantages. Dolby Digital Plus, commonly employed in broadcast and streaming services, operates at a 48 kHz sampling rate, and can be transmitted via HDMI ARC, accommodating up to 15.1 channels. Meanwhile, Blu-ray Discs leverage Dolby TrueHD format for Dolby Atmos delivery, seamlessly transferring high-fidelity audio from the Blu-ray player to the Dolby Atmos audio system via HDMI. With lossless audio coding and support for multiple sampling rates (including 48 kHz, 96 kHz, and 192 kHz) as well as 16-channel output, the Dolby TrueHD format ensures an immersive listening experience. To facilitate the transmission of Dolby TrueHD streams and PCM audio with metadata over HDMI, the Dolby Metadata-Enhanced Audio Transmission Decoder (Dolby MAT) is employed, enabling dynamic real-time encoding and low-latency transmission of Dolby Atmos content through enhanced Audio Return Channel (eARC) functionality.

Another crucial component in the Dolby Atmos serial processing chain is post-processing. The Dolby Surround upmixer is capable of upmixing stereo or legacy 5.1 mixes to a high-quality multi-channel upmix. It operates on multiple perceptually spaced frequency bands for finer-grain analysis with the ability to steer different frequency bands individually. The Dolby Virtualizer renders surround sound signal over built-in device speakers, sound bars, or a device with headphones. It uses a head-related transfer function (HRTF) to simulate the arrival of sound from different speaker locations, creating a more immersive virtual surround effect. Furthermore, there are additional content processing techniques employed to further enhance sound quality, such as advanced volume-leveler control and improved dialog features.

Every newest release in Dolby Atmos technology is followed by an RT-RK single-chip DSP solution that meets Dolby’s implementation requirements and has been certified by Dolby Atmos Laboratories, Inc. Supplying multiple manufacturers of AVR systems and sound bars such as Denon and Onkyo, these solutions are integrated into many home audio devices in consumer’s homes.

A dedicated audio DSP with multicore and multithreaded design achieves real-time execution and offers customers an affordable product.  It supports decoding formats and virtualization in various combinations. The processing stages are logically divided into four separate cores on the DSP processor, allowing for easy cooperation and fast inter-module data transmission and communication between cores. This modular design enables the execution of multiple technologies in the processing chain. For instance, after decoding Dolby Atmos content, it can undergo additional processing such as Dirac Live Room Correction or any other custom-made post-processing block available to customers.

The audio processing system operates as a standalone unit with an integrated operating system as part of the DSP firmware. This integration makes it exceptionally easy to incorporate into various setups or configurations.

As consumer engagement with interactive content grows, the importance of time to audio and lip-sync accuracy has become a significant concern within the audio industry. Thanks to advancements in Dolby Atmos technology and the extensive experience in developing digital signal processing algorithms and architectures, the latency of the DSP unit has been significantly reduced. This efficient implementation on the DSP chip positively impacts the entire audio system, allowing it to benefit from these improvements.

In conclusion, the solutions by RT-RK go beyond the development of DSP firmware. They encompass DSP application and system support, along with user-friendly GUI tools for evaluating and programming these technologies. Furthermore, high-class software testing and quality assurance processes based on robust internally developed technology ensure the reliability and excellence of the overall system. With a comprehensive range of offerings and dedication to constant innovation, we strive to expand the possibilities of audio technology to deliver exceptional audio experiences to our clients and in the end, to the end consumer.

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