APTX elevates HD digital audio with apt-X Lossless

Audio compression developer launches apt-X Lossless, a next-generation lossless audio codec technology engineered for immersive, high-definition, digital entertainment applications

NAB Show 2009, Las Vegas -- April 20, 2009 -- APTX, a leading developer of licensable intellectual-property for high-performance audio compression, today states its intention to engage with the high-definition audio-video segment of the digital entertainment applications market with a radical, new design of “lossless” audio codec codenamed apt-X Lossless. Renowned in broadcast engineering and studio post production for its commercially successful series of low-latency apt-X audio codecs – Standard apt-X, Enhanced apt-X, and recently, apt-X Live – APTX today announces the imminent availability of a “lossless” audio compression solution, the product of a concentrated internal R&D program, targeted for applications in fast-growing consumer multimedia applications. apt-X Lossless, the latest addition to the apt-X series of audio compression solutions for consumer, professional and broadcast applications, offers up to 96 kHz sampling rates and sample resolutions up to 24 bits.

Next-generation Lossless for Digital Entertainment

Designed from first principles, and invested with the latest techniques in digital signal processing, apt-X Lossless features and benefits include: high-performance lossless compression; a highly scalable and dynamically adaptive coding mechanism; mastering-grade audio; low coding delay; low computational complexity, run-time overhead and device power consumption. Furthermore, for applications in communications links that are occasionally subject to stringent bandwidth constraints, apt-X Lossless can operate in a special hybrid mode, dynamically incorporating “near lossless” coding to seamlessly mitigate against audio degradation. From a system integration stand-point, apt-X Lossless is easy to port across multiple hardware and software platforms.

Speaking about the introduction of apt-X Lossless at NAB Show, the digital broadcast industry’s premier event, Jonny McClintock, the Sales & Marketing President of APTX, said: “This brand new audio codec is a big deal. It’s becoming increasingly apparent that designers of high-definition systems for digital entertainment markets are becoming constrained by the shortcomings in the performance of first-generation lossless and lossy audio compression technology available to date, especially in rapid-evolving areas where the delivery of multi-channel surround-sound contributes greatly to the immersive user experience. Surround-sound presentation is migrating from a cinematic experience in the movie theatre into the living room, through the HDTV, the Blue-ray player, the media gateway, via the laptop and games console. And surround-sound radio is just around the corner. APTX has been listening to customers and watching the market.”

Applications in high-definition audio for apt-X Lossless include: wireless audio peripherals for media players; digital wireless microphones; music storage and archiving; audio consoles; digital audio routers; broadcast audio distribution between production, network and transmission sites.

McClintock continued: “Three years ago, APTX took venture funding and fired up an intensive R&D programme to focus on best-of-breed solutions for the coming digital entertainment paradigm. APTX believes that, going forward, apt-X Lossless addresses the needs of emerging high-definition audio applications, and presents systems developers with a much-needed alternative source of codec technology. APTX has always been about offering compression solutions that deliver the most authentic audio experience, one that meets the demands of the most discerning consumer.”

Product highlights

•   Highly scalable and dynamically adaptive coding mechanism
•   High-performance lossless compression
•   Mastering-grade audio
•   Low coding delay
•   Low computational complexity, run-time overhead and device power consumption
•   Hybrid lossy coding for communications links with stringent bandwidth constraints
•   Easily portable across multiple hardware and software platforms

apt-X Lossless for HD audio

The new apt-X Lossless audio codec supports high-definition audio up to 96 kHz sampling rates and sample resolutions up to 24 bits. The codec optionally permits a “hybrid” coding scheme for applications where average and/or peak compressed data rates must be capped at a constrained level. This involves the dynamic application of a form of “near lossless” coding – but only for those short sections of audio where completely lossless coding cannot respect the bandwidth constraints. Even for those short periods while the “near lossless” coding is active, high-definition audio quality is maintained, retaining audio frequencies up to 20 kHz and a dynamic range of at least 120 dB.

Coding latency is another scalable parameter within apt-X Lossless and can be dynamically traded against other parameters such as levels of compression and computational complexity. The latency of the apt-X Lossless codec can be scaled to as low as 1 ms for 48 kHz sampled audio, depending on the settings of other configurable parameters. apt-X Lossless performs particularly well against other lossless codecs when the coding latency is constrained to be small, such as 5 ms or less, making it particularly appropriate for delay-sensitive interactive audio applications.

Many lossless codecs possess a low computational overhead compared to well-known “lossy” codecs, such as MP3 and AAC. This is particularly important for deeply-embedded audio applications running on low-power mobile devices. apt-X Lossless promotes low computational overhead by dynamically selecting the simplest coding functions for each short segment of audio whilst complying with other operational constraints, such as levels of compression and coding delay. Depending on the settings of other scalable parameters, apt-X Lossless can encode a 48 kHz 16-bit stereo audio stream using only 10 MIPS on a modern RISC processor with signal processing extensions. The corresponding decoder represents only 6 MIPS on the same platform.

User metadata and special synchronization data can be incorporated into the compressed format at configurable rates. The latter permits rapid decoder resynchronization in the event of data corruption or loss over communications links where Quality of Service (QoS) can vary rapidly. Depending on the settings of parameters, decoder resynchronization can occur within 1-2 ms.

Available starting July 2009, apt-X Lossless is implemented as C and C++ code, and has been verified on x86 processors, ARM 9E and ARM Cortex M3, Texas Instruments C64xx, and others TBA.

About APTX

Trading in semiconductor intellectual property since 1989, APTX (the trading identity of APT Licensing Ltd) provides industry-leading audio compression solutions to the broadcast, professional audio, and consumer electronics industries. The company’s apt-X audio codec technology has earned a reputation throughout the audio industry as the ultimate high-quality, low-delay audio data compression algorithm available. Today, apt-X technology is licensed for use in broadcast audio codec hardware, professional audio systems, and consumer electronics devices, including portable media players and mobile phones, Bluetooth stereo headsets, and wireless microphones. Headquartered in Belfast, Northern Ireland, APTX also has direct sales offices in the USA, Japan and Korea. For more information, visit http://www.aptx.com