Tune IN Vol. 1, No. 1

As the leader in this industry, we are happy

to introduce “Tune In TI”. This newsletter will explore

a variety of industry viewpoints, technical challenges TI and market trends associated with this dynamic Portable Digital Technology and Trends digital audio industry. INTERNET AUDIO PORTABLE DIGITAL INDUSTRY

As a major player in the portable digital audio industry. In this digital audio player industry, issue we’ll cover the Secure Texas Instruments provides Digital Music Initiative and Digital Rights Management consumer electronics manufacturers and how these impact worldwide next step in the evolution of the with a complete hardware and digital music distribution and Internet entertainment industry. No matter software solution for these players. hotbed sites such as Napster. how chaotic this journey appears, In fact 8 of the top 10 consumer We’ll address the memory and Texas Instruments’ DSP products will electronics manufacturers have chosen media choices that are facing manufac- be there to support these developing a TI Digital Signal Processor (DSP) turers and consumers alike. And we’ll technologies. We invite you to join us solution for their players. That is more also discuss the formats and standards as we learn from each other while we than any other programmable chip in the industry. Why are there so beam down this path at light speed. vendor in the world. many… is there room for more… and As the leader in this industry, we why can’t one format play all music, are happy to introduce “Tune In TI”. voice and video? In This Issue This newsletter will explore a variety In addition, you will hear more > Editor’s Notes of industry viewpoints, technical chal- about the latest buzz—convergence. lenges and market What does this mean for cell phones, > Digital Insecurity? An introduction trends associated personal digital assistants (PDA), and overview on the state of security in the digital audio industry. with this dynamic portable digital audio players, digital cameras and other portable digital > Where does flash memory fit in? products? > Tech Talk: The anatomy of a The music industry will never be DSP-based multi-format digital audio player. SECURITY the same again. Digital distribution has taken music, > Hot off the Presses: TI’s latest video and the spoken word to the industry news.

1 Music Initiative (SDMI) originated in Las Vegas at Fall Comdex ’98. The original meeting was co-sponsored by TI and the Recording Industry Association of America (RIAA). Since DIGITAL then, SDMI membership has grown to over 180 music content, Internet and technology companies. SDMI is a means by which the international recording industry works in sync with technology and consumer INSECURITY electronics manufacturers to ensure the secure transfer of digital audio An introduction and overview on the state of security content across the Internet. The in the digital audio industry. initiative helps protect the rights of

Some of the best data encryption Does the Digital Audio Revolution have you

architects in the world are working feeling insecure about your content?

around the clock to create digital While the data recording artists by enabling copyright encryption archi- protection in SDMI compliant formats. security and Digital Rights tects are steadfastly SDMI is an “open” standard that building the appro- manufacturers can use to develop Management (DRM) software to priate locks, Texas digital audio-enabled consumer elec- Instruments is tronic devices. protect your digital audio content. working with them The goal of SDMI is to enhance to create the powerful digital keys the listening experience of consumers The fastidious development of this necessary to liberating literature by allowing them access to quality security is an important step towards and musical content for the masses digital music in new ways, while ensur- to enjoy. TI has a complete line of ing personal portability among digital the approaching boom in digital programmable DSPs specifically engi- products and services. The SDMI neered to process and decode the specification protects copyrighted audio sales and distribution via the multiple array of security encryption music in all existing and emerging formats that are bubbling throughout digital formats. Internet and the brick and mortar the digital audio industry. The pro- Understand, however, that unlike grammability of the DSP provides a standard such as the ATA/IDE inter- music retailers throughout the world. “future proof” insurance to purchasers face for hard disk drives, SDMI is not of digital audio players powered by a “standard” in the sense that most Texas Instruments solutions. Portable technology companies are used to. digital audio players with TI technology SDMI is not a single file format, a single can be easily upgraded to the latest cryptographic algorithm, a single security formats and revisions right on the Internet. TI has been involved with the development of digital audio security right from the start. The Secure Digital

2 Where does Flash Memory fit in?

decoder or a single protocol specification, The leading suppliers of memory price per MegaByte of memory is still nor is it designed for interoperability. and media cards to the portable audio high enough that competitive memory Instead, SDMI is the culmination of an industry are also developing an addi- solutions such as DataPlay and Clik overall architecture that is a work in tional layer of “physical” security, have a chance to succeed in the digital progress. It consists of a set of applica- and TI is stepping forward to meet player market. tion layer, licensed compliant module the technological integration demands In the next issue of “Tune In TI”, (LCM) layer and portable of these architectures. we will begin a segment called Market device (PD) layer refer- Intel, Sony and SanDisk Wave. This section will be dedicated ence models and a set of are just three of the compa- to covering issues in the digital audio requirements governing nies in the world who produce industry that have a direct impact on security, robustness and flash memory modules, the consumer purchases that affect the content screening. media used in over 90% of growth of the industry. The first the portable audio devices Market Wave article will focus on the on the market today. media types used by internet audio players. For the record labels and Market conditions in the flash the consumer electronics manufactur- memory business are ripe for large ers, there are a multitude of storage platforms and technologies to choose price swings similar to those seen from. Each platform carries a fairly in the DRAM business in recent distinct set of characteristics. Some are appealing to consumers (price) DSPSDMI years. Several quarters of tight flash A discussion on the relationship and some are appealing to the record between TI’s DSP and SDMI technical memory demand combined with labels (physical security) and so on. requirements will continue in the We’ll take a look at hard disk drives momentous capacity expansion next several issues of “Tune In TI”, including the IBM microdrive Sony however, if you would like, you may could lead to price cutting due to Memory Stick along with the various find an abundant amount of data on multi-media and compact flash cards. oversupply. There are signs in the And we’ll also look at the Iomega Clik the initiative at the SDMI website: drive, the emerging storage technology www.sdmi.org marketplace that flash memory from DataPlay, and how these relate to In addition to upcoming SDMI supply is catching up to demand. current CD and MiniDisc technologies. technical relationship discussions, This could be very good news for the we will feature a discussion on the digital music industry, because there evolution of DRM in the next issue of is digital player pricing elasticity due “Tune In TI”. Among others, Liquid to the fact that 32MB and 64MB flash Audio, Sony, Microsoft, and InterTrust modules sometimes cost more than are developing top-notch DRM SDMI the players. Of course, flash memory compliant software architectures for suppliers would love to continue seeing the digital audio industry. In addition fiscal quarters like they’ve to our existing software solutions recently experienced. from Microsoft and Liquid Audio, Even if flash prices start Texas Instruments and InterTrust to mimic the DRAM pricing recently announced an agreement to curves of years past, the develop secure solutions for portable audio devices. Solutions such as this will allow digital content to be securely transferred from a con- sumer’s PC to a portable digital audio device and used only as permitted by the person who owns that content.

3 techtalk Frequency Domain Coding 2 One very effective way of removing Anatomy of a Multi-Format Digital Audio Player: data redundancies is to transform the Digital Audio Compression Basics time domain data, which typically has a high level of correlation, to a domain where the components are nearly The mass popularity of Napster is a clear indication of the rapidly changing uncorrelated. Frequency transforms business environment for the record labels and the brick and mortar music are normally used to generate a set of spectral components, which have retailers. MP3 only songs are riding the first wave of popularity, but the very little correlation with each other, recent proliferation of new audio codecs and second-generation portable thus removing most of the data redun- dancies. The resultant data structure digital players with multiple audio compression format capabilities are opens up the possibility for innovative changing the game. ways of designing compression algorithms given the fact that human In this issue, we begin a journey through the anatomy of a multi-format perception of audio is frequency dependent. For example, components digital audio player powered by a DSP. On this journey, we will supply that are inaudible to the human you with an introduction to the key techniques used in audio compression auditory system can be isolated easily and discarded with minimal impact technologies. And we’ll give you a thorough description of player hardware to audio quality. Popular transforms and security technologies. are the Discrete Fourier Transform (DFT) and Discrete Cosine Transform (DCT). A hybrid transform approach Decoder Basics Auditory Masking with time domain aliasing cancellation Current popular audio coding algo- Advancements in the field of is popular with some of the more rithms use properties of the human 1 Psychoacoustics have led to much important digital audio compression auditory system to achieve 10-12 of the breakthrough in digital audio algorithms being used today. times compression ratio while main- compression. After analyzing how taining near-CD quality sound. These the human ear and the human mind Continued on pg. 5 > encoders utilize four key techniques: responds to sound, it became appar- auditory masking, frequency domain ent that the human auditory system coding, window demonstrates certain masking switching and characteristics that can be utilized dynamic bit for data compression. For instance, Audio allocations to there exists a quiet hearing threshold. remove redun- Signals that exist beneath this thresh- dancy and old can be discarded without impact irrelevancy of to sound quality since the human raw audio data. ear cannot detect such signals. Also, when there is a presence of a strong Digital signal (masker), a weaker signal (maskee) is ignored by the human ear and may be discarded if it occurs near the masker in the frequency domain.

4 t Continued > t 4 Window Switching 3 Dynamic Bit Allocations One disadvantage of frequency domain In all encoders, the final quality The typical encoder coding is pre-echoes. For example, depends largely on how bits are allo- process is as follows: when there is a sudden rise in sound cated among the various sub-bands amplitude after a period of silence, or coefficients. In order to allocate the A. The data is first segmented into it will result in a bits efficiently, the input signal has to windows according to the input signal char- large quantization be analyzed continuously and bits acteristics, and the window of time domain error. Both trans- assigned according to some model form and sub-band derived from our knowledge of the data is then transformed into the frequency coding will spread human auditory system. Bits are domain by transform coding (DCT/MDCT), this error over the allocated to areas that have the most sub-band coding or hybrid coding. whole window in effect on human auditory perception which the domain transformation while those that fall in masked areas B. The data is then quantized, (with operates. This results in the appear- will be allocated few or nobits for cod- the number of bits allocated for each ance of very audible pre-echoes in the ing. Since signals are always changing quantizer depending on the human auditory time domain. One way of reducing and the human auditory system reacts these echoes is to limit the error to a to signals differently under different system model applied) followed by some shorter time frame (shorter window), situations, a dynamic bit allocation form of entropy coding to remove symbol which not only isolates other parts of technique is required. An accurate redundancies. the audio from the pre-echoes, but model of how humans perceive sounds also allows pre-masking effects to is the main characteristic of a good C. The data streams are typically operate more effectively and to mask bit allocation scheme. multiplexed with header and various side- part or all of the pre-echoes. The dis- Reference band and ancillary information to form the advantage of this approach is that it [1] Thomas Sikora, “MPEG Digital Audio- and will add to the total number of bits Video-Coding Standards”, IEEE Signal Processing final bitstream. The decoding process is needed to represent the same data Magazine, September 1997. the reverse of the encoding process but is [2] Jason Kridner, Mark Nadeski and Pedro Gelabert, (since more side-band information is “A DSP Powered Solid State Audio System”, Texas much simpler since no psychoacoustic required as the number of coded win- Instruments Incorporated, 1999. model analysis is required. dows increases). In order to achieve [3] Khalid Sayood, “Introduction to Data the best trade off, adaptive window Compression”, Morgan Kaufmann Publisher, Inc. 1996. [4] ISO/IEC 11172-3, “Coding of Moving Pictures and D. The audio data is extracted from sizing is implemented. Large windows Associated Audio for Digital Storage Media at up to are used when signals are steady, about 1.5 Mbit/s, Part 3 (Audio)”, 1992. the bitstream and passed through entropy while smaller windows are used for [5] M. Bosi, K. Brandenburg, S. Quakenbush, L. decoding, dequantization and frequency Fielder, K. Akagiri, H. Fuchs, M. Dietz, J. Hrere, G. non-stationary signal Davidson and Y. Oikawa, “ISO/IEC MPEG-2 Advanced to time transformation to obtain the patterns with abrupt Audio Coding”, J. Audio Engineering Society. Vol 45, final output. changes in amplitude. No. 10, OCT 1997. We will apply the final output, a sample piece of audio data, to a secure DSP based hardware platform in the next issue of “Tune In TI”. Dynamic Code

5 off the Presses Next issue of TI’S LATEST INDUSTRY NEWS Tune In TI will include:

Toshiba uses TI’s DSP in new from a consumer’s PC to a portable Market Wave: Confused about Mobile Audio Player Internet audio device and used only media for portable players?... In May Toshiba announced they are as permitted by the rightful owner so is everyone else. The Great using TI’s low-power, industry-leading of the content. For more info, see: Memory Debate is on. programmable DSP to power their www.ti.com/sc/docs/news/2000/00075.htm Digital Rights Management new Mobile Audio Player, MEA110AS. discussion as part of Tune In The Toshiba player is the world’s first Sony uses TI DSP in VAIO® TI’s ongoing security coverage ™ to offer a Secure Digital (SD) memory Music Clip player Tech Talk: The second of a card slot supporting storage of copy- Sony selected the low power, industry- 2 part series on the anatomy righted content. For more info, see: leading programmable DSP developed of a DSP based multi-format www.ti.com/sc/docs/news/2000/00087.htm by TI for its sleek VAIO digital audio player. Music Clip Internet audio Hot off the Presses: Featuring a TI and InterTrust security player. The VAIO Music newly released TI DSP-powered solution in development Clip using TI’s DSP, allows digital audio player that’s worth In an effort to accelerate the growth consumers to experience a look. of the Internet audio market, TI up to five hours of contin- Registration and access to all and InterTrust Technologies Corp., uous high quality music on one issues: www.ti.com/sc/tuneinti announced an agreement to develop AA battery. For more info, see: secure solutions for www.ti.com/sc/docs/news/2000/00041.htm Editor: Chris Schairbaum ([email protected]) portable audio devices. This solution will allow Contributors: Oh Hong Lye, Bob McKune, Randy Cole, digital content to be Jennifer Walker, Chrisann Cook securely transferred All products are trademarks of their respective companies.

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