Microchip Technology Announces Royalty-Free dsPIC30F Library for Speech Compression and Decompression.CHANDLER, Ariz. -- Library Allows Engineers to Cost-Effectively Achieve High Voice Quality in Bandwidth- or Memory-Constrained Applications Using the dsPIC(R) Digital Signal Controller See DSC. Microchip Technology  Microchip Technology (NASDAQ: MCHP) is a manufacturer of microcontroller, memory and analog semiconductors, founded in 1989 when Inc. (NASDAQ NASDAQin full National Association of Securities Dealers Automated Quotations U.S. market for over-the-counter securities. Established in 1971 by the National Association of Securities Dealers (NASD), NASDAQ is an automated quotation system that reports on : MCHP MCHP Maryland Children's Health Program MCHP Microchip Technologies (stock symbol) MCHP Micro-sized Combined Heat and Power (American Honda Motor Co. & Climate Energy, LLC) MCHP Maine Community Heritage Project ), a leading provider of microcontroller and analog semiconductors, today announced a speech encoding (compression) and decoding (decompression) library for its 16-bit dsPIC(R) Digital Signal Controllers (DSCs). The dsPIC30F Speech Encoding/Decoding Library is based on the Speex open source compression format, and achieves a 16:1 compression ratio compression ratio Degree to which the fuel mixture in an internal-combustion engine is compressed before ignition. It is defined as the volume of the combustion chamber with the piston farthest out divided by the volume with the piston in the full-compression position ( and toll quality speech (PESQ PESQ Perceptual Evaluation of Speech Quality (ITU-T) 3.7-4.2). The dsPIC30F Speech Encoding/Decoding Library enables embedded designers to transmit more messages over a given bandwidth, or store longer amounts of speech in a given memory space, while maintaining excellent sound quality and intelligibility. Many design engineers are seeking to add speech compression Encoding digital speech to take up less storage space and transmission bandwidth. The PCM, ADPCM, CELP and LD-CELP methods are commonly used for speech compression. See speech codec and data compression. to their bandwidth- or memory-constrained applications, but have opted for lower compression methodologies to avoid a stiff per-unit royalty for the intellectual property. The dsPIC30F Speech Encoding/Decoding Library offers a significant cost reduction over competitive options, and brings non-royalty bearing 8 kbps encoding to the embedded world. "By adapting the open-source Speex audio compression Encoding digital audio data to take up less storage space and transmission bandwidth. Audio compression typically uses lossy methods, which eliminate bits that are not restored at the other end. ADPCM and MP3 are examples of audio compression methods. See audio codec and data compression. format, we are providing dsPIC DSC (1) (Digital Signal Controller) A microcontroller and DSP combined on the same chip. It adds the interrupt-driven capabilities normally associated with a microcontroller to a DSP, which typically functions as a continuous process. See microcontroller and DSP. users with low-cost, high-quality compression capability from the open source free software community," said Sumit Mitra, vice president of Microchip's Digital Signal Controller division. "Our customers are very cost conscious and will appreciate the ability to add or improve speech compression with a non-royalty bearing pricing structure." Any embedded application that transmits voice over limited bandwidth or has memory constrained playback can benefit from this speech compression/decompression library. Specific example applications include: voice over IP, tapeless answering machines, voice announcement systems, medical equipment, appliances, building and home safety systems, intercoms, and proprietary communications equipment. The library has a well-documented Application Programmer's Interface (API) that makes it easy to incorporate speech compression and/or decompression into an application. The library also supports optional voice activity detection. The speech encoder samples data at 8 kHz, using either the dsPIC DSC's on-chip 12-bit analog-to-digital converter or a 16-bit input obtained from an external CODEC, via the on-chip codec interface port. The encoder achieves up to a 16:1 compression ratio and generates a fixed 8 kbps output rate. Output of decoded speech can be accomplished using the dsPIC DSC's standard PWM (Pulse Width Modulation) A modulation technique that generates variable-width pulses to represent the amplitude of an analog input signal. Like its fixed-width pulse density modulation (PDM) cousin, the output switching transistor is on more of the time for a or via the interface to an external CODEC. The encoder requires 19 MIPS (Million Instructions Per Second) The execution speed of a computer. For example, .5 MIPS is 500,000 instructions per second; 100 MIPS is a hundred million instructions per second. (worst case), 33 Kbytes of program memory and 6.2 Kbytes of RAM. The decoder requires 3 MIPS, 15 Kbytes of program memory and 3.2 Kbytes of RAM. Storing speech requires 1 Kbyte of memory for each second of speech. The library permits the compressed speech data to be stored in on-chip memory (Flash, EEPROM (Electrically Erasable Programmable ROM) A rewritable memory chip that holds its content without power. Although EEPROMs spawned flash memory, EEPROMs are byte addressable at the write level, whereas flash chips must erase a block of bytes before rewriting. or RAM) or to an external Flash memory. Playback-only applications can benefit from a PC-based speech encoder utility that is included on the library CD. This utility creates encoded speech files from a PC microphone or WAV files. Related Development Tools and Devices The dsPICDEM(TM) 1.1 General Purpose Development Board (DM300014) can be used to evaluate this library. The following dsPIC DSCs have the on-chip resources needed for this library: dsPIC30F5011, dsPIC30F5013, dsPIC30F6011, dsPIC30F6012, dsPIC30F6013 and dsPIC30F6014. Availability and Pricing All licensing options for the dsPIC30F Speech Encoding/Decoding Library are immediately available. Among these options is a one-year evaluation/development license, which is unaltered from the library that is used for production and can be purchased online at http://buy.microchip.com. The evaluation/development version of the dsPIC30F Speech Encoding/Decoding Library (SW300070-EVAL) is $5. Industry-unique, one-time-fee licensing options are also available for production, which runs counter to the per-unit royalty business model that is common for this class of library. Starting at $2,500 for 5,000-unit production, the license fee that Microchip charges is attractive to many customers since it is a fraction of the cost they would incur developing it themselves. These one-time fees are based on the estimated lifetime volume of products derived from the product development effort that uses the library. For additional pricing or other information, contact any Microchip sales representative or authorized worldwide distributor, or visit Microchip's Web site at www.microchip.com/dspic. About Speex Open Source Free Software Speex is copyrighted by Jean-Marc Valin / Xiph.Org Foundation and it is available under the Xiph.org variant of the BSD (Berkeley Software Distribution) The software distribution facility of the Computer Systems Research Group (CSRG) of the University of California at Berkeley. license. For more information about Speex, go to www.speex.org/fsos.html. About dsPIC Digital Signal Controllers The dsPIC digital signal controller is a 16-bit (data) modified Harvard RISC RISC in full Reduced Instruction Set Computing Computer architecture that uses a limited number of instructions. RISC became popular in microprocessors in the 1980s. machine that combines the control advantages of a high-performance 16-bit microcontroller with the high computation speed of a fully implemented DSP (1) (Digital Signal Processor) A special-purpose CPU used for digital signal processing applications (see definition #2 below). It provides ultra-fast instruction sequences, such as shift and add, and multiply and add, which are commonly used in math-intensive to produce a tightly coupled single-chip, single-instruction stream solution for embedded systems design. All dsPIC30F DSCs integrate Flash program memory and most have EEPROM data storage. For more information on the dsPIC DSC family, please visit www.microchip.com/dspic About Microchip Technology Microchip Technology Inc. is a leading provider of microcontroller and analog semiconductors, providing low-risk product development, lower total system cost and faster time to market for thousands of diverse customer applications worldwide. Headquartered in Chandler, Ariz., Microchip offers outstanding technical support along with dependable delivery and quality. For more information, visit the Microchip Web site at www.microchip.com. Note: The Microchip name and logo, and dsPIC are registered trademarks of Microchip Technology Inc. in the United States and other countries. dsPICDEM is a trademark of Microchip Technology Inc. in the United States and other countries. All other trademarks mentioned herein are property of their respective companies. |
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