Information on 2400 bps LPC and 4800 bps CELP speech coders for Frequently Asked Questions lists (audio-formats, comp.compression) The U.S. DoD's Federal-Standard-1016 based 4800 bps code excited linear prediction voice coder version 3.2 (CELP 3.2) Fortran and C simulation source codes are available for worldwide distribution (on DOS diskettes, but configured to compile on Sun SPARC stations) from NTIS and DTIC. Example input and processed speech files are included. A Technical Information Bulletin (TIB), "Details to Assist in Implementation of Federal Standard 1016 CELP," and the official standard, "Federal Standard 1016, Telecommunications: Analog to Digital Conversion of Radio Voice by 4,800 bit/second Code Excited Linear Prediction (CELP)," are also available. This is available through the National Technical Information Service: NTIS U.S. Department of Commerce 5285 Port Royal Road Springfield, VA 22161 USA (703) 487-4650 The "AD" ordering number for the CELP software is AD M000 118 (US$ 90.00) and for the TIB it's AD A256 629 (US$ 17.50). The LPC-10 standard, described below, is FIPS Pub 137 (US$ 12.50). There is a $3.00 shipping charge on all U.S. orders. The telephone number for their automated system is 703-487-4650, or 703-487-4600 if you'd prefer to talk with a real person. (U.S. DoD personnel and contractors can receive the package from the Defense Technical Information Center: DTIC, Building 5, Cameron Station, Alexandria, VA 22304-6145. Their telephone number is 703-274-7633.) The following articles describe the Federal-Standard-1016 4.8-kbps CELP coder (it's unnecessary to read more than one): Campbell, Joseph P. Jr., Thomas E. Tremain and Vanoy C. Welch, "The Federal Standard 1016 4800 bps CELP Voice Coder," Digital Signal Processing, Academic Press, 1991, Vol. 1, No. 3, p. 145-155. Campbell, Joseph P. Jr., Thomas E. Tremain and Vanoy C. Welch, "The DoD 4.8 kbps Standard (Proposed Federal Standard 1016)," in Advances in Speech Coding, ed. Atal, Cuperman and Gersho, Kluwer Academic Publishers, 1991, Chapter 12, p. 121-133. Campbell, Joseph P. Jr., Thomas E. Tremain and Vanoy C. Welch, "The Proposed Federal Standard 1016 4800 bps Voice Coder: CELP," Speech Technology Magazine, April/May 1990, p. 58-64. The U.S. DoD's Federal-Standard-1015/NATO-STANAG-4198 based 2400 bps linear prediction coder (LPC-10) was republished as a Federal Information Processing Standards Publication 137 (FIPS Pub 137). It is described in: Thomas E. Tremain, "The Government Standard Linear Predictive Coding Algorithm: LPC-10," Speech Technology Magazine, April 1982, p. 40-49. There is also a section about FS-1015 in the book: Panos E. Papamichalis, Practical Approaches to Speech Coding, Prentice-Hall, 1987. The voicing classifier used in the enhanced LPC-10 (LPC-10e) is described in: Campbell, Joseph P., Jr. and T. E. Tremain, "Voiced/Unvoiced Classification of Speech with Applications to the U.S. Government LPC-10E Algorithm," Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing, 1986, p. 473-6. Copies of the official standard "Federal Standard 1016, Telecommunications: Analog to Digital Conversion of Radio Voice by 4,800 bit/second Code Excited Linear Prediction (CELP)" are available for US$ 5.00 each from: GSA Federal Supply Service Bureau Specification Section, Suite 8100 470 E. L'Enfant Place, S.W. Washington, DC 20407 (202)755-0325 Realtime DSP code for FS-1015 and FS-1016 is sold by: John DellaMorte DSP Software Engineering 165 Middlesex Tpk, Suite 206 Bedford, MA 01730 USA 1-617-275-3733 1-617-275-4323 (fax) dspse.bedford@channel1.com DSP Software Engineering's FS-1016 code can run on a DSP Research's Tiger 30 (a PC board with a TMS320C3x and analog interface suited to development work). DSP Research 1095 E. Duane Ave. Sunnyvale, CA 94086 USA (408)773-1042 (408)736-3451 (fax)