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