100 lines
3.1 KiB
Text
100 lines
3.1 KiB
Text
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How to get started:
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Edit the Makefile.
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You should configure a few machine-dependencies and what
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compiler you want to use.
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The code works both with ANSI and K&R-C. Use
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-DNeedFunctionPrototypes to compile with, or
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-UNeedFunctionPrototypes to compile without, function
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prototypes in the header files.
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Make addtst
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The "add" program that will be compiled and run checks whether
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the basic math functions of the gsm library work with your
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compiler. If it prints anything to stderr, complain (to us).
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Edit inc/config.h.
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Make
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Local versions of the gsm library and the "compress"-like filters
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toast, untoast and tcat will be generated.
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If the compilation aborts because of a missing function,
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declaration, or header file, see if there's something in
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inc/config.h to work around it. If not, complain.
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Try it
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Grab an audio file from somewhere (raw u-law or Sun .au is fine,
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linear 16-bit in host byte order will do), copy it, toast it,
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untoast it, and listen to the result.
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The GSM-encoded and -decoded audio should have the quality
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of a good phone line. If the resulting audio is noisier than
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your original, or if you hear compression artifacts, complain;
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that's a bug in our software, not a bug in the GSM encoding
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standard itself.
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Installation
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You can install the gsm library interface, or the toast binaries,
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or both.
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Edit the Makefile
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Fill in the directories where you want to install the
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library, header files, manual pages, and binaries.
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Turn off the installation of one half of the distribution
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(i.e., gsm library or toast binaries) by not setting the
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corresponding directory root Makefile macro.
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make install
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will install the programs "toast" with two links named
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"tcat" and "untoast", and the gsm library "libgsm.a" with
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a "gsm.h" header file, and their respective manual pages.
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Optimizing
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This code was developed on a machine without an integer
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multiplication instruction, where we obtained the fastest result by
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replacing some of the integer multiplications with floating point
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multiplications.
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If your machine does multiply integers fast enough,
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leave USE_FLOAT_MUL undefined. The results should be the
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same in both cases.
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On machines with fast floating point arithmetic, defining
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both USE_FLOAT_MUL and FAST makes a run-time library
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option available that will (in a few crucial places) use
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``native'' floating point operations rather than the bit-by-bit
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defined ones of the GSM standard. If you use this fast
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option, the outcome will not be bitwise identical to the
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results prescribed by the standard, but it is compatible with
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the standard encoding, and a user is unlikely to notice a
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difference.
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Bug Reports
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Please direct bug reports, questions, and comments to
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jutta@cs.tu-berlin.de and cabo@informatik.uni-bremen.de.
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Good luck,
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Jutta Degener,
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Carsten Bormann
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--
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Copyright 1992, 1993, 1994, by Jutta Degener and Carsten Bormann,
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Technische Universitaet Berlin. See the accompanying file "COPYRIGHT"
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for details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
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