文件列表:

BLOWFISH\BLOWFISH.DOC (6796, 1999-03-02)
LIBDES\DES.DOC (18603, 1998-10-14)
LOG.TXT (123137, 1999-04-05)
源码网说明.txt (1484, 2009-04-14)
下载说明.html (1365, 2009-04-14)
BACKUP.BAT (215, 1998-10-14)
BACKZIP.BAT (127, 1999-03-08)
BK32.BAT (272, 1998-10-14)
CLEAN.BAT (444, 1999-03-08)
MAKEBETA.BAT (396, 1999-03-08)
MAKEBIN.BAT (336, 1999-03-08)
MAKESRC.BAT (117, 1999-03-08)
ADPCM\ADPCM.H (430, 1998-10-14)
ADPCM\ADPCM_U.H (401, 1998-10-14)
BLOWFISH\BF_LOCL.H (10680, 1999-03-02)
BLOWFISH\BF_PI.H (19469, 1999-03-02)
BLOWFISH\BLOWFISH.H (4745, 1999-03-02)
LPC10\COMMON.H (107, 1998-10-14)
GSM\INC\CONFIG.H (1612, 1998-10-14)
LIBDES\DES.H (10363, 1998-10-14)
LIBDES\DES_LOCL.H (11213, 1998-10-14)
LPC10\DRIVERS.H (8364, 1998-10-14)
LPC10\FILTER.H (1061, 1998-10-14)
GSM\INC\GSM.H (2176, 1998-10-14)
IDEA\IDEA.H (495, 1998-10-14)
ADPCM\LIBST.H (3289, 1998-10-14)
LPC\LPC.H (750, 1999-04-03)
LPC10\LPCDEFS.H (1238, 1998-10-14)
MD5\MD5.H (587, 1998-10-14)
DES\NDES.H (211, 1998-10-14)
NETFONE.H (35185, 1999-04-04)
LIBDES\PODD.H (3655, 1998-10-14)
... ...

Included in this distribution is the lpc.c module, a header file for the routines in it called lpc.h, and a small test program which illustrates a typical set of calls to it called lpctest.c. To compile lpctest.c, you need to link it with lpc.o and the math library. It will take sound samples from stdin, compress & decompress them with LPC, and output the resulting samples to stdout. The subroutines in lpc.c are as follows: The lpc_init routine specifies the length of a single frame to be processed by the other LPC subroutines. This number is expressed in samples, and lpc_init should be called before anything else. It also resets all other state kept between frames, and can be called again when there's a break in what it being encoded or decoded (such as between talk spurts): int lpc_init(int framelen); The lpc_analyze routine is used to convert a group of samples into an LPC frame. State is kept between calls to smooth out transitions between frames, so this routine should be called with frames in order: void lpc_analyze(unsigned char *buf, lpcparams_t *params); The lpc_synthesize routine is used to convert an LPC frame back into a group of samples. Also, a speed parameter may be specified to speed up or slow down the speech (without altering the pitch). The length of the buffer returned depends on the speed. If speed==1.0, it will be the same as the length passed to the lpc_init call. If speed==2.0, it will be half that. The call to lpc_synthesize returns this length. Note that the speed parameter is a float -- passing an integer will cause unpredictable results: int lpc_synthesize(lpcparams_t *params, float speed, unsigned char *buf);

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