ref: 2024869a595118d686682b38386c594c717ea5bd
dir: /lpc10/chanwr.c/
/*
* Revision 1.2 1996/08/20 20:20:24 jaf
* Removed all static local variables that were SAVE'd in the Fortran
* code, and put them in struct lpc10_encoder_state that is passed as an
* argument.
*
* Revision 1.1 1996/08/19 22:40:31 jaf
* Initial revision
*
*/
/* -- translated by f2c (version 19951025).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
#include "f2c.h"
int chanwr_(integer *order, integer *ipitv, integer *irms, integer *irc, integer *ibits, struct lpc10_encoder_state *st);
int chanrd_(integer *order, integer *ipitv, integer *irms, integer *irc, integer *ibits);
/* *********************************************************************** */
/* CHANL Version 49 */
/*
* Revision 1.2 1996/08/20 20:20:24 jaf
* Removed all static local variables that were SAVE'd in the Fortran
* code, and put them in struct lpc10_encoder_state that is passed as an
* argument.
*
* Revision 1.1 1996/08/19 22:40:31 jaf
* Initial revision
* */
/* Revision 1.3 1996/03/21 15:14:57 jaf */
/* Added comments about which indices of argument arrays are read or */
/* written, and about the one bit of local state in CHANWR. CHANRD */
/* has no local state. */
/* Revision 1.2 1996/03/13 18:55:10 jaf */
/* Comments added explaining which of the local variables of this */
/* subroutine need to be saved from one invocation to the next, and which */
/* do not. */
/* Revision 1.1 1996/02/07 14:43:31 jaf */
/* Initial revision */
/* *********************************************************************** */
/* CHANWR: */
/* Place quantized parameters into bitstream */
/* Input: */
/* ORDER - Number of reflection coefficients (not really variable) */
/* IPITV - Quantized pitch/voicing parameter */
/* IRMS - Quantized energy parameter */
/* IRC - Quantized reflection coefficients */
/* Indices 1 through ORDER read. */
/* Output: */
/* IBITS - Serial bitstream */
/* Indices 1 through 54 written. */
/* Bit 54, the SYNC bit, alternates from one call to the next. */
/* Subroutine CHANWR maintains one bit of local state from one call to */
/* the next, in the variable ISYNC. I believe that this one bit is only */
/* intended to allow a receiver to resynchronize its interpretation of */
/* the bit stream, by looking for which of the 54 bits alternates every */
/* frame time. This is just a simple framing mechanism that is not */
/* useful when other, higher overhead framing mechanisms are used to */
/* transmit the coded frames. */
/* I'm not going to make an entry to reinitialize this bit, since it */
/* doesn't help a receiver much to know whether the first sync bit is a 0 */
/* or a 1. It needs to examine several frames in sequence to have */
/* reasonably good assurance that its framing is correct. */
/* CHANRD: */
/* Reconstruct parameters from bitstream */
/* Input: */
/* ORDER - Number of reflection coefficients (not really variable) */
/* IBITS - Serial bitstream */
/* Indices 1 through 53 read (SYNC bit is ignored). */
/* Output: */
/* IPITV - Quantized pitch/voicing parameter */
/* IRMS - Quantized energy parameter */
/* IRC - Quantized reflection coefficients */
/* Indices 1 through ORDER written */
/* Entry CHANRD has no local state. */
/* IBITS is 54 bits of LPC data ordered as follows: */
/* R1-0, R2-0, R3-0, P-0, A-0, */
/* R1-1, R2-1, R3-1, P-1, A-1, */
/* R1-2, R4-0, R3-2, A-2, P-2, R4-1, */
/* R1-3, R2-2, R3-3, R4-2, A-3, */
/* R1-4, R2-3, R3-4, R4-3, A-4, */
/* P-3, R2-4, R7-0, R8-0, P-4, R4-4, */
/* R5-0, R6-0, R7-1,R10-0, R8-1, */
/* R5-1, R6-1, R7-2, R9-0, P-5, */
/* R5-2, R6-2,R10-1, R8-2, P-6, R9-1, */
/* R5-3, R6-3, R7-3, R9-2, R8-3, SYNC */
static int chanwr_0_(int n__, integer *order, integer *ipitv,
integer *irms, integer *irc, integer *ibits,
struct lpc10_encoder_state *st)
{
/* Initialized data */
integer *isync;
static integer bit[10] = { 2,4,8,8,8,8,16,16,16,16 };
static integer iblist[53] = { 13,12,11,1,2,13,12,11,1,2,13,10,11,2,1,10,
13,12,11,10,2,13,12,11,10,2,1,12,7,6,1,10,9,8,7,4,6,9,8,7,5,1,9,8,
4,6,1,5,9,8,7,5,6 };
/* System generated locals */
integer i__1;
/* Local variables */
integer itab[13], i__;
/* Arguments */
/* Parameters/constants */
/* These arrays are not Fortran PARAMETER's, but they are defined */
/* by DATA statements below, and their contents are never altered.
*/
/* Local variables that need not be saved */
/* Local state */
/* ISYNC is only used by CHANWR, not by ENTRY CHANRD. */
/* Parameter adjustments */
--irc;
--ibits;
/* Function Body */
switch(n__) {
case 1: goto L_chanrd;
}
isync = &(st->isync);
/* ***********************************************************************
*/
/* Place quantized parameters into bitstream */
/* ***********************************************************************
*/
/* Place parameters into ITAB */
itab[0] = *ipitv;
itab[1] = *irms;
itab[2] = 0;
i__1 = *order;
for (i__ = 1; i__ <= i__1; ++i__) {
itab[i__ + 2] = irc[*order + 1 - i__] & 32767;
}
/* Put 54 bits into IBITS array */
for (i__ = 1; i__ <= 53; ++i__) {
ibits[i__] = itab[iblist[i__ - 1] - 1] & 1;
itab[iblist[i__ - 1] - 1] /= 2;
}
ibits[54] = *isync & 1;
*isync = 1 - *isync;
return 0;
/* ***********************************************************************
*/
/* Reconstruct parameters from bitstream */
/* ***********************************************************************
*/
L_chanrd:
/* Reconstruct ITAB */
for (i__ = 1; i__ <= 13; ++i__) {
itab[i__ - 1] = 0;
}
for (i__ = 1; i__ <= 53; ++i__) {
itab[iblist[54 - i__ - 1] - 1] = (itab[iblist[54 - i__ - 1] - 1] << 1)
+ ibits[54 - i__];
}
/* Sign extend RC's */
i__1 = *order;
for (i__ = 1; i__ <= i__1; ++i__) {
if ((itab[i__ + 2] & bit[i__ - 1]) != 0) {
itab[i__ + 2] -= bit[i__ - 1] << 1;
}
}
/* Restore variables */
*ipitv = itab[0];
*irms = itab[1];
i__1 = *order;
for (i__ = 1; i__ <= i__1; ++i__) {
irc[i__] = itab[*order + 4 - i__ - 1];
}
return 0;
} /* chanwr_ */
/* Subroutine */ int chanwr_(integer *order, integer *ipitv, integer *irms,
integer *irc, integer *ibits, struct lpc10_encoder_state *st)
{
return chanwr_0_(0, order, ipitv, irms, irc, ibits, st);
}
/* Subroutine */ int chanrd_(integer *order, integer *ipitv, integer *irms,
integer *irc, integer *ibits)
{
return chanwr_0_(1, order, ipitv, irms, irc, ibits, 0);
}