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/*
* Copyright 1996 by Jutta Degener and Carsten Bormann, Technische
* Universitaet Berlin. See the accompanying file "COPYRIGHT" for
* details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
*/
/*$Header*/
/* Generate code to pack a bit array from a name:#bits description,
* WAV #49 style.
*/
#include <stdio.h>
#include "taste.h"
#include "proto.h"
#include <limits.h>
/* This module goes back to one Jeff Chilton used for his implementation
* of the #49 WAV GSM format. (In his original patch 8, it replaced
* bitter.c.)
*
* In Microsoft's WAV #49 version of the GSM format, two 32 1/2
* byte GSM frames are packed together to make one WAV frame, and
* the GSM parameters are packed into bytes right-to-left rather
* than left-to-right.
*
* That is, where toast's GSM format writes
*
* aaaaaabb bbbbcccc cdddddee ...
* ___1____ ___2____ ___3____
*
* for parameters a (6 bits), b (6 bits), c (5 bits), d (5 bits), e ..
* the WAV format has
*
* bbaaaaaa ccccbbbb eedddddc ...
* ___1____ ___2____ ___3____
*
* (This format looks a lot prettier if one pictures octets coming
* in through a fifo queue from the left, rather than waiting in the
* right-hand remainder of a C array.)
*/
#define WORD_BITS 16 /* sizeof(uword) * CHAR_BIT on the
* target architecture---if this isn't 16,
* you're in trouble with this library anyway.
*/
#define BYTE_BITS 8 /* CHAR_BIT on the target architecture---
* if this isn't 8, you're in *deep* trouble.
*/
void write_code P2((s_spex, n_spex), struct spex * s_spex, int n_spex)
{
struct spex * sp = s_spex;
int n_in = 0;
printf("uword sr = 0;\n");
for (; n_spex > 0; n_spex--, sp++) {
/* insert old
* new var value unused
* here
*
* [____________xxxxxx**********]
*
* <----- n_in ------>
*/
printf("sr = sr >> %d | %s << %d;\n",
sp->varsize,
sp->var,
WORD_BITS - sp->varsize);
n_in += sp->varsize;
while (n_in >= BYTE_BITS) {
printf("*c++ = sr >> %d;\n",
WORD_BITS - n_in);
n_in -= BYTE_BITS;
}
}
while (n_in >= BYTE_BITS) {
printf("*c++ = sr >> %d;\n", WORD_BITS - n_in);
n_in -= BYTE_BITS;
}
if (n_in > 0) {
fprintf(stderr, "warning: %d bits left over\n", n_in);
}
}
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