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merge new_loader_completion branch, including (at least):

Browse Source 
- restructured build tree and makefiles to eliminate recursion problems
  - support for embedded modules
  - support for static builds
  - simpler cross-compilation support
  - simpler module/loader interface (no exported symbols)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@40722 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Kevin P. Fleming
2006-08-21 02:11:39 +00:00
parent f60ada0be2
commit 0a27d8bfe5
398 changed files with 5967 additions and 7194 deletions
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106
main/ulaw.c Normal file
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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2005, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief u-Law to Signed linear conversion
*
* \author Mark Spencer <markster@digium.com>
*/
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include "asterisk/ulaw.h"
#define ZEROTRAP /*!< turn on the trap as per the MIL-STD */
#define BIAS 0x84 /*!< define the add-in bias for 16 bit samples */
#define CLIP 32635
unsigned char __ast_lin2mu[16384];
short __ast_mulaw[256];
static unsigned char linear2ulaw(short sample)
{
static int exp_lut[256] = {
0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,
4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 };
int sign, exponent, mantissa;
unsigned char ulawbyte;
/* Get the sample into sign-magnitude. */
sign = (sample >> 8) & 0x80; /* set aside the sign */
if (sign != 0)
sample = -sample; /* get magnitude */
if (sample > CLIP)
sample = CLIP; /* clip the magnitude */
/* Convert from 16 bit linear to ulaw. */
sample = sample + BIAS;
exponent = exp_lut[(sample >> 7) & 0xFF];
mantissa = (sample >> (exponent + 3)) & 0x0F;
ulawbyte = ~(sign | (exponent << 4) | mantissa);
#ifdef ZEROTRAP
if (ulawbyte == 0)
ulawbyte = 0x02; /* optional CCITT trap */
#endif
return ulawbyte;
}
/*!
* \brief Set up mu-law conversion table
*/
void ast_ulaw_init(void)
{
int i;
for (i = 0; i < 256; i++) {
short mu, e, f, y;
static short etab[] = {0,132,396,924,1980,4092,8316,16764};
mu = 255 - i;
e = (mu & 0x70) / 16;
f = mu & 0x0f;
y = f * (1 << (e + 3));
y += etab[e];
if (mu & 0x80)
y = -y;
__ast_mulaw[i] = y;
}
/* set up the reverse (mu-law) conversion table */
for (i = -32768; i < 32768; i++) {
__ast_lin2mu[((unsigned short)i) >> 2] = linear2ulaw(i);
}
}