asterisk/main/ulaw.c
Matt Jordan 4a58261694 git migration: Refactor the ASTERISK_FILE_VERSION macro
Git does not support the ability to replace a token with a version
string during check-in. While it does have support for replacing a
token on clone, this is somewhat sub-optimal: the token is replaced
with the object hash, which is not particularly easy for human
consumption. What's more, in practice, the source file version was often
not terribly useful. Generally, when triaging bugs, the overall version
of Asterisk is far more useful than an individual SVN version of a file. As a
result, this patch removes Asterisk's support for showing source file
versions.

Specifically, it does the following:

* Rename ASTERISK_FILE_VERSION macro to ASTERISK_REGISTER_FILE, and
  remove passing the version in with the macro. Other facilities
  than 'core show file version' make use of the file names, such as
  setting a debug level only on a specific file. As such, the act of
  registering source files with the Asterisk core still has use. The
  macro rename now reflects the new macro purpose.

* main/asterisk:
  - Refactor the file_version structure to reflect that it no longer
    tracks a version field.
  - Remove the "core show file version" CLI command. Without the file
    version, it is no longer useful.
  - Remove the ast_file_version_find function. The file version is no
    longer tracked.
  - Rename ast_register_file_version/ast_unregister_file_version to
    ast_register_file/ast_unregister_file, respectively.

* main/manager: Remove value from the Version key of the ModuleCheck
  Action. The actual key itself has not been removed, as doing so would
  absolutely constitute a backwards incompatible change. However, since
  the file version is no longer tracked, there is no need to attempt to
  include it in the Version key.

* UPGRADE: Add notes for:
  - Modification to the ModuleCheck AMI Action
  - Removal of the "core show file version" CLI command

Change-Id: I6cf0ff280e1668bf4957dc21f32a5ff43444a40e
2015-04-13 03:48:57 -04:00

252 lines
6.7 KiB
C

/*
* 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>
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
ASTERISK_REGISTER_FILE()
#include "asterisk/ulaw.h"
#include "asterisk/logger.h"
#if 0
/* ZEROTRAP is the military recommendation to improve the encryption
* of u-Law traffic. It is irrelevant with modern encryption systems
* like AES, and will simply degrade the signal quality.
* ZEROTRAP is not implemented in AST_LIN2MU and so the coding table
* tests will fail if you use it */
#define ZEROTRAP /*!< turn on the trap as per the MIL-STD */
#endif
#define BIAS 0x84 /*!< define the add-in bias for 16 bit samples */
#define CLIP 32635
#ifndef G711_NEW_ALGORITHM
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;
}
#else
unsigned char __ast_lin2mu[AST_ULAW_TAB_SIZE];
short __ast_mulaw[256];
static unsigned char linear2ulaw(short sample, int full_coding)
{
static const unsigned 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 };
unsigned sign, exponent, mantissa, mag;
unsigned char ulawbyte;
/* Get the sample into sign-magnitude. */
ast_ulaw_get_sign_mag(sample, &sign, &mag);
if (mag > CLIP)
mag = CLIP; /* clip the 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. */
mag += BIAS;
exponent = exp_lut[(mag >> 7) & 0xFF];
mantissa = (mag >> (exponent + 3)) & 0x0F;
if (full_coding) {
/* full encoding, with sign and xform */
ulawbyte = ~(sign | (exponent << 4) | mantissa);
#ifdef ZEROTRAP
if (ulawbyte == 0)
ulawbyte = 0x02; /* optional CCITT trap */
#endif
} else {
/* half-cooked coding -- mantissa+exponent only (for lookup tab) */
ulawbyte = (exponent << 4) | mantissa;
}
return ulawbyte;
}
static inline short ulaw2linear(unsigned char ulawbyte)
{
unsigned exponent, mantissa;
short sample;
static const short etab[]={0,132,396,924,1980,4092,8316,16764};
ulawbyte = ~ulawbyte;
exponent = (ulawbyte & 0x70) >> 4;
mantissa = ulawbyte & 0x0f;
sample = mantissa << (exponent + 3);
sample += etab[exponent];
if (ulawbyte & 0x80)
sample = -sample;
return sample;
}
#endif
/*!
* \brief Set up mu-law conversion table
*/
void ast_ulaw_init(void)
{
int i;
/*
* Set up mu-law conversion table
*/
#ifndef G711_NEW_ALGORITHM
for (i = 0;i < 256;i++) {
short mu,e,f,y;
static const 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);
}
#else
for (i = 0; i < 256; i++) {
__ast_mulaw[i] = ulaw2linear(i);
}
/* set up the reverse (mu-law) conversion table */
for (i = 0; i <= 32768; i += AST_ULAW_STEP) {
AST_LIN2MU_LOOKUP(i) = linear2ulaw(i, 0 /* half-cooked */);
}
#endif
#ifdef TEST_CODING_TABLES
for (i = -32768; i < 32768; ++i) {
#ifndef G711_NEW_ALGORITHM
unsigned char e1 = linear2ulaw(i);
#else
unsigned char e1 = linear2ulaw(i, 1);
#endif
short d1 = ulaw2linear(e1);
unsigned char e2 = AST_LIN2MU(i);
short d2 = ulaw2linear(e2);
short d3 = AST_MULAW(e1);
if (e1 != e2 || d1 != d3 || d2 != d3) {
ast_log(LOG_WARNING, "u-Law coding tables test failed on %d: e1=%u, e2=%u, d1=%d, d2=%d\n",
i, (unsigned)e1, (unsigned)e2, (int)d1, (int)d2);
}
}
ast_log(LOG_NOTICE, "u-Law coding table test complete.\n");
#endif /* TEST_CODING_TABLES */
#ifdef TEST_TANDEM_TRANSCODING
/* tandem transcoding test */
for (i = -32768; i < 32768; ++i) {
unsigned char e1 = AST_LIN2MU(i);
short d1 = AST_MULAW(e1);
unsigned char e2 = AST_LIN2MU(d1);
short d2 = AST_MULAW(e2);
unsigned char e3 = AST_LIN2MU(d2);
short d3 = AST_MULAW(e3);
if (i < 0 && e1 == 0x7f && e2 == 0xff && e3 == 0xff)
continue; /* known and normal negative 0 case */
if (e1 != e2 || e2 != e3 || d1 != d2 || d2 != d3) {
ast_log(LOG_WARNING, "u-Law tandem transcoding test failed on %d: e1=%u, e2=%u, d1=%d, d2=%d, d3=%d\n",
i, (unsigned)e1, (unsigned)e2, (int)d1, (int)d2, (int)d3);
}
}
ast_log(LOG_NOTICE, "u-Law tandem transcoding test complete.\n");
#endif /* TEST_TANDEM_TRANSCODING */
}