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This change set fixes bug 8126 in trunk. It is implemented via compile time options, activated via the menuselect stuff, which defaults to the old way. non-zero sample data added. Translate tables expressed in microseconds instead of milliseconds, with 5-digit data now instead of 3, giving 2 more digits of precision.

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@80113 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Steve Murphy
2007-08-20 22:53:48 +00:00
parent c9ab65a3bf
commit 337c44236d
8 changed files with 421 additions and 55 deletions
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52
include/asterisk/alaw.h
View File

@@ -23,21 +23,67 @@
#ifndef _ASTERISK_ALAW_H
#define _ASTERISK_ALAW_H
/*! Init the ulaw conversion stuff */
/*!
* To init the ulaw to slinear conversion stuff, this needs to be run.
* To init the alaw to slinear conversion stuff, this needs to be run.
*/
void ast_alaw_init(void);
/*! converts signed linear to mulaw */
#define AST_ALAW_BIT_LOSS 4
#define AST_ALAW_STEP (1 << AST_ALAW_BIT_LOSS)
#define AST_ALAW_TAB_SIZE (32768 / AST_ALAW_STEP + 1)
#define AST_ALAW_SIGN_BIT 0x80
#define AST_ALAW_AMI_MASK 0x55
/*! converts signed linear to alaw */
/*!
*/
*/
#ifndef G711_NEW_ALGORITHM
extern unsigned char __ast_lin2a[8192];
#else
extern unsigned char __ast_lin2a[AST_ALAW_TAB_SIZE];
#endif
/*! help */
extern short __ast_alaw[256];
#ifndef G711_NEW_ALGORITHM
#define AST_LIN2A(a) (__ast_lin2a[((unsigned short)(a)) >> 3])
#else
#define AST_LIN2A_LOOKUP(mag) \
__ast_lin2a[(mag) >> AST_ALAW_BIT_LOSS]
/*! convert signed linear sample to sign-magnitude pair for a-Law */
static inline void ast_alaw_get_sign_mag(short sample, unsigned *sign, unsigned *mag)
{
/* It may look illogical to retrive the sign this way in both cases,
* but this helps gcc eliminate the branch below and produces
* faster code */
*sign = ((unsigned short)sample >> 8) & AST_ALAW_SIGN_BIT;
#if defined(G711_REDUCED_BRANCHING)
{
unsigned dual_mag = (-sample << 16) | (unsigned short)sample;
*mag = (dual_mag >> (*sign >> 3)) & 0xffffU;
}
#else
if (sample < 0)
*mag = -sample;
else
*mag = sample;
#endif /* G711_REDUCED_BRANCHING */
*sign ^= AST_ALAW_SIGN_BIT;
}
static inline unsigned char AST_LIN2A(short sample)
{
unsigned mag, sign;
ast_alaw_get_sign_mag(sample, &sign, &mag);
return (sign | AST_LIN2A_LOOKUP(mag)) ^ AST_ALAW_AMI_MASK;
}
#endif
#define AST_ALAW(a) (__ast_alaw[(int)(a)])
#endif /* _ASTERISK_ALAW_H */

47
include/asterisk/ulaw.h
View File

@@ -23,21 +23,68 @@
#ifndef _ASTERISK_ULAW_H
#define _ASTERISK_ULAW_H
/*! Init the ulaw conversion stuff */
/*!
* To init the ulaw to slinear conversion stuff, this needs to be run.
*/
void ast_ulaw_init(void);
#define AST_ULAW_BIT_LOSS 3
#define AST_ULAW_STEP (1 << AST_ULAW_BIT_LOSS)
#define AST_ULAW_TAB_SIZE (32768 / AST_ULAW_STEP + 1)
#define AST_ULAW_SIGN_BIT 0x80
/*! converts signed linear to mulaw */
/*!
*/
#ifndef G711_NEW_ALGORITHM
extern unsigned char __ast_lin2mu[16384];
#else
extern unsigned char __ast_lin2mu[AST_ULAW_TAB_SIZE];
#endif
/*! help */
extern short __ast_mulaw[256];
#ifndef G711_NEW_ALGORITHM
#define AST_LIN2MU(a) (__ast_lin2mu[((unsigned short)(a)) >> 2])
#else
#define AST_LIN2MU_LOOKUP(mag) \
__ast_lin2mu[((mag) + AST_ULAW_STEP / 2) >> AST_ULAW_BIT_LOSS]
/*! convert signed linear sample to sign-magnitude pair for u-Law */
static inline void ast_ulaw_get_sign_mag(short sample, unsigned *sign, unsigned *mag)
{
/* It may look illogical to retrive the sign this way in both cases,
* but this helps gcc eliminate the branch below and produces
* faster code */
*sign = ((unsigned short)sample >> 8) & AST_ULAW_SIGN_BIT;
#if defined(G711_REDUCED_BRANCHING)
{
unsigned dual_mag = (-sample << 16) | (unsigned short)sample;
*mag = (dual_mag >> (*sign >> 3)) & 0xffffU;
}
#else
if (sample < 0)
*mag = -sample;
else
*mag = sample;
#endif /* G711_REDUCED_BRANCHING */
}
static inline unsigned char AST_LIN2MU(short sample)
{
unsigned mag, sign;
ast_ulaw_get_sign_mag(sample, &sign, &mag);
return ~(sign | AST_LIN2MU_LOOKUP(mag));
}
#endif
#define AST_MULAW(a) (__ast_mulaw[(a)])
#endif /* _ASTERISK_ULAW_H */