This change set fixes bug 8126 in trunk. It is implemented via compile time options...
authorSteve Murphy <murf@digium.com>
Mon, 20 Aug 2007 22:53:48 +0000 (22:53 +0000)
committerSteve Murphy <murf@digium.com>
Mon, 20 Aug 2007 22:53:48 +0000 (22:53 +0000)
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@80113 65c4cc65-6c06-0410-ace0-fbb531ad65f3

build_tools/cflags.xml
codecs/slin_ulaw_ex.h
codecs/ulaw_slin_ex.h
include/asterisk/alaw.h
include/asterisk/ulaw.h
main/alaw.c
main/translate.c
main/ulaw.c

index 58a90fd..2cd423e 100644 (file)
                </member>
                <member name="LOW_MEMORY" displayname="Optimize for Low Memory Usage">
                </member>
+               <member name="G711_NEW_ALGORITHM" displayname="Use the NEW ulaw/alaw codecs (slower, but cleaner)">
+                       <defaultenabled>no</defaultenabled>
+               </member>
+               <member name="G711_REDUCED_BRANCHING" displayname="New ulaw/alaw codec, reduced branching (might help it run faster in some architectures)">
+                       <defaultenabled>yes</defaultenabled>
+                       <depend>G711_NEW_ALGORITHM</depend>
+               </member>
+               <member name="TEST_CODING_TABLES" displayname="New ulaw/alaw codec, turn on table tests on init">
+                       <depend>G711_NEW_ALGORITHM</depend>
+               </member>
+               <member name="TEST_TANDEM_TRANSCODING" displayname="New ulaw/alaw codec, turn on transcoding tests on init">
+                       <depend>G711_NEW_ALGORITHM</depend>
+               </member>
                <member name="MALLOC_DEBUG" displayname="Keep Track of Memory Allocations">
                </member>
                <member name="MTX_PROFILE" displayname="Enable Code Profiling Using TSC Counters">
index 9af79eb..083acef 100644 (file)
  */
 
 static signed short slin_ulaw_ex[] = {
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-       0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000
+       0xcac0, 0xcdeb, 0xd116, 0xd441, 0xd76c, 0xda97, 0xddc2, 0xe0ed,
+       0x0000, 0x032b, 0x0656, 0x0981, 0x0cac, 0x0fd7, 0x1302, 0x162d,
+       0x1958, 0x1c83, 0x1fae, 0x22d9, 0x2604, 0x292f, 0x2c5a, 0x2f85,
+       0x32b0, 0x35db, 0x3906, 0x3c31, 0x3f5c, 0x4287, 0x45b2, 0x48dd,
+       0xb168, 0xb493, 0xb7be, 0xbae9, 0xbe14, 0xc13f, 0xc46a, 0xc795,
+       0xe418, 0xe743, 0xea6e, 0xed99, 0xf0c4, 0xf3ef, 0xf71a, 0xfa45,
+       0x9810, 0x9b3b, 0x9e66, 0xa191, 0xa4bc, 0xa7e7, 0xab12, 0xae3d,
+       0x4c08, 0x4f33, 0x525e, 0x5589, 0x58b4, 0x5bdf, 0x5f0a, 0x6235,
+       0x6560, 0x688b, 0x6bb6, 0x6ee1, 0x720c, 0x7537, 0x7862, 0x7b8d,
+       0x7eb8, 0x81e3, 0x850e, 0x8839, 0x8b64, 0x8e8f, 0x91ba, 0x94e5,
 };
index 9f0417a..a125568 100644 (file)
  */
 
 static unsigned char ulaw_slin_ex[] = {
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+       0x00, 0x03, 0x06, 0x09, 0x0c, 0x0f, 0x12, 0x15,
+       0x10, 0x18, 0x1b, 0x1e, 0x21, 0x24, 0x27, 0x2a,
+       0x20, 0x2d, 0x30, 0x33, 0x36, 0x39, 0x3c, 0x3f,
+       0x30, 0x42, 0x45, 0x48, 0x4b, 0x4e, 0x51, 0x54,
+       0x40, 0x57, 0x5a, 0x5d, 0x60, 0x63, 0x66, 0x69,
+       0x50, 0x6c, 0x6f, 0x72, 0x75, 0x78, 0x7b, 0x7e,
+       0x60, 0x81, 0x84, 0x87, 0x8a, 0x8d, 0x90, 0x93,
+       0x70, 0x96, 0x99, 0x9c, 0x9f, 0xa2, 0xa5, 0xa8,
+       0x80, 0xab, 0xae, 0xb1, 0xb4, 0xb7, 0xba, 0xbd,
+       0x90, 0xc0, 0xc3, 0xc6, 0xc9, 0xcc, 0xcf, 0xd2
 };
index 44b3bad..3496896 100644 (file)
 #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 */
index d9ab0d1..1ac079d 100644 (file)
 #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 */
index d388d1e..fbc99b0 100644 (file)
@@ -18,7 +18,7 @@
 
 /*! \file
  *
- * \brief u-Law to Signed linear conversion
+ * \brief a-Law to Signed linear conversion
  *
  * \author Mark Spencer <markster@digium.com> 
  */
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #include "asterisk/alaw.h"
+#include "asterisk/logger.h"
 
+#ifndef G711_NEW_ALGORITHM
 #define AMI_MASK 0x55
 
-static inline unsigned char linear2alaw (short int linear)
+static inline unsigned char linear2alaw(short int linear)
 {
     int mask;
     int seg;
     int pcm_val;
     static int seg_end[8] =
-    {
-         0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF
-    };
+               {
+                       0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF
+               };
     
     pcm_val = linear;
     if (pcm_val >= 0) {
@@ -50,7 +52,7 @@ static inline unsigned char linear2alaw (short int linear)
            mask = AMI_MASK;
            pcm_val = -pcm_val;
     }
-
+       
     /* Convert the scaled magnitude to segment number. */
     for (seg = 0;  seg < 8;  seg++) {
            if (pcm_val <= seg_end[seg])
@@ -59,13 +61,56 @@ static inline unsigned char linear2alaw (short int linear)
     /* Combine the sign, segment, and quantization bits. */
     return  ((seg << 4) | ((pcm_val >> ((seg)  ?  (seg + 3)  :  4)) & 0x0F)) ^ mask;
 }
-/*- End of function --------------------------------------------------------*/
+#else
+static unsigned char linear2alaw(short sample, int full_coding)
+{
+       static const unsigned exp_lut[128] = {
+               1,1,2,2,3,3,3,3,
+               4,4,4,4,4,4,4,4,
+               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,
+               7,7,7,7,7,7,7,7,
+               7,7,7,7,7,7,7,7,
+               7,7,7,7,7,7,7,7,
+               7,7,7,7,7,7,7,7,
+               7,7,7,7,7,7,7,7,
+               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 alawbyte;
+       
+       ast_alaw_get_sign_mag(sample, &sign, &mag);
+       if (mag > 32767)
+               mag = 32767;        /* clip the magnitude for -32768 */
+       
+       exponent = exp_lut[(mag >> 8) & 0x7f];
+       mantissa = (mag >> (exponent + 3)) & 0x0f;
+       if (mag < 0x100)
+               exponent = 0;
+       
+       if (full_coding) {
+               /* full encoding, with sign and xform */
+               alawbyte = (unsigned char)(sign | (exponent << 4) | mantissa);
+               alawbyte ^= AST_ALAW_AMI_MASK;
+       } else {
+               /* half-cooked coding -- mantissa+exponent only (for lookup tab) */
+               alawbyte = (exponent << 4) | mantissa;
+       }
+       return alawbyte;
+}
+#endif
 
+#ifndef G711_NEW_ALGORITHM
 static inline short int alaw2linear (unsigned char alaw)
 {
     int i;
     int seg;
-
+       
     alaw ^= AMI_MASK;
     i = ((alaw & 0x0F) << 4);
     seg = (((int) alaw & 0x70) >> 4);
@@ -73,8 +118,31 @@ static inline short int alaw2linear (unsigned char alaw)
            i = (i + 0x100) << (seg - 1);
     return (short int) ((alaw & 0x80)  ?  i  :  -i);
 }
+#else
+static inline short alaw2linear(unsigned char alawbyte)
+{
+       unsigned exponent, mantissa;
+       short sample;
+       
+       alawbyte ^= AST_ALAW_AMI_MASK;
+       exponent = (alawbyte & 0x70) >> 4;
+       mantissa = alawbyte & 0x0f;
+       sample = (mantissa << 4) + 8 /* rounding error */;
+       if (exponent)
+               sample = (sample + 0x100) << (exponent - 1);
+       if (!(alawbyte & 0x80))
+               sample = -sample;
+       return sample;
+}
+#endif
+
 
+
+#ifndef G711_NEW_ALGORITHM
 unsigned char __ast_lin2a[8192];
+#else
+unsigned char __ast_lin2a[AST_ALAW_TAB_SIZE];
+#endif
 short __ast_alaw[256];
 
 void ast_alaw_init(void)
@@ -82,14 +150,62 @@ void ast_alaw_init(void)
        int i;
        /* 
         *  Set up mu-law conversion table
-        */
+        */ 
+#ifndef G711_NEW_ALGORITHM
        for (i = 0; i < 256; i++) {
-               __ast_alaw[i] = alaw2linear(i);
+               __ast_alaw[i] = alaw2linear(i);
        }
        /* set up the reverse (mu-law) conversion table */
        for (i = -32768; i < 32768; i++) {
                __ast_lin2a[((unsigned short)i) >> 3] = linear2alaw(i);
        }
-
+#else
+       for (i = 0; i < 256; i++) {
+               __ast_alaw[i] = alaw2linear(i);
+       }
+       /* set up the reverse (a-law) conversion table */
+       for (i = 0; i <= 32768; i += AST_ALAW_STEP) {
+               AST_LIN2A_LOOKUP(i) = linear2alaw(i, 0 /* half-cooked */);
+       }
+#endif
+       
+#ifdef TEST_CODING_TABLES
+       for (i = -32768; i < 32768; ++i) {
+#ifndef G711_NEW_ALGORITHM
+               unsigned char e1 = linear2alaw(i);
+#else
+               unsigned char e1 = linear2alaw(i, 1);
+#endif
+               short d1 = alaw2linear(e1);
+               unsigned char e2 = AST_LIN2A(i);
+               short d2 = alaw2linear(e2);
+               short d3 = AST_ALAW(e1);
+               
+               if (e1 != e2 || d1 != d3 || d2 != d3) {
+                       ast_log(LOG_WARNING, "a-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, "a-Law coding tables test complete.\n");
+#endif /* TEST_CODING_TABLES */
+       
+#ifdef TEST_TANDEM_TRANSCODING
+       /* tandem transcoding test */
+       for (i = -32768; i < 32768; ++i) {
+               unsigned char e1 = AST_LIN2A(i);
+               short d1 = AST_ALAW(e1);
+               unsigned char e2 = AST_LIN2A(d1);
+               short d2 = AST_ALAW(e2);
+               unsigned char e3 = AST_LIN2A(d2);
+               short d3 = AST_ALAW(e3);
+               
+               if (e1 != e2 || e2 != e3 || d1 != d2 || d2 != d3) {
+                       ast_log(LOG_WARNING, "a-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, "a-Law tandem transcoding test complete.\n");
+#endif /* TEST_TANDEM_TRANSCODING */
+       
 }
 
index 3f9ffd7..c26e627 100644 (file)
@@ -46,7 +46,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/cli.h"
 #include "asterisk/term.h"
 
-#define MAX_RECALC 200 /* max sample recalc */
+#define MAX_RECALC 1000 /* max sample recalc */
 
 /*! \brief the list of translators */
 static AST_RWLIST_HEAD_STATIC(translators, ast_translator);
@@ -371,6 +371,7 @@ static void calc_cost(struct ast_translator *t, int seconds)
        int sofar=0;
        struct ast_trans_pvt *pvt;
        struct timeval start;
+       struct timeval end;
        int cost;
 
        if (!seconds)
@@ -379,13 +380,13 @@ static void calc_cost(struct ast_translator *t, int seconds)
        /* If they don't make samples, give them a terrible score */
        if (!t->sample) {
                ast_log(LOG_WARNING, "Translator '%s' does not produce sample frames.\n", t->name);
-               t->cost = 99999;
+               t->cost = 999999;
                return;
        }
        pvt = newpvt(t);
        if (!pvt) {
                ast_log(LOG_WARNING, "Translator '%s' appears to be broken and will probably fail.\n", t->name);
-               t->cost = 99999;
+               t->cost = 999999;
                return;
        }
        start = ast_tvnow();
@@ -395,7 +396,7 @@ static void calc_cost(struct ast_translator *t, int seconds)
                if (!f) {
                        ast_log(LOG_WARNING, "Translator '%s' failed to produce a sample frame.\n", t->name);
                        destroy(pvt);
-                       t->cost = 99999;
+                       t->cost = 999999;
                        return;
                }
                framein(pvt, f);
@@ -405,7 +406,8 @@ static void calc_cost(struct ast_translator *t, int seconds)
                        ast_frfree(f);
                }
        }
-       cost = ast_tvdiff_ms(ast_tvnow(), start);
+       end = ast_tvnow();
+       cost = ((end.tv_sec - start.tv_sec)*1000000) + end.tv_usec - start.tv_usec;
        destroy(pvt);
        t->cost = cost / seconds;
        if (!t->cost)
@@ -516,7 +518,7 @@ static int show_translation(int fd, int argc, char *argv[])
 
        AST_RWLIST_RDLOCK(&translators);
 
-       ast_cli(fd, "         Translation times between formats (in milliseconds) for one second of data\n");
+       ast_cli(fd, "         Translation times between formats (in microseconds) for one second of data\n");
        ast_cli(fd, "          Source Format (Rows) Destination Format (Columns)\n\n");
        /* Get the length of the longest (usable?) codec name, so we know how wide the left side should be */
        for (x = 0; x < SHOW_TRANS; x++) {
@@ -530,12 +532,13 @@ static int show_translation(int fd, int argc, char *argv[])
                ast_str_set(&out, -1, " ");
                for (y = -1; y < SHOW_TRANS; y++) {
                        curlen = strlen(ast_getformatname(1 << (y)));
-
+                       if (curlen < 5)
+                               curlen = 5;
                        if (x >= 0 && y >= 0 && tr_matrix[x][y].step) {
-                               /* XXX 999 is a little hackish
+                               /* XXX 99999 is a little hackish
                                   We don't want this number being larger than the shortest (or current) codec
                                   For now, that is "gsm" */
-                               ast_str_append(&out, -1, "%*d", curlen + 1, tr_matrix[x][y].cost > 999 ? 0 : tr_matrix[x][y].cost);
+                               ast_str_append(&out, -1, "%*d", curlen + 1, tr_matrix[x][y].cost > 99999 ? 0 : tr_matrix[x][y].cost);
                        } else if (x == -1 && y >= 0) {
                                /* Top row - use a dynamic size */
                                ast_str_append(&out, -1, "%*s", curlen + 1, ast_getformatname(1 << (x + y + 1)) );
index 2735f6c..8e47d8a 100644 (file)
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #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] = {
@@ -58,26 +68,102 @@ static unsigned char linear2ulaw(short sample)
                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) 
+       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
@@ -85,22 +171,77 @@ static unsigned char linear2ulaw(short sample)
 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;
+       
+       /*
+        *  Set up mu-law conversion table
+        */
+#ifndef G711_NEW_ALGORITHM
+       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;
+               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 */
 }