Index: include/asterisk/alaw.h =================================================================== --- include/asterisk/alaw.h (revision 79361) +++ include/asterisk/alaw.h (working copy) @@ -23,21 +23,69 @@ #ifndef _ASTERISK_ALAW_H #define _ASTERISK_ALAW_H +#define G711_FAST_AND_DIRTY 1 +/* #define G711_REDUCED_BRANCHING */ + /*! Init the ulaw conversion stuff */ /*! * To init the ulaw to slinear conversion stuff, this needs to be run. */ void ast_alaw_init(void); +#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 mulaw */ /*! - */ + */ +#ifdef G711_FAST_AND_DIRTY extern unsigned char __ast_lin2a[8192]; +#else +extern unsigned char __ast_lin2a[AST_ALAW_TAB_SIZE]; +#endif /*! help */ extern short __ast_alaw[256]; +#ifdef G711_FAST_AND_DIRTY #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: include/asterisk/ulaw.h =================================================================== --- include/asterisk/ulaw.h (revision 79361) +++ include/asterisk/ulaw.h (working copy) @@ -23,21 +23,71 @@ #ifndef _ASTERISK_ULAW_H #define _ASTERISK_ULAW_H +#define G711_FAST_AND_DIRTY 1 + +/* #define G711_REDUCED_BRANCHING */ + /*! 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 */ /*! */ +#ifdef G711_FAST_AND_DIRTY extern unsigned char __ast_lin2mu[16384]; +#else +extern unsigned char __ast_lin2mu[AST_ULAW_TAB_SIZE]; +#endif /*! help */ extern short __ast_mulaw[256]; +#ifdef G711_FAST_AND_DIRTY + #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: main/alaw.c =================================================================== --- main/alaw.c (revision 80084) +++ main/alaw.c (working copy) @@ -18,7 +18,7 @@ /*! \file * - * \brief u-Law to Signed linear conversion + * \brief a-Law to Signed linear conversion * * \author Mark Spencer */ @@ -28,74 +28,189 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #include "asterisk/alaw.h" +#include "asterisk/logger.h" +/* +#define TEST_CODING_TABLES +#define TEST_TANDEM_TRANSCODING +*/ + +#ifdef G711_FAST_AND_DIRTY #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 - }; - - pcm_val = linear; - if (pcm_val >= 0) - { - /* Sign (7th) bit = 1 */ - mask = AMI_MASK | 0x80; - } - else - { - /* Sign bit = 0 */ - 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]) - break; - } - /* Combine the sign, segment, and quantization bits. */ - return ((seg << 4) | ((pcm_val >> ((seg) ? (seg + 3) : 4)) & 0x0F)) ^ mask; + int mask; + int seg; + int pcm_val; + static int seg_end[8] = + { + 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF + }; + + pcm_val = linear; + if (pcm_val >= 0) + { + /* Sign (7th) bit = 1 */ + mask = AMI_MASK | 0x80; + } + else + { + /* Sign bit = 0 */ + 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]) + break; + } + /* 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 +#ifdef G711_FAST_AND_DIRTY static inline short int alaw2linear (unsigned char alaw) + { + int i; + int seg; + + alaw ^= AMI_MASK; + i = ((alaw & 0x0F) << 4); + seg = (((int) alaw & 0x70) >> 4); + if (seg) + i = (i + 0x100) << (seg - 1); + return (short int) ((alaw & 0x80) ? i : -i); + } + +#else +static inline short alaw2linear(unsigned char alawbyte) { - int i; - int seg; + unsigned exponent, mantissa; + short sample; - alaw ^= AMI_MASK; - i = ((alaw & 0x0F) << 4); - seg = (((int) alaw & 0x70) >> 4); - if (seg) - i = (i + 0x100) << (seg - 1); - return (short int) ((alaw & 0x80) ? i : -i); + 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 +#ifdef G711_FAST_AND_DIRTY unsigned char __ast_lin2a[8192]; +#else +unsigned char __ast_lin2a[AST_ALAW_TAB_SIZE]; +#endif short __ast_alaw[256]; void ast_alaw_init(void) { int i; + /* - * Set up mu-law conversion table + * Set up a-law conversion table */ +#ifdef G711_FAST_AND_DIRTY for(i = 0;i < 256;i++) - { - __ast_alaw[i] = alaw2linear(i); - } - /* set up the reverse (mu-law) conversion table */ + { + __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) { +#ifdef G711_FAST_AND_DIRTY + 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); + } + } +#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); + } + } +#endif /* TEST_TANDEM_TRANSCODING */ } - Index: main/ulaw.c =================================================================== --- main/ulaw.c (revision 80084) +++ main/ulaw.c (working copy) @@ -28,15 +28,30 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #include "asterisk/ulaw.h" +#include "asterisk/logger.h" +/* +#define TEST_CODING_TABLES +#define TEST_TANDEM_TRANSCODING +*/ + +#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 +#ifdef G711_FAST_AND_DIRTY + unsigned char __ast_lin2mu[16384]; short __ast_mulaw[256]; - static unsigned char linear2ulaw(short sample) { static int exp_lut[256] = { @@ -58,26 +73,102 @@ 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 +176,75 @@ 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 + */ +#ifdef G711_FAST_AND_DIRTY + 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++) { + 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) { +#ifdef G711_FAST_AND_DIRTY + 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); + } + } +#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); + } + } +#endif /* TEST_TANDEM_TRANSCODING */ }