diff options
Diffstat (limited to 'gr-vocoder/lib/g7xx/g72x.c')
-rw-r--r-- | gr-vocoder/lib/g7xx/g72x.c | 576 |
1 files changed, 576 insertions, 0 deletions
diff --git a/gr-vocoder/lib/g7xx/g72x.c b/gr-vocoder/lib/g7xx/g72x.c new file mode 100644 index 000000000..9a823c755 --- /dev/null +++ b/gr-vocoder/lib/g7xx/g72x.c @@ -0,0 +1,576 @@ +/* + * This source code is a product of Sun Microsystems, Inc. and is provided + * for unrestricted use. Users may copy or modify this source code without + * charge. + * + * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING + * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR + * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. + * + * Sun source code is provided with no support and without any obligation on + * the part of Sun Microsystems, Inc. to assist in its use, correction, + * modification or enhancement. + * + * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE + * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE + * OR ANY PART THEREOF. + * + * In no event will Sun Microsystems, Inc. be liable for any lost revenue + * or profits or other special, indirect and consequential damages, even if + * Sun has been advised of the possibility of such damages. + * + * Sun Microsystems, Inc. + * 2550 Garcia Avenue + * Mountain View, California 94043 + */ +#include <stdlib.h> +/* + * g72x.c + * + * Common routines for G.721 and G.723 conversions. + */ + +#include "g72x.h" + +static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, + 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000}; + +/* + * quan() + * + * quantizes the input val against the table of size short integers. + * It returns i if table[i - 1] <= val < table[i]. + * + * Using linear search for simple coding. + */ +static int +quan( + int val, + short *table, + int size) +{ + int i; + + for (i = 0; i < size; i++) + if (val < *table++) + break; + return (i); +} + +/* + * fmult() + * + * returns the integer product of the 14-bit integer "an" and + * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn". + */ +static int +fmult( + int an, + int srn) +{ + short anmag, anexp, anmant; + short wanexp, wanmant; + short retval; + + anmag = (an > 0) ? an : ((-an) & 0x1FFF); + anexp = quan(anmag, power2, 15) - 6; + anmant = (anmag == 0) ? 32 : + (anexp >= 0) ? anmag >> anexp : anmag << -anexp; + wanexp = anexp + ((srn >> 6) & 0xF) - 13; + + wanmant = (anmant * (srn & 077) + 0x30) >> 4; + retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) : + (wanmant >> -wanexp); + + return (((an ^ srn) < 0) ? -retval : retval); +} + +/* + * g72x_init_state() + * + * This routine initializes and/or resets the g72x_state structure + * pointed to by 'state_ptr'. + * All the initial state values are specified in the CCITT G.721 document. + */ +void +g72x_init_state( + struct g72x_state *state_ptr) +{ + int cnta; + + state_ptr->yl = 34816; + state_ptr->yu = 544; + state_ptr->dms = 0; + state_ptr->dml = 0; + state_ptr->ap = 0; + for (cnta = 0; cnta < 2; cnta++) { + state_ptr->a[cnta] = 0; + state_ptr->pk[cnta] = 0; + state_ptr->sr[cnta] = 32; + } + for (cnta = 0; cnta < 6; cnta++) { + state_ptr->b[cnta] = 0; + state_ptr->dq[cnta] = 32; + } + state_ptr->td = 0; +} + +/* + * predictor_zero() + * + * computes the estimated signal from 6-zero predictor. + * + */ +int +predictor_zero( + struct g72x_state *state_ptr) +{ + int i; + int sezi; + + sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]); + for (i = 1; i < 6; i++) /* ACCUM */ + sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]); + return (sezi); +} +/* + * predictor_pole() + * + * computes the estimated signal from 2-pole predictor. + * + */ +int +predictor_pole( + struct g72x_state *state_ptr) +{ + return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) + + fmult(state_ptr->a[0] >> 2, state_ptr->sr[0])); +} +/* + * step_size() + * + * computes the quantization step size of the adaptive quantizer. + * + */ +int +step_size( + struct g72x_state *state_ptr) +{ + int y; + int dif; + int al; + + if (state_ptr->ap >= 256) + return (state_ptr->yu); + else { + y = state_ptr->yl >> 6; + dif = state_ptr->yu - y; + al = state_ptr->ap >> 2; + if (dif > 0) + y += (dif * al) >> 6; + else if (dif < 0) + y += (dif * al + 0x3F) >> 6; + return (y); + } +} + +/* + * quantize() + * + * Given a raw sample, 'd', of the difference signal and a + * quantization step size scale factor, 'y', this routine returns the + * ADPCM codeword to which that sample gets quantized. The step + * size scale factor division operation is done in the log base 2 domain + * as a subtraction. + */ +int +quantize( + int d, /* Raw difference signal sample */ + int y, /* Step size multiplier */ + short *table, /* quantization table */ + int size) /* table size of short integers */ +{ + short dqm; /* Magnitude of 'd' */ + short exp; /* Integer part of base 2 log of 'd' */ + short mant; /* Fractional part of base 2 log */ + short dl; /* Log of magnitude of 'd' */ + short dln; /* Step size scale factor normalized log */ + int i; + + /* + * LOG + * + * Compute base 2 log of 'd', and store in 'dl'. + */ + dqm = abs(d); + exp = quan(dqm >> 1, power2, 15); + mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */ + dl = (exp << 7) + mant; + + /* + * SUBTB + * + * "Divide" by step size multiplier. + */ + dln = dl - (y >> 2); + + /* + * QUAN + * + * Obtain codword i for 'd'. + */ + i = quan(dln, table, size); + if (d < 0) /* take 1's complement of i */ + return ((size << 1) + 1 - i); + else if (i == 0) /* take 1's complement of 0 */ + return ((size << 1) + 1); /* new in 1988 */ + else + return (i); +} +/* + * reconstruct() + * + * Returns reconstructed difference signal 'dq' obtained from + * codeword 'i' and quantization step size scale factor 'y'. + * Multiplication is performed in log base 2 domain as addition. + */ +int +reconstruct( + int sign, /* 0 for non-negative value */ + int dqln, /* G.72x codeword */ + int y) /* Step size multiplier */ +{ + short dql; /* Log of 'dq' magnitude */ + short dex; /* Integer part of log */ + short dqt; + short dq; /* Reconstructed difference signal sample */ + + dql = dqln + (y >> 2); /* ADDA */ + + if (dql < 0) { + return ((sign) ? -0x8000 : 0); + } else { /* ANTILOG */ + dex = (dql >> 7) & 15; + dqt = 128 + (dql & 127); + dq = (dqt << 7) >> (14 - dex); + return ((sign) ? (dq - 0x8000) : dq); + } +} + + +/* + * update() + * + * updates the state variables for each output code + */ +void +update( + int code_size, /* distinguish 723_40 with others */ + int y, /* quantizer step size */ + int wi, /* scale factor multiplier */ + int fi, /* for long/short term energies */ + int dq, /* quantized prediction difference */ + int sr, /* reconstructed signal */ + int dqsez, /* difference from 2-pole predictor */ + struct g72x_state *state_ptr) /* coder state pointer */ +{ + int cnt; + short mag, exp; /* Adaptive predictor, FLOAT A */ + short a2p = 0; /* LIMC */ + short a1ul; /* UPA1 */ + short pks1; /* UPA2 */ + short fa1; + char tr; /* tone/transition detector */ + short ylint, thr2, dqthr; + short ylfrac, thr1; + short pk0; + + pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */ + + mag = dq & 0x7FFF; /* prediction difference magnitude */ + /* TRANS */ + ylint = state_ptr->yl >> 15; /* exponent part of yl */ + ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */ + thr1 = (32 + ylfrac) << ylint; /* threshold */ + thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */ + dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */ + if (state_ptr->td == 0) /* signal supposed voice */ + tr = 0; + else if (mag <= dqthr) /* supposed data, but small mag */ + tr = 0; /* treated as voice */ + else /* signal is data (modem) */ + tr = 1; + + /* + * Quantizer scale factor adaptation. + */ + + /* FUNCTW & FILTD & DELAY */ + /* update non-steady state step size multiplier */ + state_ptr->yu = y + ((wi - y) >> 5); + + /* LIMB */ + if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */ + state_ptr->yu = 544; + else if (state_ptr->yu > 5120) + state_ptr->yu = 5120; + + /* FILTE & DELAY */ + /* update steady state step size multiplier */ + state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6); + + /* + * Adaptive predictor coefficients. + */ + if (tr == 1) { /* reset a's and b's for modem signal */ + state_ptr->a[0] = 0; + state_ptr->a[1] = 0; + state_ptr->b[0] = 0; + state_ptr->b[1] = 0; + state_ptr->b[2] = 0; + state_ptr->b[3] = 0; + state_ptr->b[4] = 0; + state_ptr->b[5] = 0; + } else { /* update a's and b's */ + pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */ + + /* update predictor pole a[1] */ + a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7); + if (dqsez != 0) { + fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0]; + if (fa1 < -8191) /* a2p = function of fa1 */ + a2p -= 0x100; + else if (fa1 > 8191) + a2p += 0xFF; + else + a2p += fa1 >> 5; + + if (pk0 ^ state_ptr->pk[1]) + /* LIMC */ + if (a2p <= -12160) + a2p = -12288; + else if (a2p >= 12416) + a2p = 12288; + else + a2p -= 0x80; + else if (a2p <= -12416) + a2p = -12288; + else if (a2p >= 12160) + a2p = 12288; + else + a2p += 0x80; + } + + /* TRIGB & DELAY */ + state_ptr->a[1] = a2p; + + /* UPA1 */ + /* update predictor pole a[0] */ + state_ptr->a[0] -= state_ptr->a[0] >> 8; + if (dqsez != 0){ + if (pks1 == 0) + state_ptr->a[0] += 192; + else + state_ptr->a[0] -= 192; + } + + /* LIMD */ + a1ul = 15360 - a2p; + if (state_ptr->a[0] < -a1ul) + state_ptr->a[0] = -a1ul; + else if (state_ptr->a[0] > a1ul) + state_ptr->a[0] = a1ul; + + /* UPB : update predictor zeros b[6] */ + for (cnt = 0; cnt < 6; cnt++) { + if (code_size == 5) /* for 40Kbps G.723 */ + state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9; + else /* for G.721 and 24Kbps G.723 */ + state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8; + if (dq & 0x7FFF) { /* XOR */ + if ((dq ^ state_ptr->dq[cnt]) >= 0) + state_ptr->b[cnt] += 128; + else + state_ptr->b[cnt] -= 128; + } + } + } + + for (cnt = 5; cnt > 0; cnt--) + state_ptr->dq[cnt] = state_ptr->dq[cnt-1]; + /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */ + if (mag == 0) { + state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20; + } else { + exp = quan(mag, power2, 15); + state_ptr->dq[0] = (dq >= 0) ? + (exp << 6) + ((mag << 6) >> exp) : + (exp << 6) + ((mag << 6) >> exp) - 0x400; + } + + state_ptr->sr[1] = state_ptr->sr[0]; + /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */ + if (sr == 0) { + state_ptr->sr[0] = 0x20; + } else if (sr > 0) { + exp = quan(sr, power2, 15); + state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp); + } else if (sr > -32768) { + mag = -sr; + exp = quan(mag, power2, 15); + state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400; + } else + state_ptr->sr[0] = 0xFC20; + + /* DELAY A */ + state_ptr->pk[1] = state_ptr->pk[0]; + state_ptr->pk[0] = pk0; + + /* TONE */ + if (tr == 1) /* this sample has been treated as data */ + state_ptr->td = 0; /* next one will be treated as voice */ + else if (a2p < -11776) /* small sample-to-sample correlation */ + state_ptr->td = 1; /* signal may be data */ + else /* signal is voice */ + state_ptr->td = 0; + + /* + * Adaptation speed control. + */ + state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */ + state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */ + + if (tr == 1) + state_ptr->ap = 256; + else if (y < 1536) /* SUBTC */ + state_ptr->ap += (0x200 - state_ptr->ap) >> 4; + else if (state_ptr->td == 1) + state_ptr->ap += (0x200 - state_ptr->ap) >> 4; + else if (abs((state_ptr->dms << 2) - state_ptr->dml) >= + (state_ptr->dml >> 3)) + state_ptr->ap += (0x200 - state_ptr->ap) >> 4; + else + state_ptr->ap += (-state_ptr->ap) >> 4; +} + +/* + * tandem_adjust(sr, se, y, i, sign) + * + * At the end of ADPCM decoding, it simulates an encoder which may be receiving + * the output of this decoder as a tandem process. If the output of the + * simulated encoder differs from the input to this decoder, the decoder output + * is adjusted by one level of A-law or u-law codes. + * + * Input: + * sr decoder output linear PCM sample, + * se predictor estimate sample, + * y quantizer step size, + * i decoder input code, + * sign sign bit of code i + * + * Return: + * adjusted A-law or u-law compressed sample. + */ +int +tandem_adjust_alaw( + int sr, /* decoder output linear PCM sample */ + int se, /* predictor estimate sample */ + int y, /* quantizer step size */ + int i, /* decoder input code */ + int sign, + short *qtab) +{ + unsigned char sp; /* A-law compressed 8-bit code */ + short dx; /* prediction error */ + char id; /* quantized prediction error */ + int sd; /* adjusted A-law decoded sample value */ + int im; /* biased magnitude of i */ + int imx; /* biased magnitude of id */ + + if (sr <= -32768) + sr = -1; + sp = linear2alaw((sr >> 1) << 3); /* short to A-law compression */ + dx = (alaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ + id = quantize(dx, y, qtab, sign - 1); + + if (id == i) { /* no adjustment on sp */ + return (sp); + } else { /* sp adjustment needed */ + /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ + im = i ^ sign; /* 2's complement to biased unsigned */ + imx = id ^ sign; + + if (imx > im) { /* sp adjusted to next lower value */ + if (sp & 0x80) { + sd = (sp == 0xD5) ? 0x55 : + ((sp ^ 0x55) - 1) ^ 0x55; + } else { + sd = (sp == 0x2A) ? 0x2A : + ((sp ^ 0x55) + 1) ^ 0x55; + } + } else { /* sp adjusted to next higher value */ + if (sp & 0x80) + sd = (sp == 0xAA) ? 0xAA : + ((sp ^ 0x55) + 1) ^ 0x55; + else + sd = (sp == 0x55) ? 0xD5 : + ((sp ^ 0x55) - 1) ^ 0x55; + } + return (sd); + } +} + +int +tandem_adjust_ulaw( + int sr, /* decoder output linear PCM sample */ + int se, /* predictor estimate sample */ + int y, /* quantizer step size */ + int i, /* decoder input code */ + int sign, + short *qtab) +{ + unsigned char sp; /* u-law compressed 8-bit code */ + short dx; /* prediction error */ + char id; /* quantized prediction error */ + int sd; /* adjusted u-law decoded sample value */ + int im; /* biased magnitude of i */ + int imx; /* biased magnitude of id */ + + if (sr <= -32768) + sr = 0; + sp = linear2ulaw(sr << 2); /* short to u-law compression */ + dx = (ulaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ + id = quantize(dx, y, qtab, sign - 1); + if (id == i) { + return (sp); + } else { + /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ + im = i ^ sign; /* 2's complement to biased unsigned */ + imx = id ^ sign; + if (imx > im) { /* sp adjusted to next lower value */ + if (sp & 0x80) + sd = (sp == 0xFF) ? 0x7E : sp + 1; + else + sd = (sp == 0) ? 0 : sp - 1; + + } else { /* sp adjusted to next higher value */ + if (sp & 0x80) + sd = (sp == 0x80) ? 0x80 : sp - 1; + else + sd = (sp == 0x7F) ? 0xFE : sp + 1; + } + return (sd); + } +} + + + + + + + + + + + + |