X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/92a19c2e7757ba742846f83e56356de0a607bdc2..b2c13097deb7736a86a278c02d0b3f7cd9873750:/contrib/src/mmedia/g72x.cpp diff --git a/contrib/src/mmedia/g72x.cpp b/contrib/src/mmedia/g72x.cpp index c6f2a016c2..2202cf8235 100644 --- a/contrib/src/mmedia/g72x.cpp +++ b/contrib/src/mmedia/g72x.cpp @@ -35,7 +35,7 @@ #include "wx/mmedia/internal/g72x.h" static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, - 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000}; + 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000}; /* * quan() @@ -47,16 +47,16 @@ static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, */ static int quan( - int val, - short *table, - int size) + int val, + short *table, + int size) { - int i; + int i; - for (i = 0; i < size; i++) - if (val < *table++) - break; - return (i); + for (i = 0; i < size; i++) + if (val < *table++) + break; + return (i); } static char quan2_tab[65536]; @@ -65,42 +65,42 @@ static int init_tabs_done = 0; inline char quan2 (unsigned short val) { - return quan2_tab[val]; + return quan2_tab[val]; } inline short base2 (unsigned short val) { - return base2_tab[val]; + return base2_tab[val]; } static void init_quan2_tab (void) { - long i; + long i; - for (i = 0; i < 65536; i++) { - quan2_tab[i] = quan (i, power2, 15); - }; + for (i = 0; i < 65536; i++) { + quan2_tab[i] = quan (i, power2, 15); + }; } static void init_base2_tab (void) { - long i; - short exp; + long i; + short exp; - for (i = 0; i < 65536; i++) { - exp = quan2 (short (i)); - base2_tab[i] = short ((exp << 6) + ((i << 6) >> exp)); - }; + for (i = 0; i < 65536; i++) { + exp = quan2 (short (i)); + base2_tab[i] = short ((exp << 6) + ((i << 6) >> exp)); + }; } static void init_tabs (void) { - if (init_tabs_done) return; + if (init_tabs_done) return; - init_quan2_tab(); - init_base2_tab(); + init_quan2_tab(); + init_base2_tab(); - init_tabs_done = 1; + init_tabs_done = 1; } /* @@ -111,24 +111,24 @@ static void init_tabs (void) */ static int fmult( - int an, - int srn) + int an, + int srn) { - short anmag, anexp, anmant; - short wanexp, wanmant; - short retval; + short anmag, anexp, anmant; + short wanexp, wanmant; + short retval; - anmag = (an > 0) ? an : ((-an) & 0x1FFF); - anexp = quan2(anmag) - 6; - anmant = (anmag == 0) ? 32 : - (anexp >= 0) ? anmag >> anexp : anmag << -anexp; - wanexp = anexp + ((srn >> 6) & 0xF) - 13; + anmag = (an > 0) ? an : ((-an) & 0x1FFF); + anexp = quan2(anmag) - 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); + wanmant = (anmant * (srn & 077) + 0x30) >> 4; + retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) : + (wanmant >> -wanexp); - return (((an ^ srn) < 0) ? -retval : retval); + return (((an ^ srn) < 0) ? -retval : retval); } /* @@ -140,27 +140,27 @@ fmult( */ void g72x_init_state( - struct g72x_state *state_ptr) + struct g72x_state *state_ptr) { - int cnta; - - init_tabs (); - - 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; + int cnta; + + init_tabs (); + + 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; } /* @@ -171,15 +171,15 @@ g72x_init_state( */ int predictor_zero( - struct g72x_state *state_ptr) + struct g72x_state *state_ptr) { - int i; - int sezi; + 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); + 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() @@ -189,10 +189,10 @@ predictor_zero( */ int predictor_pole( - struct g72x_state *state_ptr) + 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])); + return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) + + fmult(state_ptr->a[0] >> 2, state_ptr->sr[0])); } /* * step_size() @@ -202,24 +202,24 @@ predictor_pole( */ int step_size( - struct g72x_state *state_ptr) + 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); - } + 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); + } } /* @@ -233,47 +233,47 @@ step_size( */ int quantize( - int d, /* Raw difference signal sample */ - int y, /* Step size multiplier */ - short *table, /* quantization table */ - int size) /* table size of short integers */ + 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 = quan2(dqm >> 1); - 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); + 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 = quan2(dqm >> 1); + 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() @@ -284,25 +284,25 @@ quantize( */ int reconstruct( - int sign, /* 0 for non-negative value */ - int dqln, /* G.72x codeword */ - int y) /* Step size multiplier */ + 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); - } + 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); + } } @@ -313,189 +313,189 @@ reconstruct( */ 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 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; /* Adaptive predictor, FLOAT A */ - short a2p; /* 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 = short (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; - - a2p = 0; /* eliminate Compiler Warnings */ - } 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 { - state_ptr->dq[0] = (dq >= 0) ? - base2 (mag) : base2 (mag) - 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) { - state_ptr->sr[0] = base2(sr); - } else if (sr > -32768) { - mag = -sr; - state_ptr->sr[0] = base2(mag) - 0x400; - } else - state_ptr->sr[0] = short (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; + int cnt; + short mag; /* Adaptive predictor, FLOAT A */ + short a2p; /* 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 = short (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; + + a2p = 0; /* eliminate Compiler Warnings */ + } 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 { + state_ptr->dq[0] = (dq >= 0) ? + base2 (mag) : base2 (mag) - 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) { + state_ptr->sr[0] = base2(sr); + } else if (sr > -32768) { + mag = -sr; + state_ptr->sr[0] = base2(mag) - 0x400; + } else + state_ptr->sr[0] = short (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; } /* @@ -507,103 +507,103 @@ update( * 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 + * 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. + * 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) + 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); - } + 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) + 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); - } + 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); + } }