diff options
Diffstat (limited to 'src/libfaad/sbr_fbt.c')
| -rw-r--r-- | src/libfaad/sbr_fbt.c | 129 |
1 files changed, 121 insertions, 8 deletions
diff --git a/src/libfaad/sbr_fbt.c b/src/libfaad/sbr_fbt.c index b18536b69..ae241a01e 100644 --- a/src/libfaad/sbr_fbt.c +++ b/src/libfaad/sbr_fbt.c @@ -22,7 +22,7 @@ ** Commercial non-GPL licensing of this software is possible. ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com. ** -** $Id: sbr_fbt.c,v 1.2 2004/01/11 15:44:05 mroi Exp $ +** $Id: sbr_fbt.c,v 1.3 2004/01/26 22:34:11 jstembridge Exp $ **/ /* Calculate frequency band tables */ @@ -184,8 +184,8 @@ uint8_t qmf_stop_channel(uint8_t bs_stop_freq, uint32_t sample_rate, version for bs_freq_scale = 0 */ -void master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2, - uint8_t bs_alter_scale) +uint8_t master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2, + uint8_t bs_alter_scale) { int8_t incr; uint8_t k; @@ -197,7 +197,7 @@ void master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2, if (k2 <= k0) { sbr->N_master = 0; - return; + return 0; } dk = bs_alter_scale ? 2 : 1; @@ -213,6 +213,8 @@ void master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2, } #endif nrBands = min(nrBands, 63); + if (nrBands <= 0) + return 1; k2Achieved = k0 + nrBands * dk; k2Diff = k2 - k2Achieved; @@ -247,6 +249,8 @@ void master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2, } printf("\n"); #endif + + return 0; } /* @@ -255,22 +259,93 @@ void master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2, */ static int32_t find_bands(uint8_t warp, uint8_t bands, uint8_t a0, uint8_t a1) { +#ifdef FIXED_POINT + /* table with log2() values */ + static const real_t log2Table[65] = { + COEF_CONST(0.0), COEF_CONST(0.0), COEF_CONST(1.0000000000), COEF_CONST(1.5849625007), + COEF_CONST(2.0000000000), COEF_CONST(2.3219280949), COEF_CONST(2.5849625007), COEF_CONST(2.8073549221), + COEF_CONST(3.0000000000), COEF_CONST(3.1699250014), COEF_CONST(3.3219280949), COEF_CONST(3.4594316186), + COEF_CONST(3.5849625007), COEF_CONST(3.7004397181), COEF_CONST(3.8073549221), COEF_CONST(3.9068905956), + COEF_CONST(4.0000000000), COEF_CONST(4.0874628413), COEF_CONST(4.1699250014), COEF_CONST(4.2479275134), + COEF_CONST(4.3219280949), COEF_CONST(4.3923174228), COEF_CONST(4.4594316186), COEF_CONST(4.5235619561), + COEF_CONST(4.5849625007), COEF_CONST(4.6438561898), COEF_CONST(4.7004397181), COEF_CONST(4.7548875022), + COEF_CONST(4.8073549221), COEF_CONST(4.8579809951), COEF_CONST(4.9068905956), COEF_CONST(4.9541963104), + COEF_CONST(5.0000000000), COEF_CONST(5.0443941194), COEF_CONST(5.0874628413), COEF_CONST(5.1292830169), + COEF_CONST(5.1699250014), COEF_CONST(5.2094533656), COEF_CONST(5.2479275134), COEF_CONST(5.2854022189), + COEF_CONST(5.3219280949), COEF_CONST(5.3575520046), COEF_CONST(5.3923174228), COEF_CONST(5.4262647547), + COEF_CONST(5.4594316186), COEF_CONST(5.4918530963), COEF_CONST(5.5235619561), COEF_CONST(5.5545888517), + COEF_CONST(5.5849625007), COEF_CONST(5.6147098441), COEF_CONST(5.6438561898), COEF_CONST(5.6724253420), + COEF_CONST(5.7004397181), COEF_CONST(5.7279204546), COEF_CONST(5.7548875022), COEF_CONST(5.7813597135), + COEF_CONST(5.8073549221), COEF_CONST(5.8328900142), COEF_CONST(5.8579809951), COEF_CONST(5.8826430494), + COEF_CONST(5.9068905956), COEF_CONST(5.9307373376), COEF_CONST(5.9541963104), COEF_CONST(5.9772799235), + COEF_CONST(6.0) + }; + real_t r0 = log2Table[a0]; /* coef */ + real_t r1 = log2Table[a1]; /* coef */ + real_t r2 = (r1 - r0); /* coef */ + + if (warp) + r2 = MUL_C(r2, COEF_CONST(1.0/1.3)); + + /* convert r2 to real and then multiply and round */ + r2 = (r2 >> (COEF_BITS-REAL_BITS)) * bands + (1<<(REAL_BITS-1)); + + return (r2 >> REAL_BITS); +#else real_t div = (real_t)log(2.0); if (warp) div *= (real_t)1.3; return (int32_t)(bands * log((float)a1/(float)a0)/div + 0.5); +#endif } static real_t find_initial_power(uint8_t bands, uint8_t a0, uint8_t a1) { +#ifdef FIXED_POINT + /* table with log() values */ + static const real_t logTable[65] = { + COEF_CONST(0.0), COEF_CONST(0.0), COEF_CONST(0.6931471806), COEF_CONST(1.0986122887), + COEF_CONST(1.3862943611), COEF_CONST(1.6094379124), COEF_CONST(1.7917594692), COEF_CONST(1.9459101491), + COEF_CONST(2.0794415417), COEF_CONST(2.1972245773), COEF_CONST(2.3025850930), COEF_CONST(2.3978952728), + COEF_CONST(2.4849066498), COEF_CONST(2.5649493575), COEF_CONST(2.6390573296), COEF_CONST(2.7080502011), + COEF_CONST(2.7725887222), COEF_CONST(2.8332133441), COEF_CONST(2.8903717579), COEF_CONST(2.9444389792), + COEF_CONST(2.9957322736), COEF_CONST(3.0445224377), COEF_CONST(3.0910424534), COEF_CONST(3.1354942159), + COEF_CONST(3.1780538303), COEF_CONST(3.2188758249), COEF_CONST(3.2580965380), COEF_CONST(3.2958368660), + COEF_CONST(3.3322045102), COEF_CONST(3.3672958300), COEF_CONST(3.4011973817), COEF_CONST(3.4339872045), + COEF_CONST(3.4657359028), COEF_CONST(3.4965075615), COEF_CONST(3.5263605246), COEF_CONST(3.5553480615), + COEF_CONST(3.5835189385), COEF_CONST(3.6109179126), COEF_CONST(3.6375861597), COEF_CONST(3.6635616461), + COEF_CONST(3.6888794541), COEF_CONST(3.7135720667), COEF_CONST(3.7376696183), COEF_CONST(3.7612001157), + COEF_CONST(3.7841896339), COEF_CONST(3.8066624898), COEF_CONST(3.8286413965), COEF_CONST(3.8501476017), + COEF_CONST(3.8712010109), COEF_CONST(3.8918202981), COEF_CONST(3.9120230054), COEF_CONST(3.9318256327), + COEF_CONST(3.9512437186), COEF_CONST(3.9702919136), COEF_CONST(3.9889840466), COEF_CONST(4.0073331852), + COEF_CONST(4.0253516907), COEF_CONST(4.0430512678), COEF_CONST(4.0604430105), COEF_CONST(4.0775374439), + COEF_CONST(4.0943445622), COEF_CONST(4.1108738642), COEF_CONST(4.1271343850), COEF_CONST(4.1431347264), + COEF_CONST(4.158883083) + }; + /* standard Taylor polynomial coefficients for exp(x) around 0 */ + /* a polynomial around x=1 is more precise, as most values are around 1.07, + but this is just fine already */ + static const real_t c1 = COEF_CONST(1.0); + static const real_t c2 = COEF_CONST(1.0/2.0); + static const real_t c3 = COEF_CONST(1.0/6.0); + static const real_t c4 = COEF_CONST(1.0/24.0); + + real_t r0 = logTable[a0]; /* coef */ + real_t r1 = logTable[a1]; /* coef */ + real_t r2 = (r1 - r0) / bands; /* coef */ + real_t rexp = c1 + MUL_C((c1 + MUL_C((c2 + MUL_C((c3 + MUL_C(c4,r2)), r2)), r2)), r2); + + return (rexp >> (COEF_BITS-REAL_BITS)); /* real */ +#else return (real_t)pow((real_t)a1/(real_t)a0, 1.0/(real_t)bands); +#endif } /* version for bs_freq_scale > 0 */ -void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, - uint8_t bs_freq_scale, uint8_t bs_alter_scale) +uint8_t master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, + uint8_t bs_freq_scale, uint8_t bs_alter_scale) { uint8_t k, bands, twoRegions; uint8_t k1; @@ -285,12 +360,16 @@ void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, if (k2 <= k0) { sbr->N_master = 0; - return; + return 0; } bands = temp1[bs_freq_scale-1]; +#ifdef FIXED_POINT + if (REAL_CONST(k2) > MUL_R(REAL_CONST(k0),REAL_CONST(2.2449))) +#else if ((float)k2/(float)k0 > 2.2449) +#endif { twoRegions = 1; k1 = k0 << 1; @@ -301,15 +380,26 @@ void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, nrBand0 = 2 * find_bands(0, bands, k0, k1); nrBand0 = min(nrBand0, 63); + if (nrBand0 <= 0) + return 1; q = find_initial_power(nrBand0, k0, k1); qk = REAL_CONST(k0); +#ifdef FIXED_POINT + A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS); +#else A_1 = (int32_t)(qk + .5); +#endif for (k = 0; k <= nrBand0; k++) { int32_t A_0 = A_1; +#ifdef FIXED_POINT + qk = MUL_R(qk,q); + A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS); +#else qk *= q; A_1 = (int32_t)(qk + 0.5); +#endif vDk0[k] = A_1 - A_0; } @@ -320,6 +410,8 @@ void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, for (k = 1; k <= nrBand0; k++) { vk0[k] = vk0[k-1] + vDk0[k-1]; + if (vDk0[k-1] == 0) + return 1; } if (!twoRegions) @@ -329,7 +421,7 @@ void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, sbr->N_master = nrBand0; sbr->N_master = min(sbr->N_master, 64); - return; + return 0; } nrBand1 = 2 * find_bands(1 /* warped */, bands, k1, k2); @@ -337,12 +429,21 @@ void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, q = find_initial_power(nrBand1, k1, k2); qk = REAL_CONST(k1); +#ifdef FIXED_POINT + A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS); +#else A_1 = (int32_t)(qk + .5); +#endif for (k = 0; k <= nrBand1 - 1; k++) { int32_t A_0 = A_1; +#ifdef FIXED_POINT + qk = MUL_R(qk,q); + A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS); +#else qk *= q; A_1 = (int32_t)(qk + 0.5); +#endif vDk1[k] = A_1 - A_0; } @@ -363,6 +464,8 @@ void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, for (k = 1; k <= nrBand1; k++) { vk1[k] = vk1[k-1] + vDk1[k-1]; + if (vDk1[k-1] == 0) + return 1; } sbr->N_master = nrBand0 + nrBand1; @@ -384,6 +487,8 @@ void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2, } printf("\n"); #endif + + return 0; } /* calculate the derived frequency border tables from f_master */ @@ -410,6 +515,10 @@ uint8_t derived_frequency_table(sbr_info *sbr, uint8_t bs_xover_band, sbr->M = sbr->f_table_res[HI_RES][sbr->N_high] - sbr->f_table_res[HI_RES][0]; sbr->kx = sbr->f_table_res[HI_RES][0]; + if (sbr->kx > 32) + return 1; + if (sbr->kx + sbr->M > 64) + return 1; minus = (sbr->N_high & 1) ? 1 : 0; @@ -556,7 +665,11 @@ restart: #if 0 nOctaves = REAL_CONST(log((float)limTable[k]/(float)limTable[k-1])/log(2.0)); #endif +#ifdef FIXED_POINT + nOctaves = SBR_DIV(REAL_CONST(limTable[k]),REAL_CONST(limTable[k-1])); +#else nOctaves = (real_t)limTable[k]/(real_t)limTable[k-1]; +#endif else nOctaves = 0; |