ref: 70bde995b7c8d1b75a156cfdd6c34c179296081e
dir: /libfaad/sbr_fbt.c/
/* ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding ** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.com ** ** This program is free software; you can redistribute it and/or modify ** it under the terms of the GNU General Public License as published by ** the Free Software Foundation; either version 2 of the License, or ** (at your option) any later version. ** ** This program is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** GNU General Public License for more details. ** ** You should have received a copy of the GNU General Public License ** along with this program; if not, write to the Free Software ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ** ** Any non-GPL usage of this software or parts of this software is strictly ** forbidden. ** ** Commercial non-GPL licensing of this software is possible. ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com. ** ** $Id: sbr_fbt.c,v 1.1 2003/07/29 08:20:13 menno Exp $ **/ /* Calculate frequency band tables */ #include "common.h" #include "structs.h" #ifdef SBR_DEC #include <stdlib.h> #include "sbr_syntax.h" #include "sbr_fbt.h" /* calculate the start QMF channel for the master frequency band table */ /* parameter is also called k0 */ uint16_t qmf_start_channel(uint8_t bs_start_freq, uint8_t bs_samplerate_mode, uint32_t sample_rate) { static int8_t offset[7][16] = { { -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7 }, { -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13 }, { -5, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16 }, { -6, -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16 }, { -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20 }, { -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24 }, { 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24, 28, 33 } }; uint8_t startMin; if (sample_rate >= 64000) { startMin = (uint8_t)((5000.*128.)/(float)sample_rate + 0.5); } else if (sample_rate < 32000) { startMin = (uint8_t)((3000.*128.)/(float)sample_rate + 0.5); } else { startMin = (uint8_t)((4000.*128.)/(float)sample_rate + 0.5); } if (bs_samplerate_mode) { switch (sample_rate) { case 16000: return startMin + offset[0][bs_start_freq]; case 22050: return startMin + offset[1][bs_start_freq]; case 24000: return startMin + offset[2][bs_start_freq]; case 32000: return startMin + offset[3][bs_start_freq]; default: if (sample_rate > 64000) { return startMin + offset[5][bs_start_freq]; } else { /* 44100 <= sample_rate <= 64000 */ return startMin + offset[4][bs_start_freq]; } } } else { return startMin + offset[6][bs_start_freq]; } } static int32_t longcmp(const void *a, const void *b) { return ((int32_t)(*(int32_t*)a - *(int32_t*)b)); } /* calculate the stop QMF channel for the master frequency band table */ /* parameter is also called k2 */ uint16_t qmf_stop_channel(uint8_t bs_stop_freq, uint32_t sample_rate, uint16_t k0) { if (bs_stop_freq == 15) { return min(64, k0 * 3); } else if (bs_stop_freq == 14) { return min(64, k0 * 2); } else { uint8_t i; uint8_t stopMin; int32_t stopDk[13], stopDk_t[14], k2; if (sample_rate >= 64000) { stopMin = (uint8_t)((10000.*128.)/(float)sample_rate + 0.5); } else if (sample_rate < 32000) { stopMin = (uint8_t)((6000.*128.)/(float)sample_rate + 0.5); } else { stopMin = (uint8_t)((8000.*128.)/(float)sample_rate + 0.5); } for (i = 0; i <= 13; i++) { stopDk_t[i] = (int32_t)(stopMin*pow(64.0/stopMin, i/13.0) + 0.5); } for (i = 0; i < 13; i++) { stopDk[i] = stopDk_t[i+1] - stopDk_t[i]; } /* needed? or does this always reverse the array? */ qsort(stopDk, 13, sizeof(stopDk[0]), longcmp); k2 = stopMin; for (i = 0; i < bs_stop_freq; i++) { k2 += stopDk[i]; } return min(64, k2); } return 0; } /* calculate the master frequency table from k0, k2, bs_freq_scale and bs_alter_scale version for bs_freq_scale = 0 */ void master_frequency_table_fs0(sbr_info *sbr, uint16_t k0, uint16_t k2, uint8_t bs_alter_scale) { int8_t incr; uint8_t k; uint8_t dk; uint32_t nrBands, k2Achieved; int32_t k2Diff, vDk[64]; memset(vDk, 0, 64*sizeof(int32_t)); /* mft only defined for k2 > k0 */ if (k2 <= k0) { sbr->N_master = 0; return; } dk = bs_alter_scale ? 2 : 1; nrBands = 2 * (int32_t)((float)(k2-k0)/(dk*2) + (-1+dk)/2.0f); nrBands = min(nrBands, 64); k2Achieved = k0 + nrBands * dk; k2Diff = k2 - k2Achieved; /* for (k = 0; k <= nrBands; k++) Typo fix */ for (k = 0; k < nrBands; k++) vDk[k] = dk; if (k2Diff) { incr = (k2Diff > 0) ? -1 : 1; k = (k2Diff > 0) ? (nrBands-1) : 0; while (k2Diff != 0) { vDk[k] -= incr; k += incr; k2Diff += incr; } } sbr->f_master[0] = k0; for (k = 1; k <= nrBands; k++) sbr->f_master[k] = sbr->f_master[k-1] + vDk[k-1]; sbr->N_master = nrBands; sbr->N_master = min(sbr->N_master, 64); #if 0 printf("f_master[%d]: ", nrBands); for (k = 0; k <= nrBands; k++) { printf("%d ", sbr->f_master[k]); } printf("\n"); #endif } /* version for bs_freq_scale > 0 */ void master_frequency_table(sbr_info *sbr, uint16_t k0, uint16_t k2, uint8_t bs_freq_scale, uint8_t bs_alter_scale) { uint8_t k, bands, twoRegions; uint16_t k1; uint32_t nrBand0, nrBand1; int32_t vDk0[64], vDk1[64]; int32_t vk0[64], vk1[64]; float warp; uint8_t temp1[] = { 12, 10, 8 }; float temp2[] = { 1.0, 1.3 }; /* without memset code enters infinte loop, so there must be some wrong table access */ memset(vDk0, 0, 64*sizeof(int32_t)); memset(vDk1, 0, 64*sizeof(int32_t)); memset(vk0, 0, 64*sizeof(int32_t)); memset(vk1, 0, 64*sizeof(int32_t)); /* mft only defined for k2 > k0 */ if (k2 <= k0) { sbr->N_master = 0; return; } bands = temp1[bs_freq_scale-1]; warp = temp2[bs_alter_scale]; if ((float)k2/(float)k0 > 2.2449) { twoRegions = 1; k1 = 2 * k0; } else { twoRegions = 0; k1 = k2; } nrBand0 = 2 * (int32_t)(bands * log((float)k1/(float)k0)/(2.0*log(2.0)) + 0.5); nrBand0 = min(nrBand0, 64); for (k = 0; k <= nrBand0; k++) { /* MAPLE */ vDk0[k] = (int32_t)(k0 * pow((float)k1/(float)k0, (k+1)/(float)nrBand0)+0.5) - (int32_t)(k0 * pow((float)k1/(float)k0, k/(float)nrBand0)+0.5); } /* needed? */ qsort(vDk0, nrBand0, sizeof(vDk0[0]), longcmp); vk0[0] = k0; for (k = 1; k <= nrBand0; k++) { vk0[k] = vk0[k-1] + vDk0[k-1]; } if (!twoRegions) { for (k = 0; k <= nrBand0; k++) sbr->f_master[k] = vk0[k]; sbr->N_master = nrBand0; sbr->N_master = min(sbr->N_master, 64); return; } nrBand1 = 2 * (int32_t)(bands * log((float)k2/(float)k1)/(2.0 * log(2.0) * warp) + 0.5); nrBand1 = min(nrBand1, 64); for (k = 0; k <= nrBand1 - 1; k++) { vDk1[k] = (int32_t)(k1 * pow((float)k2/(float)k1, (k+1)/(float)nrBand1)+0.5) - (int32_t)(k1 * pow((float)k2/(float)k1, k/(float)nrBand1)+0.5); } if (vDk1[0] < vDk0[nrBand0 - 1]) { int32_t change; /* needed? */ qsort(vDk1, nrBand1 + 1, sizeof(vDk1[0]), longcmp); change = vDk0[nrBand0 - 1] - vDk1[0]; vDk1[0] = vDk0[nrBand0 - 1]; vDk1[nrBand1 - 1] = vDk1[nrBand1 - 1] - change; } /* needed? */ qsort(vDk1, nrBand1, sizeof(vDk1[0]), longcmp); vk1[0] = k1; for (k = 1; k <= nrBand1; k++) { vk1[k] = vk1[k-1] + vDk1[k-1]; } sbr->N_master = nrBand0 + nrBand1; sbr->N_master = min(sbr->N_master, 64); for (k = 0; k <= nrBand0; k++) { sbr->f_master[k] = vk0[k]; } for (k = nrBand0 + 1; k <= sbr->N_master; k++) { sbr->f_master[k] = vk1[k - nrBand0]; } #if 0 printf("f_master[%d]: ", sbr->N_master); for (k = 0; k <= sbr->N_master; k++) { printf("%d ", sbr->f_master[k]); } printf("\n"); #endif } /* calculate the derived frequency border tables from f_master */ void derived_frequency_table(sbr_info *sbr, uint8_t bs_xover_band, uint16_t k2) { uint8_t k, i; uint32_t minus; sbr->N_high = sbr->N_master - bs_xover_band; /* is this accurate? */ sbr->N_low = sbr->N_high/2 + (sbr->N_high - 2 * (sbr->N_high/2)); sbr->n[0] = sbr->N_low; sbr->n[1] = sbr->N_high; for (k = 0; k <= sbr->N_high; k++) { sbr->f_table_res[HI_RES][k] = sbr->f_master[k + 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]; /* correct? */ minus = (sbr->N_high & 1) ? 1 : 0; for (k = 0; k <= sbr->N_low; k++) { if (k == 0) i = 0; else i = 2*k - minus; sbr->f_table_res[LO_RES][k] = sbr->f_table_res[HI_RES][i]; } /* end correct? */ #if 0 printf("f_table_res[HI_RES][%d]: ", sbr->N_high); for (k = 0; k <= sbr->N_high; k++) { printf("%d ", sbr->f_table_res[HI_RES][k]); } printf("\n"); #endif #if 0 printf("f_table_res[LO_RES][%d]: ", sbr->N_low); for (k = 0; k <= sbr->N_low; k++) { printf("%d ", sbr->f_table_res[LO_RES][k]); } printf("\n"); #endif sbr->N_Q = 0; if (sbr->bs_noise_bands == 0) { sbr->N_Q = 1; } else { /* MAPLE */ sbr->N_Q = max(1, (int32_t)(sbr->bs_noise_bands*(log(k2/(float)sbr->kx)/log(2.0)) + 0.5)); if (sbr->N_Q == 0) sbr->N_Q = 1; } sbr->N_Q = min(5, sbr->N_Q); for (k = 0; k <= sbr->N_Q; k++) { if (k == 0) i = 0; else /* is this accurate? */ i = i + (int32_t)((sbr->N_low - i)/(sbr->N_Q + 1 - k)); sbr->f_table_noise[k] = sbr->f_table_res[LO_RES][i]; } /* build table for mapping k to g in hf patching */ for (k = 0; k < 64; k++) { uint8_t g; for (g = 0; g < sbr->N_Q; g++) { if ((sbr->f_table_noise[g] <= k) && (k < sbr->f_table_noise[g+1])) { sbr->table_map_k_to_g[k] = g; break; } } } #if 0 printf("f_table_noise[%d]: ", sbr->N_Q); for (k = 0; k <= sbr->N_Q; k++) { printf("%d ", sbr->f_table_noise[k]); } printf("\n"); #endif } /* TODO: blegh, ugly */ /* Modified to calculate for all possible bs_limiter_bands always * This reduces the number calls to this functions needed (now only on * header reset) */ void limiter_frequency_table(sbr_info *sbr) { static real_t limiterBandsPerOctave[] = { REAL_CONST(1.2), REAL_CONST(2), REAL_CONST(3) }; uint8_t k, s; int8_t nrLim; int32_t limTable[100 /*TODO*/]; uint8_t patchBorders[64/*??*/]; real_t limBands; sbr->f_table_lim[0][0] = sbr->f_table_res[LO_RES][0] - sbr->kx; sbr->f_table_lim[0][1] = sbr->f_table_res[LO_RES][sbr->N_low] - sbr->kx; sbr->N_L[0] = 1; for (s = 1; s < 4; s++) { memset(limTable, 0, 100*sizeof(int32_t)); limBands = limiterBandsPerOctave[s - 1]; patchBorders[0] = sbr->kx; for (k = 1; k <= sbr->noPatches; k++) { patchBorders[k] = patchBorders[k-1] + sbr->patchNoSubbands[k-1]; } for (k = 0; k <= sbr->N_low; k++) { limTable[k] = sbr->f_table_res[LO_RES][k]; } for (k = 1; k < sbr->noPatches; k++) { limTable[k+sbr->N_low] = patchBorders[k]; } /* needed */ qsort(limTable, sbr->noPatches + sbr->N_low, sizeof(limTable[0]), longcmp); k = 1; nrLim = sbr->noPatches + sbr->N_low - 1; if (nrLim < 0) // TODO: BIG FAT PROBLEM return; restart: if (k <= nrLim) { real_t nOctaves; if (limTable[k-1] != 0) nOctaves = REAL_CONST(log((float)limTable[k]/(float)limTable[k-1])/log(2.0)); else nOctaves = 0; if ((MUL(nOctaves,limBands)) < REAL_CONST(0.49)) { uint8_t i; if (limTable[k] != limTable[k-1]) { uint8_t found = 0, found2 = 0; for (i = 0; i <= sbr->noPatches; i++) { if (limTable[k] == patchBorders[i]) found = 1; } if (found) { found2 = 0; for (i = 0; i <= sbr->noPatches; i++) { if (limTable[k-1] == patchBorders[i]) found2 = 1; } if (found2) { k++; goto restart; } else { /* remove (k-1)th element */ limTable[k-1] = sbr->f_table_res[LO_RES][sbr->N_low]; qsort(limTable, sbr->noPatches + sbr->N_low, sizeof(limTable[0]), longcmp); nrLim--; goto restart; } } } /* remove kth element */ limTable[k] = sbr->f_table_res[LO_RES][sbr->N_low]; qsort(limTable, nrLim, sizeof(limTable[0]), longcmp); nrLim--; goto restart; } else { k++; goto restart; } } sbr->N_L[s] = nrLim; for (k = 0; k <= nrLim; k++) { sbr->f_table_lim[s][k] = limTable[k] - sbr->kx; } #if 0 printf("f_table_lim[%d][%d]: ", s, sbr->N_L[s]); for (k = 0; k <= sbr->N_L[s]; k++) { printf("%d ", sbr->f_table_lim[s][k]); } printf("\n"); #endif } } #endif