/* ** Copyright 2003-2010, VisualOn, Inc. ** ** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ** ** http://www.apache.org/licenses/LICENSE-2.0 ** ** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License. */ /*********************************************************************** * File: dtx.c * * * * Description:DTX functions * * * ************************************************************************/ #include #include #include "typedef.h" #include "basic_op.h" #include "oper_32b.h" #include "math_op.h" #include "cnst.h" #include "acelp.h" /* prototype of functions */ #include "bits.h" #include "dtx.h" #include "log2.h" #include "mem_align.h" static void aver_isf_history( Word16 isf_old[], Word16 indices[], Word32 isf_aver[] ); static void find_frame_indices( Word16 isf_old_tx[], Word16 indices[], dtx_encState * st ); static Word16 dithering_control( dtx_encState * st ); /* excitation energy adjustment depending on speech coder mode used, Q7 */ static Word16 en_adjust[9] = { 230, /* mode0 = 7k : -5.4dB */ 179, /* mode1 = 9k : -4.2dB */ 141, /* mode2 = 12k : -3.3dB */ 128, /* mode3 = 14k : -3.0dB */ 122, /* mode4 = 16k : -2.85dB */ 115, /* mode5 = 18k : -2.7dB */ 115, /* mode6 = 20k : -2.7dB */ 115, /* mode7 = 23k : -2.7dB */ 115 /* mode8 = 24k : -2.7dB */ }; /************************************************************************** * * Function : dtx_enc_init * **************************************************************************/ Word16 dtx_enc_init(dtx_encState ** st, Word16 isf_init[], VO_MEM_OPERATOR *pMemOP) { dtx_encState *s; if (st == (dtx_encState **) NULL) { fprintf(stderr, "dtx_enc_init: invalid parameter\n"); return -1; } *st = NULL; /* allocate memory */ if ((s = (dtx_encState *)mem_malloc(pMemOP, sizeof(dtx_encState), 32, VO_INDEX_ENC_AMRWB)) == NULL) { fprintf(stderr, "dtx_enc_init: can not malloc state structure\n"); return -1; } dtx_enc_reset(s, isf_init); *st = s; return 0; } /************************************************************************** * * Function : dtx_enc_reset * **************************************************************************/ Word16 dtx_enc_reset(dtx_encState * st, Word16 isf_init[]) { Word32 i; if (st == (dtx_encState *) NULL) { fprintf(stderr, "dtx_enc_reset: invalid parameter\n"); return -1; } st->hist_ptr = 0; st->log_en_index = 0; /* Init isf_hist[] */ for (i = 0; i < DTX_HIST_SIZE; i++) { Copy(isf_init, &st->isf_hist[i * M], M); } st->cng_seed = RANDOM_INITSEED; /* Reset energy history */ Set_zero(st->log_en_hist, DTX_HIST_SIZE); st->dtxHangoverCount = DTX_HANG_CONST; st->decAnaElapsedCount = 32767; for (i = 0; i < 28; i++) { st->D[i] = 0; } for (i = 0; i < DTX_HIST_SIZE - 1; i++) { st->sumD[i] = 0; } return 1; } /************************************************************************** * * Function : dtx_enc_exit * **************************************************************************/ void dtx_enc_exit(dtx_encState ** st, VO_MEM_OPERATOR *pMemOP) { if (st == NULL || *st == NULL) return; /* deallocate memory */ mem_free(pMemOP, *st, VO_INDEX_ENC_AMRWB); *st = NULL; return; } /************************************************************************** * * Function : dtx_enc * **************************************************************************/ Word16 dtx_enc( dtx_encState * st, /* i/o : State struct */ Word16 isf[M], /* o : CN ISF vector */ Word16 * exc2, /* o : CN excitation */ Word16 ** prms ) { Word32 i, j; Word16 indice[7]; Word16 log_en, gain, level, exp, exp0, tmp; Word16 log_en_int_e, log_en_int_m; Word32 L_isf[M], ener32, level32; Word16 isf_order[3]; Word16 CN_dith; /* VOX mode computation of SID parameters */ log_en = 0; for (i = 0; i < M; i++) { L_isf[i] = 0; } /* average energy and isf */ for (i = 0; i < DTX_HIST_SIZE; i++) { /* Division by DTX_HIST_SIZE = 8 has been done in dtx_buffer. log_en is in Q10 */ log_en = add(log_en, st->log_en_hist[i]); } find_frame_indices(st->isf_hist, isf_order, st); aver_isf_history(st->isf_hist, isf_order, L_isf); for (j = 0; j < M; j++) { isf[j] = (Word16)(L_isf[j] >> 3); /* divide by 8 */ } /* quantize logarithmic energy to 6 bits (-6 : 66 dB) which corresponds to -2:22 in log2(E). */ /* st->log_en_index = (short)( (log_en + 2.0) * 2.625 ); */ /* increase dynamics to 7 bits (Q8) */ log_en = (log_en >> 2); /* Add 2 in Q8 = 512 to get log2(E) between 0:24 */ log_en = add(log_en, 512); /* Multiply by 2.625 to get full 6 bit range. 2.625 = 21504 in Q13. The result is in Q6 */ log_en = mult(log_en, 21504); /* Quantize Energy */ st->log_en_index = shr(log_en, 6); if(st->log_en_index > 63) { st->log_en_index = 63; } if (st->log_en_index < 0) { st->log_en_index = 0; } /* Quantize ISFs */ Qisf_ns(isf, isf, indice); Parm_serial(indice[0], 6, prms); Parm_serial(indice[1], 6, prms); Parm_serial(indice[2], 6, prms); Parm_serial(indice[3], 5, prms); Parm_serial(indice[4], 5, prms); Parm_serial((st->log_en_index), 6, prms); CN_dith = dithering_control(st); Parm_serial(CN_dith, 1, prms); /* level = (float)( pow( 2.0f, (float)st->log_en_index / 2.625 - 2.0 ) ); */ /* log2(E) in Q9 (log2(E) lies in between -2:22) */ log_en = shl(st->log_en_index, 15 - 6); /* Divide by 2.625; log_en will be between 0:24 */ log_en = mult(log_en, 12483); /* the result corresponds to log2(gain) in Q10 */ /* Find integer part */ log_en_int_e = (log_en >> 10); /* Find fractional part */ log_en_int_m = (Word16) (log_en & 0x3ff); log_en_int_m = shl(log_en_int_m, 5); /* Subtract 2 from log_en in Q9, i.e divide the gain by 2 (energy by 4) */ /* Add 16 in order to have the result of pow2 in Q16 */ log_en_int_e = add(log_en_int_e, 16 - 1); level32 = Pow2(log_en_int_e, log_en_int_m); /* Q16 */ exp0 = norm_l(level32); level32 = (level32 << exp0); /* level in Q31 */ exp0 = (15 - exp0); level = extract_h(level32); /* level in Q15 */ /* generate white noise vector */ for (i = 0; i < L_FRAME; i++) { exc2[i] = (Random(&(st->cng_seed)) >> 4); } /* gain = level / sqrt(ener) * sqrt(L_FRAME) */ /* energy of generated excitation */ ener32 = Dot_product12(exc2, exc2, L_FRAME, &exp); Isqrt_n(&ener32, &exp); gain = extract_h(ener32); gain = mult(level, gain); /* gain in Q15 */ exp = add(exp0, exp); /* Multiply by sqrt(L_FRAME)=16, i.e. shift left by 4 */ exp += 4; for (i = 0; i < L_FRAME; i++) { tmp = mult(exc2[i], gain); /* Q0 * Q15 */ exc2[i] = shl(tmp, exp); } return 0; } /************************************************************************** * * Function : dtx_buffer Purpose : handles the DTX buffer * **************************************************************************/ Word16 dtx_buffer( dtx_encState * st, /* i/o : State struct */ Word16 isf_new[], /* i : isf vector */ Word32 enr, /* i : residual energy (in L_FRAME) */ Word16 codec_mode ) { Word16 log_en; Word16 log_en_e; Word16 log_en_m; st->hist_ptr = add(st->hist_ptr, 1); if(st->hist_ptr == DTX_HIST_SIZE) { st->hist_ptr = 0; } /* copy lsp vector into buffer */ Copy(isf_new, &st->isf_hist[st->hist_ptr * M], M); /* log_en = (float)log10(enr*0.0059322)/(float)log10(2.0f); */ Log2(enr, &log_en_e, &log_en_m); /* convert exponent and mantissa to Word16 Q7. Q7 is used to simplify averaging in dtx_enc */ log_en = shl(log_en_e, 7); /* Q7 */ log_en = add(log_en, shr(log_en_m, 15 - 7)); /* Find energy per sample by multiplying with 0.0059322, i.e subtract log2(1/0.0059322) = 7.39722 The * constant 0.0059322 takes into account windowings and analysis length from autocorrelation * computations; 7.39722 in Q7 = 947 */ /* Subtract 3 dB = 0.99658 in log2(E) = 127 in Q7. */ /* log_en = sub( log_en, 947 + en_adjust[codec_mode] ); */ /* Find energy per sample (divide by L_FRAME=256), i.e subtract log2(256) = 8.0 (1024 in Q7) */ /* Subtract 3 dB = 0.99658 in log2(E) = 127 in Q7. */ log_en = sub(log_en, add(1024, en_adjust[codec_mode])); /* Insert into the buffer */ st->log_en_hist[st->hist_ptr] = log_en; return 0; } /************************************************************************** * * Function : tx_dtx_handler Purpose : adds extra speech hangover * to analyze speech on * the decoding side. **************************************************************************/ void tx_dtx_handler(dtx_encState * st, /* i/o : State struct */ Word16 vad_flag, /* i : vad decision */ Word16 * usedMode /* i/o : mode changed or not */ ) { /* this state machine is in synch with the GSMEFR txDtx machine */ st->decAnaElapsedCount = add(st->decAnaElapsedCount, 1); if (vad_flag != 0) { st->dtxHangoverCount = DTX_HANG_CONST; } else { /* non-speech */ if (st->dtxHangoverCount == 0) { /* out of decoder analysis hangover */ st->decAnaElapsedCount = 0; *usedMode = MRDTX; } else { /* in possible analysis hangover */ st->dtxHangoverCount = sub(st->dtxHangoverCount, 1); /* decAnaElapsedCount + dtxHangoverCount < DTX_ELAPSED_FRAMES_THRESH */ if (sub(add(st->decAnaElapsedCount, st->dtxHangoverCount), DTX_ELAPSED_FRAMES_THRESH) < 0) { *usedMode = MRDTX; /* if short time since decoder update, do not add extra HO */ } /* else override VAD and stay in speech mode *usedMode and add extra hangover */ } } return; } static void aver_isf_history( Word16 isf_old[], Word16 indices[], Word32 isf_aver[] ) { Word32 i, j, k; Word16 isf_tmp[2 * M]; Word32 L_tmp; /* Memorize in isf_tmp[][] the ISF vectors to be replaced by */ /* the median ISF vector prior to the averaging */ for (k = 0; k < 2; k++) { if ((indices[k] + 1) != 0) { for (i = 0; i < M; i++) { isf_tmp[k * M + i] = isf_old[indices[k] * M + i]; isf_old[indices[k] * M + i] = isf_old[indices[2] * M + i]; } } } /* Perform the ISF averaging */ for (j = 0; j < M; j++) { L_tmp = 0; for (i = 0; i < DTX_HIST_SIZE; i++) { L_tmp = L_add(L_tmp, L_deposit_l(isf_old[i * M + j])); } isf_aver[j] = L_tmp; } /* Retrieve from isf_tmp[][] the ISF vectors saved prior to averaging */ for (k = 0; k < 2; k++) { if ((indices[k] + 1) != 0) { for (i = 0; i < M; i++) { isf_old[indices[k] * M + i] = isf_tmp[k * M + i]; } } } return; } static void find_frame_indices( Word16 isf_old_tx[], Word16 indices[], dtx_encState * st ) { Word32 L_tmp, summin, summax, summax2nd; Word16 i, j, tmp; Word16 ptr; /* Remove the effect of the oldest frame from the column */ /* sum sumD[0..DTX_HIST_SIZE-1]. sumD[DTX_HIST_SIZE] is */ /* not updated since it will be removed later. */ tmp = DTX_HIST_SIZE_MIN_ONE; j = -1; for (i = 0; i < DTX_HIST_SIZE_MIN_ONE; i++) { j = add(j, tmp); st->sumD[i] = L_sub(st->sumD[i], st->D[j]); tmp = sub(tmp, 1); } /* Shift the column sum sumD. The element sumD[DTX_HIST_SIZE-1] */ /* corresponding to the oldest frame is removed. The sum of */ /* the distances between the latest isf and other isfs, */ /* i.e. the element sumD[0], will be computed during this call. */ /* Hence this element is initialized to zero. */ for (i = DTX_HIST_SIZE_MIN_ONE; i > 0; i--) { st->sumD[i] = st->sumD[i - 1]; } st->sumD[0] = 0; /* Remove the oldest frame from the distance matrix. */ /* Note that the distance matrix is replaced by a one- */ /* dimensional array to save static memory. */ tmp = 0; for (i = 27; i >= 12; i = (Word16) (i - tmp)) { tmp = add(tmp, 1); for (j = tmp; j > 0; j--) { st->D[i - j + 1] = st->D[i - j - tmp]; } } /* Compute the first column of the distance matrix D */ /* (squared Euclidean distances from isf1[] to isf_old_tx[][]). */ ptr = st->hist_ptr; for (i = 1; i < DTX_HIST_SIZE; i++) { /* Compute the distance between the latest isf and the other isfs. */ ptr = sub(ptr, 1); if (ptr < 0) { ptr = DTX_HIST_SIZE_MIN_ONE; } L_tmp = 0; for (j = 0; j < M; j++) { tmp = sub(isf_old_tx[st->hist_ptr * M + j], isf_old_tx[ptr * M + j]); L_tmp = L_mac(L_tmp, tmp, tmp); } st->D[i - 1] = L_tmp; /* Update also the column sums. */ st->sumD[0] = L_add(st->sumD[0], st->D[i - 1]); st->sumD[i] = L_add(st->sumD[i], st->D[i - 1]); } /* Find the minimum and maximum distances */ summax = st->sumD[0]; summin = st->sumD[0]; indices[0] = 0; indices[2] = 0; for (i = 1; i < DTX_HIST_SIZE; i++) { if (L_sub(st->sumD[i], summax) > 0) { indices[0] = i; summax = st->sumD[i]; } if (L_sub(st->sumD[i], summin) < 0) { indices[2] = i; summin = st->sumD[i]; } } /* Find the second largest distance */ summax2nd = -2147483647L; indices[1] = -1; for (i = 0; i < DTX_HIST_SIZE; i++) { if ((L_sub(st->sumD[i], summax2nd) > 0) && (sub(i, indices[0]) != 0)) { indices[1] = i; summax2nd = st->sumD[i]; } } for (i = 0; i < 3; i++) { indices[i] = sub(st->hist_ptr, indices[i]); if (indices[i] < 0) { indices[i] = add(indices[i], DTX_HIST_SIZE); } } /* If maximum distance/MED_THRESH is smaller than minimum distance */ /* then the median ISF vector replacement is not performed */ tmp = norm_l(summax); summax = (summax << tmp); summin = (summin << tmp); L_tmp = L_mult(voround(summax), INV_MED_THRESH); if(L_tmp <= summin) { indices[0] = -1; } /* If second largest distance/MED_THRESH is smaller than */ /* minimum distance then the median ISF vector replacement is */ /* not performed */ summax2nd = L_shl(summax2nd, tmp); L_tmp = L_mult(voround(summax2nd), INV_MED_THRESH); if(L_tmp <= summin) { indices[1] = -1; } return; } static Word16 dithering_control( dtx_encState * st ) { Word16 tmp, mean, CN_dith, gain_diff; Word32 i, ISF_diff; /* determine how stationary the spectrum of background noise is */ ISF_diff = 0; for (i = 0; i < 8; i++) { ISF_diff = L_add(ISF_diff, st->sumD[i]); } if ((ISF_diff >> 26) > 0) { CN_dith = 1; } else { CN_dith = 0; } /* determine how stationary the energy of background noise is */ mean = 0; for (i = 0; i < DTX_HIST_SIZE; i++) { mean = add(mean, st->log_en_hist[i]); } mean = (mean >> 3); gain_diff = 0; for (i = 0; i < DTX_HIST_SIZE; i++) { tmp = abs_s(sub(st->log_en_hist[i], mean)); gain_diff = add(gain_diff, tmp); } if (gain_diff > GAIN_THR) { CN_dith = 1; } return CN_dith; }