diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/dtx.c')
-rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/dtx.c | 605 |
1 files changed, 605 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/dtx.c b/media/libstagefright/codecs/amrwbenc/src/dtx.c new file mode 100644 index 0000000..2cfaced --- /dev/null +++ b/media/libstagefright/codecs/amrwbenc/src/dtx.c @@ -0,0 +1,605 @@ +/* + ** 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 <stdio.h> +#include <stdlib.h> +#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; +} |