| /* |
| * gain code, gain pitch and pitch delay decoding |
| * |
| * Copyright (c) 2008 Vladimir Voroshilov |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg 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 |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavutil/common.h" |
| #include "libavutil/ffmath.h" |
| #include "libavutil/float_dsp.h" |
| #include "libavutil/mathematics.h" |
| #include "avcodec.h" |
| #include "acelp_pitch_delay.h" |
| #include "celp_math.h" |
| #include "audiodsp.h" |
| |
| int ff_acelp_decode_8bit_to_1st_delay3(int ac_index) |
| { |
| ac_index += 58; |
| if(ac_index > 254) |
| ac_index = 3 * ac_index - 510; |
| return ac_index; |
| } |
| |
| int ff_acelp_decode_4bit_to_2nd_delay3( |
| int ac_index, |
| int pitch_delay_min) |
| { |
| if(ac_index < 4) |
| return 3 * (ac_index + pitch_delay_min); |
| else if(ac_index < 12) |
| return 3 * pitch_delay_min + ac_index + 6; |
| else |
| return 3 * (ac_index + pitch_delay_min) - 18; |
| } |
| |
| int ff_acelp_decode_5_6_bit_to_2nd_delay3( |
| int ac_index, |
| int pitch_delay_min) |
| { |
| return 3 * pitch_delay_min + ac_index - 2; |
| } |
| |
| int ff_acelp_decode_9bit_to_1st_delay6(int ac_index) |
| { |
| if(ac_index < 463) |
| return ac_index + 105; |
| else |
| return 6 * (ac_index - 368); |
| } |
| int ff_acelp_decode_6bit_to_2nd_delay6( |
| int ac_index, |
| int pitch_delay_min) |
| { |
| return 6 * pitch_delay_min + ac_index - 3; |
| } |
| |
| void ff_acelp_update_past_gain( |
| int16_t* quant_energy, |
| int gain_corr_factor, |
| int log2_ma_pred_order, |
| int erasure) |
| { |
| int i; |
| int avg_gain=quant_energy[(1 << log2_ma_pred_order) - 1]; // (5.10) |
| |
| for(i=(1 << log2_ma_pred_order) - 1; i>0; i--) |
| { |
| avg_gain += quant_energy[i-1]; |
| quant_energy[i] = quant_energy[i-1]; |
| } |
| |
| if(erasure) |
| quant_energy[0] = FFMAX(avg_gain >> log2_ma_pred_order, -10240) - 4096; // -10 and -4 in (5.10) |
| else |
| quant_energy[0] = (6165 * ((ff_log2_q15(gain_corr_factor) >> 2) - (13 << 13))) >> 13; |
| } |
| |
| int16_t ff_acelp_decode_gain_code( |
| AudioDSPContext *adsp, |
| int gain_corr_factor, |
| const int16_t* fc_v, |
| int mr_energy, |
| const int16_t* quant_energy, |
| const int16_t* ma_prediction_coeff, |
| int subframe_size, |
| int ma_pred_order) |
| { |
| int i; |
| |
| mr_energy <<= 10; |
| |
| for(i=0; i<ma_pred_order; i++) |
| mr_energy += quant_energy[i] * ma_prediction_coeff[i]; |
| |
| #ifdef G729_BITEXACT |
| mr_energy += (((-6165LL * ff_log2(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size, 0))) >> 3) & ~0x3ff); |
| |
| mr_energy = (5439 * (mr_energy >> 15)) >> 8; // (0.15) = (0.15) * (7.23) |
| |
| return bidir_sal( |
| ((ff_exp2(mr_energy & 0x7fff) + 16) >> 5) * (gain_corr_factor >> 1), |
| (mr_energy >> 15) - 25 |
| ); |
| #else |
| mr_energy = gain_corr_factor * ff_exp10((double)mr_energy / (20 << 23)) / |
| sqrt(adsp->scalarproduct_int16(fc_v, fc_v, subframe_size)); |
| return mr_energy >> 12; |
| #endif |
| } |
| |
| float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy, |
| float *prediction_error, float energy_mean, |
| const float *pred_table) |
| { |
| // Equations 66-69: |
| // ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector) |
| // Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)). |
| float val = fixed_gain_factor * |
| ff_exp10(0.05 * |
| (avpriv_scalarproduct_float_c(pred_table, prediction_error, 4) + |
| energy_mean)) / |
| sqrtf(fixed_mean_energy ? fixed_mean_energy : 1.0); |
| |
| // update quantified prediction error energy history |
| memmove(&prediction_error[0], &prediction_error[1], |
| 3 * sizeof(prediction_error[0])); |
| prediction_error[3] = 20.0 * log10f(fixed_gain_factor); |
| |
| return val; |
| } |
| |
| void ff_decode_pitch_lag(int *lag_int, int *lag_frac, int pitch_index, |
| const int prev_lag_int, const int subframe, |
| int third_as_first, int resolution) |
| { |
| /* Note n * 10923 >> 15 is floor(x/3) for 0 <= n <= 32767 */ |
| if (subframe == 0 || (subframe == 2 && third_as_first)) { |
| |
| if (pitch_index < 197) |
| pitch_index += 59; |
| else |
| pitch_index = 3 * pitch_index - 335; |
| |
| } else { |
| if (resolution == 4) { |
| int search_range_min = av_clip(prev_lag_int - 5, PITCH_DELAY_MIN, |
| PITCH_DELAY_MAX - 9); |
| |
| // decoding with 4-bit resolution |
| if (pitch_index < 4) { |
| // integer only precision for [search_range_min, search_range_min+3] |
| pitch_index = 3 * (pitch_index + search_range_min) + 1; |
| } else if (pitch_index < 12) { |
| // 1/3 fractional precision for [search_range_min+3 1/3, search_range_min+5 2/3] |
| pitch_index += 3 * search_range_min + 7; |
| } else { |
| // integer only precision for [search_range_min+6, search_range_min+9] |
| pitch_index = 3 * (pitch_index + search_range_min - 6) + 1; |
| } |
| } else { |
| // decoding with 5 or 6 bit resolution, 1/3 fractional precision |
| pitch_index--; |
| |
| if (resolution == 5) { |
| pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN, |
| PITCH_DELAY_MAX - 19); |
| } else |
| pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN, |
| PITCH_DELAY_MAX - 9); |
| } |
| } |
| *lag_int = pitch_index * 10923 >> 15; |
| *lag_frac = pitch_index - 3 * *lag_int - 1; |
| } |
