yading@10: /* yading@10: * gain code, gain pitch and pitch delay decoding yading@10: * yading@10: * Copyright (c) 2008 Vladimir Voroshilov yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: #include "libavutil/common.h" yading@10: #include "libavutil/float_dsp.h" yading@10: #include "libavutil/libm.h" yading@10: #include "libavutil/mathematics.h" yading@10: #include "avcodec.h" yading@10: #include "acelp_pitch_delay.h" yading@10: #include "celp_math.h" yading@10: yading@10: int ff_acelp_decode_8bit_to_1st_delay3(int ac_index) yading@10: { yading@10: ac_index += 58; yading@10: if(ac_index > 254) yading@10: ac_index = 3 * ac_index - 510; yading@10: return ac_index; yading@10: } yading@10: yading@10: int ff_acelp_decode_4bit_to_2nd_delay3( yading@10: int ac_index, yading@10: int pitch_delay_min) yading@10: { yading@10: if(ac_index < 4) yading@10: return 3 * (ac_index + pitch_delay_min); yading@10: else if(ac_index < 12) yading@10: return 3 * pitch_delay_min + ac_index + 6; yading@10: else yading@10: return 3 * (ac_index + pitch_delay_min) - 18; yading@10: } yading@10: yading@10: int ff_acelp_decode_5_6_bit_to_2nd_delay3( yading@10: int ac_index, yading@10: int pitch_delay_min) yading@10: { yading@10: return 3 * pitch_delay_min + ac_index - 2; yading@10: } yading@10: yading@10: int ff_acelp_decode_9bit_to_1st_delay6(int ac_index) yading@10: { yading@10: if(ac_index < 463) yading@10: return ac_index + 105; yading@10: else yading@10: return 6 * (ac_index - 368); yading@10: } yading@10: int ff_acelp_decode_6bit_to_2nd_delay6( yading@10: int ac_index, yading@10: int pitch_delay_min) yading@10: { yading@10: return 6 * pitch_delay_min + ac_index - 3; yading@10: } yading@10: yading@10: void ff_acelp_update_past_gain( yading@10: int16_t* quant_energy, yading@10: int gain_corr_factor, yading@10: int log2_ma_pred_order, yading@10: int erasure) yading@10: { yading@10: int i; yading@10: int avg_gain=quant_energy[(1 << log2_ma_pred_order) - 1]; // (5.10) yading@10: yading@10: for(i=(1 << log2_ma_pred_order) - 1; i>0; i--) yading@10: { yading@10: avg_gain += quant_energy[i-1]; yading@10: quant_energy[i] = quant_energy[i-1]; yading@10: } yading@10: yading@10: if(erasure) yading@10: quant_energy[0] = FFMAX(avg_gain >> log2_ma_pred_order, -10240) - 4096; // -10 and -4 in (5.10) yading@10: else yading@10: quant_energy[0] = (6165 * ((ff_log2_q15(gain_corr_factor) >> 2) - (13 << 13))) >> 13; yading@10: } yading@10: yading@10: int16_t ff_acelp_decode_gain_code( yading@10: DSPContext *dsp, yading@10: int gain_corr_factor, yading@10: const int16_t* fc_v, yading@10: int mr_energy, yading@10: const int16_t* quant_energy, yading@10: const int16_t* ma_prediction_coeff, yading@10: int subframe_size, yading@10: int ma_pred_order) yading@10: { yading@10: int i; yading@10: yading@10: mr_energy <<= 10; yading@10: yading@10: for(i=0; iscalarproduct_int16(fc_v, fc_v, subframe_size, 0))) >> 3) & ~0x3ff); yading@10: yading@10: mr_energy = (5439 * (mr_energy >> 15)) >> 8; // (0.15) = (0.15) * (7.23) yading@10: yading@10: return bidir_sal( yading@10: ((ff_exp2(mr_energy & 0x7fff) + 16) >> 5) * (gain_corr_factor >> 1), yading@10: (mr_energy >> 15) - 25 yading@10: ); yading@10: #else yading@10: mr_energy = gain_corr_factor * exp(M_LN10 / (20 << 23) * mr_energy) / yading@10: sqrt(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size)); yading@10: return mr_energy >> 12; yading@10: #endif yading@10: } yading@10: yading@10: float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy, yading@10: float *prediction_error, float energy_mean, yading@10: const float *pred_table) yading@10: { yading@10: // Equations 66-69: yading@10: // ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector) yading@10: // Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)). yading@10: float val = fixed_gain_factor * yading@10: exp2f(M_LOG2_10 * 0.05 * yading@10: (avpriv_scalarproduct_float_c(pred_table, prediction_error, 4) + yading@10: energy_mean)) / yading@10: sqrtf(fixed_mean_energy); yading@10: yading@10: // update quantified prediction error energy history yading@10: memmove(&prediction_error[0], &prediction_error[1], yading@10: 3 * sizeof(prediction_error[0])); yading@10: prediction_error[3] = 20.0 * log10f(fixed_gain_factor); yading@10: yading@10: return val; yading@10: } yading@10: yading@10: void ff_decode_pitch_lag(int *lag_int, int *lag_frac, int pitch_index, yading@10: const int prev_lag_int, const int subframe, yading@10: int third_as_first, int resolution) yading@10: { yading@10: /* Note n * 10923 >> 15 is floor(x/3) for 0 <= n <= 32767 */ yading@10: if (subframe == 0 || (subframe == 2 && third_as_first)) { yading@10: yading@10: if (pitch_index < 197) yading@10: pitch_index += 59; yading@10: else yading@10: pitch_index = 3 * pitch_index - 335; yading@10: yading@10: } else { yading@10: if (resolution == 4) { yading@10: int search_range_min = av_clip(prev_lag_int - 5, PITCH_DELAY_MIN, yading@10: PITCH_DELAY_MAX - 9); yading@10: yading@10: // decoding with 4-bit resolution yading@10: if (pitch_index < 4) { yading@10: // integer only precision for [search_range_min, search_range_min+3] yading@10: pitch_index = 3 * (pitch_index + search_range_min) + 1; yading@10: } else if (pitch_index < 12) { yading@10: // 1/3 fractional precision for [search_range_min+3 1/3, search_range_min+5 2/3] yading@10: pitch_index += 3 * search_range_min + 7; yading@10: } else { yading@10: // integer only precision for [search_range_min+6, search_range_min+9] yading@10: pitch_index = 3 * (pitch_index + search_range_min - 6) + 1; yading@10: } yading@10: } else { yading@10: // decoding with 5 or 6 bit resolution, 1/3 fractional precision yading@10: pitch_index--; yading@10: yading@10: if (resolution == 5) { yading@10: pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN, yading@10: PITCH_DELAY_MAX - 19); yading@10: } else yading@10: pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN, yading@10: PITCH_DELAY_MAX - 9); yading@10: } yading@10: } yading@10: *lag_int = pitch_index * 10923 >> 15; yading@10: *lag_frac = pitch_index - 3 * *lag_int - 1; yading@10: }