yading@10: /* yading@10: * various filters for ACELP-based codecs 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 yading@10: yading@10: #include "libavutil/avassert.h" yading@10: #include "libavutil/common.h" yading@10: #include "avcodec.h" yading@10: #include "acelp_filters.h" yading@10: yading@10: const int16_t ff_acelp_interp_filter[61] = { /* (0.15) */ yading@10: 29443, 28346, 25207, 20449, 14701, 8693, yading@10: 3143, -1352, -4402, -5865, -5850, -4673, yading@10: -2783, -672, 1211, 2536, 3130, 2991, yading@10: 2259, 1170, 0, -1001, -1652, -1868, yading@10: -1666, -1147, -464, 218, 756, 1060, yading@10: 1099, 904, 550, 135, -245, -514, yading@10: -634, -602, -451, -231, 0, 191, yading@10: 308, 340, 296, 198, 78, -36, yading@10: -120, -163, -165, -132, -79, -19, yading@10: 34, 73, 91, 89, 70, 38, yading@10: 0, yading@10: }; yading@10: yading@10: void ff_acelp_interpolate(int16_t* out, const int16_t* in, yading@10: const int16_t* filter_coeffs, int precision, yading@10: int frac_pos, int filter_length, int length) yading@10: { yading@10: int n, i; yading@10: yading@10: av_assert1(frac_pos >= 0 && frac_pos < precision); yading@10: yading@10: for (n = 0; n < length; n++) { yading@10: int idx = 0; yading@10: int v = 0x4000; yading@10: yading@10: for (i = 0; i < filter_length;) { yading@10: yading@10: /* The reference G.729 and AMR fixed point code performs clipping after yading@10: each of the two following accumulations. yading@10: Since clipping affects only the synthetic OVERFLOW test without yading@10: causing an int type overflow, it was moved outside the loop. */ yading@10: yading@10: /* R(x):=ac_v[-k+x] yading@10: v += R(n-i)*ff_acelp_interp_filter(t+6i) yading@10: v += R(n+i+1)*ff_acelp_interp_filter(6-t+6i) */ yading@10: yading@10: v += in[n + i] * filter_coeffs[idx + frac_pos]; yading@10: idx += precision; yading@10: i++; yading@10: v += in[n - i] * filter_coeffs[idx - frac_pos]; yading@10: } yading@10: if (av_clip_int16(v >> 15) != (v >> 15)) yading@10: av_log(NULL, AV_LOG_WARNING, "overflow that would need cliping in ff_acelp_interpolate()\n"); yading@10: out[n] = v >> 15; yading@10: } yading@10: } yading@10: yading@10: void ff_acelp_interpolatef(float *out, const float *in, yading@10: const float *filter_coeffs, int precision, yading@10: int frac_pos, int filter_length, int length) yading@10: { yading@10: int n, i; yading@10: yading@10: for (n = 0; n < length; n++) { yading@10: int idx = 0; yading@10: float v = 0; yading@10: yading@10: for (i = 0; i < filter_length;) { yading@10: v += in[n + i] * filter_coeffs[idx + frac_pos]; yading@10: idx += precision; yading@10: i++; yading@10: v += in[n - i] * filter_coeffs[idx - frac_pos]; yading@10: } yading@10: out[n] = v; yading@10: } yading@10: } yading@10: yading@10: yading@10: void ff_acelp_high_pass_filter(int16_t* out, int hpf_f[2], yading@10: const int16_t* in, int length) yading@10: { yading@10: int i; yading@10: int tmp; yading@10: yading@10: for (i = 0; i < length; i++) { yading@10: tmp = (hpf_f[0]* 15836LL) >> 13; yading@10: tmp += (hpf_f[1]* -7667LL) >> 13; yading@10: tmp += 7699 * (in[i] - 2*in[i-1] + in[i-2]); yading@10: yading@10: /* With "+0x800" rounding, clipping is needed yading@10: for ALGTHM and SPEECH tests. */ yading@10: out[i] = av_clip_int16((tmp + 0x800) >> 12); yading@10: yading@10: hpf_f[1] = hpf_f[0]; yading@10: hpf_f[0] = tmp; yading@10: } yading@10: } yading@10: yading@10: void ff_acelp_apply_order_2_transfer_function(float *out, const float *in, yading@10: const float zero_coeffs[2], yading@10: const float pole_coeffs[2], yading@10: float gain, float mem[2], int n) yading@10: { yading@10: int i; yading@10: float tmp; yading@10: yading@10: for (i = 0; i < n; i++) { yading@10: tmp = gain * in[i] - pole_coeffs[0] * mem[0] - pole_coeffs[1] * mem[1]; yading@10: out[i] = tmp + zero_coeffs[0] * mem[0] + zero_coeffs[1] * mem[1]; yading@10: yading@10: mem[1] = mem[0]; yading@10: mem[0] = tmp; yading@10: } yading@10: } yading@10: yading@10: void ff_tilt_compensation(float *mem, float tilt, float *samples, int size) yading@10: { yading@10: float new_tilt_mem = samples[size - 1]; yading@10: int i; yading@10: yading@10: for (i = size - 1; i > 0; i--) yading@10: samples[i] -= tilt * samples[i - 1]; yading@10: yading@10: samples[0] -= tilt * *mem; yading@10: *mem = new_tilt_mem; yading@10: } yading@10: yading@10: void ff_acelp_filter_init(ACELPFContext *c) yading@10: { yading@10: c->acelp_interpolatef = ff_acelp_interpolatef; yading@10: c->acelp_apply_order_2_transfer_function = ff_acelp_apply_order_2_transfer_function; yading@10: yading@10: if(HAVE_MIPSFPU) yading@10: ff_acelp_filter_init_mips(c); yading@10: }