webRTC中回声消除(AEC)模块编译时aec_rdft.c文件报错。
原因是：
局部变量ip跟全局变量冲突的问题，可以将局部变量重新命名一下，就可以通过编译了。
aec_rdft.c修改以后文件代码为：
/* * http://www.kurims.kyoto-u.ac.jp/~ooura/fft.html * Copyright Takuya OOURA, 1996-2001 * * You may use, copy, modify and distribute this code for any purpose (include * commercial use) and without fee. Please refer to this package when you modify * this code. * * Changes by the WebRTC authors: * - Trivial type modifications. * - Minimal code subset to do rdft of length 128. * - Optimizations because of known length. * * All changes are covered by the WebRTC license and IP grant: * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include "webrtc/modules/audio_processing/aec/aec_rdft.h" #include <math.h> #include "webrtc/system_wrappers/interface/cpu_features_wrapper.h" #include "webrtc/typedefs.h" // constants shared by all paths (C, SSE2). float rdft_w[64]; // constants used by the C path. float rdft_wk3ri_first[32]; float rdft_wk3ri_second[32]; // constants used by SSE2 but initialized in C path. ALIGN16_BEG float ALIGN16_END rdft_wk1r[32]; ALIGN16_BEG float ALIGN16_END rdft_wk2r[32]; ALIGN16_BEG float ALIGN16_END rdft_wk3r[32]; ALIGN16_BEG float ALIGN16_END rdft_wk1i[32]; ALIGN16_BEG float ALIGN16_END rdft_wk2i[32]; ALIGN16_BEG float ALIGN16_END rdft_wk3i[32]; ALIGN16_BEG float ALIGN16_END cftmdl_wk1r[4]; static int ip[16]; static void bitrv2_32(int* ip1, float* a) { const int n = 32; int j, j1, k, k1, m, m2; float xr, xi, yr, yi; ip1[0] = 0; { int l = n; m = 1; while ((m << 3) < l) { l >>= 1; for (j = 0; j < m; j++) { ip1[m + j] = ip1[j] + l; } m <<= 1; } } m2 = 2 * m; for (k = 0; k < m; k++) { for (j = 0; j < k; j++) { j1 = 2 * j + ip1[k]; k1 = 2 * k + ip1[j]; xr = a[j1]; xi = a[j1 + 1]; yr = a[k1]; yi = a[k1 + 1]; a[j1] = yr; a[j1 + 1] = yi; a[k1] = xr; a[k1 + 1] = xi; j1 += m2; k1 += 2 * m2; xr = a[j1]; xi = a[j1 + 1]; yr = a[k1]; yi = a[k1 + 1]; a[j1] = yr; a[j1 + 1] = yi; a[k1] = xr; a[k1 + 1] = xi; j1 += m2; k1 -= m2; xr = a[j1]; xi = a[j1 + 1]; yr = a[k1]; yi = a[k1 + 1]; a[j1] = yr; a[j1 + 1] = yi; a[k1] = xr; a[k1 + 1] = xi; j1 += m2; k1 += 2 * m2; xr = a[j1]; xi = a[j1 + 1]; yr = a[k1]; yi = a[k1 + 1]; a[j1] = yr; a[j1 + 1] = yi; a[k1] = xr; a[k1 + 1] = xi; } j1 = 2 * k + m2 + ip1[k]; k1 = j1 + m2; xr = a[j1]; xi = a[j1 + 1]; yr = a[k1]; yi = a[k1 + 1]; a[j1] = yr; a[j1 + 1] = yi; a[k1] = xr; a[k1 + 1] = xi; } } static void bitrv2_128(float* a) { /* Following things have been attempted but are no faster: (a) Storing the swap indexes in a LUT (index calculations are done for 'free' while waiting on memory/L1). (b) Consolidate the load/store of two consecutive floats by a 64 bit integer (execution is memory/L1 bound). (c) Do a mix of floats and 64 bit integer to maximize register utilization (execution is memory/L1 bound). (d) Replacing ip[i] by ((k<<31)>>25) + ((k >> 1)<<5). (e) Hard-coding of the offsets to completely eliminates index calculations. */ unsigned int j, j1, k, k1; float xr, xi, yr, yi; static const int ip2[4] = {0, 64, 32, 96}; for (k = 0; k < 4; k++) { for (j = 0; j < k; j++) { j1 = 2 * j + ip2[k]; k1 = 2 * k + ip2[j]; xr = a[j1 + 0]; xi = a[j1 + 1]; yr = a[k1 + 0]; yi = a[k1 + 1]; a[j1 + 0] = yr; a[j1 + 1] = yi; a[k1 + 0] = xr; a[k1 + 1] = xi; j1 += 8; k1 += 16; xr = a[j1 + 0]; xi = a[j1 + 1]; yr = a[k1 + 0]; yi = a[k1 + 1]; a[j1 + 0] = yr; a[j1 + 1] = yi; a[k1 + 0] = xr; a[k1 + 1] = xi; j1 += 8; k1 -= 8; xr = a[j1 + 0]; xi = a[j1 + 1]; yr = a[k1 + 0]; yi = a[k1 + 1]; a[j1 + 0] = yr; a[j1 + 1] = yi; a[k1 + 0] = xr; a[k1 + 1] = xi; j1 += 8; k1 += 16; xr = a[j1 + 0]; xi = a[j1 + 1]; yr = a[k1 + 0]; yi = a[k1 + 1]; a[j1 + 0] = yr; a[j1 + 1] = yi; a[k1 + 0] = xr; a[k1 + 1] = xi; } j1 = 2 * k + 8 + ip2[k]; k1 = j1 + 8; xr = a[j1 + 0]; xi = a[j1 + 1]; yr = a[k1 + 0]; yi = a[k1 + 1]; a[j1 + 0] = yr; a[j1 + 1] = yi; a[k1 + 0] = xr; a[k1 + 1] = xi; } } static void makewt_32(void) { const int nw = 32; int j, nwh; float delta, x, y; ip[0] = nw; ip[1] = 1; nwh = nw >> 1; delta = atanf(1.0f) / nwh; rdft_w[0] = 1; rdft_w[1] = 0; rdft_w[nwh] = cosf(delta * nwh); rdft_w[nwh + 1] = rdft_w[nwh]; for (j = 2; j < nwh; j += 2) { x = cosf(delta * j); y = sinf(delta * j); rdft_w[j] = x; rdft_w[j + 1] = y; rdft_w[nw - j] = y; rdft_w[nw - j + 1] = x; } bitrv2_32(ip + 2, rdft_w); // pre-calculate constants used by cft1st_128 and cftmdl_128... cftmdl_wk1r[0] = rdft_w[2]; cftmdl_wk1r[1] = rdft_w[2]; cftmdl_wk1r[2] = rdft_w[2]; cftmdl_wk1r[3] = -rdft_w[2]; { int k1; for (k1 = 0, j = 0; j < 128; j += 16, k1 += 2) { const int k2 = 2 * k1; const float wk2r = rdft_w[k1 + 0]; const float wk2i = rdft_w[k1 + 1]; float wk1r, wk1i; // ... scalar version. wk1r = rdft_w[k2 + 0]; wk1i = rdft_w[k2 + 1]; rdft_wk3ri_first[k1 + 0] = wk1r - 2 * wk2i * wk1i; rdft_wk3ri_first[k1 + 1] = 2 * wk2i * wk1r - wk1i; wk1r = rdft_w[k2 + 2]; wk1i = rdft_w[k2 + 3]; rdft_wk3ri_second[k1 + 0] = wk1r - 2 * wk2r * wk1i; rdft_wk3ri_second[k1 + 1] = 2 * wk2r * wk1r - wk1i; // ... vector version. rdft_wk1r[k2 + 0] = rdft_w[k2 + 0]; rdft_wk1r[k2 + 1] = rdft_w[k2 + 0]; rdft_wk1r[k2 + 2] = rdft_w[k2 + 2]; rdft_wk1r[k2 + 3] = rdft_w[k2 + 2]; rdft_wk2r[k2 + 0] = rdft_w[k1 + 0]; rdft_wk2r[k2 + 1] = rdft_w[k1 + 0]; rdft_wk2r[k2 + 2] = -rdft_w[k1 + 1]; rdft_wk2r[k2 + 3] = -rdft_w[k1 + 1]; rdft_wk3r[k2 + 0] = rdft_wk3ri_first[k1 + 0]; rdft_wk3r[k2 + 1] = rdft_wk3ri_first[k1 + 0]; rdft_wk3r[k2 + 2] = rdft_wk3ri_second[k1 + 0]; rdft_wk3r[k2 + 3] = rdft_wk3ri_second[k1 + 0]; rdft_wk1i[k2 + 0] = -rdft_w[k2 + 1]; rdft_wk1i[k2 + 1] = rdft_w[k2 + 1]; rdft_wk1i[k2 + 2] = -rdft_w[k2 + 3]; rdft_wk1i[k2 + 3] = rdft_w[k2 + 3]; rdft_wk2i[k2 + 0] = -rdft_w[k1 + 1]; rdft_wk2i[k2 + 1] = rdft_w[k1 + 1]; rdft_wk2i[k2 + 2] = -rdft_w[k1 + 0]; rdft_wk2i[k2 + 3] = rdft_w[k1 + 0]; rdft_wk3i[k2 + 0] = -rdft_wk3ri_first[k1 + 1]; rdft_wk3i[k2 + 1] = rdft_wk3ri_first[k1 + 1]; rdft_wk3i[k2 + 2] = -rdft_wk3ri_second[k1 + 1]; rdft_wk3i[k2 + 3] = rdft_wk3ri_second[k1 + 1]; } } } static void makect_32(void) { float* c = rdft_w + 32; const int nc = 32; int j, nch; float delta; ip[1] = nc; nch = nc >> 1; delta = atanf(1.0f) / nch; c[0] = cosf(delta * nch); c[nch] = 0.5f * c[0]; for (j = 1; j < nch; j++) { c[j] = 0.5f * cosf(delta * j); c[nc - j] = 0.5f * sinf(delta * j); } } static void cft1st_128_C(float* a) { const int n = 128; int j, k1, k2; float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i; float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i; x0r = a[0] + a[2]; x0i = a[1] + a[3]; x1r = a[0] - a[2]; x1i = a[1] - a[3]; x2r = a[4] + a[6]; x2i = a[5] + a[7]; x3r = a[4] - a[6]; x3i = a[5] - a[7]; a[0] = x0r + x2r; a[1] = x0i + x2i; a[4] = x0r - x2r; a[5] = x0i - x2i; a[2] = x1r - x3i; a[3] = x1i + x3r; a[6] = x1r + x3i; a[7] = x1i - x3r; wk1r = rdft_w[2]; x0r = a[8] + a[10]; x0i = a[9] + a[11]; x1r = a[8] - a[10]; x1i = a[9] - a[11]; x2r = a[12] + a[14]; x2i = a[13] + a[15]; x3r = a[12] - a[14]; x3i = a[13] - a[15]; a[8] = x0r + x2r; a[9] = x0i + x2i; a[12] = x2i - x0i; a[13] = x0r - x2r; x0r = x1r - x3i; x0i = x1i + x3r; a[10] = wk1r * (x0r - x0i); a[11] = wk1r * (x0r + x0i); x0r = x3i + x1r; x0i = x3r - x1i; a[14] = wk1r * (x0i - x0r); a[15] = wk1r * (x0i + x0r); k1 = 0; for (j = 16; j < n; j += 16) { k1 += 2; k2 = 2 * k1; wk2r = rdft_w[k1 + 0]; wk2i = rdft_w[k1 + 1]; wk1r = rdft_w[k2 + 0]; wk1i = rdft_w[k2 + 1]; wk3r = rdft_wk3ri_first[k1 + 0]; wk3i = rdft_wk3ri_first[k1 + 1]; x0r = a[j + 0] + a[j + 2]; x0i = a[j + 1] + a[j + 3]; x1r = a[j + 0] - a[j + 2]; x1i = a[j + 1] - a[j + 3]; x2r = a[j + 4] + a[j + 6]; x2i = a[j + 5] + a[j + 7]; x3r = a[j + 4] - a[j + 6]; x3i = a[j + 5] - a[j + 7]; a[j + 0] = x0r + x2r; a[j + 1] = x0i + x2i; x0r -= x2r; x0i -= x2i; a[j + 4] = wk2r * x0r - wk2i * x0i; a[j + 5] = wk2r * x0i + wk2i * x0r; x0r = x1r - x3i; x0i = x1i + x3r; a[j + 2] = wk1r * x0r - wk1i * x0i; a[j + 3] = wk1r * x0i + wk1i * x0r; x0r = x1r + x3i; x0i = x1i - x3r; a[j + 6] = wk3r * x0r - wk3i * x0i; a[j + 7] = wk3r * x0i + wk3i * x0r; wk1r = rdft_w[k2 + 2]; wk1i = rdft_w[k2 + 3]; wk3r = rdft_wk3ri_second[k1 + 0]; wk3i = rdft_wk3ri_second[k1 + 1]; x0r = a[j + 8] + a[j + 10]; x0i = a[j + 9] + a[j + 11]; x1r = a[j + 8] - a[j + 10]; x1i = a[j + 9] - a[j + 11]; x2r = a[j + 12] + a[j + 14]; x2i = a[j + 13] + a[j + 15]; x3r = a[j + 12] - a[j + 14]; x3i = a[j + 13] - a[j + 15]; a[j + 8] = x0r + x2r; a[j + 9] = x0i + x2i; x0r -= x2r; x0i -= x2i; a[j + 12] = -wk2i * x0r - wk2r * x0i; a[j + 13] = -wk2i * x0i + wk2r * x0r; x0r = x1r - x3i; x0i = x1i + x3r; a[j + 10] = wk1r * x0r - wk1i * x0i; a[j + 11] = wk1r * x0i + wk1i * x0r; x0r = x1r + x3i; x0i = x1i - x3r; a[j + 14] = wk3r * x0r - wk3i * x0i; a[j + 15] = wk3r * x0i + wk3i * x0r; } } static void cftmdl_128_C(float* a) { const int l = 8; const int n = 128; const int m = 32; int j0, j1, j2, j3, k, k1, k2, m2; float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i; float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i; for (j0 = 0; j0 < l; j0 += 2) { j1 = j0 + 8; j2 = j0 + 16; j3 = j0 + 24; x0r = a[j0 + 0] + a[j1 + 0]; x0i = a[j0 + 1] + a[j1 + 1]; x1r = a[j0 + 0] - a[j1 + 0]; x1i = a[j0 + 1] - a[j1 + 1]; x2r = a[j2 + 0] + a[j3 + 0]; x2i = a[j2 + 1] + a[j3 + 1]; x3r = a[j2 + 0] - a[j3 + 0]; x3i = a[j2 + 1] - a[j3 + 1]; a[j0 + 0] = x0r + x2r; a[j0 + 1] = x0i + x2i; a[j2 + 0] = x0r - x2r; a[j2 + 1] = x0i - x2i; a[j1 + 0] = x1r - x3i; a[j1 + 1] = x1i + x3r; a[j3 + 0] = x1r + x3i; a[j3 + 1] = x1i - x3r; } wk1r = rdft_w[2]; for (j0 = m; j0 < l + m; j0 += 2) { j1 = j0 + 8; j2 = j0 + 16; j3 = j0 + 24; x0r = a[j0 + 0] + a[j1 + 0]; x0i = a[j0 + 1] + a[j1 + 1]; x1r = a[j0 + 0] - a[j1 + 0]; x1i = a[j0 + 1] - a[j1 + 1]; x2r = a[j2 + 0] + a[j3 + 0]; x2i = a[j2 + 1] + a[j3 + 1]; x3r = a[j2 + 0] - a[j3 + 0]; x3i = a[j2 + 1] - a[j3 + 1]; a[j0 + 0] = x0r + x2r; a[j0 + 1] = x0i + x2i; a[j2 + 0] = x2i - x0i; a[j2 + 1] = x0r - x2r; x0r = x1r - x3i; x0i = x1i + x3r; a[j1 + 0] = wk1r * (x0r - x0i); a[j1 + 1] = wk1r * (x0r + x0i); x0r = x3i + x1r; x0i = x3r - x1i; a[j3 + 0] = wk1r * (x0i - x0r); a[j3 + 1] = wk1r * (x0i + x0r); } k1 = 0; m2 = 2 * m; for (k = m2; k < n; k += m2) { k1 += 2; k2 = 2 * k1; wk2r = rdft_w[k1 + 0]; wk2i = rdft_w[k1 + 1]; wk1r = rdft_w[k2 + 0]; wk1i = rdft_w[k2 + 1]; wk3r = rdft_wk3ri_first[k1 + 0]; wk3i = rdft_wk3ri_first[k1 + 1]; for (j0 = k; j0 < l + k; j0 += 2) { j1 = j0 + 8; j2 = j0 + 16; j3 = j0 + 24; x0r = a[j0 + 0] + a[j1 + 0]; x0i = a[j0 + 1] + a[j1 + 1]; x1r = a[j0 + 0] - a[j1 + 0]; x1i = a[j0 + 1] - a[j1 + 1]; x2r = a[j2 + 0] + a[j3 + 0]; x2i = a[j2 + 1] + a[j3 + 1]; x3r = a[j2 + 0] - a[j3 + 0]; x3i = a[j2 + 1] - a[j3 + 1]; a[j0 + 0] = x0r + x2r; a[j0 + 1] = x0i + x2i; x0r -= x2r; x0i -= x2i; a[j2 + 0] = wk2r * x0r - wk2i * x0i; a[j2 + 1] = wk2r * x0i + wk2i * x0r; x0r = x1r - x3i; x0i = x1i + x3r; a[j1 + 0] = wk1r * x0r - wk1i * x0i; a[j1 + 1] = wk1r * x0i + wk1i * x0r; x0r = x1r + x3i; x0i = x1i - x3r; a[j3 + 0] = wk3r * x0r - wk3i * x0i; a[j3 + 1] = wk3r * x0i + wk3i * x0r; } wk1r = rdft_w[k2 + 2]; wk1i = rdft_w[k2 + 3]; wk3r = rdft_wk3ri_second[k1 + 0]; wk3i = rdft_wk3ri_second[k1 + 1]; for (j0 = k + m; j0 < l + (k + m); j0 += 2) { j1 = j0 + 8; j2 = j0 + 16; j3 = j0 + 24; x0r = a[j0 + 0] + a[j1 + 0]; x0i = a[j0 + 1] + a[j1 + 1]; x1r = a[j0 + 0] - a[j1 + 0]; x1i = a[j0 + 1] - a[j1 + 1]; x2r = a[j2 + 0] + a[j3 + 0]; x2i = a[j2 + 1] + a[j3 + 1]; x3r = a[j2 + 0] - a[j3 + 0]; x3i = a[j2 + 1] - a[j3 + 1]; a[j0 + 0] = x0r + x2r; a[j0 + 1] = x0i + x2i; x0r -= x2r; x0i -= x2i; a[j2 + 0] = -wk2i * x0r - wk2r * x0i; a[j2 + 1] = -wk2i * x0i + wk2r * x0r; x0r = x1r - x3i; x0i = x1i + x3r; a[j1 + 0] = wk1r * x0r - wk1i * x0i; a[j1 + 1] = wk1r * x0i + wk1i * x0r; x0r = x1r + x3i; x0i = x1i - x3r; a[j3 + 0] = wk3r * x0r - wk3i * x0i; a[j3 + 1] = wk3r * x0i + wk3i * x0r; } } } static void cftfsub_128(float* a) { int j, j1, j2, j3, l; float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i; cft1st_128(a); cftmdl_128(a); l = 32; for (j = 0; j < l; j += 2) { j1 = j + l; j2 = j1 + l; j3 = j2 + l; x0r = a[j] + a[j1]; x0i = a[j + 1] + a[j1 + 1]; x1r = a[j] - a[j1]; x1i = a[j + 1] - a[j1 + 1]; x2r = a[j2] + a[j3]; x2i = a[j2 + 1] + a[j3 + 1]; x3r = a[j2] - a[j3]; x3i = a[j2 + 1] - a[j3 + 1]; a[j] = x0r + x2r; a[j + 1] = x0i + x2i; a[j2] = x0r - x2r; a[j2 + 1] = x0i - x2i; a[j1] = x1r - x3i; a[j1 + 1] = x1i + x3r; a[j3] = x1r + x3i; a[j3 + 1] = x1i - x3r; } } static void cftbsub_128(float* a) { int j, j1, j2, j3, l; float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i; cft1st_128(a); cftmdl_128(a); l = 32; for (j = 0; j < l; j += 2) { j1 = j + l; j2 = j1 + l; j3 = j2 + l; x0r = a[j] + a[j1]; x0i = -a[j + 1] - a[j1 + 1]; x1r = a[j] - a[j1]; x1i = -a[j + 1] + a[j1 + 1]; x2r = a[j2] + a[j3]; x2i = a[j2 + 1] + a[j3 + 1]; x3r = a[j2] - a[j3]; x3i = a[j2 + 1] - a[j3 + 1]; a[j] = x0r + x2r; a[j + 1] = x0i - x2i; a[j2] = x0r - x2r; a[j2 + 1] = x0i + x2i; a[j1] = x1r - x3i; a[j1 + 1] = x1i - x3r; a[j3] = x1r + x3i; a[j3 + 1] = x1i + x3r; } } static void rftfsub_128_C(float* a) { const float* c = rdft_w + 32; int j1, j2, k1, k2; float wkr, wki, xr, xi, yr, yi; for (j1 = 1, j2 = 2; j2 < 64; j1 += 1, j2 += 2) { k2 = 128 - j2; k1 = 32 - j1; wkr = 0.5f - c[k1]; wki = c[j1]; xr = a[j2 + 0] - a[k2 + 0]; xi = a[j2 + 1] + a[k2 + 1]; yr = wkr * xr - wki * xi; yi = wkr * xi + wki * xr; a[j2 + 0] -= yr; a[j2 + 1] -= yi; a[k2 + 0] += yr; a[k2 + 1] -= yi; } } static void rftbsub_128_C(float* a) { const float* c = rdft_w + 32; int j1, j2, k1, k2; float wkr, wki, xr, xi, yr, yi; a[1] = -a[1]; for (j1 = 1, j2 = 2; j2 < 64; j1 += 1, j2 += 2) { k2 = 128 - j2; k1 = 32 - j1; wkr = 0.5f - c[k1]; wki = c[j1]; xr = a[j2 + 0] - a[k2 + 0]; xi = a[j2 + 1] + a[k2 + 1]; yr = wkr * xr + wki * xi; yi = wkr * xi - wki * xr; a[j2 + 0] = a[j2 + 0] - yr; a[j2 + 1] = yi - a[j2 + 1]; a[k2 + 0] = yr + a[k2 + 0]; a[k2 + 1] = yi - a[k2 + 1]; } a[65] = -a[65]; } void aec_rdft_forward_128(float* a) { float xi; bitrv2_128(a); cftfsub_128(a); rftfsub_128(a); xi = a[0] - a[1]; a[0] += a[1]; a[1] = xi; } void aec_rdft_inverse_128(float* a) { a[1] = 0.5f * (a[0] - a[1]); a[0] -= a[1]; rftbsub_128(a); bitrv2_128(a); cftbsub_128(a); } // code path selection rft_sub_128_t cft1st_128; rft_sub_128_t cftmdl_128; rft_sub_128_t rftfsub_128; rft_sub_128_t rftbsub_128; void aec_rdft_init(void) { cft1st_128 = cft1st_128_C; cftmdl_128 = cftmdl_128_C; rftfsub_128 = rftfsub_128_C; rftbsub_128 = rftbsub_128_C; #if defined(WEBRTC_ARCH_X86_FAMILY) if (WebRtc_GetCPUInfo(kSSE2)) { aec_rdft_init_sse2(); } #endif // init library constants. makewt_32(); makect_32(); }