| /* |
| * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. |
| * |
| * 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 <stdbool.h> |
| #include <stdint.h> |
| |
| #include "dl/api/omxtypes.h" |
| #include "dl/sp/api/omxSP.h" |
| #include "dl/sp/api/x86SP.h" |
| #include "dl/sp/src/x86/x86SP_SSE_Math.h" |
| |
| extern OMX_F32* x86SP_F32_radix2_kernel_OutOfPlace( |
| const OMX_F32 *src, |
| OMX_F32 *buf1, |
| OMX_F32 *buf2, |
| const OMX_F32 *twiddle, |
| OMX_INT n, |
| bool forward_fft); |
| |
| extern OMX_F32* x86SP_F32_radix4_kernel_OutOfPlace_sse( |
| const OMX_F32 *src, |
| OMX_F32 *buf1, |
| OMX_F32 *buf2, |
| const OMX_F32 *twiddle, |
| OMX_INT n, |
| bool forward_fft); |
| |
| /** |
| * A two-for-one algorithm is used here to do the real fft: |
| * |
| * Input x[n], (n = 0, ..., N - 1) |
| * Output X[k] = DFT(N, k){x} |
| * a[n] = x[2n], (n = 0, ..., N/2 - 1) |
| * b[n] = x[2n + 1], (n = 0, ..., N/2 - 1) |
| * z[n] = a[n] + j * b[n] |
| * Z[k] = DFT(N/2, k){z} |
| * Z' is the complex conjugate of Z |
| * A[k] = (Z[k] + Z'[N/2 - k]) / 2 |
| * B[k] = -j * (Z[k] - Z'[N/2 - k]) / 2 |
| * X[k] = A[k] + B[k] * W[k], (W = exp(-j*2*PI*k/N); k = 0, ..., N/2 - 1) |
| * X[k] = A[k] - B[k], (k = N/2) |
| * X' is complex conjugate of X |
| * X[k] = X'[N - k], (k = N/2 + 1, ..., N - 1) |
| */ |
| |
| /** |
| * This function is the last permutation of two-for-one FFT algorithm. |
| * We move the division by 2 to the last step in the implementation, so: |
| * A[k] = (Z[k] + Z'[N/2 - k]) |
| * B[k] = -j * (Z[k] - Z'[N/2 - k]) |
| * X[k] = (A[k] + B[k] * W[k]) / 2, (k = 0, ..., N/2 - 1) |
| * X[k] = (A[k] - B[k]), (k = N/2) |
| * X[k] = X'[N - k], (k = N/2 + 1, ..., N - 1) |
| */ |
| static void RevbinPermuteFwd( |
| const OMX_F32 *in, |
| OMX_F32 *out, |
| const OMX_F32 *twiddle, |
| OMX_INT n) { |
| OMX_INT i; |
| OMX_INT j; |
| OMX_INT n_by_2 = n >> 1; |
| OMX_INT n_by_4 = n >> 2; |
| |
| OMX_FC32 big_a; |
| OMX_FC32 big_b; |
| OMX_FC32 temp; |
| const OMX_F32 *tw; |
| |
| for (i = 1, j = n_by_2 - 1; i < n_by_4; i++, j--) { |
| // A[k] = (Z[k] + Z'[N/2 - k]) |
| big_a.Re = in[i] + in[j]; |
| big_a.Im = in[j + n_by_2] - in[i + n_by_2]; |
| |
| // B[k] = -j * (Z[k] - Z'[N/2 - k]) |
| big_b.Re = in[j] - in[i]; |
| big_b.Im = in[j + n_by_2] + in[i + n_by_2]; |
| |
| // W[k] |
| tw = twiddle + i; |
| |
| // temp = B[k] * W[k] |
| temp.Re = big_b.Re * tw[0] + big_b.Im * tw[n]; |
| temp.Im = big_b.Re * tw[n] - big_b.Im * tw[0]; |
| |
| // Convert split format to interleaved format. |
| // X[k] = (A[k] + B[k] * W[k]) / 2, (k = 0, ..., N/2 - 1) |
| out[i << 1] = 0.5f * (big_a.Re - temp.Im); |
| out[(i << 1) + 1] = 0.5f * (temp.Re - big_a.Im); |
| // X[k] = X'[N - k] (k = N/2 + 1, ..., N - 1) |
| out[j << 1] = 0.5f * (big_a.Re + temp.Im); |
| out[(j << 1) + 1] = 0.5f * (temp.Re + big_a.Im); |
| } |
| |
| // X[k] = A[k] - B[k] (k = N/2) |
| out[n_by_2] = in[n_by_4]; |
| out[n_by_2 + 1] = -in[n_by_4 + n_by_2]; |
| |
| out[0] = in[0] + in[n_by_2]; |
| out[1] = 0; |
| out[n] = in[0] - in[n_by_2]; |
| out[n + 1] = 0; |
| } |
| |
| // Sse version of RevbinPermuteFwd function. |
| static void RevbinPermuteFwdSse( |
| const OMX_F32 *in, |
| OMX_F32 *out, |
| const OMX_F32 *twiddle, |
| OMX_INT n) { |
| OMX_INT i; |
| OMX_INT j; |
| OMX_INT n_by_2 = n >> 1; |
| OMX_INT n_by_4 = n >> 2; |
| |
| VC v_i; |
| VC v_j; |
| VC v_big_a; |
| VC v_big_b; |
| VC v_temp; |
| VC v_x0; |
| VC v_x1; |
| VC v_tw; |
| |
| __m128 factor = _mm_set1_ps(0.5f); |
| |
| for (i = 0, j = n_by_2 - 3; i < n_by_4; i += 4, j -= 4) { |
| VC_LOAD_SPLIT(&v_i, (in + i), n_by_2); |
| |
| VC_LOADU_SPLIT(&v_j, (in + j), n_by_2); |
| VC_REVERSE(&v_j); |
| |
| // A[k] = (Z[k] + Z'[N/2 - k]) |
| VC_ADD_SUB(&v_big_a, &v_j, &v_i); |
| |
| // B[k] = -j * (Z[k] - Z'[N/2 - k]) |
| VC_SUB_ADD(&v_big_b, &v_j, &v_i); |
| |
| // W[k] |
| VC_LOAD_SPLIT(&v_tw, (twiddle + i), n); |
| |
| // temp = B[k] * W[k] |
| VC_CONJ_MUL(&v_temp, &v_big_b, &v_tw); |
| |
| VC_SUB_X(&v_x0, &v_big_a, &v_temp); |
| VC_ADD_X(&v_x1, &v_big_a, &v_temp); |
| |
| VC_MUL_F(&v_x0, &v_x0, factor); |
| VC_MUL_F(&v_x1, &v_x1, factor); |
| |
| // X[k] = A[k] + B[k] * W[k] (k = 0, ..., N/2 - 1) |
| VC_STORE_INTERLEAVE((out + (i << 1)), &v_x0); |
| |
| // X[k] = X'[N - k] (k = N/2 + 1, ..., N - 1) |
| VC_REVERSE(&v_x1); |
| VC_STOREU_INTERLEAVE((out + (j << 1)), &v_x1); |
| } |
| |
| out[n_by_2] = in[n_by_4]; |
| out[n_by_2 + 1] = -in[n_by_4 + n_by_2]; |
| |
| out[0] = in[0] + in[n_by_2]; |
| out[1] = 0; |
| out[n] = in[0] - in[n_by_2]; |
| out[n + 1] = 0; |
| } |
| |
| OMXResult omxSP_FFTFwd_RToCCS_F32_Sfs(const OMX_F32 *pSrc, OMX_F32 *pDst, |
| const OMXFFTSpec_R_F32 *pFFTSpec) { |
| OMX_INT n; |
| OMX_INT n_by_2; |
| OMX_INT n_by_4; |
| const OMX_F32 *twiddle; |
| OMX_F32 *buf; |
| |
| const X86FFTSpec_R_FC32 *pFFTStruct = (const X86FFTSpec_R_FC32*) pFFTSpec; |
| |
| // Input must be 32 byte aligned |
| if (!pSrc || !pDst || (const uintptr_t)pSrc & 31 || (uintptr_t)pDst & 31) |
| return OMX_Sts_BadArgErr; |
| |
| n = pFFTStruct->N; |
| |
| // This is to handle the case of order == 1. |
| if (n == 2) { |
| pDst[0] = (pSrc[0] + pSrc[1]); |
| pDst[1] = 0.0f; |
| pDst[2] = (pSrc[0] - pSrc[1]); |
| pDst[3] = 0.0f; |
| return OMX_Sts_NoErr; |
| } |
| |
| n_by_2 = n >> 1; |
| n_by_4 = n >> 2; |
| buf = pFFTStruct->pBuf1; |
| twiddle = pFFTStruct->pTwiddle; |
| |
| if(n_by_2 >= 16) { |
| buf = x86SP_F32_radix4_kernel_OutOfPlace_sse( |
| pSrc, |
| pFFTStruct->pBuf2, |
| buf, |
| twiddle, |
| n_by_2, |
| 1); |
| } else { |
| buf = x86SP_F32_radix2_kernel_OutOfPlace( |
| pSrc, |
| pFFTStruct->pBuf2, |
| buf, |
| twiddle, |
| n_by_2, |
| 1); |
| } |
| |
| if(n >= 8) |
| RevbinPermuteFwdSse(buf, pDst, twiddle, n); |
| else |
| RevbinPermuteFwd(buf, pDst, twiddle, n); |
| |
| return OMX_Sts_NoErr; |
| } |