From dbd2b7e4ebfe7a586b1db4459cf6aa032a7f8719 Mon Sep 17 00:00:00 2001 From: Chia-chi Yeh Date: Thu, 19 Aug 2010 15:34:10 +0800 Subject: Visualizer: replace the FFT implementation with a faster one. This implementation uses fixed points instead of floating points. It is slightly inaccurate compared to the old one but still perfect for visualization purpose. It runs 40% faster on passion, 5 times faster on sholes, and of course 14 times faster on sapphire. Change-Id: I1e868417bcffda091becf106a7b941d02813faec --- media/libmedia/Android.mk | 7 +- media/libmedia/Visualizer.cpp | 41 ++++------- media/libmedia/fixedfft.cpp | 160 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 177 insertions(+), 31 deletions(-) create mode 100644 media/libmedia/fixedfft.cpp (limited to 'media/libmedia') diff --git a/media/libmedia/Android.mk b/media/libmedia/Android.mk index 977e6be..b4d01f5 100644 --- a/media/libmedia/Android.mk +++ b/media/libmedia/Android.mk @@ -31,7 +31,8 @@ LOCAL_SRC_FILES:= \ IEffect.cpp \ IEffectClient.cpp \ AudioEffect.cpp \ - Visualizer.cpp + Visualizer.cpp \ + fixedfft.cpp.arm LOCAL_SHARED_LIBRARIES := \ libui libcutils libutils libbinder libsonivox libicuuc libexpat libsurfaceflinger_client libcamera_client @@ -50,11 +51,7 @@ LOCAL_C_INCLUDES := \ $(JNI_H_INCLUDE) \ $(call include-path-for, graphics corecg) \ $(TOP)/external/opencore/extern_libs_v2/khronos/openmax/include \ - external/speex/include \ - external/speex/libspeex \ external/icu4c/common \ external/expat/lib -LOCAL_STATIC_LIBRARIES := libspeex - include $(BUILD_SHARED_LIBRARY) diff --git a/media/libmedia/Visualizer.cpp b/media/libmedia/Visualizer.cpp index 32cdb49..39552b6 100644 --- a/media/libmedia/Visualizer.cpp +++ b/media/libmedia/Visualizer.cpp @@ -26,10 +26,7 @@ #include -extern "C" { -#define FLOATING_POINT 1 -#include "fftwrap.h" -} +extern void fixed_fft_real(int n, int32_t *v); namespace android { @@ -47,18 +44,10 @@ Visualizer::Visualizer (int32_t priority, mCaptureCbkUser(NULL) { initCaptureSize(); - if (mCaptureSize != 0) { - mFftTable = spx_fft_init(mCaptureSize); - } else { - mFftTable = NULL; - } } Visualizer::~Visualizer() { - if (mFftTable != NULL) { - spx_fft_destroy(mFftTable); - } } status_t Visualizer::setEnabled(bool enabled) @@ -163,11 +152,6 @@ status_t Visualizer::setCaptureSize(uint32_t size) } if (status == NO_ERROR) { mCaptureSize = size; - if (mFftTable != NULL) { - spx_fft_destroy(mFftTable); - } - mFftTable = spx_fft_init(mCaptureSize); - LOGV("setCaptureSize size %d mFftTable %p", mCaptureSize, mFftTable); } return status; @@ -219,19 +203,24 @@ status_t Visualizer::getFft(uint8_t *fft) status_t Visualizer::doFft(uint8_t *fft, uint8_t *waveform) { - if (mFftTable == NULL) { - return NO_INIT; + int32_t workspace[mCaptureSize >> 1]; + int32_t nonzero = 0; + + for (uint32_t i = 0; i < mCaptureSize; i += 2) { + workspace[i >> 1] = (waveform[i] ^ 0x80) << 23; + workspace[i >> 1] |= (waveform[i + 1] ^ 0x80) << 7; + nonzero |= workspace[i >> 1]; } - float fsrc[mCaptureSize]; - for (uint32_t i = 0; i < mCaptureSize; i++) { - fsrc[i] = (int16_t)(waveform[i] ^ 0x80) << 8; + if (nonzero) { + fixed_fft_real(mCaptureSize >> 1, workspace); } - float fdst[mCaptureSize]; - spx_fft_float(mFftTable, fsrc, fdst); - for (uint32_t i = 0; i < mCaptureSize; i++) { - fft[i] = (uint8_t)((int32_t)fdst[i] >> 8); + + for (uint32_t i = 0; i < mCaptureSize; i += 2) { + fft[i] = workspace[i >> 1] >> 23; + fft[i + 1] = workspace[i >> 1] >> 7; } + return NO_ERROR; } diff --git a/media/libmedia/fixedfft.cpp b/media/libmedia/fixedfft.cpp new file mode 100644 index 0000000..28eb05a --- /dev/null +++ b/media/libmedia/fixedfft.cpp @@ -0,0 +1,160 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* A Fixed point implementation of Fast Fourier Transform (FFT). Complex numbers + * are represented by 32-bit integers, where higher 16 bits are real part and + * lower ones are imaginary part. Few compromises are made between efficiency, + * accuracy, and maintainability. To make it fast, arithmetic shifts are used + * instead of divisions, and bitwise inverses are used instead of negates. To + * keep it small, only radix-2 Cooley-Tukey algorithm is implemented, and only + * half of the twiddle factors are stored. Although there are still ways to make + * it even faster or smaller, it costs too much on one of the aspects. + */ + +#include +#include +#include + +#define LOG_FFT_SIZE 10 +#define MAX_FFT_SIZE (1 << LOG_FFT_SIZE) + +static const int32_t twiddle[MAX_FFT_SIZE / 4] = { + 0x00008000, 0xff378001, 0xfe6e8002, 0xfda58006, 0xfcdc800a, 0xfc13800f, + 0xfb4a8016, 0xfa81801e, 0xf9b88027, 0xf8ef8032, 0xf827803e, 0xf75e804b, + 0xf6958059, 0xf5cd8068, 0xf5058079, 0xf43c808b, 0xf374809e, 0xf2ac80b2, + 0xf1e480c8, 0xf11c80de, 0xf05580f6, 0xef8d8110, 0xeec6812a, 0xedff8146, + 0xed388163, 0xec718181, 0xebab81a0, 0xeae481c1, 0xea1e81e2, 0xe9588205, + 0xe892822a, 0xe7cd824f, 0xe7078276, 0xe642829d, 0xe57d82c6, 0xe4b982f1, + 0xe3f4831c, 0xe3308349, 0xe26d8377, 0xe1a983a6, 0xe0e683d6, 0xe0238407, + 0xdf61843a, 0xde9e846e, 0xdddc84a3, 0xdd1b84d9, 0xdc598511, 0xdb998549, + 0xdad88583, 0xda1885be, 0xd95885fa, 0xd8988637, 0xd7d98676, 0xd71b86b6, + 0xd65c86f6, 0xd59e8738, 0xd4e1877b, 0xd42487c0, 0xd3678805, 0xd2ab884c, + 0xd1ef8894, 0xd13488dd, 0xd0798927, 0xcfbe8972, 0xcf0489be, 0xce4b8a0c, + 0xcd928a5a, 0xccd98aaa, 0xcc218afb, 0xcb698b4d, 0xcab28ba0, 0xc9fc8bf5, + 0xc9468c4a, 0xc8908ca1, 0xc7db8cf8, 0xc7278d51, 0xc6738dab, 0xc5c08e06, + 0xc50d8e62, 0xc45b8ebf, 0xc3a98f1d, 0xc2f88f7d, 0xc2488fdd, 0xc198903e, + 0xc0e990a1, 0xc03a9105, 0xbf8c9169, 0xbedf91cf, 0xbe329236, 0xbd86929e, + 0xbcda9307, 0xbc2f9371, 0xbb8593dc, 0xbadc9448, 0xba3394b5, 0xb98b9523, + 0xb8e39592, 0xb83c9603, 0xb7969674, 0xb6f196e6, 0xb64c9759, 0xb5a897ce, + 0xb5059843, 0xb46298b9, 0xb3c09930, 0xb31f99a9, 0xb27f9a22, 0xb1df9a9c, + 0xb1409b17, 0xb0a29b94, 0xb0059c11, 0xaf689c8f, 0xaecc9d0e, 0xae319d8e, + 0xad979e0f, 0xacfd9e91, 0xac659f14, 0xabcd9f98, 0xab36a01c, 0xaaa0a0a2, + 0xaa0aa129, 0xa976a1b0, 0xa8e2a238, 0xa84fa2c2, 0xa7bda34c, 0xa72ca3d7, + 0xa69ca463, 0xa60ca4f0, 0xa57ea57e, 0xa4f0a60c, 0xa463a69c, 0xa3d7a72c, + 0xa34ca7bd, 0xa2c2a84f, 0xa238a8e2, 0xa1b0a976, 0xa129aa0a, 0xa0a2aaa0, + 0xa01cab36, 0x9f98abcd, 0x9f14ac65, 0x9e91acfd, 0x9e0fad97, 0x9d8eae31, + 0x9d0eaecc, 0x9c8faf68, 0x9c11b005, 0x9b94b0a2, 0x9b17b140, 0x9a9cb1df, + 0x9a22b27f, 0x99a9b31f, 0x9930b3c0, 0x98b9b462, 0x9843b505, 0x97ceb5a8, + 0x9759b64c, 0x96e6b6f1, 0x9674b796, 0x9603b83c, 0x9592b8e3, 0x9523b98b, + 0x94b5ba33, 0x9448badc, 0x93dcbb85, 0x9371bc2f, 0x9307bcda, 0x929ebd86, + 0x9236be32, 0x91cfbedf, 0x9169bf8c, 0x9105c03a, 0x90a1c0e9, 0x903ec198, + 0x8fddc248, 0x8f7dc2f8, 0x8f1dc3a9, 0x8ebfc45b, 0x8e62c50d, 0x8e06c5c0, + 0x8dabc673, 0x8d51c727, 0x8cf8c7db, 0x8ca1c890, 0x8c4ac946, 0x8bf5c9fc, + 0x8ba0cab2, 0x8b4dcb69, 0x8afbcc21, 0x8aaaccd9, 0x8a5acd92, 0x8a0cce4b, + 0x89becf04, 0x8972cfbe, 0x8927d079, 0x88ddd134, 0x8894d1ef, 0x884cd2ab, + 0x8805d367, 0x87c0d424, 0x877bd4e1, 0x8738d59e, 0x86f6d65c, 0x86b6d71b, + 0x8676d7d9, 0x8637d898, 0x85fad958, 0x85beda18, 0x8583dad8, 0x8549db99, + 0x8511dc59, 0x84d9dd1b, 0x84a3dddc, 0x846ede9e, 0x843adf61, 0x8407e023, + 0x83d6e0e6, 0x83a6e1a9, 0x8377e26d, 0x8349e330, 0x831ce3f4, 0x82f1e4b9, + 0x82c6e57d, 0x829de642, 0x8276e707, 0x824fe7cd, 0x822ae892, 0x8205e958, + 0x81e2ea1e, 0x81c1eae4, 0x81a0ebab, 0x8181ec71, 0x8163ed38, 0x8146edff, + 0x812aeec6, 0x8110ef8d, 0x80f6f055, 0x80def11c, 0x80c8f1e4, 0x80b2f2ac, + 0x809ef374, 0x808bf43c, 0x8079f505, 0x8068f5cd, 0x8059f695, 0x804bf75e, + 0x803ef827, 0x8032f8ef, 0x8027f9b8, 0x801efa81, 0x8016fb4a, 0x800ffc13, + 0x800afcdc, 0x8006fda5, 0x8002fe6e, 0x8001ff37, +}; + +/* Returns the multiplication of \conj{a} and {b}. */ +static inline int32_t mult(int32_t a, int32_t b) +{ +#if __ARM_ARCH__ >= 6 + int32_t t = b; + __asm__("smuad %0, %0, %1" : "+r" (t) : "r" (a)); + __asm__("smusdx %0, %0, %1" : "+r" (b) : "r" (a)); + __asm__("pkhtb %0, %0, %1, ASR #16" : "+r" (t) : "r" (b)); + return t; +#else + return (((a >> 16) * (b >> 16) + (int16_t)a * (int16_t)b) & ~0xFFFF) | + ((((a >> 16) * (int16_t)b - (int16_t)a * (b >> 16)) >> 16) & 0xFFFF); +#endif +} + +static inline int32_t half(int32_t a) +{ +#if __ARM_ARCH__ >= 6 + __asm__("shadd16 %0, %0, %1" : "+r" (a) : "r" (0)); + return a; +#else + return ((a >> 1) & ~0x8000) | (a & 0x8000); +#endif +} + +void fixed_fft(int n, int32_t *v) +{ + int scale = LOG_FFT_SIZE, i, p, r; + + for (r = 0, i = 1; i < n; ++i) { + for (p = n; !(p & r); p >>= 1, r ^= p); + if (i < r) { + int32_t t = v[i]; + v[i] = v[r]; + v[r] = t; + } + } + + for (p = 1; p < n; p <<= 1) { + --scale; + + for (i = 0; i < n; i += p << 1) { + int32_t x = half(v[i]); + int32_t y = half(v[i + p]); + v[i] = x + y; + v[i + p] = x - y; + } + + for (r = 1; r < p; ++r) { + int32_t w = MAX_FFT_SIZE / 4 - (r << scale); + i = w >> 31; + w = twiddle[(w ^ i) - i] ^ (i << 16); + for (i = r; i < n; i += p << 1) { + int32_t x = half(v[i]); + int32_t y = mult(w, v[i + p]); + v[i] = x - y; + v[i + p] = x + y; + } + } + } +} + +void fixed_fft_real(int n, int32_t *v) +{ + int scale = LOG_FFT_SIZE, m = n >> 1, i; + + fixed_fft(n, v); + for (i = 1; i <= n; i <<= 1, --scale); + v[0] = mult(~v[0], 0x80008000); + v[m] = half(v[m]); + + for (i = 1; i < n >> 1; ++i) { + int32_t x = half(v[i]); + int32_t z = half(v[n - i]); + int32_t y = z - (x ^ 0xFFFF); + x = half(x + (z ^ 0xFFFF)); + y = mult(y, twiddle[i << scale]); + v[i] = x - y; + v[n - i] = (x + y) ^ 0xFFFF; + } +} -- cgit v1.1