Visualizer: replace the FFT implementation with a faster one. (58d3bd08) · Commits · e / os / android_frameworks_base

include/media/Visualizer.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -151,7 +151,6 @@ private:
		void *mCaptureCbkUser;
		sp<CaptureThread> mCaptureThread;
		uint32_t mCaptureFlags;
		void *mFftTable;
		};

media/libmedia/Android.mk

+2 −5

Original line number	Diff line number	Diff line
		@@ -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)

media/libmedia/Visualizer.cpp

+15 −26

Original line number	Diff line number	Diff line
		@@ -26,10 +26,7 @@

		#include <media/Visualizer.h>

		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;
		}

media/libmedia/fixedfft.cpp

0 → 100644

+160 −0

Original line number	Diff line number	Diff line
		/*
		* 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 <stdio.h>
		#include <stdint.h>
		#include <machine/cpu-features.h>

		#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;
		}
		}