stagefright: Remove unused ClockEstimator and TimeSource (f76ecd3c) · Commits · e / os / android_frameworks_av

include/media/stagefright/ClockEstimator.h

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		/*
		**
		** Copyright 2014, 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.
		*/

		#ifndef CLOCK_ESTIMATOR_H_

		#define CLOCK_ESTIMATOR_H_

		#include "foundation/ABase.h"
		#include <utils/RefBase.h>
		#include <utils/Vector.h>

		namespace android {
		// ---------------------------------------------------------------------------

		struct ClockEstimator : RefBase {
		virtual double estimate(double x, double y) = 0;
		virtual void reset() = 0;
		};

		struct WindowedLinearFitEstimator : ClockEstimator {
		struct LinearFit {
		/**
		* Fit y = a * x + b, where each input has a weight
		*/
		double mX; // sum(w_i * x_i)
		double mXX; // sum(w_i * x_i^2)
		double mY; // sum(w_i * y_i)
		double mYY; // sum(w_i * y_i^2)
		double mXY; // sum(w_i * x_i * y_i)
		double mW; // sum(w_i)

		LinearFit();
		void reset();
		void combine(const LinearFit &lf);
		void add(double x, double y, double w);
		void scale(double w);
		double interpolate(double x);
		double size() const;

		DISALLOW_EVIL_CONSTRUCTORS(LinearFit);
		};

		/**
		* Estimator for f(x) = y' where input y' is noisy, but
		* theoretically linear:
		*
		* y' =~ y = a * x + b
		*
		* It uses linear fit regression over a tapering rolling window
		* to get an estimate for y (from the current and past inputs
		* (x, y')).
		*
		* ____________
		* /\| \|\
		* / \| \| \
		* / \| \| \ <--- new data (x, y')
		* / \| main \| \
		* <--><----------><-->
		* tail head
		*
		* weight is 1 under the main window, tapers exponentially by
		* the factors given in the head and the tail.
		*
		* Assuming that x and y' are monotonic, that x is somewhat
		* evenly sampled, and that a =~ 1, the estimated y is also
		* going to be monotonic.
		*/
		WindowedLinearFitEstimator(
		size_t headLength = 5, double headFactor = 0.5,
		size_t mainLength = 0, double tailFactor = 0.99);

		virtual void reset();

		// add a new sample (x -> y') and return an estimated value for the true y
		virtual double estimate(double x, double y);

		private:
		Vector<double> mXHistory; // circular buffer
		Vector<double> mYHistory; // circular buffer
		LinearFit mHead;
		LinearFit mMain;
		LinearFit mTail;
		double mHeadFactorInv;
		double mTailFactor;
		double mFirstWeight;
		size_t mHistoryLength;
		size_t mHeadLength;
		size_t mNumSamples;
		size_t mSampleIx;

		DISALLOW_EVIL_CONSTRUCTORS(WindowedLinearFitEstimator);
		};

		}; // namespace android

		#endif

include/media/stagefright/TimeSource.h

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		/*
		* Copyright (C) 2009 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.
		*/

		#ifndef TIME_SOURCE_H_

		#define TIME_SOURCE_H_

		#include <stdint.h>

		namespace android {

		class TimeSource {
		public:
		TimeSource() {}
		virtual ~TimeSource() {}

		virtual int64_t getRealTimeUs() = 0;

		private:
		TimeSource(const TimeSource &);
		TimeSource &operator=(const TimeSource &);
		};

		class SystemTimeSource : public TimeSource {
		public:
		SystemTimeSource();

		virtual int64_t getRealTimeUs();

		private:
		int64_t mStartTimeUs;
		};

		} // namespace android

		#endif // TIME_SOURCE_H_

media/libstagefright/Android.mk

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		@@ -13,7 +13,6 @@ LOCAL_SRC_FILES:= \
		CallbackDataSource.cpp \
		CameraSource.cpp \
		CameraSourceTimeLapse.cpp \
		ClockEstimator.cpp \
		CodecBase.cpp \
		DataSource.cpp \
		DataURISource.cpp \
		@@ -58,7 +57,6 @@ LOCAL_SRC_FILES:= \
		SurfaceMediaSource.cpp \
		SurfaceUtils.cpp \
		ThrottledSource.cpp \
		TimeSource.cpp \
		Utils.cpp \
		VBRISeeker.cpp \
		VideoFrameScheduler.cpp \

media/libstagefright/ClockEstimator.cpp

deleted100644 → 0

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		/*
		**
		** Copyright 2014, 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.
		*/

		//#define LOG_NDEBUG 0
		#define LOG_TAG "ClockEstimator"
		#include <utils/Log.h>

		#include <math.h>
		#include <media/stagefright/ClockEstimator.h>

		#include <media/stagefright/foundation/ADebug.h>

		namespace android {

		WindowedLinearFitEstimator::WindowedLinearFitEstimator(
		size_t headLength, double headFactor, size_t mainLength, double tailFactor)
		: mHeadFactorInv(1. / headFactor),
		mTailFactor(tailFactor),
		mHistoryLength(mainLength + headLength),
		mHeadLength(headLength) {
		reset();
		mXHistory.resize(mHistoryLength);
		mYHistory.resize(mHistoryLength);
		mFirstWeight = pow(headFactor, mHeadLength);
		}

		WindowedLinearFitEstimator::LinearFit::LinearFit() {
		reset();
		}

		void WindowedLinearFitEstimator::LinearFit::reset() {
		mX = mXX = mY = mYY = mXY = mW = 0.;
		}

		double WindowedLinearFitEstimator::LinearFit::size() const {
		double s = mW * mW + mX * mX + mY * mY + mXX * mXX + mXY * mXY + mYY * mYY;
		if (s > 1e72) {
		// 1e72 corresponds to clock monotonic time of about 8 years
		ALOGW("estimator is overflowing: w=%g x=%g y=%g xx=%g xy=%g yy=%g",
		mW, mX, mY, mXX, mXY, mYY);
		}
		return s;
		}

		void WindowedLinearFitEstimator::LinearFit::add(double x, double y, double w) {
		mW += w;
		mX += w * x;
		mY += w * y;
		mXX += w * x * x;
		mXY += w * x * y;
		mYY += w * y * y;
		}

		void WindowedLinearFitEstimator::LinearFit::combine(const LinearFit &lf) {
		mW += lf.mW;
		mX += lf.mX;
		mY += lf.mY;
		mXX += lf.mXX;
		mXY += lf.mXY;
		mYY += lf.mYY;
		}

		void WindowedLinearFitEstimator::LinearFit::scale(double w) {
		mW *= w;
		mX *= w;
		mY *= w;
		mXX *= w;
		mXY *= w;
		mYY *= w;
		}

		double WindowedLinearFitEstimator::LinearFit::interpolate(double x) {
		double div = mW * mXX - mX * mX;
		if (fabs(div) < 1e-5 * mW * mW) {
		// this only should happen on the first value
		return x;
		// assuming a = 1, we could also return x + (mY - mX) / mW;
		}
		double a_div = (mW * mXY - mX * mY);
		double b_div = (mXX * mY - mX * mXY);
		ALOGV("a=%.4g b=%.4g in=%g out=%g",
		a_div / div, b_div / div, x, (a_div * x + b_div) / div);
		return (a_div * x + b_div) / div;
		}

		double WindowedLinearFitEstimator::estimate(double x, double y) {
		/*
		* TODO: We could update the head by adding the new sample to it
		* and amplifying it, but this approach can lead to unbounded
		* error. Instead, we recalculate the head at each step, which
		* is computationally more expensive. We could balance the two
		* methods by recalculating just before the error becomes
		* significant.
		*/
		const bool update_head = false;
		if (update_head) {
		// add new sample to the head
		mHead.scale(mHeadFactorInv); // amplify head
		mHead.add(x, y, mFirstWeight);
		}

		/*
		* TRICKY: place elements into the circular buffer at decreasing
		* indices, so that we can access past elements by addition
		* (thereby avoiding potentially negative indices.)
		*/
		if (mNumSamples >= mHeadLength) {
		// move last head sample from head to the main window
		size_t lastHeadIx = (mSampleIx + mHeadLength) % mHistoryLength;
		if (update_head) {
		mHead.add(mXHistory[lastHeadIx], mYHistory[lastHeadIx], -1.); // remove
		}
		mMain.add(mXHistory[lastHeadIx], mYHistory[lastHeadIx], 1.);
		if (mNumSamples >= mHistoryLength) {
		// move last main sample from main window to tail
		mMain.add(mXHistory[mSampleIx], mYHistory[mSampleIx], -1.); // remove
		mTail.add(mXHistory[mSampleIx], mYHistory[mSampleIx], 1.);
		mTail.scale(mTailFactor); // attenuate tail
		}
		}

		mXHistory.editItemAt(mSampleIx) = x;
		mYHistory.editItemAt(mSampleIx) = y;
		if (mNumSamples < mHistoryLength) {
		++mNumSamples;
		}

		// recalculate head unless we were using the update method
		if (!update_head) {
		mHead.reset();
		double w = mFirstWeight;
		for (size_t headIx = 0; headIx < mHeadLength && headIx < mNumSamples; ++headIx) {
		size_t ix = (mSampleIx + headIx) % mHistoryLength;
		mHead.add(mXHistory[ix], mYHistory[ix], w);
		w *= mHeadFactorInv;
		}
		}

		if (mSampleIx > 0) {
		--mSampleIx;
		} else {
		mSampleIx = mHistoryLength - 1;
		}

		// return estimation result
		LinearFit total;
		total.combine(mHead);
		total.combine(mMain);
		total.combine(mTail);
		return total.interpolate(x);
		}

		void WindowedLinearFitEstimator::reset() {
		mHead.reset();
		mMain.reset();
		mTail.reset();
		mNumSamples = 0;
		mSampleIx = mHistoryLength - 1;
		}

		}; // namespace android

media/libstagefright/TimeSource.cpp

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		/*
		* Copyright (C) 2009 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.
		*/

		#include <stddef.h>
		#include <sys/time.h>

		#include <media/stagefright/foundation/ALooper.h>
		#include <media/stagefright/TimeSource.h>

		namespace android {

		SystemTimeSource::SystemTimeSource()
		: mStartTimeUs(ALooper::GetNowUs()) {
		}

		int64_t SystemTimeSource::getRealTimeUs() {
		return ALooper::GetNowUs() - mStartTimeUs;
		}

		} // namespace android