The Tor Browser: comparison media/libsoundtouch/src/RateTransposer.h

--1:000000000000
+:94c8c427b506
+////////////////////////////////////////////////////////////////////////////////
+///
+/// Sample rate transposer. Changes sample rate by using linear interpolation
+/// together with anti-alias filtering (first order interpolation with anti-
+/// alias filtering should be quite adequate for this application).
+///
+/// Use either of the derived classes of 'RateTransposerInteger' or
+/// 'RateTransposerFloat' for corresponding integer/floating point tranposing
+/// algorithm implementation.
+///
+/// Author        : Copyright (c) Olli Parviainen
+/// Author e-mail : oparviai 'at' iki.fi
+/// SoundTouch WWW: http://www.surina.net/soundtouch
+///
+////////////////////////////////////////////////////////////////////////////////
+//
+// Last changed  : $Date: 2014-04-06 10:57:21 -0500 (Sun, 06 Apr 2014) $
+// File revision : $Revision: 4 $
+//
+// $Id: RateTransposer.h 195 2014-04-06 15:57:21Z oparviai $
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// License :
+//
+//  SoundTouch audio processing library
+//  Copyright (c) Olli Parviainen
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+////////////////////////////////////////////////////////////////////////////////
+#ifndef RateTransposer_H
+#define RateTransposer_H
+#include <stddef.h>
+#include "AAFilter.h"
+#include "FIFOSamplePipe.h"
+#include "FIFOSampleBuffer.h"
+#include "STTypes.h"
+namespace soundtouch
+{
+/// Abstract base class for transposer implementations (linear, advanced vs integer, float etc)
+class TransposerBase
+{
+public:
+enum ALGORITHM {
+LINEAR = 0,
+CUBIC,
+SHANNON
+};
+protected:
+virtual void resetRegisters() = 0;
+virtual int transposeMono(SAMPLETYPE *dest,
+const SAMPLETYPE *src,
+int &srcSamples)  = 0;
+virtual int transposeStereo(SAMPLETYPE *dest,
+const SAMPLETYPE *src,
+int &srcSamples) = 0;
+virtual int transposeMulti(SAMPLETYPE *dest,
+const SAMPLETYPE *src,
+int &srcSamples) = 0;
+static ALGORITHM algorithm;
+public:
+float rate;
+int numChannels;
+TransposerBase();
+virtual ~TransposerBase();
+virtual int transpose(FIFOSampleBuffer &dest, FIFOSampleBuffer &src);
+virtual void setRate(float newRate);
+virtual void setChannels(int channels);
+// static factory function
+static TransposerBase *newInstance();
+// static function to set interpolation algorithm
+static void setAlgorithm(ALGORITHM a);
+};
+/// A common linear samplerate transposer class.
+///
+class RateTransposer : public FIFOProcessor
+{
+protected:
+/// Anti-alias filter object
+AAFilter *pAAFilter;
+TransposerBase *pTransposer;
+/// Buffer for collecting samples to feed the anti-alias filter between
+/// two batches
+FIFOSampleBuffer inputBuffer;
+/// Buffer for keeping samples between transposing & anti-alias filter
+FIFOSampleBuffer midBuffer;
+/// Output sample buffer
+FIFOSampleBuffer outputBuffer;
+bool bUseAAFilter;
+/// Transposes sample rate by applying anti-alias filter to prevent folding.
+/// Returns amount of samples returned in the "dest" buffer.
+/// The maximum amount of samples that can be returned at a time is set by
+/// the 'set_returnBuffer_size' function.
+void processSamples(const SAMPLETYPE *src,
+uint numSamples);
+public:
+RateTransposer();
+virtual ~RateTransposer();
+/// Operator 'new' is overloaded so that it automatically creates a suitable instance
+/// depending on if we're to use integer or floating point arithmetics.
+//    static void *operator new(size_t s);
+/// Use this function instead of "new" operator to create a new instance of this class.
+/// This function automatically chooses a correct implementation, depending on if
+/// integer ot floating point arithmetics are to be used.
+//    static RateTransposer *newInstance();
+/// Returns the output buffer object
+FIFOSamplePipe *getOutput() { return &outputBuffer; };
+/// Returns the store buffer object
+//    FIFOSamplePipe *getStore() { return &storeBuffer; };
+/// Return anti-alias filter object
+AAFilter *getAAFilter();
+/// Enables/disables the anti-alias filter. Zero to disable, nonzero to enable
+void enableAAFilter(bool newMode);
+/// Returns nonzero if anti-alias filter is enabled.
+bool isAAFilterEnabled() const;
+/// Sets new target rate. Normal rate = 1.0, smaller values represent slower
+/// rate, larger faster rates.
+virtual void setRate(float newRate);
+/// Sets the number of channels, 1 = mono, 2 = stereo
+void setChannels(int channels);
+/// Adds 'numSamples' pcs of samples from the 'samples' memory position into
+/// the input of the object.
+void putSamples(const SAMPLETYPE *samples, uint numSamples);
+/// Clears all the samples in the object
+void clear();
+/// Returns nonzero if there aren't any samples available for outputting.
+int isEmpty() const;
+};
+}
+#endif

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comparison: media/libsoundtouch/src/RateTransposer.h

media/libsoundtouch/src/RateTransposer.h