1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libsoundtouch/src/RateTransposer.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,179 @@
1.4 +////////////////////////////////////////////////////////////////////////////////
1.5 +///
1.6 +/// Sample rate transposer. Changes sample rate by using linear interpolation
1.7 +/// together with anti-alias filtering (first order interpolation with anti-
1.8 +/// alias filtering should be quite adequate for this application).
1.9 +///
1.10 +/// Use either of the derived classes of 'RateTransposerInteger' or
1.11 +/// 'RateTransposerFloat' for corresponding integer/floating point tranposing
1.12 +/// algorithm implementation.
1.13 +///
1.14 +/// Author : Copyright (c) Olli Parviainen
1.15 +/// Author e-mail : oparviai 'at' iki.fi
1.16 +/// SoundTouch WWW: http://www.surina.net/soundtouch
1.17 +///
1.18 +////////////////////////////////////////////////////////////////////////////////
1.19 +//
1.20 +// Last changed : $Date: 2014-04-06 10:57:21 -0500 (Sun, 06 Apr 2014) $
1.21 +// File revision : $Revision: 4 $
1.22 +//
1.23 +// $Id: RateTransposer.h 195 2014-04-06 15:57:21Z oparviai $
1.24 +//
1.25 +////////////////////////////////////////////////////////////////////////////////
1.26 +//
1.27 +// License :
1.28 +//
1.29 +// SoundTouch audio processing library
1.30 +// Copyright (c) Olli Parviainen
1.31 +//
1.32 +// This library is free software; you can redistribute it and/or
1.33 +// modify it under the terms of the GNU Lesser General Public
1.34 +// License as published by the Free Software Foundation; either
1.35 +// version 2.1 of the License, or (at your option) any later version.
1.36 +//
1.37 +// This library is distributed in the hope that it will be useful,
1.38 +// but WITHOUT ANY WARRANTY; without even the implied warranty of
1.39 +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1.40 +// Lesser General Public License for more details.
1.41 +//
1.42 +// You should have received a copy of the GNU Lesser General Public
1.43 +// License along with this library; if not, write to the Free Software
1.44 +// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
1.45 +//
1.46 +////////////////////////////////////////////////////////////////////////////////
1.47 +
1.48 +#ifndef RateTransposer_H
1.49 +#define RateTransposer_H
1.50 +
1.51 +#include <stddef.h>
1.52 +#include "AAFilter.h"
1.53 +#include "FIFOSamplePipe.h"
1.54 +#include "FIFOSampleBuffer.h"
1.55 +
1.56 +#include "STTypes.h"
1.57 +
1.58 +namespace soundtouch
1.59 +{
1.60 +
1.61 +/// Abstract base class for transposer implementations (linear, advanced vs integer, float etc)
1.62 +class TransposerBase
1.63 +{
1.64 +public:
1.65 + enum ALGORITHM {
1.66 + LINEAR = 0,
1.67 + CUBIC,
1.68 + SHANNON
1.69 + };
1.70 +
1.71 +protected:
1.72 + virtual void resetRegisters() = 0;
1.73 +
1.74 + virtual int transposeMono(SAMPLETYPE *dest,
1.75 + const SAMPLETYPE *src,
1.76 + int &srcSamples) = 0;
1.77 + virtual int transposeStereo(SAMPLETYPE *dest,
1.78 + const SAMPLETYPE *src,
1.79 + int &srcSamples) = 0;
1.80 + virtual int transposeMulti(SAMPLETYPE *dest,
1.81 + const SAMPLETYPE *src,
1.82 + int &srcSamples) = 0;
1.83 +
1.84 + static ALGORITHM algorithm;
1.85 +
1.86 +public:
1.87 + float rate;
1.88 + int numChannels;
1.89 +
1.90 + TransposerBase();
1.91 + virtual ~TransposerBase();
1.92 +
1.93 + virtual int transpose(FIFOSampleBuffer &dest, FIFOSampleBuffer &src);
1.94 + virtual void setRate(float newRate);
1.95 + virtual void setChannels(int channels);
1.96 +
1.97 + // static factory function
1.98 + static TransposerBase *newInstance();
1.99 +
1.100 + // static function to set interpolation algorithm
1.101 + static void setAlgorithm(ALGORITHM a);
1.102 +};
1.103 +
1.104 +
1.105 +/// A common linear samplerate transposer class.
1.106 +///
1.107 +class RateTransposer : public FIFOProcessor
1.108 +{
1.109 +protected:
1.110 + /// Anti-alias filter object
1.111 + AAFilter *pAAFilter;
1.112 + TransposerBase *pTransposer;
1.113 +
1.114 + /// Buffer for collecting samples to feed the anti-alias filter between
1.115 + /// two batches
1.116 + FIFOSampleBuffer inputBuffer;
1.117 +
1.118 + /// Buffer for keeping samples between transposing & anti-alias filter
1.119 + FIFOSampleBuffer midBuffer;
1.120 +
1.121 + /// Output sample buffer
1.122 + FIFOSampleBuffer outputBuffer;
1.123 +
1.124 + bool bUseAAFilter;
1.125 +
1.126 +
1.127 + /// Transposes sample rate by applying anti-alias filter to prevent folding.
1.128 + /// Returns amount of samples returned in the "dest" buffer.
1.129 + /// The maximum amount of samples that can be returned at a time is set by
1.130 + /// the 'set_returnBuffer_size' function.
1.131 + void processSamples(const SAMPLETYPE *src,
1.132 + uint numSamples);
1.133 +
1.134 +public:
1.135 + RateTransposer();
1.136 + virtual ~RateTransposer();
1.137 +
1.138 + /// Operator 'new' is overloaded so that it automatically creates a suitable instance
1.139 + /// depending on if we're to use integer or floating point arithmetics.
1.140 +// static void *operator new(size_t s);
1.141 +
1.142 + /// Use this function instead of "new" operator to create a new instance of this class.
1.143 + /// This function automatically chooses a correct implementation, depending on if
1.144 + /// integer ot floating point arithmetics are to be used.
1.145 +// static RateTransposer *newInstance();
1.146 +
1.147 + /// Returns the output buffer object
1.148 + FIFOSamplePipe *getOutput() { return &outputBuffer; };
1.149 +
1.150 + /// Returns the store buffer object
1.151 +// FIFOSamplePipe *getStore() { return &storeBuffer; };
1.152 +
1.153 + /// Return anti-alias filter object
1.154 + AAFilter *getAAFilter();
1.155 +
1.156 + /// Enables/disables the anti-alias filter. Zero to disable, nonzero to enable
1.157 + void enableAAFilter(bool newMode);
1.158 +
1.159 + /// Returns nonzero if anti-alias filter is enabled.
1.160 + bool isAAFilterEnabled() const;
1.161 +
1.162 + /// Sets new target rate. Normal rate = 1.0, smaller values represent slower
1.163 + /// rate, larger faster rates.
1.164 + virtual void setRate(float newRate);
1.165 +
1.166 + /// Sets the number of channels, 1 = mono, 2 = stereo
1.167 + void setChannels(int channels);
1.168 +
1.169 + /// Adds 'numSamples' pcs of samples from the 'samples' memory position into
1.170 + /// the input of the object.
1.171 + void putSamples(const SAMPLETYPE *samples, uint numSamples);
1.172 +
1.173 + /// Clears all the samples in the object
1.174 + void clear();
1.175 +
1.176 + /// Returns nonzero if there aren't any samples available for outputting.
1.177 + int isEmpty() const;
1.178 +};
1.179 +
1.180 +}
1.181 +
1.182 +#endif
