The Tor Browser: media/libsoundtouch/src/InterpolateLinear.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 ////////////////////////////////////////////////////////////////////////////////

     2 ///

     3 /// Linear interpolation algorithm.

     4 ///

     5 /// Author        : Copyright (c) Olli Parviainen

     6 /// Author e-mail : oparviai 'at' iki.fi

     7 /// SoundTouch WWW: http://www.surina.net/soundtouch

     8 ///

     9 ////////////////////////////////////////////////////////////////////////////////

    10 //

    11 // $Id: InterpolateLinear.cpp 180 2014-01-06 19:16:02Z oparviai $

    12 //

    13 ////////////////////////////////////////////////////////////////////////////////

    14 //

    15 // License :

    16 //

    17 //  SoundTouch audio processing library

    18 //  Copyright (c) Olli Parviainen

    19 //

    20 //  This library is free software; you can redistribute it and/or

    21 //  modify it under the terms of the GNU Lesser General Public

    22 //  License as published by the Free Software Foundation; either

    23 //  version 2.1 of the License, or (at your option) any later version.

    24 //

    25 //  This library is distributed in the hope that it will be useful,

    26 //  but WITHOUT ANY WARRANTY; without even the implied warranty of

    27 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    28 //  Lesser General Public License for more details.

    29 //

    30 //  You should have received a copy of the GNU Lesser General Public

    31 //  License along with this library; if not, write to the Free Software

    32 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    33 //

    34 ////////////////////////////////////////////////////////////////////////////////

    36 #include <assert.h>

    37 #include <stdlib.h>

    38 #include "InterpolateLinear.h"

    40 using namespace soundtouch;

    42 //////////////////////////////////////////////////////////////////////////////

    43 //

    44 // InterpolateLinearInteger - integer arithmetic implementation

    45 //

    47 /// fixed-point interpolation routine precision

    48 #define SCALE    65536

    51 // Constructor

    52 InterpolateLinearInteger::InterpolateLinearInteger() : TransposerBase()

    53 {

    54     // Notice: use local function calling syntax for sake of clarity,

    55     // to indicate the fact that C++ constructor can't call virtual functions.

    56     resetRegisters();

    57     setRate(1.0f);

    58 }

    61 void InterpolateLinearInteger::resetRegisters()

    62 {

    63     iFract = 0;

    64 }

    67 // Transposes the sample rate of the given samples using linear interpolation.

    68 // 'Mono' version of the routine. Returns the number of samples returned in

    69 // the "dest" buffer

    70 int InterpolateLinearInteger::transposeMono(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)

    71 {

    72     int i;

    73     int srcSampleEnd = srcSamples - 1;

    74     int srcCount = 0;

    76     i = 0;

    77     while (srcCount < srcSampleEnd)

    78     {

    79         LONG_SAMPLETYPE temp;

    81         assert(iFract < SCALE);

    83         temp = (SCALE - iFract) * src[0] + iFract * src[1];

    84         dest[i] = (SAMPLETYPE)(temp / SCALE);

    85         i++;

    87         iFract += iRate;

    89         int iWhole = iFract / SCALE;

    90         iFract -= iWhole * SCALE;

    91         srcCount += iWhole;

    92         src += iWhole;

    93     }

    94     srcSamples = srcCount;

    96     return i;

    97 }

   100 // Transposes the sample rate of the given samples using linear interpolation.

   101 // 'Stereo' version of the routine. Returns the number of samples returned in

   102 // the "dest" buffer

   103 int InterpolateLinearInteger::transposeStereo(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)

   104 {

   105     int i;

   106     int srcSampleEnd = srcSamples - 1;

   107     int srcCount = 0;

   109     i = 0;

   110     while (srcCount < srcSampleEnd)

   111     {

   112         LONG_SAMPLETYPE temp0;

   113         LONG_SAMPLETYPE temp1;

   115         assert(iFract < SCALE);

   117         temp0 = (SCALE - iFract) * src[0] + iFract * src[2];

   118         temp1 = (SCALE - iFract) * src[1] + iFract * src[3];

   119         dest[0] = (SAMPLETYPE)(temp0 / SCALE);

   120         dest[1] = (SAMPLETYPE)(temp1 / SCALE);

   121         dest += 2;

   122         i++;

   124         iFract += iRate;

   126         int iWhole = iFract / SCALE;

   127         iFract -= iWhole * SCALE;

   128         srcCount += iWhole;

   129         src += 2*iWhole;

   130     }

   131     srcSamples = srcCount;

   133     return i;

   134 }

   137 int InterpolateLinearInteger::transposeMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)

   138 {

   139     int i;

   140     int srcSampleEnd = srcSamples - 1;

   141     int srcCount = 0;

   143     i = 0;

   144     while (srcCount < srcSampleEnd)

   145     {

   146         LONG_SAMPLETYPE temp, vol1;

   148         assert(iFract < SCALE);

   149         vol1 = (SCALE - iFract);

   150         for (int c = 0; c < numChannels; c ++)

   151         {

   152             temp = vol1 * src[c] + iFract * src[c + numChannels];

   153             dest[0] = (SAMPLETYPE)(temp / SCALE);

   154             dest ++;

   155         }

   156         i++;

   158         iFract += iRate;

   160         int iWhole = iFract / SCALE;

   161         iFract -= iWhole * SCALE;

   162         srcCount += iWhole;

   163         src += iWhole * numChannels;

   164     }

   165     srcSamples = srcCount;

   167     return i;

   168 }

   171 // Sets new target iRate. Normal iRate = 1.0, smaller values represent slower

   172 // iRate, larger faster iRates.

   173 void InterpolateLinearInteger::setRate(float newRate)

   174 {

   175     iRate = (int)(newRate * SCALE + 0.5f);

   176     TransposerBase::setRate(newRate);

   177 }

   180 //////////////////////////////////////////////////////////////////////////////

   181 //

   182 // InterpolateLinearFloat - floating point arithmetic implementation

   183 //

   184 //////////////////////////////////////////////////////////////////////////////

   187 // Constructor

   188 InterpolateLinearFloat::InterpolateLinearFloat() : TransposerBase()

   189 {

   190     // Notice: use local function calling syntax for sake of clarity,

   191     // to indicate the fact that C++ constructor can't call virtual functions.

   192     resetRegisters();

   193     setRate(1.0f);

   194 }

   197 void InterpolateLinearFloat::resetRegisters()

   198 {

   199     fract = 0;

   200 }

   203 // Transposes the sample rate of the given samples using linear interpolation.

   204 // 'Mono' version of the routine. Returns the number of samples returned in

   205 // the "dest" buffer

   206 int InterpolateLinearFloat::transposeMono(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)

   207 {

   208     int i;

   209     int srcSampleEnd = srcSamples - 1;

   210     int srcCount = 0;

   212     i = 0;

   213     while (srcCount < srcSampleEnd)

   214     {

   215         double out;

   216         assert(fract < 1.0);

   218         out = (1.0 - fract) * src[0] + fract * src[1];

   219         dest[i] = (SAMPLETYPE)out;

   220         i ++;

   222         // update position fraction

   223         fract += rate;

   224         // update whole positions

   225         int whole = (int)fract;

   226         fract -= whole;

   227         src += whole;

   228         srcCount += whole;

   229     }

   230     srcSamples = srcCount;

   231     return i;

   232 }

   235 // Transposes the sample rate of the given samples using linear interpolation.

   236 // 'Mono' version of the routine. Returns the number of samples returned in

   237 // the "dest" buffer

   238 int InterpolateLinearFloat::transposeStereo(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)

   239 {

   240     int i;

   241     int srcSampleEnd = srcSamples - 1;

   242     int srcCount = 0;

   244     i = 0;

   245     while (srcCount < srcSampleEnd)

   246     {

   247         double out0, out1;

   248         assert(fract < 1.0);

   250         out0 = (1.0 - fract) * src[0] + fract * src[2];

   251         out1 = (1.0 - fract) * src[1] + fract * src[3];

   252         dest[2*i]   = (SAMPLETYPE)out0;

   253         dest[2*i+1] = (SAMPLETYPE)out1;

   254         i ++;

   256         // update position fraction

   257         fract += rate;

   258         // update whole positions

   259         int whole = (int)fract;

   260         fract -= whole;

   261         src += 2*whole;

   262         srcCount += whole;

   263     }

   264     srcSamples = srcCount;

   265     return i;

   266 }

   269 int InterpolateLinearFloat::transposeMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, int &srcSamples)

   270 {

   271     int i;

   272     int srcSampleEnd = srcSamples - 1;

   273     int srcCount = 0;

   275     i = 0;

   276     while (srcCount < srcSampleEnd)

   277     {

   278         float temp, vol1;

   280         vol1 = (1.0f- fract);

   281         for (int c = 0; c < numChannels; c ++)

   282         {

   283             temp = vol1 * src[c] + fract * src[c + numChannels];

   284             *dest = (SAMPLETYPE)temp;

   285             dest ++;

   286         }

   287         i++;

   289         fract += rate;

   291         int iWhole = (int)fract;

   292         fract -= iWhole;

   293         srcCount += iWhole;

   294         src += iWhole * numChannels;

   295     }

   296     srcSamples = srcCount;

   298     return i;

   299 }

The Tor Browser / file revision

media/libsoundtouch/src/InterpolateLinear.cpp@b8a032363ba2

media/libsoundtouch/src/InterpolateLinear.cpp