FFmpeg + SoundTouch实现音频的变调变速

//////////////////////////////////////////////////////////////////////////////// /// /// Sampled sound tempo changer/time stretch algorithm. Changes the sound tempo /// while maintaining the original pitch by using a time domain WSOLA-like /// method with several performance-increasing tweaks. /// /// Note : MMX optimized functions reside in a separate, platform-specific /// file, e.g. 'mmx_win.cpp' or 'mmx_gcc.cpp' /// /// Author : Copyright (c) Olli Parviainen /// Author e-mail : oparviai 'at' iki.fi /// SoundTouch WWW: http://www.surina.net/soundtouch /// //////////////////////////////////////////////////////////////////////////////// // // Last changed : $Date: 2015-08-09 00:00:15 +0300 (Sun, 09 Aug 2015) $ // File revision : $Revision: 1.12 $ // // $Id: TDStretch.cpp 226 2015-08-08 21:00:15Z 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 // //////////////////////////////////////////////////////////////////////////////// #include <string.h> #include <limits.h> #include <assert.h> #include <math.h> #include <float.h> #include "STTypes.h" #include "cpu_detect.h" #include "TDStretch.h" using namespace soundtouch; #define max(x, y) (((x) > (y)) ? (x) : (y)) /***************************************************************************** * * Constant definitions * *****************************************************************************/ // Table for the hierarchical mixing position seeking algorithm const short _scanOffsets[5][24]={ { 124, 186, 248, 310, 372, 434, 496, 558, 620, 682, 744, 806, 868, 930, 992, 1054, 1116, 1178, 1240, 1302, 1364, 1426, 1488, 0}, {-100, -75, -50, -25, 25, 50, 75, 100, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { -20, -15, -10, -5, 5, 10, 15, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { -4, -3, -2, -1, 1, 2, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 121, 114, 97, 114, 98, 105, 108, 32, 104, 99, 117, 111, 116, 100, 110, 117, 111, 115, 0, 0, 0, 0, 0, 0}}; /***************************************************************************** * * Implementation of the class 'TDStretch' * *****************************************************************************/ TDStretch::TDStretch() : FIFOProcessor(&outputBuffer) { bQuickSeek = false; channels = 2; pMidBuffer = NULL; pMidBufferUnaligned = NULL; overlapLength = 0; bAutoSeqSetting = true; bAutoSeekSetting = true; maxnorm = 0; maxnormf = 1e8; skipFract = 0; tempo = 1.0f; setParameters(44100, DEFAULT_SEQUENCE_MS, DEFAULT_SEEKWINDOW_MS, DEFAULT_OVERLAP_MS); setTempo(1.0f); clear(); } TDStretch::~TDStretch() { delete[] pMidBufferUnaligned; } // Sets routine control parameters. These control are certain time constants // defining how the sound is stretched to the desired duration. // // 'sampleRate' = sample rate of the sound // 'sequenceMS' = one processing sequence length in milliseconds (default = 82 ms) // 'seekwindowMS' = seeking window length for scanning the best overlapping // position (default = 28 ms) // 'overlapMS' = overlapping length (default = 12 ms) void TDStretch::setParameters(int aSampleRate, int aSequenceMS, int aSeekWindowMS, int aOverlapMS) { // accept only positive parameter values - if zero or negative, use old values instead if (aSampleRate > 0) this->sampleRate = aSampleRate; if (aOverlapMS > 0) this->overlapMs = aOverlapMS; if (aSequenceMS > 0) { this->sequenceMs = aSequenceMS; bAutoSeqSetting = false; } else if (aSequenceMS == 0) { // if zero, use automatic setting bAutoSeqSetting = true; } if (aSeekWindowMS > 0) { this->seekWindowMs = aSeekWindowMS; bAutoSeekSetting = false; } else if (aSeekWindowMS == 0) { // if zero, use automatic setting bAutoSeekSetting = true; } calcSeqParameters(); calculateOverlapLength(overlapMs); // set tempo to recalculate 'sampleReq' setTempo(tempo); } /// Get routine control parameters, see setParameters() function. /// Any of the parameters to this function can be NULL, in such case corresponding parameter /// value isn't returned. void TDStretch::getParameters(int *pSampleRate, int *pSequenceMs, int *pSeekWindowMs, int *pOverlapMs) const { if (pSampleRate) { *pSampleRate = sampleRate; } if (pSequenceMs) { *pSequenceMs = (bAutoSeqSetting) ? (USE_AUTO_SEQUENCE_LEN) : sequenceMs; } if (pSeekWindowMs) { *pSeekWindowMs = (bAutoSeekSetting) ? (USE_AUTO_SEEKWINDOW_LEN) : seekWindowMs; } if (pOverlapMs) { *pOverlapMs = overlapMs; } } // Overlaps samples in 'midBuffer' with the samples in 'pInput' void TDStretch::overlapMono(SAMPLETYPE *pOutput, const SAMPLETYPE *pInput) const { int i; SAMPLETYPE m1, m2; m1 = (SAMPLETYPE)0; m2 = (SAMPLETYPE)overlapLength; for (i = 0; i < overlapLength ; i ++) { pOutput[i] = (pInput[i] * m1 + pMidBuffer[i] * m2 ) / overlapLength; m1 += 1; m2 -= 1; } } void TDStretch::clearMidBuffer() { memset(pMidBuffer, 0, channels * sizeof(SAMPLETYPE) * overlapLength); } void TDStretch::clearInput() { inputBuffer.clear(); clearMidBuffer(); } // Clears the sample buffers void TDStretch::clear() { outputBuffer.clear(); clearInput(); } // Enables/disables the quick position seeking algorithm. Zero to disable, nonzero // to enable void TDStretch::enableQuickSeek(bool enable) { bQuickSeek = enable; } // Returns nonzero if the quick seeking algorithm is enabled. bool TDStretch::isQuickSeekEnabled() const { return bQuickSeek; } // Seeks for the optimal overlap-mixing position. int TDStretch::seekBestOverlapPosition(const SAMPLETYPE *refPos) { if (bQuickSeek) { return seekBestOverlapPositionQuick(refPos); } else { return seekBestOverlapPositionFull(refPos); } } // Overlaps samples in 'midBuffer' with the samples in 'pInputBuffer' at position // of 'ovlPos'. inline void TDStretch::overlap(SAMPLETYPE *pOutput, const SAMPLETYPE *pInput, uint ovlPos) const { #ifndef USE_MULTICH_ALWAYS if (channels == 1) { // mono sound. overlapMono(pOutput, pInput + ovlPos); } else if (channels == 2) { // stereo sound overlapStereo(pOutput, pInput + 2 * ovlPos); } else #endif // USE_MULTICH_ALWAYS { assert(c