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Diffstat (limited to 'media/libsoundtouch/src/FIFOSampleBuffer.cpp')
-rw-r--r-- | media/libsoundtouch/src/FIFOSampleBuffer.cpp | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/media/libsoundtouch/src/FIFOSampleBuffer.cpp b/media/libsoundtouch/src/FIFOSampleBuffer.cpp new file mode 100644 index 000000000..4e75c8a43 --- /dev/null +++ b/media/libsoundtouch/src/FIFOSampleBuffer.cpp @@ -0,0 +1,274 @@ +//////////////////////////////////////////////////////////////////////////////// +/// +/// A buffer class for temporarily storaging sound samples, operates as a +/// first-in-first-out pipe. +/// +/// Samples are added to the end of the sample buffer with the 'putSamples' +/// function, and are received from the beginning of the buffer by calling +/// the 'receiveSamples' function. The class automatically removes the +/// outputted samples from the buffer, as well as grows the buffer size +/// whenever necessary. +/// +/// Author : Copyright (c) Olli Parviainen +/// Author e-mail : oparviai 'at' iki.fi +/// SoundTouch WWW: http://www.surina.net/soundtouch +/// +//////////////////////////////////////////////////////////////////////////////// +// +// Last changed : $Date: 2012-11-08 18:53:01 +0000 (Thu, 08 Nov 2012) $ +// File revision : $Revision: 4 $ +// +// $Id: FIFOSampleBuffer.cpp 160 2012-11-08 18:53:01Z 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 <stdlib.h> +#include <memory.h> +#include <string.h> +#include <assert.h> + +#include "FIFOSampleBuffer.h" + +using namespace soundtouch; + +// Constructor +FIFOSampleBuffer::FIFOSampleBuffer(int numChannels) +{ + assert(numChannels > 0); + sizeInBytes = 0; // reasonable initial value + buffer = NULL; + bufferUnaligned = NULL; + samplesInBuffer = 0; + bufferPos = 0; + channels = (uint)numChannels; + ensureCapacity(32); // allocate initial capacity +} + + +// destructor +FIFOSampleBuffer::~FIFOSampleBuffer() +{ + delete[] bufferUnaligned; + bufferUnaligned = NULL; + buffer = NULL; +} + + +// Sets number of channels, 1 = mono, 2 = stereo +void FIFOSampleBuffer::setChannels(int numChannels) +{ + uint usedBytes; + + assert(numChannels > 0); + usedBytes = channels * samplesInBuffer; + channels = (uint)numChannels; + samplesInBuffer = usedBytes / channels; +} + + +// if output location pointer 'bufferPos' isn't zero, 'rewinds' the buffer and +// zeroes this pointer by copying samples from the 'bufferPos' pointer +// location on to the beginning of the buffer. +void FIFOSampleBuffer::rewind() +{ + if (buffer && bufferPos) + { + memmove(buffer, ptrBegin(), sizeof(SAMPLETYPE) * channels * samplesInBuffer); + bufferPos = 0; + } +} + + +// Adds 'numSamples' pcs of samples from the 'samples' memory position to +// the sample buffer. +void FIFOSampleBuffer::putSamples(const SAMPLETYPE *samples, uint nSamples) +{ + memcpy(ptrEnd(nSamples), samples, sizeof(SAMPLETYPE) * nSamples * channels); + samplesInBuffer += nSamples; +} + + +// Increases the number of samples in the buffer without copying any actual +// samples. +// +// This function is used to update the number of samples in the sample buffer +// when accessing the buffer directly with 'ptrEnd' function. Please be +// careful though! +void FIFOSampleBuffer::putSamples(uint nSamples) +{ + uint req; + + req = samplesInBuffer + nSamples; + ensureCapacity(req); + samplesInBuffer += nSamples; +} + + +// Returns a pointer to the end of the used part of the sample buffer (i.e. +// where the new samples are to be inserted). This function may be used for +// inserting new samples into the sample buffer directly. Please be careful! +// +// Parameter 'slackCapacity' tells the function how much free capacity (in +// terms of samples) there _at least_ should be, in order to the caller to +// succesfully insert all the required samples to the buffer. When necessary, +// the function grows the buffer size to comply with this requirement. +// +// When using this function as means for inserting new samples, also remember +// to increase the sample count afterwards, by calling the +// 'putSamples(numSamples)' function. +SAMPLETYPE *FIFOSampleBuffer::ptrEnd(uint slackCapacity) +{ + ensureCapacity(samplesInBuffer + slackCapacity); + return buffer + samplesInBuffer * channels; +} + + +// Returns a pointer to the beginning of the currently non-outputted samples. +// This function is provided for accessing the output samples directly. +// Please be careful! +// +// When using this function to output samples, also remember to 'remove' the +// outputted samples from the buffer by calling the +// 'receiveSamples(numSamples)' function +SAMPLETYPE *FIFOSampleBuffer::ptrBegin() +{ + assert(buffer); + return buffer + bufferPos * channels; +} + + +// Ensures that the buffer has enought capacity, i.e. space for _at least_ +// 'capacityRequirement' number of samples. The buffer is grown in steps of +// 4 kilobytes to eliminate the need for frequently growing up the buffer, +// as well as to round the buffer size up to the virtual memory page size. +void FIFOSampleBuffer::ensureCapacity(uint capacityRequirement) +{ + SAMPLETYPE *tempUnaligned, *temp; + + if (capacityRequirement > getCapacity()) + { + // enlarge the buffer in 4kbyte steps (round up to next 4k boundary) + sizeInBytes = (capacityRequirement * channels * sizeof(SAMPLETYPE) + 4095) & (uint)-4096; + assert(sizeInBytes % 2 == 0); + tempUnaligned = new SAMPLETYPE[sizeInBytes / sizeof(SAMPLETYPE) + 16 / sizeof(SAMPLETYPE)]; + if (tempUnaligned == NULL) + { + ST_THROW_RT_ERROR("Couldn't allocate memory!\n"); + } + // Align the buffer to begin at 16byte cache line boundary for optimal performance + temp = (SAMPLETYPE *)SOUNDTOUCH_ALIGN_POINTER_16(tempUnaligned); + if (samplesInBuffer) + { + memcpy(temp, ptrBegin(), samplesInBuffer * channels * sizeof(SAMPLETYPE)); + } + delete[] bufferUnaligned; + buffer = temp; + bufferUnaligned = tempUnaligned; + bufferPos = 0; + } + else + { + // simply rewind the buffer (if necessary) + rewind(); + } +} + + +// Returns the current buffer capacity in terms of samples +uint FIFOSampleBuffer::getCapacity() const +{ + return sizeInBytes / (channels * sizeof(SAMPLETYPE)); +} + + +// Returns the number of samples currently in the buffer +uint FIFOSampleBuffer::numSamples() const +{ + return samplesInBuffer; +} + + +// Output samples from beginning of the sample buffer. Copies demanded number +// of samples to output and removes them from the sample buffer. If there +// are less than 'numsample' samples in the buffer, returns all available. +// +// Returns number of samples copied. +uint FIFOSampleBuffer::receiveSamples(SAMPLETYPE *output, uint maxSamples) +{ + uint num; + + num = (maxSamples > samplesInBuffer) ? samplesInBuffer : maxSamples; + + memcpy(output, ptrBegin(), channels * sizeof(SAMPLETYPE) * num); + return receiveSamples(num); +} + + +// Removes samples from the beginning of the sample buffer without copying them +// anywhere. Used to reduce the number of samples in the buffer, when accessing +// the sample buffer with the 'ptrBegin' function. +uint FIFOSampleBuffer::receiveSamples(uint maxSamples) +{ + if (maxSamples >= samplesInBuffer) + { + uint temp; + + temp = samplesInBuffer; + samplesInBuffer = 0; + return temp; + } + + samplesInBuffer -= maxSamples; + bufferPos += maxSamples; + + return maxSamples; +} + + +// Returns nonzero if the sample buffer is empty +int FIFOSampleBuffer::isEmpty() const +{ + return (samplesInBuffer == 0) ? 1 : 0; +} + + +// Clears the sample buffer +void FIFOSampleBuffer::clear() +{ + samplesInBuffer = 0; + bufferPos = 0; +} + + +/// allow trimming (downwards) amount of samples in pipeline. +/// Returns adjusted amount of samples +uint FIFOSampleBuffer::adjustAmountOfSamples(uint numSamples) +{ + if (numSamples < samplesInBuffer) + { + samplesInBuffer = numSamples; + } + return samplesInBuffer; +} + |