1 ////////////////////////////////////////////////////////////////////////////////
3 /// A buffer class for temporarily storaging sound samples, operates as a
4 /// first-in-first-out pipe.
6 /// Samples are added to the end of the sample buffer with the 'putSamples'
7 /// function, and are received from the beginning of the buffer by calling
8 /// the 'receiveSamples' function. The class automatically removes the
9 /// outputted samples from the buffer, as well as grows the buffer size
10 /// whenever necessary.
12 /// Author : Copyright (c) Olli Parviainen
13 /// Author e-mail : oparviai @ iki.fi
14 /// SoundTouch WWW: http://www.iki.fi/oparviai/soundtouch
16 ////////////////////////////////////////////////////////////////////////////////
18 // Last changed : $Date$
19 // File revision : $Revision$
23 ////////////////////////////////////////////////////////////////////////////////
27 // SoundTouch audio processing library
28 // Copyright (c) Olli Parviainen
30 // This library is free software; you can redistribute it and/or
31 // modify it under the terms of the GNU Lesser General Public
32 // License as published by the Free Software Foundation; either
33 // version 2.1 of the License, or (at your option) any later version.
35 // This library is distributed in the hope that it will be useful,
36 // but WITHOUT ANY WARRANTY; without even the implied warranty of
37 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
38 // Lesser General Public License for more details.
40 // You should have received a copy of the GNU Lesser General Public
41 // License along with this library; if not, write to the Free Software
42 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
44 ////////////////////////////////////////////////////////////////////////////////
52 #include "FIFOSampleBuffer.h"
54 using namespace soundtouch;
57 FIFOSampleBuffer::FIFOSampleBuffer(uint numChannels)
59 sizeInBytes = 0; // reasonable initial value
60 buffer = NULL; //new SAMPLETYPE[sizeInBytes / sizeof(SAMPLETYPE)];
61 bufferUnaligned = NULL;
64 channels = numChannels;
69 FIFOSampleBuffer::~FIFOSampleBuffer()
71 delete[] bufferUnaligned;
75 // Sets number of channels, 1 = mono, 2 = stereo
76 void FIFOSampleBuffer::setChannels(const uint numChannels)
80 usedBytes = channels * samplesInBuffer;
81 channels = numChannels;
82 samplesInBuffer = usedBytes / channels;
86 // if output location pointer 'bufferPos' isn't zero, 'rewinds' the buffer and
87 // zeroes this pointer by copying samples from the 'bufferPos' pointer
88 // location on to the beginning of the buffer.
89 void FIFOSampleBuffer::rewind()
93 memmove(buffer, ptrBegin(), sizeof(SAMPLETYPE) * channels * samplesInBuffer);
99 // Adds 'numSamples' pcs of samples from the 'samples' memory position to
100 // the sample buffer.
101 void FIFOSampleBuffer::putSamples(const SAMPLETYPE *samples, uint numSamples)
103 memcpy(ptrEnd(numSamples), samples, sizeof(SAMPLETYPE) * numSamples * channels);
104 samplesInBuffer += numSamples;
108 // Increases the number of samples in the buffer without copying any actual
111 // This function is used to update the number of samples in the sample buffer
112 // when accessing the buffer directly with 'ptrEnd' function. Please be
114 void FIFOSampleBuffer::putSamples(uint numSamples)
118 req = samplesInBuffer + numSamples;
120 samplesInBuffer += numSamples;
124 // Returns a pointer to the end of the used part of the sample buffer (i.e.
125 // where the new samples are to be inserted). This function may be used for
126 // inserting new samples into the sample buffer directly. Please be careful!
128 // Parameter 'slackCapacity' tells the function how much free capacity (in
129 // terms of samples) there _at least_ should be, in order to the caller to
130 // succesfully insert all the required samples to the buffer. When necessary,
131 // the function grows the buffer size to comply with this requirement.
133 // When using this function as means for inserting new samples, also remember
134 // to increase the sample count afterwards, by calling the
135 // 'putSamples(numSamples)' function.
136 SAMPLETYPE *FIFOSampleBuffer::ptrEnd(uint slackCapacity)
138 ensureCapacity(samplesInBuffer + slackCapacity);
139 return buffer + samplesInBuffer * channels;
143 // Returns a pointer to the beginning of the currently non-outputted samples.
144 // This function is provided for accessing the output samples directly.
145 // Please be careful!
147 // When using this function to output samples, also remember to 'remove' the
148 // outputted samples from the buffer by calling the
149 // 'receiveSamples(numSamples)' function
150 SAMPLETYPE *FIFOSampleBuffer::ptrBegin() const
152 return buffer + bufferPos * channels;
156 // Ensures that the buffer has enought capacity, i.e. space for _at least_
157 // 'capacityRequirement' number of samples. The buffer is grown in steps of
158 // 4 kilobytes to eliminate the need for frequently growing up the buffer,
159 // as well as to round the buffer size up to the virtual memory page size.
160 void FIFOSampleBuffer::ensureCapacity(uint capacityRequirement)
162 SAMPLETYPE *tempUnaligned, *temp;
164 if (capacityRequirement > getCapacity())
166 // enlarge the buffer in 4kbyte steps (round up to next 4k boundary)
167 sizeInBytes = (capacityRequirement * channels * sizeof(SAMPLETYPE) + 4095) & -4096;
168 assert(sizeInBytes % 2 == 0);
169 tempUnaligned = new SAMPLETYPE[sizeInBytes / sizeof(SAMPLETYPE) + 16 / sizeof(SAMPLETYPE)];
170 if (tempUnaligned == NULL)
172 throw std::runtime_error("Couldn't allocate memory!\n");
174 temp = (SAMPLETYPE *)(((ulong)tempUnaligned + 15) & -16);
175 memcpy(temp, ptrBegin(), samplesInBuffer * channels * sizeof(SAMPLETYPE));
176 delete[] bufferUnaligned;
178 bufferUnaligned = tempUnaligned;
183 // simply rewind the buffer (if necessary)
189 // Returns the current buffer capacity in terms of samples
190 uint FIFOSampleBuffer::getCapacity() const
192 return sizeInBytes / (channels * sizeof(SAMPLETYPE));
196 // Returns the number of samples currently in the buffer
197 uint FIFOSampleBuffer::numSamples() const
199 return samplesInBuffer;
203 // Output samples from beginning of the sample buffer. Copies demanded number
204 // of samples to output and removes them from the sample buffer. If there
205 // are less than 'numsample' samples in the buffer, returns all available.
207 // Returns number of samples copied.
208 uint FIFOSampleBuffer::receiveSamples(SAMPLETYPE *output, uint maxSamples)
212 num = (maxSamples > samplesInBuffer) ? samplesInBuffer : maxSamples;
214 memcpy(output, ptrBegin(), channels * sizeof(SAMPLETYPE) * num);
215 return receiveSamples(num);
219 // Removes samples from the beginning of the sample buffer without copying them
220 // anywhere. Used to reduce the number of samples in the buffer, when accessing
221 // the sample buffer with the 'ptrBegin' function.
222 uint FIFOSampleBuffer::receiveSamples(uint maxSamples)
224 if (maxSamples >= samplesInBuffer)
228 temp = samplesInBuffer;
233 samplesInBuffer -= maxSamples;
234 bufferPos += maxSamples;
240 // Returns nonzero if the sample buffer is empty
241 int FIFOSampleBuffer::isEmpty() const
243 return (samplesInBuffer == 0) ? 1 : 0;
247 // Clears the sample buffer
248 void FIFOSampleBuffer::clear()