OpenShot Audio Library | OpenShotAudio  0.3.2
juce_BufferingAudioFormatReader.cpp
1 /*
2  ==============================================================================
3 
4  This file is part of the JUCE library.
5  Copyright (c) 2017 - ROLI Ltd.
6 
7  JUCE is an open source library subject to commercial or open-source
8  licensing.
9 
10  By using JUCE, you agree to the terms of both the JUCE 5 End-User License
11  Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
12  27th April 2017).
13 
14  End User License Agreement: www.juce.com/juce-5-licence
15  Privacy Policy: www.juce.com/juce-5-privacy-policy
16 
17  Or: You may also use this code under the terms of the GPL v3 (see
18  www.gnu.org/licenses).
19 
20  JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
21  EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
22  DISCLAIMED.
23 
24  ==============================================================================
25 */
26 
27 namespace juce
28 {
29 
31  TimeSliceThread& timeSliceThread,
32  int samplesToBuffer)
33  : AudioFormatReader (nullptr, sourceReader->getFormatName()),
34  source (sourceReader), thread (timeSliceThread),
35  numBlocks (1 + (samplesToBuffer / samplesPerBlock))
36 {
37  sampleRate = source->sampleRate;
38  lengthInSamples = source->lengthInSamples;
39  numChannels = source->numChannels;
40  metadataValues = source->metadataValues;
41  bitsPerSample = 32;
42  usesFloatingPointData = true;
43 
44  for (int i = 3; --i >= 0;)
45  readNextBufferChunk();
46 
47  timeSliceThread.addTimeSliceClient (this);
48 }
49 
50 BufferingAudioReader::~BufferingAudioReader()
51 {
52  thread.removeTimeSliceClient (this);
53 }
54 
55 void BufferingAudioReader::setReadTimeout (int timeoutMilliseconds) noexcept
56 {
57  timeoutMs = timeoutMilliseconds;
58 }
59 
60 bool BufferingAudioReader::readSamples (int** destSamples, int numDestChannels, int startOffsetInDestBuffer,
61  int64 startSampleInFile, int numSamples)
62 {
63  auto startTime = Time::getMillisecondCounter();
64  clearSamplesBeyondAvailableLength (destSamples, numDestChannels, startOffsetInDestBuffer,
65  startSampleInFile, numSamples, lengthInSamples);
66 
67  const ScopedLock sl (lock);
68  nextReadPosition = startSampleInFile;
69 
70  while (numSamples > 0)
71  {
72  if (auto block = getBlockContaining (startSampleInFile))
73  {
74  auto offset = (int) (startSampleInFile - block->range.getStart());
75  auto numToDo = jmin (numSamples, (int) (block->range.getEnd() - startSampleInFile));
76 
77  for (int j = 0; j < numDestChannels; ++j)
78  {
79  if (auto dest = (float*) destSamples[j])
80  {
81  dest += startOffsetInDestBuffer;
82 
83  if (j < (int) numChannels)
84  FloatVectorOperations::copy (dest, block->buffer.getReadPointer (j, offset), numToDo);
85  else
86  FloatVectorOperations::clear (dest, numToDo);
87  }
88  }
89 
90  startOffsetInDestBuffer += numToDo;
91  startSampleInFile += numToDo;
92  numSamples -= numToDo;
93  }
94  else
95  {
96  if (timeoutMs >= 0 && Time::getMillisecondCounter() >= startTime + (uint32) timeoutMs)
97  {
98  for (int j = 0; j < numDestChannels; ++j)
99  if (auto dest = (float*) destSamples[j])
100  FloatVectorOperations::clear (dest + startOffsetInDestBuffer, numSamples);
101 
102  break;
103  }
104  else
105  {
106  ScopedUnlock ul (lock);
107  Thread::yield();
108  }
109  }
110  }
111 
112  return true;
113 }
114 
115 BufferingAudioReader::BufferedBlock::BufferedBlock (AudioFormatReader& reader, int64 pos, int numSamples)
116  : range (pos, pos + numSamples),
117  buffer ((int) reader.numChannels, numSamples)
118 {
119  reader.read (&buffer, 0, numSamples, pos, true, true);
120 }
121 
122 BufferingAudioReader::BufferedBlock* BufferingAudioReader::getBlockContaining (int64 pos) const noexcept
123 {
124  for (auto* b : blocks)
125  if (b->range.contains (pos))
126  return b;
127 
128  return nullptr;
129 }
130 
131 int BufferingAudioReader::useTimeSlice()
132 {
133  return readNextBufferChunk() ? 1 : 100;
134 }
135 
136 bool BufferingAudioReader::readNextBufferChunk()
137 {
138  auto pos = nextReadPosition.load();
139  auto startPos = ((pos - 1024) / samplesPerBlock) * samplesPerBlock;
140  auto endPos = startPos + numBlocks * samplesPerBlock;
141 
142  OwnedArray<BufferedBlock> newBlocks;
143 
144  for (int i = blocks.size(); --i >= 0;)
145  if (blocks.getUnchecked(i)->range.intersects (Range<int64> (startPos, endPos)))
146  newBlocks.add (blocks.getUnchecked(i));
147 
148  if (newBlocks.size() == numBlocks)
149  {
150  newBlocks.clear (false);
151  return false;
152  }
153 
154  for (auto p = startPos; p < endPos; p += samplesPerBlock)
155  {
156  if (getBlockContaining (p) == nullptr)
157  {
158  newBlocks.add (new BufferedBlock (*source, p, samplesPerBlock));
159  break; // just do one block
160  }
161  }
162 
163  {
164  const ScopedLock sl (lock);
165  newBlocks.swapWith (blocks);
166  }
167 
168  for (int i = blocks.size(); --i >= 0;)
169  newBlocks.removeObject (blocks.getUnchecked(i), false);
170 
171  return true;
172 }
173 
174 } // namespace juce
bool read(float *const *destChannels, int numDestChannels, int64 startSampleInSource, int numSamplesToRead)
static void clearSamplesBeyondAvailableLength(int **destChannels, int numDestChannels, int startOffsetInDestBuffer, int64 startSampleInFile, int &numSamples, int64 fileLengthInSamples)
bool readSamples(int **destSamples, int numDestChannels, int startOffsetInDestBuffer, int64 startSampleInFile, int numSamples) override
BufferingAudioReader(AudioFormatReader *sourceReader, TimeSliceThread &timeSliceThread, int samplesToBuffer)
void setReadTimeout(int timeoutMilliseconds) noexcept
static void JUCE_CALLTYPE clear(float *dest, int numValues) noexcept
static void JUCE_CALLTYPE copy(float *dest, const float *src, int numValues) noexcept
static void JUCE_CALLTYPE yield()
void removeTimeSliceClient(TimeSliceClient *clientToRemove)
void addTimeSliceClient(TimeSliceClient *clientToAdd, int millisecondsBeforeStarting=0)
static uint32 getMillisecondCounter() noexcept
Definition: juce_Time.cpp:226