OpenShot Library | OpenShotAudio  0.2.2
juce_AudioTransportSource.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  The code included in this file is provided under the terms of the ISC license
11  http://www.isc.org/downloads/software-support-policy/isc-license. Permission
12  To use, copy, modify, and/or distribute this software for any purpose with or
13  without fee is hereby granted provided that the above copyright notice and
14  this permission notice appear in all copies.
15 
16  JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
17  EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
18  DISCLAIMED.
19 
20  ==============================================================================
21 */
22 
23 namespace juce
24 {
25 
27 {
28 }
29 
31 {
32  setSource (nullptr);
33  releaseMasterResources();
34 }
35 
37  int readAheadSize, TimeSliceThread* readAheadThread,
38  double sourceSampleRateToCorrectFor, int maxNumChannels)
39 {
40  if (source == newSource)
41  {
42  if (source == nullptr)
43  return;
44 
45  setSource (nullptr, 0, nullptr); // deselect and reselect to avoid releasing resources wrongly
46  }
47 
48  readAheadBufferSize = readAheadSize;
49  sourceSampleRate = sourceSampleRateToCorrectFor;
50 
51  ResamplingAudioSource* newResamplerSource = nullptr;
52  BufferingAudioSource* newBufferingSource = nullptr;
53  PositionableAudioSource* newPositionableSource = nullptr;
54  AudioSource* newMasterSource = nullptr;
55 
56  std::unique_ptr<ResamplingAudioSource> oldResamplerSource (resamplerSource);
57  std::unique_ptr<BufferingAudioSource> oldBufferingSource (bufferingSource);
58  AudioSource* oldMasterSource = masterSource;
59 
60  if (newSource != nullptr)
61  {
62  newPositionableSource = newSource;
63 
64  if (readAheadSize > 0)
65  {
66  // If you want to use a read-ahead buffer, you must also provide a TimeSliceThread
67  // for it to use!
68  jassert (readAheadThread != nullptr);
69 
70  newPositionableSource = newBufferingSource
71  = new BufferingAudioSource (newPositionableSource, *readAheadThread,
72  false, readAheadSize, maxNumChannels);
73  }
74 
75  newPositionableSource->setNextReadPosition (0);
76 
77  if (sourceSampleRateToCorrectFor > 0)
78  newMasterSource = newResamplerSource
79  = new ResamplingAudioSource (newPositionableSource, false, maxNumChannels);
80  else
81  newMasterSource = newPositionableSource;
82 
83  if (isPrepared)
84  {
85  if (newResamplerSource != nullptr && sourceSampleRate > 0 && sampleRate > 0)
86  newResamplerSource->setResamplingRatio (sourceSampleRate / sampleRate);
87 
88  newMasterSource->prepareToPlay (blockSize, sampleRate);
89  }
90  }
91 
92  {
93  const ScopedLock sl (callbackLock);
94 
95  source = newSource;
96  resamplerSource = newResamplerSource;
97  bufferingSource = newBufferingSource;
98  masterSource = newMasterSource;
99  positionableSource = newPositionableSource;
100 
101  inputStreamEOF = false;
102  playing = false;
103  }
104 
105  if (oldMasterSource != nullptr)
106  oldMasterSource->releaseResources();
107 }
108 
110 {
111  if ((! playing) && masterSource != nullptr)
112  {
113  {
114  const ScopedLock sl (callbackLock);
115  playing = true;
116  stopped = false;
117  inputStreamEOF = false;
118  }
119 
121  }
122 }
123 
125 {
126  if (playing)
127  {
128  playing = false;
129 
130  int n = 500;
131  while (--n >= 0 && ! stopped)
132  Thread::sleep (2);
133 
135  }
136 }
137 
138 void AudioTransportSource::setPosition (double newPosition)
139 {
140  if (sampleRate > 0.0)
141  setNextReadPosition ((int64) (newPosition * sampleRate));
142 }
143 
145 {
146  if (sampleRate > 0.0)
147  return (double) getNextReadPosition() / sampleRate;
148 
149  return 0.0;
150 }
151 
153 {
154  if (sampleRate > 0.0)
155  return (double) getTotalLength() / sampleRate;
156 
157  return 0.0;
158 }
159 
161 {
162  if (positionableSource != nullptr)
163  {
164  if (sampleRate > 0 && sourceSampleRate > 0)
165  newPosition = (int64) ((double) newPosition * sourceSampleRate / sampleRate);
166 
167  positionableSource->setNextReadPosition (newPosition);
168 
169  if (resamplerSource != nullptr)
170  resamplerSource->flushBuffers();
171 
172  inputStreamEOF = false;
173  }
174 }
175 
177 {
178  if (positionableSource != nullptr)
179  {
180  const double ratio = (sampleRate > 0 && sourceSampleRate > 0) ? sampleRate / sourceSampleRate : 1.0;
181  return (int64) ((double) positionableSource->getNextReadPosition() * ratio);
182  }
183 
184  return 0;
185 }
186 
188 {
189  const ScopedLock sl (callbackLock);
190 
191  if (positionableSource != nullptr)
192  {
193  const double ratio = (sampleRate > 0 && sourceSampleRate > 0) ? sampleRate / sourceSampleRate : 1.0;
194  return (int64) ((double) positionableSource->getTotalLength() * ratio);
195  }
196 
197  return 0;
198 }
199 
201 {
202  const ScopedLock sl (callbackLock);
203  return positionableSource != nullptr && positionableSource->isLooping();
204 }
205 
206 void AudioTransportSource::setGain (const float newGain) noexcept
207 {
208  gain = newGain;
209 }
210 
211 void AudioTransportSource::prepareToPlay (int samplesPerBlockExpected, double newSampleRate)
212 {
213  const ScopedLock sl (callbackLock);
214 
215  sampleRate = newSampleRate;
216  blockSize = samplesPerBlockExpected;
217 
218  if (masterSource != nullptr)
219  masterSource->prepareToPlay (samplesPerBlockExpected, sampleRate);
220 
221  if (resamplerSource != nullptr && sourceSampleRate > 0)
222  resamplerSource->setResamplingRatio (sourceSampleRate / sampleRate);
223 
224  inputStreamEOF = false;
225  isPrepared = true;
226 }
227 
228 void AudioTransportSource::releaseMasterResources()
229 {
230  const ScopedLock sl (callbackLock);
231 
232  if (masterSource != nullptr)
233  masterSource->releaseResources();
234 
235  isPrepared = false;
236 }
237 
239 {
240  releaseMasterResources();
241 }
242 
244 {
245  const ScopedLock sl (callbackLock);
246 
247  if (masterSource != nullptr && ! stopped)
248  {
249  masterSource->getNextAudioBlock (info);
250 
251  if (! playing)
252  {
253  // just stopped playing, so fade out the last block..
254  for (int i = info.buffer->getNumChannels(); --i >= 0;)
255  info.buffer->applyGainRamp (i, info.startSample, jmin (256, info.numSamples), 1.0f, 0.0f);
256 
257  if (info.numSamples > 256)
258  info.buffer->clear (info.startSample + 256, info.numSamples - 256);
259  }
260 
261  if (positionableSource->getNextReadPosition() > positionableSource->getTotalLength() + 1
262  && ! positionableSource->isLooping())
263  {
264  playing = false;
265  inputStreamEOF = true;
267  }
268 
269  stopped = ! playing;
270 
271  for (int i = info.buffer->getNumChannels(); --i >= 0;)
272  info.buffer->applyGainRamp (i, info.startSample, info.numSamples, lastGain, gain);
273  }
274  else
275  {
277  stopped = true;
278  }
279 
280  lastGain = gain;
281 }
282 
283 } // namespace juce
int getNumChannels() const noexcept
Returns the number of channels of audio data that this buffer contains.
void clear() noexcept
Clears all the samples in all channels.
void applyGainRamp(int channel, int startSample, int numSamples, Type startGain, Type endGain) noexcept
Applies a range of gains to a region of a channel.
Base class for objects that can produce a continuous stream of audio.
virtual void releaseResources()=0
Allows the source to release anything it no longer needs after playback has stopped.
virtual void prepareToPlay(int samplesPerBlockExpected, double sampleRate)=0
Tells the source to prepare for playing.
virtual void getNextAudioBlock(const AudioSourceChannelInfo &bufferToFill)=0
Called repeatedly to fetch subsequent blocks of audio data.
void prepareToPlay(int samplesPerBlockExpected, double sampleRate) override
Implementation of the AudioSource method.
int64 getNextReadPosition() const override
Implements the PositionableAudioSource method.
double getCurrentPosition() const
Returns the position that the next data block will be read from This is a time in seconds.
void releaseResources() override
Implementation of the AudioSource method.
void getNextAudioBlock(const AudioSourceChannelInfo &) override
Implementation of the AudioSource method.
int64 getTotalLength() const override
Implements the PositionableAudioSource method.
~AudioTransportSource() override
Destructor.
void setPosition(double newPosition)
Changes the current playback position in the source stream.
double getLengthInSeconds() const
Returns the stream's length in seconds.
void setGain(float newGain) noexcept
Changes the gain to apply to the output.
void setSource(PositionableAudioSource *newSource, int readAheadBufferSize=0, TimeSliceThread *readAheadThread=nullptr, double sourceSampleRateToCorrectFor=0.0, int maxNumChannels=2)
Sets the reader that is being used as the input source.
bool isLooping() const override
Implements the PositionableAudioSource method.
AudioTransportSource()
Creates an AudioTransportSource.
void start()
Starts playing (if a source has been selected).
void setNextReadPosition(int64 newPosition) override
Implements the PositionableAudioSource method.
An AudioSource which takes another source as input, and buffers it using a thread.
void sendChangeMessage()
Causes an asynchronous change message to be sent to all the registered listeners.
Automatically locks and unlocks a mutex object.
A type of AudioSource which can be repositioned.
virtual bool isLooping() const =0
Returns true if this source is actually playing in a loop.
virtual int64 getNextReadPosition() const =0
Returns the position from which the next block will be returned.
virtual int64 getTotalLength() const =0
Returns the total length of the stream (in samples).
virtual void setNextReadPosition(int64 newPosition)=0
Tells the stream to move to a new position.
A type of AudioSource that takes an input source and changes its sample rate.
void flushBuffers()
Clears any buffers and filters that the resampler is using.
void setResamplingRatio(double samplesInPerOutputSample)
Changes the resampling ratio.
static void JUCE_CALLTYPE sleep(int milliseconds)
Suspends the execution of the current thread until the specified timeout period has elapsed (note tha...
A thread that keeps a list of clients, and calls each one in turn, giving them all a chance to run so...
Used by AudioSource::getNextAudioBlock().
int numSamples
The number of samples in the buffer which the callback is expected to fill with data.
void clearActiveBufferRegion() const
Convenient method to clear the buffer if the source is not producing any data.
AudioBuffer< float > * buffer
The destination buffer to fill with audio data.
int startSample
The first sample in the buffer from which the callback is expected to write data.