OpenShot Library | libopenshot-audio  0.1.9
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  {
129  const ScopedLock sl (callbackLock);
130  playing = false;
131  }
132 
133  int n = 500;
134  while (--n >= 0 && ! stopped)
135  Thread::sleep (2);
136 
138  }
139 }
140 
141 void AudioTransportSource::setPosition (double newPosition)
142 {
143  if (sampleRate > 0.0)
144  setNextReadPosition ((int64) (newPosition * sampleRate));
145 }
146 
148 {
149  if (sampleRate > 0.0)
150  return (double) getNextReadPosition() / sampleRate;
151 
152  return 0.0;
153 }
154 
156 {
157  if (sampleRate > 0.0)
158  return (double) getTotalLength() / sampleRate;
159 
160  return 0.0;
161 }
162 
164 {
165  if (positionableSource != nullptr)
166  {
167  if (sampleRate > 0 && sourceSampleRate > 0)
168  newPosition = (int64) ((double) newPosition * sourceSampleRate / sampleRate);
169 
170  positionableSource->setNextReadPosition (newPosition);
171 
172  if (resamplerSource != nullptr)
173  resamplerSource->flushBuffers();
174 
175  inputStreamEOF = false;
176  }
177 }
178 
180 {
181  if (positionableSource != nullptr)
182  {
183  const double ratio = (sampleRate > 0 && sourceSampleRate > 0) ? sampleRate / sourceSampleRate : 1.0;
184  return (int64) ((double) positionableSource->getNextReadPosition() * ratio);
185  }
186 
187  return 0;
188 }
189 
191 {
192  const ScopedLock sl (callbackLock);
193 
194  if (positionableSource != nullptr)
195  {
196  const double ratio = (sampleRate > 0 && sourceSampleRate > 0) ? sampleRate / sourceSampleRate : 1.0;
197  return (int64) ((double) positionableSource->getTotalLength() * ratio);
198  }
199 
200  return 0;
201 }
202 
204 {
205  const ScopedLock sl (callbackLock);
206  return positionableSource != nullptr && positionableSource->isLooping();
207 }
208 
209 void AudioTransportSource::setGain (const float newGain) noexcept
210 {
211  gain = newGain;
212 }
213 
214 void AudioTransportSource::prepareToPlay (int samplesPerBlockExpected, double newSampleRate)
215 {
216  const ScopedLock sl (callbackLock);
217 
218  sampleRate = newSampleRate;
219  blockSize = samplesPerBlockExpected;
220 
221  if (masterSource != nullptr)
222  masterSource->prepareToPlay (samplesPerBlockExpected, sampleRate);
223 
224  if (resamplerSource != nullptr && sourceSampleRate > 0)
225  resamplerSource->setResamplingRatio (sourceSampleRate / sampleRate);
226 
227  inputStreamEOF = false;
228  isPrepared = true;
229 }
230 
231 void AudioTransportSource::releaseMasterResources()
232 {
233  const ScopedLock sl (callbackLock);
234 
235  if (masterSource != nullptr)
236  masterSource->releaseResources();
237 
238  isPrepared = false;
239 }
240 
242 {
243  releaseMasterResources();
244 }
245 
247 {
248  const ScopedLock sl (callbackLock);
249 
250  if (masterSource != nullptr && ! stopped)
251  {
252  masterSource->getNextAudioBlock (info);
253 
254  if (! playing)
255  {
256  // just stopped playing, so fade out the last block..
257  for (int i = info.buffer->getNumChannels(); --i >= 0;)
258  info.buffer->applyGainRamp (i, info.startSample, jmin (256, info.numSamples), 1.0f, 0.0f);
259 
260  if (info.numSamples > 256)
261  info.buffer->clear (info.startSample + 256, info.numSamples - 256);
262  }
263 
264  if (positionableSource->getNextReadPosition() > positionableSource->getTotalLength() + 1
265  && ! positionableSource->isLooping())
266  {
267  playing = false;
268  inputStreamEOF = true;
270  }
271 
272  stopped = ! playing;
273 
274  for (int i = info.buffer->getNumChannels(); --i >= 0;)
275  info.buffer->applyGainRamp (i, info.startSample, info.numSamples, lastGain, gain);
276  }
277  else
278  {
280  stopped = true;
281  }
282 
283  lastGain = gain;
284 }
285 
286 } // namespace juce
void clearActiveBufferRegion() const
Convenient method to clear the buffer if the source is not producing any data.
void setGain(float newGain) noexcept
Changes the gain to apply to the output.
double getCurrentPosition() const
Returns the position that the next data block will be read from This is a time in seconds...
virtual void getNextAudioBlock(const AudioSourceChannelInfo &bufferToFill)=0
Called repeatedly to fetch subsequent blocks of audio data.
int numSamples
The number of samples in the buffer which the callback is expected to fill with data.
~AudioTransportSource() override
Destructor.
int64 getTotalLength() const override
Implements the PositionableAudioSource method.
virtual void releaseResources()=0
Allows the source to release anything it no longer needs after playback has stopped.
virtual int64 getTotalLength() const =0
Returns the total length of the stream (in samples).
virtual int64 getNextReadPosition() const =0
Returns the position from which the next block will be returned.
void prepareToPlay(int samplesPerBlockExpected, double sampleRate) override
Implementation of the AudioSource method.
void start()
Starts playing (if a source has been selected).
A type of AudioSource that takes an input source and changes its sample rate.
void releaseResources() override
Implementation of the AudioSource method.
void flushBuffers()
Clears any buffers and filters that the resampler is using.
Base class for objects that can produce a continuous stream of audio.
int getNumChannels() const noexcept
Returns the number of channels of audio data that this buffer contains.
void setNextReadPosition(int64 newPosition) override
Implements the PositionableAudioSource method.
virtual void prepareToPlay(int samplesPerBlockExpected, double sampleRate)=0
Tells the source to prepare for playing.
bool isLooping() const override
Implements the PositionableAudioSource method.
virtual void setNextReadPosition(int64 newPosition)=0
Tells the stream to move to a new position.
void setPosition(double newPosition)
Changes the current playback position in the source stream.
An AudioSource which takes another source as input, and buffers it using a thread.
A thread that keeps a list of clients, and calls each one in turn, giving them all a chance to run so...
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.
void applyGainRamp(int channel, int startSample, int numSamples, Type startGain, Type endGain) noexcept
Applies a range of gains to a region of a channel.
int startSample
The first sample in the buffer from which the callback is expected to write data. ...
virtual bool isLooping() const =0
Returns true if this source is actually playing in a loop.
void sendChangeMessage()
Causes an asynchronous change message to be sent to all the registered listeners. ...
A type of AudioSource which can be repositioned.
AudioTransportSource()
Creates an AudioTransportSource.
void getNextAudioBlock(const AudioSourceChannelInfo &) override
Implementation of the AudioSource method.
AudioBuffer< float > * buffer
The destination buffer to fill with audio data.
double getLengthInSeconds() const
Returns the stream&#39;s length in seconds.
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...
Used by AudioSource::getNextAudioBlock().
int64 getNextReadPosition() const override
Implements the PositionableAudioSource method.
Automatically locks and unlocks a mutex object.
void clear() noexcept
Clears all the samples in all channels.