OpenShot Library | libopenshot-audio 0.2.0
juce_AudioSourcePlayer.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
23namespace juce
24{
25
27{
28}
29
31{
32 setSource (nullptr);
33}
34
36{
37 if (source != newSource)
38 {
39 auto* oldSource = source;
40
41 if (newSource != nullptr && bufferSize > 0 && sampleRate > 0)
42 newSource->prepareToPlay (bufferSize, sampleRate);
43
44 {
45 const ScopedLock sl (readLock);
46 source = newSource;
47 }
48
49 if (oldSource != nullptr)
50 oldSource->releaseResources();
51 }
52}
53
54void AudioSourcePlayer::setGain (const float newGain) noexcept
55{
56 gain = newGain;
57}
58
59void AudioSourcePlayer::audioDeviceIOCallback (const float** inputChannelData,
60 int totalNumInputChannels,
61 float** outputChannelData,
62 int totalNumOutputChannels,
63 int numSamples)
64{
65 // these should have been prepared by audioDeviceAboutToStart()...
66 jassert (sampleRate > 0 && bufferSize > 0);
67
68 const ScopedLock sl (readLock);
69
70 if (source != nullptr)
71 {
72 int numActiveChans = 0, numInputs = 0, numOutputs = 0;
73
74 // messy stuff needed to compact the channels down into an array
75 // of non-zero pointers..
76 for (int i = 0; i < totalNumInputChannels; ++i)
77 {
78 if (inputChannelData[i] != nullptr)
79 {
80 inputChans [numInputs++] = inputChannelData[i];
81 if (numInputs >= numElementsInArray (inputChans))
82 break;
83 }
84 }
85
86 for (int i = 0; i < totalNumOutputChannels; ++i)
87 {
88 if (outputChannelData[i] != nullptr)
89 {
90 outputChans [numOutputs++] = outputChannelData[i];
91 if (numOutputs >= numElementsInArray (outputChans))
92 break;
93 }
94 }
95
96 if (numInputs > numOutputs)
97 {
98 // if there aren't enough output channels for the number of
99 // inputs, we need to create some temporary extra ones (can't
100 // use the input data in case it gets written to)
101 tempBuffer.setSize (numInputs - numOutputs, numSamples,
102 false, false, true);
103
104 for (int i = 0; i < numOutputs; ++i)
105 {
106 channels[numActiveChans] = outputChans[i];
107 memcpy (channels[numActiveChans], inputChans[i], sizeof (float) * (size_t) numSamples);
108 ++numActiveChans;
109 }
110
111 for (int i = numOutputs; i < numInputs; ++i)
112 {
113 channels[numActiveChans] = tempBuffer.getWritePointer (i - numOutputs);
114 memcpy (channels[numActiveChans], inputChans[i], sizeof (float) * (size_t) numSamples);
115 ++numActiveChans;
116 }
117 }
118 else
119 {
120 for (int i = 0; i < numInputs; ++i)
121 {
122 channels[numActiveChans] = outputChans[i];
123 memcpy (channels[numActiveChans], inputChans[i], sizeof (float) * (size_t) numSamples);
124 ++numActiveChans;
125 }
126
127 for (int i = numInputs; i < numOutputs; ++i)
128 {
129 channels[numActiveChans] = outputChans[i];
130 zeromem (channels[numActiveChans], sizeof (float) * (size_t) numSamples);
131 ++numActiveChans;
132 }
133 }
134
135 AudioBuffer<float> buffer (channels, numActiveChans, numSamples);
136
137 AudioSourceChannelInfo info (&buffer, 0, numSamples);
138 source->getNextAudioBlock (info);
139
140 for (int i = info.buffer->getNumChannels(); --i >= 0;)
141 buffer.applyGainRamp (i, info.startSample, info.numSamples, lastGain, gain);
142
143 lastGain = gain;
144 }
145 else
146 {
147 for (int i = 0; i < totalNumOutputChannels; ++i)
148 if (outputChannelData[i] != nullptr)
149 zeromem (outputChannelData[i], sizeof (float) * (size_t) numSamples);
150 }
151}
152
154{
157}
158
159void AudioSourcePlayer::prepareToPlay (double newSampleRate, int newBufferSize)
160{
161 sampleRate = newSampleRate;
162 bufferSize = newBufferSize;
163 zeromem (channels, sizeof (channels));
164
165 if (source != nullptr)
166 source->prepareToPlay (bufferSize, sampleRate);
167}
168
170{
171 if (source != nullptr)
172 source->releaseResources();
173
174 sampleRate = 0.0;
175 bufferSize = 0;
176
177 tempBuffer.setSize (2, 8);
178}
179
180} // namespace juce
A multi-channel buffer containing floating point audio samples.
void setSize(int newNumChannels, int newNumSamples, bool keepExistingContent=false, bool clearExtraSpace=false, bool avoidReallocating=false)
Changes the buffer's size or number of channels.
Type * getWritePointer(int channelNumber) noexcept
Returns a writeable pointer to one of the buffer's channels.
int getNumChannels() const noexcept
Returns the number of channels of audio data that this buffer contains.
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 an audio device with synchronised input and output channels.
virtual double getCurrentSampleRate()=0
Returns the sample rate that the device is currently using.
virtual int getCurrentBufferSizeSamples()=0
Returns the buffer size that the device is currently using.
void setGain(float newGain) noexcept
Sets a gain to apply to the audio data.
void setSource(AudioSource *newSource)
Changes the current audio source to play from.
AudioSourcePlayer()
Creates an empty AudioSourcePlayer.
void audioDeviceStopped() override
Implementation of the AudioIODeviceCallback method.
void audioDeviceIOCallback(const float **inputChannelData, int totalNumInputChannels, float **outputChannelData, int totalNumOutputChannels, int numSamples) override
Implementation of the AudioIODeviceCallback method.
~AudioSourcePlayer() override
Destructor.
void prepareToPlay(double sampleRate, int blockSize)
An alternative method for initialising the source without an AudioIODevice.
void audioDeviceAboutToStart(AudioIODevice *device) override
Implementation of the AudioIODeviceCallback method.
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.
Automatically locks and unlocks a mutex object.
Used by AudioSource::getNextAudioBlock().
int numSamples
The number of samples in the buffer which the callback is expected to fill with 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.