OpenShot Library | libopenshot-audio 0.2.0
juce_ChannelRemappingAudioSource.h
1
2/** @weakgroup juce_audio_basics-sources
3 * @{
4 */
5/*
6 ==============================================================================
7
8 This file is part of the JUCE library.
9 Copyright (c) 2017 - ROLI Ltd.
10
11 JUCE is an open source library subject to commercial or open-source
12 licensing.
13
14 The code included in this file is provided under the terms of the ISC license
15 http://www.isc.org/downloads/software-support-policy/isc-license. Permission
16 To use, copy, modify, and/or distribute this software for any purpose with or
17 without fee is hereby granted provided that the above copyright notice and
18 this permission notice appear in all copies.
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
27namespace juce
28{
29
30//==============================================================================
31/**
32 An AudioSource that takes the audio from another source, and re-maps its
33 input and output channels to a different arrangement.
34
35 You can use this to increase or decrease the number of channels that an
36 audio source uses, or to re-order those channels.
37
38 Call the reset() method before using it to set up a default mapping, and then
39 the setInputChannelMapping() and setOutputChannelMapping() methods to
40 create an appropriate mapping, otherwise no channels will be connected and
41 it'll produce silence.
42
43 @see AudioSource
44
45 @tags{Audio}
46*/
48{
49public:
50 //==============================================================================
51 /** Creates a remapping source that will pass on audio from the given input.
52
53 @param source the input source to use. Make sure that this doesn't
54 get deleted before the ChannelRemappingAudioSource object
55 @param deleteSourceWhenDeleted if true, the input source will be deleted
56 when this object is deleted, if false, the caller is
57 responsible for its deletion
58 */
60 bool deleteSourceWhenDeleted);
61
62 /** Destructor. */
64
65 //==============================================================================
66 /** Specifies a number of channels that this audio source must produce from its
67 getNextAudioBlock() callback.
68 */
69 void setNumberOfChannelsToProduce (int requiredNumberOfChannels);
70
71 /** Clears any mapped channels.
72
73 After this, no channels are mapped, so this object will produce silence. Create
74 some mappings with setInputChannelMapping() and setOutputChannelMapping().
75 */
76 void clearAllMappings();
77
78 /** Creates an input channel mapping.
79
80 When the getNextAudioBlock() method is called, the data in channel sourceChannelIndex of the incoming
81 data will be sent to destChannelIndex of our input source.
82
83 @param destChannelIndex the index of an input channel in our input audio source (i.e. the
84 source specified when this object was created).
85 @param sourceChannelIndex the index of the input channel in the incoming audio data buffer
86 during our getNextAudioBlock() callback
87 */
90
91 /** Creates an output channel mapping.
92
93 When the getNextAudioBlock() method is called, the data returned in channel sourceChannelIndex by
94 our input audio source will be copied to channel destChannelIndex of the final buffer.
95
96 @param sourceChannelIndex the index of an output channel coming from our input audio source
97 (i.e. the source specified when this object was created).
98 @param destChannelIndex the index of the output channel in the incoming audio data buffer
99 during our getNextAudioBlock() callback
100 */
102 int destChannelIndex);
103
104 /** Returns the channel from our input that will be sent to channel inputChannelIndex of
105 our input audio source.
106 */
108
109 /** Returns the output channel to which channel outputChannelIndex of our input audio
110 source will be sent to.
111 */
113
114
115 //==============================================================================
116 /** Returns an XML object to encapsulate the state of the mappings.
117 @see restoreFromXml
118 */
119 XmlElement* createXml() const;
120
121 /** Restores the mappings from an XML object created by createXML().
122 @see createXml
123 */
124 void restoreFromXml (const XmlElement&);
125
126 //==============================================================================
127 void prepareToPlay (int samplesPerBlockExpected, double sampleRate) override;
128 void releaseResources() override;
129 void getNextAudioBlock (const AudioSourceChannelInfo&) override;
130
131
132private:
133 //==============================================================================
135 Array<int> remappedInputs, remappedOutputs;
136 int requiredNumberOfChannels;
137
138 AudioBuffer<float> buffer;
139 AudioSourceChannelInfo remappedInfo;
140 CriticalSection lock;
141
142 JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ChannelRemappingAudioSource)
143};
144
145} // namespace juce
146
147/** @}*/
Holds a resizable array of primitive or copy-by-value objects.
Definition juce_Array.h:60
Base class for objects that can produce a continuous stream of audio.
An AudioSource that takes the audio from another source, and re-maps its input and output channels to...
void setOutputChannelMapping(int sourceChannelIndex, int destChannelIndex)
Creates an output channel mapping.
void getNextAudioBlock(const AudioSourceChannelInfo &) override
Called repeatedly to fetch subsequent blocks of audio data.
void prepareToPlay(int samplesPerBlockExpected, double sampleRate) override
Tells the source to prepare for playing.
void setNumberOfChannelsToProduce(int requiredNumberOfChannels)
Specifies a number of channels that this audio source must produce from its getNextAudioBlock() callb...
XmlElement * createXml() const
Returns an XML object to encapsulate the state of the mappings.
void restoreFromXml(const XmlElement &)
Restores the mappings from an XML object created by createXML().
void clearAllMappings()
Clears any mapped channels.
void releaseResources() override
Allows the source to release anything it no longer needs after playback has stopped.
int getRemappedInputChannel(int inputChannelIndex) const
Returns the channel from our input that will be sent to channel inputChannelIndex of our input audio ...
int getRemappedOutputChannel(int outputChannelIndex) const
Returns the output channel to which channel outputChannelIndex of our input audio source will be sent...
void setInputChannelMapping(int destChannelIndex, int sourceChannelIndex)
Creates an input channel mapping.
Used to build a tree of elements representing an XML document.
Used by AudioSource::getNextAudioBlock().