OpenShot Library | libopenshot-audio 0.2.0
juce_AudioFormat.h
1
2/** @weakgroup juce_audio_formats-format
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 By using JUCE, you agree to the terms of both the JUCE 5 End-User License
15 Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
16 27th April 2017).
17
18 End User License Agreement: www.juce.com/juce-5-licence
19 Privacy Policy: www.juce.com/juce-5-privacy-policy
20
21 Or: You may also use this code under the terms of the GPL v3 (see
22 www.gnu.org/licenses).
23
24 JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
25 EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
26 DISCLAIMED.
27
28 ==============================================================================
29*/
30
31namespace juce
32{
33
34//==============================================================================
35/**
36 Subclasses of AudioFormat are used to read and write different audio
37 file formats.
38
39 @see AudioFormatReader, AudioFormatWriter, WavAudioFormat, AiffAudioFormat
40
41 @tags{Audio}
42*/
44{
45public:
46 //==============================================================================
47 /** Destructor. */
48 virtual ~AudioFormat();
49
50 //==============================================================================
51 /** Returns the name of this format.
52 e.g. "WAV file" or "AIFF file"
53 */
54 const String& getFormatName() const;
55
56 //==============================================================================
57 /** Returns all the file extensions that might apply to a file of this format.
58 The first item will be the one that's preferred when creating a new file.
59 So for a wav file this might just return ".wav"; for an AIFF file it might
60 return two items, ".aif" and ".aiff"
61 */
62 virtual StringArray getFileExtensions() const;
63
64 /** Returns true if this the given file can be read by this format.
65 Subclasses shouldn't do too much work here, just check the extension or
66 file type. The base class implementation just checks the file's extension
67 against one of the ones that was registered in the constructor.
68 */
69 virtual bool canHandleFile (const File& fileToTest);
70
71 /** Returns a set of sample rates that the format can read and write. */
73
74 /** Returns a set of bit depths that the format can read and write. */
76
77 /** Returns true if the format can do 2-channel audio. */
78 virtual bool canDoStereo() = 0;
79
80 /** Returns true if the format can do 1-channel audio. */
81 virtual bool canDoMono() = 0;
82
83 /** Returns true if the format uses compressed data. */
84 virtual bool isCompressed();
85
86 /** Returns true if the channel layout is supported by this format. */
87 virtual bool isChannelLayoutSupported (const AudioChannelSet& channelSet);
88
89 /** Returns a list of different qualities that can be used when writing.
90
91 Non-compressed formats will just return an empty array, but for something
92 like Ogg-Vorbis or MP3, it might return a list of bit-rates, etc.
93
94 When calling createWriterFor(), an index from this array is passed in to
95 tell the format which option is required.
96 */
97 virtual StringArray getQualityOptions();
98
99 //==============================================================================
100 /** Tries to create an object that can read from a stream containing audio
101 data in this format.
102
103 The reader object that is returned can be used to read from the stream, and
104 should then be deleted by the caller.
105
106 @param sourceStream the stream to read from - the AudioFormatReader object
107 that is returned will delete this stream when it no longer
108 needs it.
109 @param deleteStreamIfOpeningFails if no reader can be created, this determines whether this method
110 should delete the stream object that was passed-in. (If a valid
111 reader is returned, it will always be in charge of deleting the
112 stream, so this parameter is ignored)
113 @see AudioFormatReader
114 */
117
118 /** Attempts to create a MemoryMappedAudioFormatReader, if possible for this format.
119 If the format does not support this, the method will return nullptr;
120 */
121 virtual MemoryMappedAudioFormatReader* createMemoryMappedReader (const File& file);
122 virtual MemoryMappedAudioFormatReader* createMemoryMappedReader (FileInputStream* fin);
123
124 /** Tries to create an object that can write to a stream with this audio format.
125
126 The writer object that is returned can be used to write to the stream, and
127 should then be deleted by the caller.
128
129 If the stream can't be created for some reason (e.g. the parameters passed in
130 here aren't suitable), this will return nullptr.
131
132 @param streamToWriteTo the stream that the data will go to - this will be
133 deleted by the AudioFormatWriter object when it's no longer
134 needed. If no AudioFormatWriter can be created by this method,
135 the stream will NOT be deleted, so that the caller can re-use it
136 to try to open a different format, etc
137 @param sampleRateToUse the sample rate for the file, which must be one of the ones
138 returned by getPossibleSampleRates()
139 @param numberOfChannels the number of channels - this must be either 1 or 2, and
140 the choice will depend on the results of canDoMono() and
141 canDoStereo()
142 @param bitsPerSample the bits per sample to use - this must be one of the values
143 returned by getPossibleBitDepths()
144 @param metadataValues a set of metadata values that the writer should try to write
145 to the stream. Exactly what these are depends on the format,
146 and the subclass doesn't actually have to do anything with
147 them if it doesn't want to. Have a look at the specific format
148 implementation classes to see possible values that can be
149 used
150 @param qualityOptionIndex the index of one of compression qualities returned by the
151 getQualityOptions() method. If there aren't any quality options
152 for this format, just pass 0 in this parameter, as it'll be
153 ignored
154 @see AudioFormatWriter
155 */
157 double sampleRateToUse,
158 unsigned int numberOfChannels,
159 int bitsPerSample,
160 const StringPairArray& metadataValues,
161 int qualityOptionIndex) = 0;
162
163 /** Tries to create an object that can write to a stream with this audio format.
164
165 The writer object that is returned can be used to write to the stream, and
166 should then be deleted by the caller.
167
168 If the stream can't be created for some reason (e.g. the parameters passed in
169 here aren't suitable), this will return nullptr.
170
171 @param streamToWriteTo the stream that the data will go to - this will be
172 deleted by the AudioFormatWriter object when it's no longer
173 needed. If no AudioFormatWriter can be created by this method,
174 the stream will NOT be deleted, so that the caller can re-use it
175 to try to open a different format, etc
176 @param sampleRateToUse the sample rate for the file, which must be one of the ones
177 returned by getPossibleSampleRates()
178 @param channelLayout the channel layout for the file. Use isChannelLayoutSupported
179 to check if the writer supports this layout.
180 @param bitsPerSample the bits per sample to use - this must be one of the values
181 returned by getPossibleBitDepths()
182 @param metadataValues a set of metadata values that the writer should try to write
183 to the stream. Exactly what these are depends on the format,
184 and the subclass doesn't actually have to do anything with
185 them if it doesn't want to. Have a look at the specific format
186 implementation classes to see possible values that can be
187 used
188 @param qualityOptionIndex the index of one of compression qualities returned by the
189 getQualityOptions() method. If there aren't any quality options
190 for this format, just pass 0 in this parameter, as it'll be
191 ignored
192 @see AudioFormatWriter
193 */
194 virtual AudioFormatWriter* createWriterFor (OutputStream* streamToWriteTo,
195 double sampleRateToUse,
196 const AudioChannelSet& channelLayout,
197 int bitsPerSample,
198 const StringPairArray& metadataValues,
200
201protected:
202 /** Creates an AudioFormat object.
203
204 @param formatName this sets the value that will be returned by getFormatName()
205 @param fileExtensions an array of file extensions - these will be returned by getFileExtensions()
206 */
207 AudioFormat (String formatName, StringArray fileExtensions);
208
209 /** Creates an AudioFormat object.
210
211 @param formatName this sets the value that will be returned by getFormatName()
212 @param fileExtensions a whitespace-separated list of file extensions - these will
213 be returned by getFileExtensions()
214 */
215 AudioFormat (StringRef formatName, StringRef fileExtensions);
216
217private:
218 //==============================================================================
219 String formatName;
220 StringArray fileExtensions;
221};
222
223} // namespace juce
224
225/** @}*/
Holds a resizable array of primitive or copy-by-value objects.
Definition juce_Array.h:60
Represents a set of audio channel types.
Reads samples from an audio file stream.
Writes samples to an audio file stream.
Subclasses of AudioFormat are used to read and write different audio file formats.
virtual AudioFormatWriter * createWriterFor(OutputStream *streamToWriteTo, double sampleRateToUse, unsigned int numberOfChannels, int bitsPerSample, const StringPairArray &metadataValues, int qualityOptionIndex)=0
Tries to create an object that can write to a stream with this audio format.
virtual bool canDoStereo()=0
Returns true if the format can do 2-channel audio.
virtual bool canDoMono()=0
Returns true if the format can do 1-channel audio.
virtual Array< int > getPossibleBitDepths()=0
Returns a set of bit depths that the format can read and write.
virtual AudioFormatReader * createReaderFor(InputStream *sourceStream, bool deleteStreamIfOpeningFails)=0
Tries to create an object that can read from a stream containing audio data in this format.
virtual Array< int > getPossibleSampleRates()=0
Returns a set of sample rates that the format can read and write.
An input stream that reads from a local file.
Represents a local file or directory.
Definition juce_File.h:45
The base class for streams that read data.
A specialised type of AudioFormatReader that uses a MemoryMappedFile to read directly from an audio f...
The base class for streams that write data to some kind of destination.
A special array for holding a list of strings.
A container for holding a set of strings which are keyed by another string.
A simple class for holding temporary references to a string literal or String.
The JUCE String class!
Definition juce_String.h:43
#define JUCE_API
This macro is added to all JUCE public class declarations.