JUCE  v5.1.1-3-g1a0b28c73
JUCE API
AudioFormat Class Referenceabstract

Subclasses of AudioFormat are used to read and write different audio file formats. More...

#include <juce_AudioFormat.h>

Inheritance diagram for AudioFormat:
Collaboration diagram for AudioFormat:

Public Member Functions

virtual ~AudioFormat ()
 Destructor. More...
 
virtual bool canDoMono ()=0
 Returns true if the format can do 1-channel audio. More...
 
virtual bool canDoStereo ()=0
 Returns true if the format can do 2-channel audio. More...
 
virtual bool canHandleFile (const File &fileToTest)
 Returns true if this the given file can be read by this format. More...
 
virtual MemoryMappedAudioFormatReadercreateMemoryMappedReader (const File &file)
 Attempts to create a MemoryMappedAudioFormatReader, if possible for this format. More...
 
virtual MemoryMappedAudioFormatReadercreateMemoryMappedReader (FileInputStream *fin)
 
virtual AudioFormatReadercreateReaderFor (InputStream *sourceStream, bool deleteStreamIfOpeningFails)=0
 Tries to create an object that can read from a stream containing audio data in this format. More...
 
virtual AudioFormatWritercreateWriterFor (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. More...
 
virtual AudioFormatWritercreateWriterFor (OutputStream *streamToWriteTo, double sampleRateToUse, const AudioChannelSet &channelLayout, int bitsPerSample, const StringPairArray &metadataValues, int qualityOptionIndex)
 Tries to create an object that can write to a stream with this audio format. More...
 
const StringArraygetFileExtensions () const
 Returns all the file extensions that might apply to a file of this format. More...
 
const StringgetFormatName () const
 Returns the name of this format. More...
 
virtual Array< intgetPossibleBitDepths ()=0
 Returns a set of bit depths that the format can read and write. More...
 
virtual Array< intgetPossibleSampleRates ()=0
 Returns a set of sample rates that the format can read and write. More...
 
virtual StringArray getQualityOptions ()
 Returns a list of different qualities that can be used when writing. More...
 
virtual bool isChannelLayoutSupported (const AudioChannelSet &channelSet)
 Returns true if the channel layout is supported by this format. More...
 
virtual bool isCompressed ()
 Returns true if the format uses compressed data. More...
 

Protected Member Functions

 AudioFormat (String formatName, StringArray fileExtensions)
 Creates an AudioFormat object. More...
 
 AudioFormat (StringRef formatName, StringRef fileExtensions)
 Creates an AudioFormat object. More...
 

Private Attributes

StringArray fileExtensions
 
String formatName
 

Detailed Description

Subclasses of AudioFormat are used to read and write different audio file formats.

See also
AudioFormatReader, AudioFormatWriter, WavAudioFormat, AiffAudioFormat

Constructor & Destructor Documentation

◆ ~AudioFormat()

virtual AudioFormat::~AudioFormat ( )
virtual

Destructor.

◆ AudioFormat() [1/2]

AudioFormat::AudioFormat ( String  formatName,
StringArray  fileExtensions 
)
protected

Creates an AudioFormat object.

Parameters
formatNamethis sets the value that will be returned by getFormatName()
fileExtensionsan array of file extensions - these will be returned by getFileExtensions()

◆ AudioFormat() [2/2]

AudioFormat::AudioFormat ( StringRef  formatName,
StringRef  fileExtensions 
)
protected

Creates an AudioFormat object.

Parameters
formatNamethis sets the value that will be returned by getFormatName()
fileExtensionsa whitespace-separated list of file extensions - these will be returned by getFileExtensions()

Member Function Documentation

◆ canDoMono()

virtual bool AudioFormat::canDoMono ( )
pure virtual

◆ canDoStereo()

virtual bool AudioFormat::canDoStereo ( )
pure virtual

◆ canHandleFile()

virtual bool AudioFormat::canHandleFile ( const File fileToTest)
virtual

Returns true if this the given file can be read by this format.

Subclasses shouldn't do too much work here, just check the extension or file type. The base class implementation just checks the file's extension against one of the ones that was registered in the constructor.

Reimplemented in AiffAudioFormat, and LAMEEncoderAudioFormat.

◆ createMemoryMappedReader() [1/2]

virtual MemoryMappedAudioFormatReader* AudioFormat::createMemoryMappedReader ( const File file)
virtual

Attempts to create a MemoryMappedAudioFormatReader, if possible for this format.

If the format does not support this, the method will return nullptr;

Reimplemented in WavAudioFormat, and AiffAudioFormat.

◆ createMemoryMappedReader() [2/2]

virtual MemoryMappedAudioFormatReader* AudioFormat::createMemoryMappedReader ( FileInputStream fin)
virtual

Reimplemented in WavAudioFormat, and AiffAudioFormat.

◆ createReaderFor()

virtual AudioFormatReader* AudioFormat::createReaderFor ( InputStream sourceStream,
bool  deleteStreamIfOpeningFails 
)
pure virtual

Tries to create an object that can read from a stream containing audio data in this format.

The reader object that is returned can be used to read from the stream, and should then be deleted by the caller.

Parameters
sourceStreamthe stream to read from - the AudioFormatReader object that is returned will delete this stream when it no longer needs it.
deleteStreamIfOpeningFailsif no reader can be created, this determines whether this method should delete the stream object that was passed-in. (If a valid reader is returned, it will always be in charge of deleting the stream, so this parameter is ignored)
See also
AudioFormatReader

Implemented in WavAudioFormat, OggVorbisAudioFormat, AiffAudioFormat, CoreAudioFormat, LAMEEncoderAudioFormat, MP3AudioFormat, FlacAudioFormat, and WindowsMediaAudioFormat.

◆ createWriterFor() [1/2]

virtual AudioFormatWriter* AudioFormat::createWriterFor ( OutputStream streamToWriteTo,
double  sampleRateToUse,
unsigned int  numberOfChannels,
int  bitsPerSample,
const StringPairArray metadataValues,
int  qualityOptionIndex 
)
pure virtual

Tries to create an object that can write to a stream with this audio format.

The writer object that is returned can be used to write to the stream, and should then be deleted by the caller.

If the stream can't be created for some reason (e.g. the parameters passed in here aren't suitable), this will return nullptr.

Parameters
streamToWriteTothe stream that the data will go to - this will be deleted by the AudioFormatWriter object when it's no longer needed. If no AudioFormatWriter can be created by this method, the stream will NOT be deleted, so that the caller can re-use it to try to open a different format, etc
sampleRateToUsethe sample rate for the file, which must be one of the ones returned by getPossibleSampleRates()
numberOfChannelsthe number of channels - this must be either 1 or 2, and the choice will depend on the results of canDoMono() and canDoStereo()
bitsPerSamplethe bits per sample to use - this must be one of the values returned by getPossibleBitDepths()
metadataValuesa set of metadata values that the writer should try to write to the stream. Exactly what these are depends on the format, and the subclass doesn't actually have to do anything with them if it doesn't want to. Have a look at the specific format implementation classes to see possible values that can be used
qualityOptionIndexthe index of one of compression qualities returned by the getQualityOptions() method. If there aren't any quality options for this format, just pass 0 in this parameter, as it'll be ignored
See also
AudioFormatWriter

Implemented in WavAudioFormat, OggVorbisAudioFormat, AiffAudioFormat, CoreAudioFormat, LAMEEncoderAudioFormat, MP3AudioFormat, FlacAudioFormat, and WindowsMediaAudioFormat.

◆ createWriterFor() [2/2]

virtual AudioFormatWriter* AudioFormat::createWriterFor ( OutputStream streamToWriteTo,
double  sampleRateToUse,
const AudioChannelSet channelLayout,
int  bitsPerSample,
const StringPairArray metadataValues,
int  qualityOptionIndex 
)
virtual

Tries to create an object that can write to a stream with this audio format.

The writer object that is returned can be used to write to the stream, and should then be deleted by the caller.

If the stream can't be created for some reason (e.g. the parameters passed in here aren't suitable), this will return nullptr.

Parameters
streamToWriteTothe stream that the data will go to - this will be deleted by the AudioFormatWriter object when it's no longer needed. If no AudioFormatWriter can be created by this method, the stream will NOT be deleted, so that the caller can re-use it to try to open a different format, etc
sampleRateToUsethe sample rate for the file, which must be one of the ones returned by getPossibleSampleRates()
channelLayoutthe channel layout for the file. Use isChannelLayoutSupported to check if the writer supports this layout.
bitsPerSamplethe bits per sample to use - this must be one of the values returned by getPossibleBitDepths()
metadataValuesa set of metadata values that the writer should try to write to the stream. Exactly what these are depends on the format, and the subclass doesn't actually have to do anything with them if it doesn't want to. Have a look at the specific format implementation classes to see possible values that can be used
qualityOptionIndexthe index of one of compression qualities returned by the getQualityOptions() method. If there aren't any quality options for this format, just pass 0 in this parameter, as it'll be ignored
See also
AudioFormatWriter

Reimplemented in WavAudioFormat.

◆ getFileExtensions()

const StringArray& AudioFormat::getFileExtensions ( ) const

Returns all the file extensions that might apply to a file of this format.

The first item will be the one that's preferred when creating a new file.

So for a wav file this might just return ".wav"; for an AIFF file it might return two items, ".aif" and ".aiff"

◆ getFormatName()

const String& AudioFormat::getFormatName ( ) const

Returns the name of this format.

e.g. "WAV file" or "AIFF file"

◆ getPossibleBitDepths()

virtual Array<int> AudioFormat::getPossibleBitDepths ( )
pure virtual

Returns a set of bit depths that the format can read and write.

Implemented in WavAudioFormat, AiffAudioFormat, CoreAudioFormat, LAMEEncoderAudioFormat, MP3AudioFormat, FlacAudioFormat, OggVorbisAudioFormat, and WindowsMediaAudioFormat.

◆ getPossibleSampleRates()

virtual Array<int> AudioFormat::getPossibleSampleRates ( )
pure virtual

Returns a set of sample rates that the format can read and write.

Implemented in WavAudioFormat, AiffAudioFormat, CoreAudioFormat, LAMEEncoderAudioFormat, MP3AudioFormat, FlacAudioFormat, OggVorbisAudioFormat, and WindowsMediaAudioFormat.

◆ getQualityOptions()

virtual StringArray AudioFormat::getQualityOptions ( )
virtual

Returns a list of different qualities that can be used when writing.

Non-compressed formats will just return an empty array, but for something like Ogg-Vorbis or MP3, it might return a list of bit-rates, etc.

When calling createWriterFor(), an index from this array is passed in to tell the format which option is required.

Reimplemented in LAMEEncoderAudioFormat, MP3AudioFormat, FlacAudioFormat, and OggVorbisAudioFormat.

◆ isChannelLayoutSupported()

virtual bool AudioFormat::isChannelLayoutSupported ( const AudioChannelSet channelSet)
virtual

Returns true if the channel layout is supported by this format.

Reimplemented in WavAudioFormat.

◆ isCompressed()

virtual bool AudioFormat::isCompressed ( )
virtual

Returns true if the format uses compressed data.

Reimplemented in LAMEEncoderAudioFormat, MP3AudioFormat, FlacAudioFormat, OggVorbisAudioFormat, and WindowsMediaAudioFormat.

Member Data Documentation

◆ fileExtensions

StringArray AudioFormat::fileExtensions
private

◆ formatName

String AudioFormat::formatName
private

The documentation for this class was generated from the following file: