Software-based MP3 decoding format (doesn't currently provide an encoder). More...

#include <juce_MP3AudioFormat.h>

Inheritance diagram for MP3AudioFormat:

Collaboration diagram for MP3AudioFormat:

[legend]

Public Member Functions
	MP3AudioFormat ()

	~MP3AudioFormat ()

bool	canDoMono () override
	Returns true if the format can do 1-channel audio. More...

bool	canDoStereo () override
	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 MemoryMappedAudioFormatReader *	createMemoryMappedReader (const File &file)
	Attempts to create a MemoryMappedAudioFormatReader, if possible for this format. More...

virtual MemoryMappedAudioFormatReader *	createMemoryMappedReader (FileInputStream *fin)

AudioFormatReader *	createReaderFor (InputStream *, bool deleteStreamIfOpeningFails) override
	Tries to create an object that can read from a stream containing audio data in this format. More...

AudioFormatWriter *	createWriterFor (OutputStream *, double sampleRateToUse, unsigned int numberOfChannels, int bitsPerSample, const StringPairArray &metadataValues, int qualityOptionIndex) override
	Tries to create an object that can write to a stream with this audio format. More...

virtual AudioFormatWriter *	createWriterFor (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 StringArray &	getFileExtensions () const
	Returns all the file extensions that might apply to a file of this format. More...

const String &	getFormatName () const
	Returns the name of this format. More...

Array< int >	getPossibleBitDepths () override
	Returns a set of bit depths that the format can read and write. More...

Array< int >	getPossibleSampleRates () override
	Returns a set of sample rates that the format can read and write. More...

StringArray	getQualityOptions () override
	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...

bool	isCompressed () override
	Returns true if the format uses compressed data. More...

Detailed Description

Software-based MP3 decoding format (doesn't currently provide an encoder).

IMPORTANT DISCLAIMER: By choosing to enable the JUCE_USE_MP3AUDIOFORMAT flag and to compile the MP3 code into your software, you do so AT YOUR OWN RISK! By doing so, you are agreeing that ROLI Ltd. is in no way responsible for any patent, copyright, or other legal issues that you may suffer as a result.

The code in juce_MP3AudioFormat.cpp is NOT guaranteed to be free from infringements of 3rd-party intellectual property. If you wish to use it, please seek your own independent advice about the legality of doing so. If you are not willing to accept full responsibility for the consequences of using this code, then do not enable the JUCE_USE_MP3AUDIOFORMAT setting.

Constructor & Destructor Documentation

◆ MP3AudioFormat()

MP3AudioFormat::MP3AudioFormat ( )

◆ ~MP3AudioFormat()

MP3AudioFormat::~MP3AudioFormat ( )

Member Function Documentation

◆ canDoMono()

bool MP3AudioFormat::canDoMono ( )

overridevirtual

Returns true if the format can do 1-channel audio.

Implements AudioFormat.

◆ canDoStereo()

bool MP3AudioFormat::canDoStereo ( )

overridevirtual

Returns true if the format can do 2-channel audio.

Implements AudioFormat.

◆ canHandleFile()

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

virtualinherited

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 )

virtualinherited

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 )

virtualinherited

Reimplemented in WavAudioFormat, and AiffAudioFormat.

◆ createReaderFor()

AudioFormatReader* MP3AudioFormat::createReaderFor	(	InputStream *	sourceStream,
		bool	deleteStreamIfOpeningFails
	)

overridevirtual

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

sourceStream	the stream to read from - the AudioFormatReader object that is returned will delete this stream when it no longer needs it.
deleteStreamIfOpeningFails	if 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

Implements AudioFormat.

◆ createWriterFor() [1/2]

AudioFormatWriter* MP3AudioFormat::createWriterFor	(	OutputStream *	streamToWriteTo,
		double	sampleRateToUse,
		unsigned int	numberOfChannels,
		int	bitsPerSample,
		const StringPairArray &	metadataValues,
		int	qualityOptionIndex
	)

overridevirtual

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

streamToWriteTo	the 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
sampleRateToUse	the sample rate for the file, which must be one of the ones returned by getPossibleSampleRates()
numberOfChannels	the number of channels - this must be either 1 or 2, and the choice will depend on the results of canDoMono() and canDoStereo()
bitsPerSample	the bits per sample to use - this must be one of the values returned by getPossibleBitDepths()
metadataValues	a 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
qualityOptionIndex	the 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

Implements AudioFormat.

◆ createWriterFor() [2/2]

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

virtualinherited

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

streamToWriteTo	the 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
sampleRateToUse	the sample rate for the file, which must be one of the ones returned by getPossibleSampleRates()
channelLayout	the channel layout for the file. Use isChannelLayoutSupported to check if the writer supports this layout.
bitsPerSample	the bits per sample to use - this must be one of the values returned by getPossibleBitDepths()
metadataValues	a 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
qualityOptionIndex	the 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

inherited

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

inherited

Returns the name of this format.

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

◆ getPossibleBitDepths()

Array<int> MP3AudioFormat::getPossibleBitDepths ( )

overridevirtual

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

Implements AudioFormat.

◆ getPossibleSampleRates()

Array<int> MP3AudioFormat::getPossibleSampleRates ( )

overridevirtual

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

Implements AudioFormat.

◆ getQualityOptions()

StringArray MP3AudioFormat::getQualityOptions ( )

overridevirtual

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 from AudioFormat.

◆ isChannelLayoutSupported()

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

virtualinherited

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

Reimplemented in WavAudioFormat.

◆ isCompressed()

bool MP3AudioFormat::isCompressed ( )

overridevirtual

Returns true if the format uses compressed data.

Reimplemented from AudioFormat.

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

juce_MP3AudioFormat.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ MP3AudioFormat()

◆ ~MP3AudioFormat()

Member Function Documentation

◆ canDoMono()

◆ canDoStereo()

◆ canHandleFile()

◆ createMemoryMappedReader() [1/2]

◆ createMemoryMappedReader() [2/2]

◆ createReaderFor()

◆ createWriterFor() [1/2]

◆ createWriterFor() [2/2]

◆ getFileExtensions()

◆ getFormatName()

◆ getPossibleBitDepths()

◆ getPossibleSampleRates()

◆ getQualityOptions()

◆ isChannelLayoutSupported()

◆ isCompressed()