#include <CUAudioDecoder.h>

Inheritance diagram for cugl::audio::AudioDecoder:

Public Member Functions
	AudioDecoder ()

	~AudioDecoder ()

virtual bool	init (const char *file)

virtual bool	init (const std::string &file)=0

virtual void	dispose ()=0

double	getDuration () const

Uint32	getSampleRate () const

Uint64	getLength () const

Uint32	getChannels () const

std::string	getFile () const

Uint32	getPageSize () const

bool	ready ()

virtual Sint32	pagein (float *buffer)=0

Uint64	getPage () const

virtual void	setPage (Uint64 page)=0

Uint64	getPageCount () const

void	rewind ()

Sint32	decode (float *buffer)

Protected Attributes
Uint8	_channels

Uint32	_rate

Uint64	_frames

std::string	_file

Uint32	_pagesize

Uint64	_currpage

Uint64	_lastpage

Detailed Description

This class abstracts an audio codec for decoding.

By providing a single interface for all audio codecs, we make it easy to to support multiple file types. Currently we support four file types: WAV (including ADPCM encodings), MP3, Ogg (Vorbis), and Flac. As a general rule, we prefer WAV for sound effects and Ogg for music.

A decoder breaks up the sound into pages for streaming access. While some codecs refer to pages as "frames', we reserve that term for groups of samples at a single moment in time, as is the case for the rest of the API.

A decoder is NOT thread safe. If a decoder is used by an audio thread, then it should not be accessed directly in the main thread, and vice versa.

Constructor & Destructor Documentation

◆ AudioDecoder()

cugl::audio::AudioDecoder::AudioDecoder ( )

Creates an initialized audio decoder

NEVER USE A CONSTRUCTOR WITH NEW. If you want to allocate an asset on the heap, use one of the static constructors instead.

◆ ~AudioDecoder()

cugl::audio::AudioDecoder::~AudioDecoder ( )

inline

Deletes this decoder, disposing of all resources.

Member Function Documentation

◆ decode()

Sint32 cugl::audio::AudioDecoder::decode ( float * buffer )

Decodes the entire audio file, storing its value in buffer.

The buffer should be able to hold channels * frames many elements. The data is interpretted as floats and channels are all interleaved. If the method returns -1, then an error occurred during reading.

Parameters

buffer The buffer to store the audio data

Returns: the number of frames actually read (-1 on error).

◆ dispose()

virtual void cugl::audio::AudioDecoder::dispose ( )

pure virtual

Deletes the decoder resources and resets all attributes.

This will close the associated file. You must reinitialize the decoder to use it.

Implemented in cugl::audio::WAVDecoder, cugl::audio::FLACDecoder, cugl::audio::OGGDecoder, and cugl::audio::MP3Decoder.

◆ getChannels()

Uint32 cugl::audio::AudioDecoder::getChannels ( ) const

inline

Returns the number of channels used by this sound source

A value of 1 means mono, while 2 means stereo. Depending on the file format, other channels are possible. For example, 6 channels means support for 5.1 surround sound.

We support up to 32 possible channels.

Returns: the number of channels used by this sound asset

◆ getDuration()

double cugl::audio::AudioDecoder::getDuration ( ) const

inline

Returns the length of this sound source in seconds.

The accuracy of this method depends on the specific implementation.

Returns: the length of this sound source in seconds.

◆ getFile()

std::string cugl::audio::AudioDecoder::getFile ( ) const

inline

Returns the file for this audio source

This value is the empty string if there was no source file.

Returns: the file for this audio source

◆ getLength()

Uint64 cugl::audio::AudioDecoder::getLength ( ) const

inline

Returns the frame length of this sound source.

The frame length is the duration times the sample rate.

Returns: the frame length of this sound source.

◆ getPage()

Uint64 cugl::audio::AudioDecoder::getPage ( ) const

inline

Returns the current page of this decoder

This value is the next page to be read in with the pagein() command.

Returns: the current page of this decoder

◆ getPageCount()

Uint64 cugl::audio::AudioDecoder::getPageCount ( ) const

inline

Returns the total number of pages in this decoder

This value is the maximum value for the setPage command.

Returns: total number of pages in this decoder

◆ getPageSize()

Uint32 cugl::audio::AudioDecoder::getPageSize ( ) const

inline

Returns the number of frames in a single page of data

When multiplied by the number of channels, this gives the number of samples read per page

Returns: the number of frames in a single page of data

◆ getSampleRate()

Uint32 cugl::audio::AudioDecoder::getSampleRate ( ) const

inline

Returns the sample rate of this sound source.

Returns: the sample rate of this sound source.

◆ init() [1/2]

virtual bool cugl::audio::AudioDecoder::init ( const char * file )

inlinevirtual

Initializes a new decoder for the given file.

This initializer is an abstract method in the base class. The file is either streamed or completely read into memory according to the specific implementation.

Parameters

file	the source file for the decoder

Returns: true if the decoder was initialized successfully

Reimplemented in cugl::audio::WAVDecoder, cugl::audio::FLACDecoder, cugl::audio::OGGDecoder, and cugl::audio::MP3Decoder.

◆ init() [2/2]

virtual bool cugl::audio::AudioDecoder::init ( const std::string & file )

pure virtual

Initializes a new decoder for the given file.

This initializer is an abstract method in the base class. The file is either streamed or completely read into memory according to the specific implementation.

Parameters

file	the source file for the decoder

Returns: true if the decoder was initialized successfully

Implemented in cugl::audio::WAVDecoder, cugl::audio::FLACDecoder, cugl::audio::OGGDecoder, and cugl::audio::MP3Decoder.

◆ pagein()

virtual Sint32 cugl::audio::AudioDecoder::pagein ( float * buffer )

pure virtual

Reads a page of data into the provided buffer.

The buffer should be able to hold channels * page size many elements. The data is interpretted as floats and channels are all interleaved. If a full page is read, this method should return the page size. If it reads less, it will return the number of frames read. It will return -1 on a processing error.

Parameters

buffer The buffer to store the audio data

Returns: the number of frames actually read (-1 on error).

Implemented in cugl::audio::WAVDecoder, cugl::audio::FLACDecoder, cugl::audio::OGGDecoder, and cugl::audio::MP3Decoder.

◆ ready()

bool cugl::audio::AudioDecoder::ready ( )

inline

Returns true if there are still data to be read by the decoder

This value will return false if the decoder is at the end of the file

Returns: true if there are still data to be read by the decoder

◆ rewind()

void cugl::audio::AudioDecoder::rewind ( )

inline

Rewinds this decoder back the beginning of the stream

◆ setPage()

virtual void cugl::audio::AudioDecoder::setPage ( Uint64 page )

pure virtual

Sets the current page of this decoder

This value is the next page to be read in with the pagein() command. If the page is greater than the total number of pages, it will be set just beyond the last page.

Parameters

page	The new page of this decoder

Implemented in cugl::audio::WAVDecoder, cugl::audio::OGGDecoder, cugl::audio::FLACDecoder, and cugl::audio::MP3Decoder.

Member Data Documentation

◆ _channels

Uint8 cugl::audio::AudioDecoder::_channels

protected

The number of channels in this sound source (max 32)

◆ _currpage

Uint64 cugl::audio::AudioDecoder::_currpage

protected

The current page in the stream

◆ _file

std::string cugl::audio::AudioDecoder::_file

protected

The source for this buffer (may be empty)

◆ _frames

Uint64 cugl::audio::AudioDecoder::_frames

protected

The number of frames in this sounds source

◆ _lastpage

Uint64 cugl::audio::AudioDecoder::_lastpage

protected

The previous page in the stream

◆ _pagesize

Uint32 cugl::audio::AudioDecoder::_pagesize

protected

The size of a decoder chunk

◆ _rate

Uint32 cugl::audio::AudioDecoder::_rate

protected

The sampling rate (frequency) of this sound source

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

include/cugl/audio/codecs/CUAudioDecoder.h

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ AudioDecoder()

◆ ~AudioDecoder()

Member Function Documentation

◆ decode()

◆ dispose()

◆ getChannels()

◆ getDuration()

◆ getFile()

◆ getLength()

◆ getPage()

◆ getPageCount()

◆ getPageSize()

◆ getSampleRate()

◆ init() [1/2]

◆ init() [2/2]

◆ pagein()

◆ ready()

◆ rewind()

◆ setPage()

Member Data Documentation

◆ _channels

◆ _currpage

◆ _file

◆ _frames

◆ _lastpage

◆ _pagesize

◆ _rate