MP3FILE Class Reference

Interface for mp3 decoders and encoders that support input/output using standard streams. More...

Inheritance diagram for MP3FILE:

List of all members.

Public Member Functions
	MP3FILE (const std::string &name="")
virtual MP3FILE *	clone (void) const
	Virtual method that clones the current object and returns a pointer to it.
virtual MP3FILE *	new_expr (void) const
	Virtual method that creates a new object of current type.
virtual std::string	name (void) const
	Object name used to identify the object type.
virtual std::string	description (void) const
	Object description.
virtual std::string	parameter_names (void) const
	A comma-separated list of parameters names.
virtual bool	locked_audio_format (void) const
	Whether audio format is locked.
virtual int	supported_io_modes (void) const
	Returns info about supported I/O modes (bitwise-OR).
virtual bool	supports_seeking (void) const
	Whether device supports non-blocking I/O mode.
virtual void	open (void) throw (AUDIO_IO::SETUP_ERROR &)
	Opens the audio object (possibly in exclusive mode).
virtual void	close (void)
	Closes audio object.
virtual long int	read_samples (void *target_buffer, long int samples)
	Low-level routine for reading samples.
virtual void	write_samples (void *target_buffer, long int samples)
	Low-level routine for writing samples.
virtual bool	finished (void) const
	Whether all data has been processed? If opened in mode 'io_read', this means that end of stream has been reached.
virtual void	seek_position (void)
virtual void	set_parameter (int param, std::string value)
virtual std::string	get_parameter (int param) const
	Get parameter value.
Static Public Member Functions
static void	set_input_cmd (const std::string &value)
static void	set_output_cmd (const std::string &value)
Static Public Attributes
static long int	default_output_default_bitrate = 128000

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Detailed Description

Interface for mp3 decoders and encoders that support input/output using standard streams.

Defaults to mpg123 and lame.

Author:

Kai Vehmanen

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Member Function Documentation

virtual MP3FILE* MP3FILE::clone (  void   )  const [inline, virtual]

Virtual method that clones the current object and returns a pointer to it. This must be implemented by all subclasses! Implements AUDIO_IO.

void MP3FILE::close (  void   )  [virtual]

Closes audio object. After calling this routine, all resources (for instance files and devices) must be freed so that they can be used by other processes. Precondition: is_open() == true Postcondition: readable() != true writable() != true Reimplemented from AUDIO_IO.

virtual std::string MP3FILE::description (  void   )  const [inline, virtual]

Object description. Description should be short, informative and unformatted. Reimplemented from ECA_OBJECT.

virtual bool MP3FILE::finished (  void   )  const [inline, virtual]

Whether all data has been processed? If opened in mode 'io_read', this means that end of stream has been reached. If opened in 'io_write' or 'io_readwrite' modes, finished status usually means that an error has occured (no space left, etc). After finished() has returned 'true', further calls to read_buffer() and/or write_buffer() won't process any data. For output for which 'finite_length_stream()' is true, when 'finished()' returns true, that means an error has occured. Otherwise 'finished()' just tells that further attempts to do i/o will fail. Implements AUDIO_IO.

std::string MP3FILE::get_parameter (  int  param  )  const [virtual]

Get parameter value. Parameters: param  parameter id, require: param > 0 Reimplemented from AUDIO_IO.

virtual bool MP3FILE::locked_audio_format (  void   )  const [inline, virtual]

Whether audio format is locked. If this is true, audio object has a known audio format, and doesn't allow overriding it. By default, audio format is not locked. Reimplemented from AUDIO_IO.

virtual std::string MP3FILE::name (  void   )  const [inline, virtual]

Object name used to identify the object type. In most cases, object name is same for all class instances. Must be implemented in all subclasses. Implements ECA_OBJECT.

virtual MP3FILE* MP3FILE::new_expr (  void   )  const [inline, virtual]

Virtual method that creates a new object of current type. This must be implemented by all subclasses! Implements AUDIO_IO.

void MP3FILE::open (  void   )  throw (AUDIO_IO::SETUP_ERROR &) [virtual]

Opens the audio object (possibly in exclusive mode). This routine is used for initializing external connections (opening files or devices, loading shared libraries, opening IPC connections). As it's impossible to know in advance what might happen, open() may throw an exception. This way it becomes possible to provide more verbose information about the problem that caused open() to fail. At this point the various audio parameters are used for the first time. Unless locked_audio_format() is 'true', object tries to use the audio format parameters set prior to this call. If object doesn't support the given parameter combination, it can either try adjust them to closest matching, or in the worst case, throw an SETUP_ERROR exception (see above). Precondition: is_open() != true Postcondition: readable() == true || writable() == true || is_open() != true Reimplemented from AUDIO_IO.

virtual std::string MP3FILE::parameter_names (  void   )  const [inline, virtual]

A comma-separated list of parameters names. Derived classes must implement this. Reimplemented from AUDIO_IO.

long int MP3FILE::read_samples (  void *  target_buffer, long int  samples )  [virtual]

Low-level routine for reading samples. Number of read sample frames is returned. This must be implemented by all subclasses. Implements AUDIO_IO_BUFFERED.

virtual int MP3FILE::supported_io_modes (  void   )  const [inline, virtual]

Returns info about supported I/O modes (bitwise-OR). By default, all I/O modes are supported. Reimplemented from AUDIO_IO.

virtual bool MP3FILE::supports_seeking (  void   )  const [inline, virtual]

Whether device supports non-blocking I/O mode. By default, seeking is supported. Reimplemented from AUDIO_IO.

void MP3FILE::write_samples (  void *  target_buffer, long int  samples )  [virtual]

Low-level routine for writing samples. This must be implemented by all subclasses. Implements AUDIO_IO_BUFFERED.

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

• audioio-mp3.h
• audioio-mp3.cpp

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