mpg123 advanced parameter API

Typedefs
typedef struct mpg123_pars_struct	mpg123_pars
Functions
mpg123_handle *	mpg123_parnew (mpg123_pars *mp, const char *decoder, int *error)
mpg123_pars *	mpg123_new_pars (int *error)
void	mpg123_delete_pars (mpg123_pars *mp)
int	mpg123_fmt_none (mpg123_pars *mp)
int	mpg123_fmt_all (mpg123_pars *mp)
int	mpg123_fmt (mpg123_pars *mh, long rate, int channels, int encodings)
int	mpg123_fmt_support (mpg123_pars *mh, long rate, int encoding)
int	mpg123_par (mpg123_pars *mp, enum mpg123_parms type, long value, double fvalue)
int	mpg123_getpar (mpg123_pars *mp, enum mpg123_parms type, long *val, double *fval)

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Detailed Description

Direct access to a parameter set without full handle around it. Possible uses:

• Influence behaviour of library _during_ initialization of handle (MPG123_VERBOSE).
• Use one set of parameters for multiple handles.

The functions for handling mpg123_pars (mpg123_par() and mpg123_fmt() family) directly return a fully qualified mpg123 error code, the ones operating on full handles normally MPG123_OK or MPG123_ERR, storing the specific error code itseld inside the handle.

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Typedef Documentation

typedef struct mpg123_pars_struct mpg123_pars

Opaque structure for the libmpg123 decoder parameters.

Definition at line 992 of file mpg123.h.

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Function Documentation

mpg123_handle* mpg123_parnew	(	mpg123_pars *	mp,
		const char *	decoder,
		int *	error
	)

Create a handle with preset parameters.

mpg123_pars* mpg123_new_pars

(

int *

error

)

Allocate memory for and return a pointer to a new mpg123_pars

void mpg123_delete_pars

(

mpg123_pars *

mp

)

Delete and free up memory used by a mpg123_pars data structure

int mpg123_fmt_none

(

mpg123_pars *

mp

)

Configure mpg123 parameters to accept no output format at all, use before specifying supported formats with mpg123_format

int mpg123_fmt_all

(

mpg123_pars *

mp

)

Configure mpg123 parameters to accept all formats (also any custom rate you may set) -- this is default.

int mpg123_fmt	(	mpg123_pars *	mh,
		long	rate,
		int	channels,
		int	encodings
	)

Set the audio format support of a mpg123_pars in detail:

Parameters:

	rate	The sample rate value (in Hertz).
	channels	A combination of MPG123_STEREO and MPG123_MONO.
	encodings	A combination of accepted encodings for rate and channels, p.ex MPG123_ENC_SIGNED16|MPG123_ENC_ULAW_8 (or 0 for no support).

Returns:

0 on success, -1 if there was an error. /

int mpg123_fmt_support	(	mpg123_pars *	mh,
		long	rate,
		int	encoding
	)

Check to see if a specific format at a specific rate is supported by mpg123_pars.

Returns:

0 for no support (that includes invalid parameters), MPG123_STEREO, MPG123_MONO or MPG123_STEREO|MPG123_MONO.

int mpg123_par	(	mpg123_pars *	mp,
		enum mpg123_parms	type,
		long	value,
		double	fvalue
	)

Set a specific parameter, for a specific mpg123_pars, using a parameter type key chosen from the mpg123_parms enumeration, to the specified value.

int mpg123_getpar	(	mpg123_pars *	mp,
		enum mpg123_parms	type,
		long *	val,
		double *	fval
	)

Get a specific parameter, for a specific mpg123_pars. See the mpg123_parms enumeration for a list of available parameters.