Audio meter API

Collaboration diagram for Audio meter API:

Data Structures
struct	vlc_audio_loudness
	Audio loudness measurement. More...
struct	vlc_audio_meter_cbs
	Audio meter callback. More...
struct	vlc_audio_meter_plugin_owner
	Audio meter plugin owner structure. More...
struct	vlc_audio_meter
	Audio meter structure. More...

Macros
#define	vlc_audio_meter_Init(a, b)   vlc_audio_meter_Init(a, VLC_OBJECT(b))

Typedefs
typedef struct vlc_audio_meter_plugin	vlc_audio_meter_plugin
	Audio meter plugin opaque structure.

Functions
void	vlc_audio_meter_Init (struct vlc_audio_meter *meter, vlc_object_t *parent)
	Initialize the audio meter structure.
void	vlc_audio_meter_Destroy (struct vlc_audio_meter *meter)
	Free allocated resource from the audio meter structure.
int	vlc_audio_meter_Reset (struct vlc_audio_meter *meter, const audio_sample_format_t *fmt)
	Set or reset the audio format.
vlc_audio_meter_plugin *	vlc_audio_meter_AddPlugin (struct vlc_audio_meter *meter, const char *chain, const struct vlc_audio_meter_plugin_owner *owner)
	Add an "audio meter" plugin.
void	vlc_audio_meter_RemovePlugin (struct vlc_audio_meter *meter, vlc_audio_meter_plugin *plugin)
	Remove an "audio meter" plugin.
void	vlc_audio_meter_Process (struct vlc_audio_meter *meter, block_t *block, vlc_tick_t date)
	Process an audio block.
void	vlc_audio_meter_Flush (struct vlc_audio_meter *meter)
	Flush all "audio meter" plugins.

Detailed Description

Macro Definition Documentation

vlc_audio_meter_Init

#define vlc_audio_meter_Init	(		a,
			b
	)		vlc_audio_meter_Init(a, VLC_OBJECT(b))

Typedef Documentation

vlc_audio_meter_plugin

typedef struct vlc_audio_meter_plugin vlc_audio_meter_plugin

Audio meter plugin opaque structure.

This opaque structure is returned by vlc_audio_meter_AddPlugin().

Function Documentation

vlc_audio_meter_AddPlugin()

vlc_audio_meter_plugin * vlc_audio_meter_AddPlugin	(	struct vlc_audio_meter *	meter,
		const char *	chain,
		const struct vlc_audio_meter_plugin_owner *	owner
	)

Add an "audio meter" plugin.

The module to be loaded if meter->fmt is valid, otherwise, the module will be loaded from a next call to vlc_audio_meter_Reset()

Parameters

meter	audio meter structure
chain	name of the module, can contain specific module options using the following chain convention:"name{option1=a,option2=b}"
owner	pointer to a vlc_audio_meter_plugin_owner structure, the structure must stay valid during the lifetime of the plugin

Returns

a valid audio meter plugin, or NULL in case of error

References vlc_audio_meter_plugin_owner::cbs, vlc_audio_meter_plugin::cfg, config_ChainCreate(), config_ChainDestroy(), vlc_filter_operations::drain_audio, vlc_audio_meter_plugin::filter, vlc_audio_meter::fmt, vlc_audio_meter_plugin::last_date, vlc_audio_meter::lock, vlc_audio_meter_plugin::name, vlc_audio_meter_plugin::node, filter_t::ops, vlc_audio_meter_plugin::owner, vlc_audio_meter::plugins, vlc_audio_meter_CreatePluginFilter(), vlc_list_append(), vlc_mutex_lock(), vlc_mutex_unlock(), and VLC_TICK_INVALID.

Referenced by aout_AddMeterPlugin().

vlc_audio_meter_Destroy()

void vlc_audio_meter_Destroy

(

struct vlc_audio_meter *

meter

)

Free allocated resource from the audio meter structure.

Parameters

meter

allocated audio meter structure

References vlc_audio_meter::plugins, vlc_audio_meter_RemovePlugin(), and vlc_list_foreach.

Referenced by aout_Destroy().

vlc_audio_meter_Flush()

void vlc_audio_meter_Flush

(

struct vlc_audio_meter *

meter

)

Flush all "audio meter" plugins.

vlc_audio_meter_events callbacks can be triggered from this function.

Parameters

meter

audio meter structure

References vlc_audio_meter_plugin::filter, filter_Flush(), vlc_audio_meter::lock, vlc_audio_meter::plugins, vlc_list_foreach, vlc_mutex_lock(), and vlc_mutex_unlock().

Referenced by stream_Reset().

vlc_audio_meter_Init()

void vlc_audio_meter_Init	(	struct vlc_audio_meter *	meter,
		vlc_object_t *	parent
	)

Initialize the audio meter structure.

Parameters

meter	allocated audio meter structure
parent	object that will be used to create audio filters

References vlc_audio_meter::fmt, vlc_audio_meter::lock, vlc_audio_meter::parent, vlc_audio_meter::plugins, vlc_list_init(), and vlc_mutex_init().

vlc_audio_meter_Process()

void vlc_audio_meter_Process	(	struct vlc_audio_meter *	meter,
		block_t *	block,
		vlc_tick_t	date
	)

Process an audio block.

vlc_audio_meter_events callbacks can be triggered from this function.

Parameters

meter	audio meter structure
block	pointer to a block, this block won't be released of modified from this function
date	absolute date (likely in the future) when this block should be rendered

References vlc_audio_meter_plugin::filter, vlc_filter_operations::filter_audio, vlc_frame_t::i_length, vlc_audio_meter_plugin::last_date, vlc_audio_meter::lock, filter_t::ops, vlc_audio_meter::plugins, vlc_list_foreach, vlc_mutex_lock(), and vlc_mutex_unlock().

Referenced by vlc_aout_stream_Play().

vlc_audio_meter_RemovePlugin()

void vlc_audio_meter_RemovePlugin	(	struct vlc_audio_meter *	meter,
		vlc_audio_meter_plugin *	plugin
	)

Remove an "audio meter" plugin.

Parameters

meter	audio meter structure
plugin	plugin returned by vlc_audio_meter_AddPlugin()

References vlc_audio_meter_plugin::cfg, config_ChainDestroy(), vlc_audio_meter_plugin::filter, vlc_audio_meter::lock, vlc_audio_meter_plugin::name, vlc_audio_meter_plugin::node, vlc_filter_Delete(), vlc_list_remove(), vlc_mutex_lock(), and vlc_mutex_unlock().

Referenced by aout_RemoveMeterPlugin(), and vlc_audio_meter_Destroy().

vlc_audio_meter_Reset()

int vlc_audio_meter_Reset	(	struct vlc_audio_meter *	meter,
		const audio_sample_format_t *	fmt
	)

Set or reset the audio format.

This will reload all plugins added with vlc_audio_meter_AddPlugin()

Parameters

meter	audio meter structure
fmt	NULL to unload all plugins or a valid pointer to an audio format, must stay valid during the lifetime of the audio meter (until vlc_audio_meter_Reset() or vlc_audio_meter_Destroy() are called)

Returns

VLC_SUCCESS on success, VLC_EGENERIC if a plugin failed to load

References vlc_audio_meter_plugin::filter, vlc_audio_meter::fmt, vlc_audio_meter_plugin::last_date, vlc_audio_meter::lock, vlc_audio_meter::plugins, vlc_audio_meter_CreatePluginFilter(), VLC_EGENERIC, vlc_filter_Delete(), vlc_list_foreach, vlc_mutex_lock(), vlc_mutex_unlock(), VLC_SUCCESS, and VLC_TICK_INVALID.

Referenced by stream_CheckReady(), vlc_aout_stream_Delete(), and vlc_aout_stream_New().