JS Filter API

JavaScript API for filters. More...

Collaboration diagram for JS Filter API:

Data Structures
interface	JSFilter
	JSFilter API. More...
interface	FilterInstance
interface	FilterPid
interface	FilterPacket
interface	FilterEvent
interface	JSArgDesc
interface	JSCapDesc

Typedefs
typedef Object	FilterProperty

Functions
void	print (DOMString log)
void	print (long log_level, DOMString log_str)

Variables
attribute Array	args
attribute JSFilter	filter

Detailed Description

This section documents the JavaScript API used when developing JavaScript-based filters. JavaScript filters support all tools from native filters, see Filter Management.

Errors are handled through exceptions, except for callback function return values of the Filter object.

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Data Structure Documentation

JSArgDesc

interface JSArgDesc

interface used to describe filter arguments

Data Fields
attribute DOMString	name	name of the argument
attribute DOMString	desc	description of the argument
attribute unsigned long	type	type of the argument
optional attribute DOMString	def	default value of the argument
optional attribute DOMString	minmax_enum	min/max or enum values of the argument
optional attribute DOMString	hint	argument hint type: "advanced", "expert", "hide" or null

JSCapDesc

interface JSCapDesc

interface used to describe filter capability

Data Fields
attribute DOMString	id	PropertyID of the capability - mandatory
attribute DOMString	value	value of the property - mandatory
attribute boolean	inout	input and output flag of the capability - if true, the output flag is ignored
attribute boolean	output	output flag of the capability - if undefined, the capability is an input one
optional attribute boolean	excluded	excluded flag of the capability
optional attribute boolean	loaded_filter_only	loaded filter only flag of the capability
optional attribute boolean	static	static flag of the capability
optional attribute boolean	optional	optional flag of the capability

Typedef Documentation

FilterProperty

typedef Object FilterProperty

Properties are mapped to JavaScript values as follows:

GF_PROP_PID_CODECID: string containing the codec name
GF_PROP_PID_STREAM_TYPE: string containing the stream type name

Other properties are mapped by property type:
GF_PROP_BOOL: boolean
GF_PROP_UINT: integer
GF_PROP_4CC: string
GF_PROP_SINT: integer
GF_PROP_LUINT: large integer
GF_PROP_LSINT: large integer
GF_PROP_FLOAT: double
GF_PROP_FLOAT: double
GF_PROP_STRING: string
GF_PROP_STRING_NO_COPY: string
GF_PROP_VEC2: object with number properties "x" and "y"
GF_PROP_VEC2I: object with integer properties "x" and "y"
GF_PROP_VEC3I: object with integer properties "x", "y" and "z"
GF_PROP_VEC4I: object with integer properties "x", "y", "z" and "w"
GF_PROP_FRACTION: object with integer properties "n" and "d", representing fraction n/d
GF_PROP_FRACTION64: object with large integer properties "n" and "d", representing fraction n/d
GF_PROP_UINT_LIST: array of integers
GF_PROP_4CC_LIST: array of strings
GF_PROP_STRING_LIST: array of strings
All enumeration properties (pixel format, audio format, etc): string

Function Documentation

print() [1/2]

void print

(

DOMString

log

)

global context function for printing

Parameters

log	the string to write

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print() [2/2]

void print	(	long	log_level,
		DOMString	log_str
	)

global context function for printing

Parameters

log_level	the log level to use: GF_LOG_DEBUG, GF_LOG_INFO, GF_LOG_WARNING, GF_LOG_ERROR. The special value -2 means print as gf_sys_format_help without highlight, the special value -1 means print as gf_sys_format_help with hightlight of first)
log_str	the string to write

Variable Documentation

args

attribute Array args

global context property containing the launch arguments

filter

attribute JSFilter filter

global context property representing the one and only JSFilter object attached to the loaded filter