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Parse-Matroska-0.003
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/ Parse::Matroska::Definitions

NAME

Parse::Matroska::Definitions - internal EBML grammar definitions

VERSION

version 0.003

SYNOPSIS

use Parse::Matroska::Definitions qw{elem_by_hexid};
my $ebml_id = elem_by_hexid('1a45dfa3');
print "EBML ID $ebml_id->{elid}'s name: $ebml_id->{name}";

DESCRIPTION

Contains the definition of the EBML grammar as expected in Matroska files. This module is meant mostly for internal use.

As this was extended from a script in mpv-player, some data generated is apparently useless for regular module users but is still relevant to the mpv-player script. Such data is annotated as being for mpv compatibility.

METHODS

elem_by_hexid($id)

Returns an EBML Element Definition corresponding to the provided hexadecimal string. Returns undef if the element is unknown.

elem($name,$elid,$valtype)

NOTE: never call this function yourself; it changes data structures that are considered immutable outside of this package.

Internal API function that generates the EBML Element Definitions.

This API function returns an array which first element is $elid and the second is a generated hash. The generated hash is stored in the @global_elem_list and %global_elem_dict.

The generated hash contains:

name

The EBML Element's name, given through $name.

elid

The EBML Element's hex id, given through $elid. Used for lookups by "elem_by_hexid($id)".

valtype

The EBML Element's type, given through $valtype, except when $valtype is an arrayref.

multiple

If $name ends with a *, this is set as true and strips the * from "name". Used to mark elements that may be repeated.

subelements

An arrayref of elements that may be children of this element, given through $valtype if it is an arrayref. Sets "valtype" to sub if there are subelements.

subids

An arrayref listing all the "elid"s of subelements, uniqified.

The following elements are for mpv compatibility:

definename

Name used for generating C #defines.

fieldname

Name used for generating C struct fields.

structname

Name used for generating C struct names.

ebmltype

A pre-#defined constant to describe the element's type.

valname

Typename used when declaring a struct field referring to this element.

define_ebml

Internal function that defines the EBML generic grammar.

Must not be called from outside the package.

define_matroska

Internal function that defines the Matroska-specific EBML grammar.

Must not be called from outside the package.

NOTE

The API of this module is not yet considered stable.

GLOBALS

These global variables are considered immutable.

@Parse::Matroska::Definitions::global_elem_list

A global list of known matroska elements. Useful for mpv's matroska script, used for generating C headers that parse matroska.

%Parse::Matroska::Definitions::global_elem_dict

A global hash of known matroska elements. Used internally by "elem_by_hexid($id)".

%EBML_DEFINITION

Optionally-importable hash of known EBML IDs belonging to the EBML generic grammar.

%MATROSKA_DEFINITION

Optionally-importable hash of known EBML IDs belonging to the Matroska-specific grammar.

AUTHOR

Kovensky <diogomfranco@gmail.com>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2012 by Diogo Franco.

This is free software, licensed under:

The (two-clause) FreeBSD License