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filter is not described

wp_video_extensions filter-hook . WP 3.6.0

Filters the list of supported video formats.

Usage

add_filter( 'wp_video_extensions', 'filter_function_name_4049' );
function filter_function_name_4049( $extensions ){
	// filter...

	return $extensions;
}
$extensions(array)
An array of support video formats.
Default: are 'mp4', 'm4v', 'webm', 'ogv', 'flv'

Where the hook is called

wp_get_video_extensions()
wp-includes/media.php 2397
return apply_filters( 'wp_video_extensions', array( 'mp4', 'm4v', 'webm', 'ogv', 'flv' ) );

Where the hook is used (in WP core)

Does not used.