Hooked code to disable like feature for user on its own media.

function.php

<?php 
add_action('init','rtmedia_disable_media_like_init');
/**
 * Function to extend like disable check functionality.
 */
function rtmedia_disable_media_like_init(){
	if( function_exists( 'rtmedia_disable_own_media_like' ) ) {
	    add_filter( 'rtmedia_check_enable_disable_like','rtmedia_disable_own_media_like' , 10, 1 );
	}
}
/**
 * Function to add check for user media so that we could disable like feature for user on its own media.
 * @param boolean $enable_like value whether to enable like feature or not extended code form rtmedia_check_enable_disable_like action.
 * @return boolean value whether to enable like.
 */
function rtmedia_disable_own_media_like( $enable_like ) {
	global $rtmedia;
	$options = $rtmedia->options;
	$model = new RTMediaModel();   
	$media = $model->get_media( array(
		'id'	=> rtmedia_id(),
	), 0, 1 );
	
	$author = (isset($media[0]->media_author) )? intval($media[0]->media_author) : 0;
	$current_user_id = get_current_user_id();
	
	if (( ( isset( $options['general_enableLikes'] ) && '1' == $options['general_enableLikes'] ) || ! isset( $options['general_enableLikes'] ) ) && $author  !==  $current_user_id ) {
		return true;
	} else {
		return false;
	}
	return false;
}

Add this code in functions.php file of your theme.