Good question .
Well.. After reading Rcalleja answer ..
You can use the plugin provided , but there is really no need for it, nor for code hacking or php juggling ..
All you have to do is to use the quicktags in the attachments fields :
[:en]English Description[:fr]French description[:de]German description
After that ( and now it depends on the access you have to theme files, but if you are here - I assume it is not a problem ) you will need to use a small built in function called
qtrans_use() which tells qtranslate which language to use ..
so for example, if you are using the very popular function
the_post_thumbnail() , you will have to translate itßs attributes . since it is using
wp_get_attachment_image, we know the attributes are for example (from codex ) :
$default_attr = array(
'src' => $src,
'class' => "attachment-$size",
'alt' => trim(strip_tags( $wp_postmeta->_wp_attachment_image_alt )),
Now , we need to get the alt and title like so :
$thumb_id = get_post_thumbnail_id(get_the_ID());
$alt = get_post_meta($thumb_id, '_wp_attachment_image_alt', true);
$title = get_post_meta($thumb_id, '_wp_attachment_image_title', true);
So putting 2 and 2 together :
$attr = array(
'alt' => qtrans_use('de',$alt,false),
'title' => qtrans_use('de',$alt,false),
et voila ! the
description will be in german .. (
( the 'de' is just an example, to automate the process one would another built-in qtrans function -
I have used this method in the past , and it always worked for me .
In fact, it is possible to translate any and all aspects of wordpress with qtranslate , without the needs for extra plugins ..
qtranlaste is one of the best written plugins ( albeit a bit old.. ) and I myself am a big fan of it . The author has used internal filters and hooks long before most of the current "experts" have started to apply them in plugins or even knew existed. in fact, It is ( IMHO ) the best translation plugin .
The problem is that ( like wordpress itself ) it is very extensive and extendable , but it has a lot of filter and functions that are poorly documented , which require to "dig into the code " .
Luckily , someone has already done so .
EDIT I :
There is also another method to filter the whole
post thumbnail produced HTML using the
post_thumbnail_html filter. But since the above method is general and can be applied on any element ( not just post thumbnail ) , and since you did not specifically inquired for post thumbs but media in general - I thought it is preferred to explain it rather then a much more specific one .