How to change the render of an atom

When an atom is rendered, it is first transcoded (if possible and necessary), then rendered by a player. A player is configurable per context per atom type. What it does is that in the hook_scald_prerender() it prepares a markup for $atom->rendered->player.

You could prepare/modify that value in two places: as the atom provider or as the player provider.

• For special atom types such as Twitter where the default player cannot do much, you need to prepare the markup in $atom->rendered->player in the role of atom provider (cf. Twitter or YouTube modules).
• For atom types such as image, a player makes more sense because you can customize your markup, even that of a local file, or a Flickr image, to defined attributes like alt or title, or to use HTML5 tags like figure and figcaption.

To make your own player, simply implement hook_scald_player, configure the context to use your player, then in hook_scald_prerender($mode = 'player') prepare your markup with the transcoded file at $atom->file_transcoded.