+ Addapt the rest of the code to make use of it
+ Make GESAssetFileSource a subclass of it + Remove ges_asset_filesource_get_supported_type as it is now in GESAssetTimelineObject + Remove the GES_META_TIMELINE_OBJECT_SUPPORTED_FORMATS as it is useless now
+ Generate the documentation + Make the new Asset infrastructure compile Co-Authored-By: Thibault Saunier <thibault.saunier@collabora.com>