VLC_CODEC_TEXT should never be set as a chroma in a
video_format_t, it's a codec.
v8: longer version where fields are not directly accessible
Only the next field remains. It may be possible to split the parts that can handle a list of regions and those who deal with a single region (like text renderers).
v9: not rebased on top of !4460 (merged) but it should.
v10: rebased on top of !4460 (merged) and the patches moving the text fields in a structure are usable without hiding the structure(s)
v12: rebased on master after many region changes
VideoLAN code repository instance