Ancillaries can be attached to any vlc_frame_t or picture_t (in next
commits).
Ancillaries can be created from:
- packetized demuxer modules
- packetizer modules
- decoder modules
It can't be created from a non packetized demuxer module since the
attachement to the vlc_frame will be lost by the packetizer module that
will be automatically inserted.
Ancillaries are automatically forwarded from a vlc_frame_t to an other
vlc_frame_t and from a picture_t to an other picture_t. This allow to keep
ancillaries untouched when audio filters or video filters are used (these
filters don't have to know about the ancillary).
Ancillary readers can be either:
- A decoder module
- An audio output
- A video output
- Any filters
Refs #18762
Thomas Guillem