Make voctomix a c3tt recording worker

[derpeter]

The c3tt is the ticket tracker used by c3voc and developed bei FeM. One task in this system is xmlrpc client which tells the ticket system when a talk is recorded. On the other hand the ticket system tells this worker some meta information about the currently running talk. Allowing vocotomix to act as such an worker would allow

EDIT: Some of the features reuqested in this ticket have been implemented but different (see https://github.com/voc/voctomix/issues/159#issuecomment-727899755)

• [x] Display the Name of the current talk in the GUI

• [ ] Allowing to set a talk as recoded in the tracker by the voctogui operator, this can reduce the time until a talk is published e.g. if the talk ans earlery then scheduled

• [x] Generate lower thirds from this ( see #115 )

• [x] Detect wrong meta data. E.g. if the speaker has changed its talk title in the last minute the operator would see the title stored in the ticket system and can report the issue.

• [ ] Generate a simple "coming up next" pause loop dynamical

[jjeising]

Recording workers were already imagined for the Tracker. In planning and discussions together with @a-tze we thought recorders should keep a ticket while it is being recorded and only finish recording when all parts are successfully on disk (or even copied to a central storage, although this may be a later state). As the recording worker gets all ticket data the other ideas should be easily done.

[MaZderMind]

With the Recording-Ticket info we could also show a Countdown-Clock as requested in #163

[a-tze]

Voctomix could also write back some useful information, at least in log entries. Like when has pause-mode been ended or started, or even more important: has the recording been interrupted (set ticket failed) or were there some strange things happening (needs attention) etc. This could also save some work in the postproduction.

[yoe]

Might be useful to note:

• FOSDEM & DebConf use voctomix, but use SReview for review and transcode (for which I'm in the process of implementing a RESTful API)
• @CarlFK uses his veyepar, which may or may not have something similar (I have no idea whether it does).

It might be good to keep the part of voctomix that tells the transcoding system "things" modular, so that it can be replaced by a module for veyepar/SReview where and when relevant.

[derpeter]

While this ticket was not updated in while the code was. Voctomix can now read a schedule XML and load lower third images which than can be selected. Lower thirds can now be generated by our intro outro generator. So this is implemented decoupled from the tracker and therefore will also work for other workflows. I will update the ticket to reflect the current state.