[mythtv] MythArchive extension - request for discussion

[Shawn C. Powell]

On Friday 28 March 2008 09:37, Peter Schachte wrote:
> ... my script compares the DVD version of the file with
> the on disk version, and then deletes the on-disk version if they're
> identical. That seems simpler.

I agree its simpler.  I thought of that too.  I guess my paranoia prompted the 
uncertainty that it might be possible to have an unplayable disk despite a 
successful binary verification.  You're pretty satisfied thats sufficient? :)

> I think ideally it should be part of mytharchive.  

I think probably so too.  I haven't started studying the MythArchive internals 
yet. :)  That'll be the next thing.

> At the time you create 
> the archive, you could tick a box saying you want the original files
> deleted if the DVD burn is successfully verified, 

I agree.

> and another tick box 
> saying you want the metadata kept around so you can still select the
> videos/recordings from within myth.

Wouldn't it be rare that one would want to delete the meta-data?  If so, one 
could just delete the recording from MythTV in the usual way.

> I found the tricky parts of the whole thing are popping up an
> appropriate-looking dialog asking the user to insert a particular disk (I
> use zenity, but it doesn't look good), and getting the internal player to
> play it once inserted (I couldn't find a way to do this, so I use mplayer).
>  I gather you're using a soft link to a mount point for the DVD; I didn't
> want to do that because I couldn't think of a way to prompt for a
> particular disk when the recording is selected.  My script replaces a file
> foo.avi with foo.avi.dvd, which includes which DVD the recording is on. 
> Then I just configured myth to handle .dvd files by running my little
> script to prompt for the disk and play the file.

Would we really need to prompt for a particular disk?  Presumably the archive 
disk would be labelled appropriately and MythTV already indicates that files 
are not present on disk by dimming the recording title. (I think there's also 
a message indicating "file not found".)  This holds true btw for symlinks;  
If the archive is not mounted the recording is dimmed.  Perhaps a 
simple "Please  insert the archive containing 'Stargate SG-1 Children of the 
Gods' and press OK" would be sufficient?  Whereupon the DVD would be mounted 
and the player could continue normally.  Unmounting would have to be handled.  
And there's a possible conflict with the CD/DVD monitoring functionality.  
(Some additional discussion that touches on this is in my reply to Steve 
Smith's post, same topic.)

However, if we do decide to track disk labels, should that be implemented in 
the database?  Could get messy.  What if you had multiple archives of the 
same recording?

I still kind of favor the symlink approach but am willing to be convinced 
otherwise. :)

>
> > 	2. To what degree is a concurrency mechanism
> > 	needed for these operations and does any
> > 	such support already exist within MythTV?
>
> Hadn't thought of that.  It's probably a good idea from the standpoint of
> safety, but I doubt the lack of a lock would bite anyone very often.

I've noticed there is a "delete pending" column in the "recorded" table.  This 
would seem to imply some level of locking or awareness of "in-use" recordings 
but I haven't delved deeply, at least yet.

I agree that in home use it wouldn't be a large issue.  Do you suppose MythTV 
has or will have many business/multi-user use?

> I think it's a great idea and would be happy to help with the coding.

Sounds like a fun and useful project to me too. :)

-Shawn