[mythtv] MythArchive extension - request for discussion

[Peter Schachte]

Shawn C. Powell wrote:

> I have found use, after creating a native archive, for the following features:
> 
> 	1.  Temporarily back up the on-disk version of an archived file,
> 	2. The archived version can be viewed/tested
> 	3. Removing the temporary backup from 
> 	on-disk storage, leaving the link to the
> 	removable media archived version in place.
> 	It can then be viewed when desired by mounting
> 	the archive.
> 	4. Removing the link to removable media
> 	and restoring the backup in the event
> 	the archived version was found to be
> 	defective.

This sounds very much like what I've been doing.  But instead of backing up
the on-disk version, making a link for testing, and finally deleting the
original if it's OK, 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.

> 	1.  Should the funtionality be better implemented, 
> 	for public use, in the MythTV proper as opposed 
> 	to a command line script?

I think ideally it should be part of mytharchive.  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, and another tick box saying you want
the metadata kept around so you can still select the videos/recordings from
within myth.

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.

> 	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.

> What do you think? Any interest? Potential problems?

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

-- 
Peter Schachte              I worry that 10 or 15 years from now, [my child]
schachte at cs.mu.OZ.AU        will come to me and say 'Daddy, where were you
www.cs.mu.oz.au/~schachte/  when they took freedom of the press away from
Phone: +61 3 8344 1338      the Internet?' -- Mike Godwin