INTERACT FORUM

More => Old Versions => Media Center 16 (Development Ended) => Topic started by: bil1010105 on September 14, 2011, 03:38:51 am

Title: Thumbnails / coverart keeps disappearing & being regenerated
Post by: bil1010105 on September 14, 2011, 03:38:51 am
Okay, I'm stumped.

I've got an MC16 library (predominantly video) on a NAS shared folder. I also have Cover Art and Thumbnails on the NAS drive. I have two PCs, one in the study (which I use for editing the library etc) and another in the living room which I use for playback on the TV. Both systems access the same library / cover art / thumbnails from the NAS. I used the instructions in http://yabb.jriver.com/interact/index.php?topic=63918.msg427626#msg427626 (http://yabb.jriver.com/interact/index.php?topic=63918.msg427626#msg427626) to do this, with the exception of copying everything to the local drives through a .BAT file, because both systems are pointing to the same (shared NAS) location in the registry so it should "just work".

I would like to be able to create the thumbnail for the video on the study's PC, and have it visible on the living room PC. I use the 'use screen grab as thumbnail' function to do this.

However, as soon as I go into the file on the living room PC, the thumbnail (whilst initially showing the correct one) just clears itself and re-does it, at completely the wrong point in the video from what I originally set.

How can I stop MC from doing this?  ?
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: Matt on September 14, 2011, 07:51:03 am
It's not officially supported to share thumbnails between multiple clients.

I would recommend sharing the library, but letting each client build their own set of thumbnails.
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: bil1010105 on September 15, 2011, 03:53:56 am
The auto generated thumbnails are no good. Because I can only grab from the same point for ALL videos, it grabs at the wrong point to a) remind me what the video is and b) not be a blurry mess. That's why I painstakingly go through each video to set a thumbnail that's appropriate & useful for that video.  :-\

Since the living room client picks up the thumbnails I generate in this way to begin with, the thumbnails are clearly there, is it not possible to turn off auto-generation on one of the clients? That would solve my problem completely.
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: MrHaugen on September 15, 2011, 07:26:53 am
Check the options. It's under Tree & View, Thumbnails. You can disable thumbnail creation there. Even a search for "thumbnails" gives all the relevant options. Do people fear the options page?  :-\
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: bil1010105 on September 16, 2011, 12:43:03 pm
I already have "Create thumbnails for videos" unchecked. Also, "Thumbnail Exit Behaviour" is set to "Leave".

Thumbnails are still regenerated though.

Am I missing something?  ?
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: MrHaugen on September 16, 2011, 07:59:16 pm
Oh darn. I was quite sure that would do the trick.
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: bil1010105 on September 17, 2011, 02:54:25 pm
Yes, me too - hence my original question. Is it a bug?  :-\
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: Alex B on September 17, 2011, 05:14:44 pm
The library specific thumbnail cache must be exactly in sync with the database files. You can use a single thumbnail location and a single library location for several MC instances only if you never run more than one MC instance at a time.

You can copy the thumbnails and library files from one MC instance to another when the MC instances are not running. When the MC instances use separate locations for these files the thumbnails will be preserved.

In general I would recommend saving the captured images to disk files (Screen Grab to File) and linking those files as video cover art. Then the thumbnail source would be a jpg file and if you ever need to recreate the thumbnails it will be easy and fast. You would also be able to have a single library location, two separate thumbnail locations, and see the captured images on both MC instances.

EDIT

In addition I would recommend keeping the thumbnail caches on fast local drives (you will probably need to use two separate locations anyway). The thumbnail files can be quite big and MC accesses them constantly when the library views are browsed. You may be unnecessarily sacrificing some of the browsing speed when the thumbnails are read through LAN.
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: bil1010105 on September 17, 2011, 08:49:42 pm
The library specific thumbnail cache must be exactly in sync with the database files. You can use a single thumbnail location and a single library location for several MC instances only if you never run more than one MC instance at a time.

What, never??  ? I was under the impression that you could have two copies of MC open and accessing the same library, but that only the first MC that was opened would have write access to the library. Is that wrong? Could the simple act of opening MC on both machines corrupt the database in some way?

In general I would recommend saving the captured images to disk files (Screen Grab to File) and linking those files as video cover art. Then the thumbnail source would be a jpg file and if you ever need to recreate the thumbnails it will be easy and fast. You would also be able to have a single library location, two separate thumbnail locations, and see the captured images on both MC instances.

I think this is probably the way to go. I've tried capturing the thumbnail as normal, then 'Save Cover Art To External Location Specified In Options' (which points to another NAS folder), in the hope that I can add cover art quickly from that folder when it messes up again.
 
In addition I would recommend keeping the thumbnail caches on fast local drives (you will probably need to use two separate locations anyway). The thumbnail files can be quite big and MC accesses them constantly when the library views are browsed. You may be unnecessarily sacrificing some of the browsing speed when the thumbnails are read through LAN.

I know what you're saying, but speed isn't much of an issue to me at the moment - plus I find it's pretty quick running over a Gigabit network. If I ever get this working the way I want, I might go down the route of setting up an elaborate sync mechanism to do this, but right now it's not a priority for me.  :)
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: Alex B on September 18, 2011, 06:16:19 am
The library files and the thumbnail cache files are in a constant state of change when MC is running. Neither the library nor the thumbnail cache is designed to be used by more than one program instance at a time, but sharing just the library is fine. If the library is already in use MC creates a temporary work copy of it. The same does not happen with the thumbnail cache. Each MC instance must have exclusive access to its own thumbnail cache.
Title: Re: Thumbnails / coverart keeps disappearing & being regenerated
Post by: bil1010105 on September 18, 2011, 10:01:19 am
The library files and the thumbnail cache files are in a constant state of change when MC is running. Neither the library nor the thumbnail cache is designed to be used by more than one program instance at a time, but sharing just the library is fine. If the library is already in use MC creates a temporary work copy of it. The same does not happen with the thumbnail cache. Each MC instance must have exclusive access to its own thumbnail cache.

Gotcha. I think that was the crucial piece of information that I was missing.

Okay, so it looks like the solution will be to create that elaborate sync mechanism we were talking about before - maintain the "master" cache on the NAS, but copy it locally before use and after update... pointing each client at the local copy.

I'll try it and let you know. Thanks Alex.  :)