[mythtv-users] The PNG Thumbnail generated by Default: Is it used for anything?

[Michael T. Dean]

On 05/14/2007 01:20 PM, Mike Perkins wrote:
> Michael T. Dean wrote:
> <snip>
>   
>> and has nothing to do with whether they're created--only whether they're 
>> displayed.  Short of hacking the code, you cannot stop the creation of 
>> these thumbnails.  We create them so that they're available /if/ they're 
>> ever needed because doing so doesn't hurt anything.
> It would be useful if one could get rid of them.

Because you're saying that the 14MiB would be useful...how?  Compared to 
my 1.5TiB of recordings it's nothing.  Even with a (pitifully-low for 
MPEG-2, but about right for MPEG-4 in standard definition) bitrate of 
2200kbps that 14MiB is less than 1 minute of video (about 54 seconds or 
so of video only, but that drops by about 1 second for each 32kbps of 
audio bitrate).  And, I have 412 recordings--for which I have 824 
thumbnails--so, on /many/ Myth systems the preview thumbnails will take 
up much less space.

Having code to turn off preview thumbnail creation is a waste of code.  
Having a setting to turn off preview thumbnail creation is annoying (we 
have too many settings already).  And, explaining to all the users (who 
will say MythTV is broken because it doesn't have preview thumbnails or 
that thumbnail display is broken because after turning on your new 
switch for the first time it takes 20 minutes to create all the 
thumbnails or ...) how to properly configure their system is a waste of 
time.

>  In the UK, at least, 
> the contents of the thumbnails almost never have anything to do with the 
> program they are connected to. i.e. BBC, you get a random shot of the 
> end of the previous program, other channels, a random shot of some 
> advert or trailer.
>   

That will be fixed by the work that Robert Tsai has been doing to 
improve (especially-non-US) commflagging.  But, in the meantime, that's 
why there's an option to not display the thumbnails--so you can ignore 
them if they're not useful to you.  Or, you may find they're actually 
useful once you fix, for your configuration, the value in the setting:

Time offset for thumbnail preview images
MythTV will use this offset to make a thumbnail image this many seconds 
from the beginning of the recording, unless this offset happens to be 
between cutpoints or inside a flagged advertisement.

> Having a static thumbnail is one thing. I have to get rid of the 'show 
> the entire show as a stamp-sized image' things since they make the 
> program browse process slow down while the system creates these mini-movies.
>   

For the preview video, mythfrontend just plays back the recording the 
same as playing it back fullscreen (and scaling happens on the video 
card--unless you don't have Xv support--meaning it has virtually no 
effect on processor usage).  For the preview thumbnails, if you don't 
delete them it won't waste resources re-creating them.

> Ditto Mythweb. The thumbnails are completely irrelevant, and just take 
> up valuable screen space.
>
> Don't get me wrong, I can see that some people may get some benefit out 
> of them. I just don't find them useful at all, and the mini-previews are 
> a nuisance.

The point isn't that the thumbnail images are useful or not useful, the 
point is that they don't use enough resources to even allow a person 
<quietly>with control issues</quietly> to disable them.  ;)  If you can 
convince me of a reason why that 14MiB of space on your recordings 
directory is important, I will personally write a patch to allow 
disabling the creation of preview thumbnail images.

Mike