[mythtv-users] grabbing individual frames/images for "poster"

Bill Evans BillEvans at TulaneAlumni.net
Tue Nov 1 01:54:02 EST 2005

I'm trying to implement a simple image grabber, either as a (user) 
filter or perhaps differently.  I'd like to be able to:

(1) specify a specific time (or frame) in a .nuv file and grab that 
frame as a jpeg; I know I don't know enough about the frame process to 
know the best way to do it, but I'd like it to be as complete a frame as 
possible (without pixelation, incomplete blocks, etc).

The current method of using mplayer and the "-vo jpeg:..." works in that 
it'll create a lot of jpeg images for me.  However, I really don't want 
to create that many images and don't want to go through them all.  When 
I specify an offset into the show (with "-sb x" or "-ss x") and limit it 
with "-frames 10", it starts giving me partial blocks.  I have to use 10 
for frames since it does not tend to give me an image if I specify only 
1 frame.

I'm doing this wrong.  Even if I'm close to doing it correctly with this 
tool, it doesn't seem to be the most efficient.  When asking mplayer to 
go "deep" into a show, it appears to take a while processing everything 
ahead of it.  I'm sure that this is possible at least on a small level, 
but is there a better way?

(2) Anyway, once this works consistently and accurately, I'd like to 
automate it into a script so that I can call it as a user filter.  I'd 
like to be able to look in the mysql database and find either the 
bookmark's location or use editing marks to determine which frame(s) to 
grab as images.  (Where to store them is secondary at this point and, I 
suspect, easy to safely configure.)

I don't really care at this point if the images are useful to current 
mythtv programs; though that is perhaps my #3 goal, the first two would 
be a 90% solution for my needs.

Thanks for any help.


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