Master of Tech

[kerravonsen]

I have conquered! Well, sort of. I may have mentioned that I couldn't play my Pretender DVDs on my main computer, though I could play them on my laptop. So I thought I'd see what I could do about it. Turns out that all I needed to do was to install VLC, and it all worked! I hadn't realized that VLC was still better than xine in that department. Downside: screencapping is not as easy as with xine. You can't just click a button. You have to
(a) start up VLC with special options
(b) pause when you want a screencap (and the pause isn't as good as with xine)
(c) run an external image-capture program to capture the contents of the window in question.

But I did do a few little screencaps once I'd figured out how to do it. And I made an icon.

Comments

[dawnmist]

Or (in Gentoo):
1. Install vlc with the wxwidgets use flag enabled - this gives the gui menu.
2. Run vlc, and in Settings->Preferences, Select the 'Video' settings section title and set the "Video snapshot directory". Close and restart vlc (it doesn't apply the directory preference until you restart). You might need to select the "Advanced Options" checkbox at the bottom of the preferences menu to see the snapshot directory option.
3. When playing, pause and select menu item Video->Screenshot.

Depending on which version of wxGTK (which provides the wxwidgets interface) you install, you may run into issues with all this - if you have problems, let me know and I'll chase up the exact versions of the additional libraries that I'm running - they're in a changeover period for gnome 2.12, so some conflict with each other...

vlc is what I've been using, and I've found that it works well. I'd *love* to find something where I can give it a DVD episode, and tell it to "grab a screen shot every 0.5 seconds" or "grab every 12th frame" - but I've only been able to find something that grabs *every* frame (at 25 per second, that's a *lot* of images to wade through...)

[kerravonsen]

Select the 'Video' settings section title and set the "Video snapshot directory"

No such option.
I'm using vlc 0.8.1

I'd *love* to find something where I can give it a DVD episode, and tell it to "grab a screen shot every 0.5 seconds" or "grab every 12th frame" - but I've only been able to find something that grabs *every* frame (at 25 per second, that's a *lot* of images to wade through...)

Well, one could perhaps write a script to go through and delete all but the Nth image, afterwards -- if one hadn't run out of disk space.
So what's the thing that grabs every frame?

[dawnmist]

No such option.
I'm using vlc 0.8.1

They must have moved the location of the option.

It will be somewhere under either the Video or the Output options, but I think you will need to turn on "Advanced Options" to find it. I've upgraded to 0.8.4 on all my machines, so I can't remember exactly where it used to be - but I know it *was* an option previously. Have to upgrade quite a few things to unstable versions to run 0.8.4; I only did it 'cause I have gnome here as well, and that upgraded the wxwidgets interface which then clashed with anything prior to 0.8.4.

So what's the thing that grabs every frame?

mplayer can grab every frame. Google the mplayer manual; 'tis a *heap* of command line options. The last command I did with it to screencap a 42 minutes episode was:
mplayer dvd://3 -dvd-device /dev/hdd -nosound -vo jpeg

-vo jpeg
output jpegs (can also do png's, but is *slow*)
dvd://3
3rd track on the dvd
-dvd-device /dev/hdd
Device that holds the dvd
-nosound
No need for sound if just screencapping - can't *see* the movie anyway.

For the episode, I ended up with a bit over 72,000 images... hence why I wanted to be able to tell it to skip most of them!!

[kerravonsen]

This: http://forum.videolan.org/viewtopic.php?t=8213&highlight=screenshot seems to indicate that one can set up VLC to grab every N frames.

[dawnmist]

That looks like *exactly* what I was looking for, thanks!!!

[kerravonsen]

Well, I've now changed the keywords on vlc so I have the latest version, and I've figured out how to get it to do the automatic screencapping (and have written a quick script to call vlc with all the right arguments) and right now I'm letting it run with one cap every 100 frames. We'll see how it goes. I know that a lower ratio would miss less, but I'd rather winnow through 650 images than a few thousand. As I said, we'll see.

[dawnmist]

Be careful.

There seems to be a critical memory leak in the auto-cap function; after 14 minutes the memory usage was up to 500M Ram (of 512M) and 1.8G Swap (of 2G), with 0 memory left on my stable machine (the DVD drive died on the Gentoo machine, not sure yet if that was just coincidence or if the memory use caused something wrong to be sent to the drive and killed the drive)...

*sighs* Was the right idea...but when it consistantly hangs the system it's not a lot of use.

Keeps looking for another auto-cap progie.

[kerravonsen]

(shrug) I just left it running and I didn't seem to have a problem. I stopped it and changed it to 25 frames (I was missing too many nice shots) and then left it running last night, and I came back this morning and -- ah. It must have crashed. No enlightening error messages, though.

And the drive seems to be okay now.

So I think I could probably still use it if I did it in bite-sized chunks, like a chapter at a time.