Sunday, 2 December 2012

AGU Fall Meeting Poster

It's been a busy week, but my poster for AGU is finally printed and ready to go. Here's a small copy of it:

Note, ImageMagick doesn't seem to convert to colours exactly correct, so you may want to check out the PDF. If you want to have a look at the full PDF, check out the ePoster at the AGU. That page has the abstract, and you can click "View ePoster" for the poster.

This poster was the result of a monster-combination of Scribus, LaTeX, GMT, and even a bit of Inkscape. But at least I didn't use PowerPoint! I was planning to write some information about the process, but that's turning into a rather large post. I want to post this one before AGU and I'll write separate posts about the process later.

Wednesday, 13 June 2012

Missing Library in Rhythmbox on F17

One of the bugs I encountered after upgrading to Fedora 17 is that my music library seemed to have disappeared in Rhythmbox. In fact, everything appeared in the Missing Files view. The strange thing is that all the files appeared exactly where Rhythmbox thought they should be. In fact, I could even play them directly from the Missing Files view!

Anyway, after a bit of searching, it appears that I am facing this bug. You see, on my laptop, I encrypt the /home directory. Back on Fedora 16, some bug in gvfs or udisks caused things to think that that directory was a removable partition. Something must have been fixed in Fedora 17, because it's no longer marked that way (which is good, because I hate seeing it in nautilus.) However, Rhythmbox still thinks those files should be on a separate partition and doesn't correctly update itself (the aforementioned bug.)

This is pretty easy to fix, in fact. Since /home is now no longer considered a separate mount point, you just have to remove those indicators from Rhythmbox's config. The config is an XML file that's been pretty-printed, so the offending information appears on a single line (per file entry). That makes fixing it a pretty simple thing to do:

$ cd ~/.local/share/rhythmbox/
$ cp rhythmdb.xml rhythmdb.xml.backup
$ sed -i -e '/<mountpoint>/d' rhythmdb.xml

Friday, 8 June 2012

The Fedora 17 "Beefy Miracle"

So, a new release of Fedora was set free just last week, the so-called "Beefy Miracle". A couple of releases ago (or maybe last release), I had really thought I might wait at least a month after a release before upgrading. Turns out my curiosity got the best of me, and I went and upgraded my laptop mere days after the release.

Fortunately, this release has been much much better right out of the box. Having read the release notes, I was prepared for the one major bug, namely the kernel being stuck at an old version. Since it only affected shutdown, it wasn't too big of a deal, just a bit annoying.

Being the third release with GNOME3, it's finally starting to come together into something usable. With the right extensions, it's even better than GNOME2 was. I can't say exactly what changes went into it, but I guess it's a lot of behind the scenes changes to make things Just Work.

There are still a few things that need work, of course. I'm still not a big fan of the grey theme, but at least the window decoration is not huge anymore. It's still a bit difficult to find good complete themes that fix that. Also, it seems they introduced a fade-out of windows that are not in focus. It's sort of like it's disabled-in-appearance-only. I'm sort of yes-no on this change. It seems like it might be good for accessibility, but they don't seem to have tried this out all too much. Sometimes widgets remain faded even when the rest of the application is back in focus. Using some dialogs (like gedit's Replace) do weird things.

One last point is going to be about the wallpaper. I know I don't see it all too much, but the last three releases have had wallpapers that are really quite nice. Fedora's wallpapers have been traditionally mostly blue, the trademark colour. This one deviates a bit with a splash of pink, but I think it's just enough to make it pop. And who could not like fireworks?

Thursday, 31 May 2012

"Video" Editing in Linux

Video editing is one of those domains for which there are some expensive options and several attempts at open source alternatives. Unfortunately, few efforts have even gotten past the first few months.

A couple months ago, I had to do some "video" editing. I put that in quotes because in fact, it was more of a slideshow. I had done something similar a few years ago in PowerPoint. After the pain of that experience, I was quite certain I didn't want to do it that way again. I looked for some alternatives, but pretty much knew what my list of prerequisites was:

  1. Background music and voiceover audio
  2. Easy positioning of audio clips (Possibly meaning multi-track editing)
  3. Good set of transitions
  4. HD output, if possible, since all my photos were high resolution already

Weighing the Options

I know there are dedicated slideshow tools out there, like Imagination, but I wasn't sure how to get points 1 and 2 taken care of. I was pretty much certain that I'd have to use a video editor of some sort. There are really only about three or four I'd expect to work.

I was originally thinking of OpenShot, but annoyingly, you can't drag multiple clips from the Project to the Timeline. This might seem like a small issue, but for a slideshow of a few hundred images, it becomes a bit tedious. That's one of the reasons I didn't like PowerPoint, since you had to create a slide per picture and then add it. Overall, OpenShot just seemed to be a bit too simplified to be usable. On the upside, it did seem to have a good selection of transition effects.

The next option was PiTiVi. A long time ago, when I had to settle for PowerPoint, I had looked at PiTiVi. It was really just not ready to use for much of anything then. Just loading files used to cause a caught-in-abrt-but-not-totally-fatal exception. Nowadays, it's become much more polished. The UI looks much nicer with a good layout of controls. Unfortunately, it's limited in the transition aspect. Basically, you've got crossfading and that's about it. With no transition wipes, that pretty much cut out PiTiVi, although I really do like the direction it's going.

A possible contender?

The final choice was Kdenlive. Kdenlive uses the same video processing toolkit as OpenShot (MLT), but has been around since before OpenShot and PiTiVi. I can't say whether this longer development time is the sole reason or not, but it's certainly turned out to be the best of the three at this time. It's obviously multi-track (points 1 and 2), there's a good selection of transitions (point 3), and it'll render almost whatever resolution you want (point 4).

Now, does editing real video have its issues? I can't exactly say, but for what I had to do, I found Kdenlive to be extremely stable. In the course of this project, I saw maybe two crashes. That's two crashes too many, but video editing seems to be a tricky art (likely due to there being too many video specs, with poor descriptions, and poorer implementations). Actually, I did have to insert two real video clips, and they didn't cause any trouble.

Kdenlive was certainly up to the task for this slideshow/video project. It was perhaps of a moderate size, a few hundred images, two video clips, a dozen music tracks, plus 15-20 audio voice clips, resulting in about 25 minutes of final video.

Alas, it's not quite perfect...

Let's not say that Kdenlive doesn't still have its rough edges. It did appear to use a large amount of RAM, but I think that's because the project was 1080p, and I wasn't using proxies. Randomly (but thankfully not too many times), an invisible spacer would insert itself on a track and shift all the subsequent clips. Eventually, I did find the Lock Track button, and then could shift the incorrect track back. Once, a clip became half-deleted, getting in the way of other clips, but staying immovable and un-deletable until I re-opened the file.

While there are many to choose from, there are twenty transitions that are just named numerically, meaning you have to pick a point in the middle of a transition, look at the result, and guess which direction it's going (it doesn't auto-preview the whole thing, for example). What would be really useful is a "base" transition set, with an editor to tweak a few settings. For example, if you had a expanding star, the editor could enable you to position that star over some important object instead of dead-centre.

The other transitions that were missing were some good 3D effects. I tried following these instructions to create a page curl effect, but ended up keying every frame of the overlay position just to make sure it looked good. For another effect, I used a rotate about Z to create a sort of full page flip, but the Z rotate doesn't seem to cause any perspective changes (the far end does not shrink in height and the near end does not grow in height). It didn't look too bad in the end, but it could have been easier to do.

Wrapping up

In the end, I managed to finish my project relatively easily with Kdenlive. OpenShot is really just not up there at this time, although it does have a nice set of 3D titles in Blender. PiTiVi is also moving along quite nicely, and if it wasn't for the lack of transitions, I might have used it. Kdenlive seems to be the best choice right now. But everything's under rapid development, so this might change any time soon.