Linux Movies Group

Linux Movies Group: Highlights of Meeting #7

Wednesday, August 7, 2002, 7pm
Nation's Giant Hamburgers
El Cerrito, California (near Berkeley)

Drew described Gimpeon, a new compositor project that recently released an alpha version. It's mostly just GUI now, without a lot of working features. Whether all those features could be implemented soon is a question. Drew also talked about the DV editor Kino, whose designer recently asked for comment on the LMG list. Drew had pointed out a number of bugs. Drew started his own editor because he wants advanced editing capabilities that would be difficult to add to Kino. Drew talked about his lighting control system that outputs DMX (the theater lighting signal protocol) via a Microchip PIC.

Robin says that a new version of Film Gimp is coming soon, based on a secret internal effort long underway at SPI. That SPI is making their enhancements and bug fixes available seems like a big boost for the project.

Drew talked about Python, and the Swig automatic interface builder. "One of swig's features is that C structs can become python objects automatically", says Drew. "SWIG writes set/get functions (in C) and then makes a python object that calls the C accessor functions when you try to access its attributes."

Drew says, "An advantage of Python is that function arguments are self-documenting, the difference between "foo(mode=NTSC)" and "foo(NTSC)". Most languages would let you make a 'NTSC' identifier that corresponded to the right value. It's rare to be able to show the argument's own name in the function invocation, though."

The place to get help on Python projects is irc.openprojects.net where there are typically a hundred Python programmers on at all times. Also see, the ebook "How to Think Like a Computer Scientist in Python".

Zope is a large python system typically used for serving web applications. Zope has its own database system called ZODB (zope object database).

Jason described his OpenSlate project. Using a PIC 877 this will provide a hardware movie slate for use in making motion pictures. Drew mentioned that Quinn's Electronics is a good location to get components. Jason has another project to build a zoom lense controller using LANC, a phono-plug serial protocol that is 96 baud. There is a full PIC compiler available in Linux.

Drew talked about how to jump the mouse x2x across dual-head displays, mapping extra keys from the Microsoft keyboard. He mentioned that his boss at the ferry company likes to use VNC with JavaScript to control many machines. Jason mentioned he doesn't like Xinerama, that he finds it annoying to have one window stretch across two displays. Drew mentioned a nifty feature in Emacs to let you select what display the window appears on. The emacs feature is a command called make-frame-on-display.

Since the meeting, Drew patched x2x so he can use the dead windows keys to flip screens. "x2x lets me use one mouse/keyboard on multiple screens. normal x2x modes: slide the mouse off the edge of one screen and have it appear on the other screen; or, click on a special x2x window to toggle screens", says Drew. "My new mode lets me leave the mouse where it is when i jump to the opposite screen (and vice versa). I sent the patch to the original author who last touched x2x at least 5 years ago. No response. I have since found some weird bugs in my patches, so I'm not releasing them yet. x2x needs a rewrite (and i have some ideas of what language should be used)."

Drew mentioned Fam, an alternative file system that is NFS aware. "Fam is 'file access monitor' () which
reports to programs when files have changed. the apps no longer have to poll the files", says Drew. "Depending on your OS, fam itself may not need to poll. It has kernel modules that watch the filesystem 'from below' and actively report file accesses back to fam. fam also has a special nfs mode where, instead of polling a file over nfs, you can run another fam server on the other side which will do the polling/vfs-watching locally."

Thanks to everyone who came and helped make the meeting a success! Headcount was 7: Robin R., Mike A., Drew P., Joe R., Ramona H., Jason H., and Michael G.