Thoughts and Ramblings

General things I find of interest.

Wall•E

Some friends and I went to see Wall•E last night. It is definitely the funniest movie I have seen all year and I’m glad to see that Pixar hasn’t gone too far downhill. I was afraid that Disney would attempt to destroy them, but it seems they haven’t succeeded quite yet.

On the other hand, the movie did have a lot of technical point which were severely wrong.

  • One scene had a space ship traveling through a large sphere of satellites to get away from Earth. You cannot have a sphere of satellites in orbit and expect them to stay up for a year, much less 700. They’d crash into each other and change their orbits.
  • Even with satellites in the same orbit, you cannot have them sitting within a meter of each other for the same reason.
  • Rotating a ship in space doesn’t change the gravity experienced on the ship (to get any gravity in the first place requires creating it yourself, but that’s another issue).
  • The movie shows a spaceship dumping a large chunk of trash into space. While this make be a convenient means of waste disposal, the sheer mass of disposal shown is completely impractical for a space ship of that size. It would have lost it’s entire mass to trash within a year and it was supposed to be there for 700. What happened to conservation of mass?
  • And the biggest issue: I seriously doubt that humans have the ability to trash the planet to the extent shown in the film, even if we wanted to. We just don’t have that kind of an impact on our environment. Besides, even if we did, rather than sending the entire population to space while cleaning up the planet, wouldn’t it be more practical and cheaper to just send up the trash for disposal?

There are a few more issues; but if you ignore the distortion of science and reason, the movie is quite enjoyable. The sad thing is, the movie could have adhered to both science and reason without destroying the major plot points.


Xcode Filling Log Files

If anyone has ever used Xcode, and tried to debug an app through console messages, then they know how annoying this can be without the development tools getting in the way. An example for me is debugging a frontrow plugin, where sometimes it is easier to print debug info to the console rather than the trouble of using a second machine to fire up gdb. Anyway, Xcode is very good at spewing lots of extraneous and effectively useless information to the console log, such as the following: 6/13/08 5:19:17 PM Xcode[32580] Xcode(32580,0xb0103000) malloc: free_garbage: garbage ptr = 0x456bee0, has non-zero refcount = 1 Of the past 4000 messages in the console, over 3500 of these were xcode. That’s including debugging information from my programs. This is one of the most annoying examples of development tools hindering the development they are supposed to enable.


Rescuing videos from AVI

As I wrote in a previous entry, people have used avi for things which it was never designed.  One of the more notable examples is multi-channel audio bitstreams. In addition, the people who make such files went as far as to do in the completely wrong manner. So, as a result, I looked for a way to rescue data from the avi format so it is actually usable.

Basically, use mkvmerge from mkvtoolnix to convert the avi file to an mkv file. Then, open the file with Perian, and save it as a .mov file. The result is a file which both has the proper framing for AC3 data, and also has the proper frame decode and display information. This means that one can do real AC3 passthrough on avi files. Maybe this will be the ultimate solution.


Expensive Hotels internet access

Well, Infocom is over and I am back home. While I was there, I often used my iPod Touch to do quick things on the net when pulling out the laptop would have taken too much time. The only issue is the wireless AP there required a web based login where one would have to enter in the email address they used to register for the conference. This can be annoying at best on the iPod when all I really wanted to do was look up something really quick and this stage takes 50-80% of the time.


The Hall of Shame

So, the good folk over at FFmpeg have stared a Hall of Shame. Basically, it is a page of projects which are using FFmpeg in direct violation of its license. The developers have asked that people link to that page, thereby increasing its ranking in Google. Well, here’s my part. Why should I care about this? Simple, if you look at the list of projects using FFmpeg, you will see Perian listed. Some parts of Perian rely so heavily on FFmpeg that it has an entire section in the code base. Going further, some of the Perian developers are contributing back to FFmpeg, so our copyright is being infringed along with many others.