Archive for Beginner

Scripting Basics: pulling random values from within a defined range in After Effects

A common scripting requirement is to pull random values from within a defined range. For example, in the block dissolve transition the individual blocks of video are extracted from the video in a random order. Let’s revisit our float away video wall script and customize it to work in the same manner as a block dissolve but with a little more flair. We will scale the individual blocks up instead of just transitioning on and off.

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When you apply a filter can make a big difference

I was browsing around Apple’s Tech Note website when I ran into this technote. Apply the Broadcast Safe filter last in Final Cut Pro. The article discusses the importance of applying the Broadcast Safe last in a filter stack to insure that you really are limiting the colors in a sequence to broadcast safe colors.

The idea of a pipeline is one of the trickier ideas to master for new users of image processing applications. In image processing each new operation like a blur, composite operation or color adjustment is applied and then passed to the next operation. In the example that Apple gives above, a Proc Amp operation applied late in the pipeline could boost the color levels outside of a safe range even though Broadcast Safe filter was applied in the stack. I’ve often found when you’ve got a visually unexpected output, moving the filter arrangement will restore some sanity to the expected output.

Additionally, as applications like After Effects transition to 32 bit float environments you’ll see additions to pipelines like HDR Compander which can compress and decompress the pixel pipeline to work with 8 and 16bit effects.

It is important to get a strong conceptual understanding of core concepts like image processing pipelines. These ideas become even more important with programs moving to 32 bit float color and using pixel-level operations via the GPU like in Apple’s Core Image. Finally, I really recommend that you keep up with what Stu Maschwitz posts at Prolost. He writes about really hard tech like color space and image processing but with attention to form and artistry I can only aspire to.

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Beginning javascript tutorial: Parsing a date from a sequenced jpeg filename

The other day I ran across another post at aenhancers.com. (aenhancers is a really great AE scripting forum by the way). The poster, Dan wrote:

I have shot thousands of stills
that I am now wanting to make
a time lapse movie out of. Each
still is named with the date and time
it was taken. For example
0507270505011.jpg would have been
taken yy/mm/dd/hh/mm/ss/(camera ID).
...
is there a way to parse the filename
to convert it into something more
legible? So 0507230004461.jpg would
translate into July 23, 2005 - 12:10 AM?...


The more I thought about it, this is exactly the kind of task I’m hoping to cover here at Creative Workflow Hacks. So in addition to posting a usable solution at aenhancers I decided to do a tutorial here with the problem solving steps involved. You know, teach a guy to fish and all.

I’m also going to try something new here. From the feedback I’m getting from users, the skill level and interest in DIY varies a lot. Some of you are hoping for beginners tutorials, some are looking for more advanced ideas and inspiration, and some of you are looking for solutions that are already thought through where you can download a bit of software, do your work and forget about it. So, I’m going to try labeling categories with beginner, intermediate, advanced and shrinkwrapped (although not that much software is actually shrinkwrapped anymore) depending on the skill level and the degree of involvement necessary to get the solution working. Send some feedback if you find it useful or not.

Back to our date parsing problem. Like almost all computer problems, the key here is to break down the big problem into a series of smaller problems. Read the rest of this entry »

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Analyzing access logs to find patterns, or “Just how many bots are out there anyway?”: In which we give a gentle introduction to command-line tools.

You find the most interesting stuff in access logs. I spend a fair amount of time digging around in web analytic software. Looking at who is referring to us, analyzing traffic patterns, figuring out peak usage times…you get the picture. Sometimes though, you just need to get right down into the raw logs to figure out what’s going on, and that situation happened to me a while back.

Around the middle of last year a security exploit was found in the implementation of the XML-RPC protocol in PHP. PHP is obviously a very popular web scripting language and dozens of content management systems, including the blogging software I use for this blog, utilize the language. Now an open security hole in such a popular language is just an invitation for the underground to attempt to exploit the situation, and try to exploit they did.

It started out as just a trickle, but before long it became obvious that the underground was attempting to exploit the security hole. How’d we know? By analyzing our logs.

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Diagnosing an OSX slowdown

Most of the hacks I post here are about getting things done. Today I’m going to write about avoiding obstacles that might stop you from getting things done. Namely, I’m going to case-study debugging a sluggish OSX machine.

THE SCENARIO

My boss approached me about a weird slowdown he was having where his machine was slowing to a crawl. Trying to move the cursor was taking a lifetime to move a couple of inches. There wasn’t a beachball cursor indicating an application was sucking up resources and I was able to launch programs, just very S L O W L Y.

So, what did we do?

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