Journey vs. Destination

I just cross compiled an application for Raspberry Pi: camcv combines the Pi’s camera program raspivid with OpenCV.

It took hours and hours. Not just to build the cross compilers (though that did hours) and figure out cmake and figure out what code I needed, it took hours of tweaking and fiddling to make it work.

I suppose now I’m supposed to write up how I accomplished it, so you can reproduce it, glossing over the tricky bits and making it sound like a walk in the park.

First, I must give credit to

• Kitware for the lengthy, detailed and mostly still correct instructions on how to set up cross compiling for the RPi
• Stuff about code for (native) compiling raspivid
• ThinkRPi for the exhaustive (but native) write-up of OpenCV and Pi Camera
• ThinkRPi’s commenters for their suggestions for OpenCV & Pi Step 3: create you own project

Well, and to be fair, I’m still at Step 3 of OpenCV and Pi Camera’s instructions (of 7 (and a half)). I finally got the program to compile but I have a new Raspberry Pi board and haven’t even powered it on. Oh heck, if I’m reading step 4 correctly, I haven’t actually managed to pull in OpenCV.

I had this neat plan for what to do with the Pi, a camera (two maybe!), and a small display. But I’ve been so battered by compiling something that already existed and isn’t even really what I meant to compile anyway.

I find that many Linux projects have this exponentially expanding scope. My initial initial plan was to play with the camera in python using the actually pretty simple SimpleCV computer vision tools. But it was horrifically slow (a known issue to people who have tried the python and camera but a new issue to a newbie like me).

Worse, I don’t know cross-compiling has been truly worth it. Is multiple hours of setup worth many times two minutes of recompile time? Also, the RPi Compute doesn’t have an Ethernet port so it isn’t as easy to set up a tftp that would all my device access to the cross compiled executables without even a scp copy.

So I’m not going to give you the “here’s how I did it”… I’m not even sure how to post my trees. And I went through so many strange turns, I’m not sure my results will be useful (“and then at step 1123, spin in your chair, clockwise three times, the next cmake .; make instruction will then work”).