Entries in helpful hints (7)

Wednesday
Feb192014

Steadicam Smoothee with a GoPro H3 Black

One thing I really can't stand in my GoPro videos is all the shaky, jarring footage.  This is pretty hard to get away from if you have the camera mounted to your helmet or on a chest mount, but if you're planning on doing some hand held shots, there are a few options out there, one of which is the Steadicam Smoothee.

Full blown Steadicams are used all over professional film making, but one of my favorite examples is from the movie Goodfellas:

 

You can see you get one long, continuous shot, that is very smooth and dream like.  Once you're aware of the technology, you'll be spotting it everywhere.

Like so many things these days, the technology has come into reach of amateurs like myself and for around $100 you can create some pretty nice shots.  The trick with consumer level steadicams is that they take a little more work to get them just right.  In the case of the Smoothee, you'll notice that it takes a bit to learn how to "steer" it when your thumb and index finger.  You'll also find that getting a smooth shot goes up in difficulty as the wind does.

One thing to note is that the original Smoothee was developed for the GoPro H2 series which is a bit heavier than the H3 series.  To compound that, the device was intended to be used with the LCD backpack which also adds a bit of heft to the GoPro.  What this means is that when you first get the rig, if you just mount a standard GoPro H3 with no LCD backpack, the device is going to tend to swing.  You'll notice this in some of the shots in my sample video where I'm filming my wife on her horse.  These shots were before I decided to adjust the weight.  The swinging is also really compounded with wind and sunded changes in direction, so you're unlikely to get any great footage without adjusting the balance on the device.

After shooting some test footage with the camera, I decided to try and adjust the weight that comes on the front of the device and see if I could get a better dynamic weight setup.  Turns out, I was able to easily adjust the weight, and the results were perfect.  Here's a picture of how I moved the weight up:

 

I had to fiddle with the weight a few times to get it just right, but it's worth spending a few minutes to get the proper balance as your videos will turn out A LOT better.  Anyway, check out the a few clips I put together using my lovely wife as a subject:

 

Next up, I'll be showing the home made cable cam I built.  Stay tuned.

 

-- Rob

Friday
May142010

Custom search in Chrome & Firefox

I don't know about you, but I use quite a few sites that are just forums with tons of information.  Land Rover forums, Kawasaki forums, motorcycle forums.  You name it, I'm probably an active member or at the very lest a lurker.  There is one common problem I find with most forums though: the search is terrible.  It seems to me that search should be near the top of the priority list for sites that are just piles of information that needs to be sorted through.  What I do to get around this is use Google to search these sites; but, I make it easier on myself by adding a custom search in Chrome, so I can quickly search the forums I use the most.  Below is a quick screen cast of how I do it (sorry for my heavy breathing, and next time I'll lower the resolution on my laptop, so you can see it better):

Note: I'm using Ubuntu, and I used a program called recordMyDesktop to create the screencast.

Tuesday
Apr272010

Laying down tracks

I'm currently saving money, and in August, I plan on buying an adventure touring motorcycle.  Specifically, I'll be buying the KTM 990 Adventure.  Anyway, I could talk all day about adventure touring, and motorcycles, and my exploits on my old KLR, but the point is, I've been researching routes that I plan on riding.  Part of this research is creating GPS tracks to follow over specific passes/trails I want to ride.  I looked around for easy ways to do this and I setteled on using Google Earth to create my tracks, and then convert those tracks to GPX so I can upload them to my unit (a Garmin Gecko 201, and iPhone 3Gs).   Just a note though, Garmin has a program called MapSource, that you can also use to do this type of trip planning.  I just wanted to stick with GE because I use Linux at home, and that's what I'll be doing most of my planning in.

I created a quick screen cast that shows how to create your tracks and then convert them.  I did this at work, and I didn't have a mic, so it's silent.  Sorry about that.  The key points to take from the video are:

1. When creating a new track, you have to leave the dialog open while you are creating.  It's not super user friendly IMO, and may throw you off at first.

2. You can right click to erase a placed point on your track.

3. You pan around the map with the arrow keys while creating tracks.

4. Save your track as KML not KMZ.

5. Use the following command to convert your track: gpsbabel -i kml -f file.kml -o gpx -F file.gpx

Here is the video:

 

Other misc updates:

1. I'm still slowly working on the ski stats xml file.  I've decided I don't need it until next ski season anyway, so I'm taking my time.

2. I updated the README file in the QTCanon repo to have instruction on how to build the app on Linux. On Windows you still need to have the Canon SDK to build the app.  I hope to have binaries built soon for download.

Friday
Nov132009

Using ffmpeg to manage video

This is going to be a quick and dirty how-to on ffmpeg and you can find this stuff all over the net (well except the slow motion trick, I couldn't find that anywhere). Here goes:

Where to get ffmpeg
Ubuntu - sudo apt-get install ffmpeg
Windows - Install ImageMagick or Use a binary someone has built

Mac - Aren't you using Final Cut anyway? [Edit: Use this guide to build ffmpeg on the Mac]

 

Easiest way to convert video

 ffmpeg -i video.wmv -sameq video.mpg

Create video from a series of images
Assuming your images are named like this - IMG_0001.JPG, IMG_0002.JPG...
Also, I'm setting the frame rate low here.
ffmpeg -r 15 -b 1800 -i IMG_%04d.JPG movie.mpg

Create a time lapse from a regular video
movie.mpg is the original, and I'm going to save every 5th frame. Then we stitch them back together.
ffmpeg -i movie.mpg -r 5 -f image2 %d.jpg
ffmpeg -b 1800 -i %d.jpg tt_movie.mpg

Make a video slow motion (kind of a hack, but I couldn't find another way)
This will make images from every frame in the clip. Then you stitch them back together with a different frame rate. The lower the rate, the slower the vid.
ffmpeg -i movie.mpg %d.jpeg
ffmpeg -r 10 -b 1800 -i %d.jpg tt_movie.mpg

Add audio to a video
ffmpeg -sameq -ar 22050 -ab 32k -i song.mp3 -i video.mpg videoWithMusic.mpg

Make an image into a video clip (for an intro or credits or something)
This will play for 10 seconds
ffmpeg -loop_input -i image.jpg -t 10 -r 30 -qscale 2 vid.mpg

Trim a video
This will clip the first 30 seconds of the video
ffmpeg -i video.mpg -sameq -ss 00:00:00 -t 00:00:30 trim.mpg

Stitch clips together (no ffmpeg needed)
This only works with a few formats. I tend to always work with mpeg, so this works great for me
cat video.mpg video2.mpg video3.mpg > finalVid.mpg

 

Wednesday
Jul292009

Geotagging photos with your iPhone

Ever since I starting using my iPhone to take photos and upload them to the net, I've really become interested in geotagging my photos. I didn't realize how cool it is to be able to see your photos on a map (or Google Earth) until all my photos started showing up tagged (thanks to the GPS in the iPhone). Having low res photos tagged is cool and all, but I want to tag them with my SLR. You could buy an adapter for you camera from Amazon or you could just use the GPS you're carrying with you every where you go. Here's how:

First, get an app from the app store that logs GPS data points. There are a ton of them, and one app specifically tailored to this called GeoLogTag. Anything that allows you to export your data in a GPX file with times should work. I just use MotionX GPS because it's super cheap for what you get, I use it for hiking as well, and it makes it super easy to share/get the GPX file.

Next you'll need an app that allows you to tie your GPS location and timestamps to your photos. There is a ton of software that does this, but I chose to use a perl script because I wanted something cross platform and any time I can use the command line, I'm happy. You can find the handy dandy perl script called gpsPhoto here. You'll need to install two more perl packages if you don't already have them installed. The site goes over how to install them if you don't already know how.

So let's go step by step:

0. Make sure the time is set correctly on your camera.
1. Turn on MotionX GPS and start logging.
2. Walk around and take pictures like a mofo.
3. When you're done taking pictures, stop MotionX, save the track, and email yourself the GPX log (called sharing in MotionX)
4. Go home and dump the pictures from your camera into a folder.
5. Fire up a command window and change into the directory where you pictures are.
6. Run the perl script. Here is the command I used:

./gpsPhoto.pl --dir geotag --gpsfile Track.gpx --timeoffset 21600

There are a ton of options that you can use, but these 3 should get you by. The first two args are pretty self explanatory, but the third isn't at first. The timeoffset is the UTC offset in your timezone in seconds. I live in Denver, and my offset is 7 hours, minus 1 hour since we are on daylight savings. Just google the local time in your city if you don't know what your offset is, and then multiply that by 60 minutes and 60 seconds.

Anyway, this should get you started, and I was able to get this to work on Windows, Mac OSX, and Ubuntu, so you should be able to follow my instructions on any OS that supports perl. Lastly, you can use any old GPS to get the GPX file, it's just a matter of having your GPS with you as well as the ease of getting the GPX file to your computer.