Article Linux Video

Pentax K-5: Experiment in video editing.

This embedded video below is a clipped together “music video” from full 1080p HD clips I recorded with the new Pentax K-5 camera.

Click here full-sized version:

The example video using the K-5.

As I was saying, I used a Pentax K-5 (1080p @ 25 FPS), at the highest quality setting. All clips were set to 40% speed and patched together in kdenlive ( for Linux with a creative commons licensed song (see the end of video for credits). The project was rendered in H264 @ 1280×720 and uploaded to Youtube.

It looks to me that my K-5 has a few troubled pixels that are stuck to a shade of red when the ISO gain is high enough. You probably won’t be able to notice them, but I’ll have to look into software solutions to see if I can easily correct those pixels. I was using a firmware that was one upgrade back from current, so I’ll be eventually testing the new firmware and consecutive ones that are released to see if they correct those stuck pixels in video mode. The camera has a “pixel mapping” functionality that finds dead pixels and compensates for them in resulting images, but I don’t know if it applies to video. I have yet to research the issue…

Options for quality video editing software in the Linux world are slim. Kdenlive is a surprisingly functional NLE-type video editor that is available on Linux and live-CD/USB disk. It appears to be pretty stable, although I did have one quirk where I could not delete two clips (solved that by restarting the editor). I’d have to say this is the best editor I’ve used on Linux, and it’s pretty close to the one I used a lot on Windows (Sony Vegas Platinum Pro that retails for around $120). With the source material on my RAID 10 four disk array and using a quad-core processor, editing felt fast overall. Considering I was editing compressed motion-jpeg 1080p source material directly, I’d say it’s quite good speed wise. Simple transitions and fading felt near real-time, but most other effects were jerky.

There was an issue with my K-5 (and K-7) video clip audio. Popping/crackling is heard throughout when editing. So that’s another issue I’ll have to look into eventually. The sound is fine when I just watch the videos in say, VideoLan player. Edit: I believe that was caused by the project having a different frame rate than the source clips. I have started editing a video that uses the audio and it is working fine. I set the project to be the same as the source.

If you are using Ubuntu, they advise you to add their current-build repository to your software sources.