Editing video on Linux

So driven by a mixture of geekiness curiosity and the motivation of doing something special. With just one week getting on with this program I was able to do a video mashup which surprisingly came out really really good. At least more than I thought I could achieve. So the whole project took me all night to finish it up but when it was done I was able to appreciate even better.So cinelerra…. many people think is hard but is not at all.The first thing I wanted to do was watching a show from the source show which give a small tour of Cinelerra. Althought the tutorial wasn’t really what I was expecting because it was too basic. What I wanted to achieve was using the multi-tracking system and also had some video transitions specially zoom and face. I also wanted to mix the audio of one video with the other and have a slide-show generated from pictures I have. None of these things were explained on that tutorial.


The next step was going on one of my most effective ways on research which was asking people at the IRC. Freenode is known as the premier IRC server for all things open source. Even if most of the gnome stuff is on a different server at irc.gimp.org, freenode contains most projects that you will find related to KDE, Puppy, distros, etc.So I just bluntly typed /join #cinelerra and boom, I was there. After a few minutes I got people ready to answer any question I thought I should get. One of the first ones was file format specific since cinelerra didn’t seem to read my JPEG images.After a few minutes the response was that the images need to be resized to the format of the video. That means if the video was 320×240 the images should be around that size, so having a 1200×1020 image cinelerra would read it as a wav file.So I used image magic and even if the bash script that they recommend on their wiki didn’t work. I was able to just do a single convert for each image that I trully needed. I went to the imagemagick site and saw their basic tutorial on resizing.convert rose.jpg -resize 50% rose.pngCinelerra didn’t complain once I resize the images, however I will get a 1 image per frame which can be as small as a millisecond. Since I wasn’t making any subliminal movie I really wanted more than 1 miliseconds. So reading around, on the wiki I saw that I specify enable Import images with a duration of XX seconds. This can be enabled at the Settings > Preferences > Recording, the option is at the bottom of the dialog.This solution make me able to also be able to expand the exposure time on the timeline by just using the mouse and dragging the block to expand it. With my slideshow setup almost done, what will come next was adding transitional effects so they well do things like fade and zoom.So the way cinelerra’s timeline works it will show you screenshots of the sequence from the video or image or the soundwave from the audio. But it will also have lines that will go across the timeline. These lines will have different colors and will be there for different reasons. Also this lines can be turned visible or not by poping out the Overlays at Windows > Show Overlay. This will give you a small dialog giving a check list of things like:

  • Assets
  • Titles
  • Transitions
  • Fade
  • etc

We will focus on Fade, Camera X, Camera Y and Camera Z, this will give us the way to manipulate the different tracks. Having them appear or disappear will prevent us from creating nodes on a different line. So when you click on any of the lines a square (we call them nodes) will appear and you can drag them across the timeline. The dragging up and down will specify the value of that specific line, so for example if the Fade (white line) is dragged down, the element of that track will fade out.You will be able to see a representation of those changes at the Compositor window. However, the compositor will just show the frame in which the cursor (vertical line) is positioned at. So make sure you have that cursor around the period you are producing the effect.Another thing to watch out when dealing with timelines is that each timeline has some individual controls. I haven’t played with many of them, but an important button is the ‘record’ button or output (red circle). If you are manipulating the lines, the changes will affect ALL THE TIMELINES hat have the record button activated. So make sure to isolate the record on the track you are working at.


Another interesting area was using the video effects, even thought I didn’t used that many effects I was able to use the Title effect to insert text at the beginning of the video. I wont get much about effect manipulation except that when you insert an effect into a timeline you will have a bar with a key on one extreme and a lens and icon on the other end. When you click on the lens a configuration dialog for the effect will come up.So in the end, the video came up alright, I did a Rendering with Shift-R and took around 6 minutes to encode. Then I re-encode it on a smaller file format and upload it to Youtube.I will still need to play more with this, but the end result was an awesome video. Try it yourself.Interesting Links