How to use Avidemux for Video Editing
Thankfully, the open source world offers many good choices when it comes to video editing. Some of the most popular choices are the PiTiVi, OpenShot, Kdenlive and Blender. Avidemux is another one - maybe the one with the worst name, but being one of the oldest (five years old) it is now quite mature and stable as well as relatively feature rich. I personally started using Avidemux because it supports many video file formats and it used the GTK+ toolkit for its graphical user interface, so it matches the looks of my GNOME system.
First thing is to load the video you want to edit. This can be done by pressing the “open” button located on the upper left, or by navigating the file menu and choosing the “open” option. This will open a file manager window from which you will be able to locate your video file. The file that I will be using to demonstrate Avidemux is a sample from the Big Buck Bunny movie in 1080x720 resolution.
Notice the play controls on the bottom of the interface. Using them you may navigate through your video and watch any parts. The “A” and “B” buttons correspond to the start and end of a selection. I frequently use this before any other editing in order to remove silence in the beginning and the ending of a video. You may also enter the frame number, or the exact millisecond you want to navigate to before pressing the “A” and “B” position markers. Now if the “Save” button is pressed, you will be allowed to save your selection (the portion from A to B markers) only, thus cutting out the rest. You should give a new filename to this exported video and you may load this one to Avidemux for further editing.
The next step is to choose a format for your output video. You may choose a video and an audio codec from the options list on the left. This action will open up choices for further editing as the format of a video is determining the numerical limits of its characteristics. For this reason, you may find that some formats may not be suitable for a particular aspect ratio or resolution so you should keep trying to find out what works for your needs.
Pressing the “configure” button below your codec choices will let you fiddle with its corresponding options. Proceeding to the basic editing, I will press the “Filters” button below the video codec that will open up a menu of the available filters. Let's suppose that I want to change the size of the video from 1080x720 to 720x480. To do this, I choose the “Transform” tab and then add the “Resize” filter by pressing the little green button on the center. After this, I am prompt to configure the filter by entering the rezising values as shown in the screenshot below.
Let's say I also want to crop the video too, and cut a bit from its sides. By choosing to add the “Crop” filter, I am given a handy video previewer that indicates the cropped area in light green.
Notice how all of my added filters were added on the right column as I also created some fade in and fade out effects to smooth the transitions. After I have finished adding and configuring my editing filters, I can save the file under a new name and re-open it to continue working on it.
Effect filters may be applied in the same way that we performed basic editing. One of the most widely used filters is the “Logo” one that allows users to browse for a .png image file (logo) and embed it in the video. I inserted the HowToForge logo on the top left as an example.
Avidemux may be able to help you when in need of removing a watermark from a video through its “delogo” filter that tries to blend an existing logo by interpolating its surrounding box. You simply define the area and hope for the best. Another useful filter that may come in handy is the “Swap U and V” found under the “Colors” category. This usually corrects the inverted chroma that is the case in some webm videos.
Further exploring the filters collection, you will also find sharpness / smoothing filters, subtitle adders, transition effects, noise removers, light de-noisers and several more. Like in most cases with such software, experimenting will make you both learn more and get the best possible results out of your editing process, so spend some time on the filters and try various settings before you press that “Save” button.
Changing Rates and Using Templates
If the output video seems to be playing too slowly or too quickly, you may have to change the frame rate. You can do this by pressing the “video” options menu and choosing the “Frame Rate” entry. You can either set it manually, or choose fixed settings for PAL (25 fps), FILM (24 fps), or NTSC (30 fps). Another useful feature is the template settings that can be chosen in order for Avidemux to set all parameters to fit a medium or device. By pressing the “Auto” options menu, you may choose between DVD, Video CD, Super Video CD, Apple iPod or Sony Play Station Portable and Avidemux will take care of setting the appropriate codecs for the transcoding process, resolution, frame rates etc.
Have fun exploring Avidemux!