Video compositing with Natron

Knotting Techniques

To change this, click the workspace with the right mouse button and select the point Image | Readers | ReadFFmpeg . Then, select a video from your hard drive. Natron cannot currently import videos directly from a camera. You must therefore first copy videos to your hard disk and, if applicable, convert to another format.

You have now added a new node that opens and displays a video from disk (Figure 3). The node appears within the drawing surface as a box. Note that sometimes it conceals the Viewer1 node. Click and drag it to show the viewer node.

Figure 3: The node type ReadFFmpeg loads a video using FFmpeg.

The new node, labeled ReadFFmpeg1 , is highlighted in yellow, which means it's selected. The settings for this can be found on the right side of the window in the yellow marked area. Do not be daunted by the plethora of settings; most can be left at their defaults. In the case of new nodes, you can find ReadFFmpeg1 under File once the node is imported. You can also always select a different file and change the result later.

Entangled

On the NodeGraph tab, you can move each node using drag and drop. Position the ReadFFmpeg1 node near Viewer1 . The node ReadFFmpeg1 has a connector hanging out of its lower end. You want to connect both nodes. Here, you have two options. You can click ReadFFmpeg1 's connector with your mouse and then drag it onto Viewer1 while holding down the mouse button.

Because this action is somewhat fiddly, you can alternatively just pull the ReadFFmpeg1 node in the direction of Viewer1 . Eventually, a green connecting line will appear between the two. If you then release the mouse button, the two nodes will be connected automatically. In any case, the result should look like Figure 4. The node ReadFFmpeg1 now reads the video from the hard disk and pushes it through its output into the input of node Viewer1 . This displays the video in the preview.

Figure 4: The viewer displays the video output from the ReadFFmpeg1 node.

You can control the preview by using the buttons under the preview screen. With the triangle pointing to the right, you start playback. Between the preview and the NodeGraph register, you will find a small timeline. Natron does not work just with time designations; it also counts the images (frames) from the start.

The number above the orange triangle shows the number of the currently displayed frame. As soon as you touch the mouse to the timeline, a slightly darkened orange triangle will appear. If you click this, the preview will jump to the corresponding image. You can also hold down the left mouse button and then quickly go through the motions with your mouse through the video. This called scrubbing .