The example above applies fade-in effect for audio, but not for video. The parameters are pretty much self explanatory. A combination of different parameters can be used to meet your editing requirements.
FFMPEG can be used to convert a video from one format to another. Very often, the video itself to be converted is already encoded in an appropriate format. You just want to convert the container format.
In the following example, the source video is encoded in MPEG-2 in an MKV container. It will be converted to an MPG video. No re-encoding is required since the source video is already in the target format. You can also select one or more audio tracks during conversion if this is part of the requirements.
If you would like to extract a portion of a video without re-encoding, consider using FFMPEG. The following example illustrates a command to extract a video from the 24th minute line and for 4 minutes 8 seconds, keeping all audio tracks.
Here is another use case for FFMPEG. In some projects, after you mixed and matched video and audio streams from different files, the resultant file may not have the default audio stream as desired. You can use the following command to set the default audio stream while you are mixing the video/audio streams.