FFmpeg

FFmpeg (Fast Forward MPEG)

FFmpeg is an open-source multimedia project for working with audio, video, images. It is a command-line tool to handle videos, pictures, audios, and their multimedia files and streams.

FFmpeg also includes ffplay, ffprobe. Both are command line tools.

FFplay is a very simple and portable media player using the FFmpeg libraries and the SDL library. It is mostly used as a testbed for the various FFmpeg APIs.

FFprobe gathers information from multimedia streams and prints it in a human- and machine-readable fashion. For example, it can be used to check the format of the container used by a multimedia stream and the format and type of each media stream contained in it.

Probably the most popular use is converting audio and video formats back and forth, but you can do many other things with ffmpeg, like:

Trim videos or break them up into clips, merge videos together into a single video, merge video and audio, remove and replace audio from a video, change the frame rate, use ffmpeg in a variety of programming languages, set up video streams, mute a video, convert a video into an animated GIF, extract frames from a video and then make them into a trailer or use those as a thumbnail, extract audio or video from a video with audio, convert a video into a series of images, convert images into a video, resize a video, rotate the video, speed up or slow down the audio and the video, there are lots of other things you can do with FFMPEG. It supports pretty much every video and audio format imaginable. And, from their site, it can be used to “decode, encode, transcode, mux, demux, stream, filter and play pretty much anything that humans and machines have created. Compressing/transcoding audio or video files, joining multiple audio/video files into a single file, adding or removing subtitles from a video file, adding a graphic overlay (like a logo) to a video, capturing your screen/webcam and recording the content to a file.

Trimming/Cutting media files, increase the volume of audio (or some other property), change the frame rate or the resolution of a video, these should get you started, it's a really powerful tool that is worth learning, because if you work with digital media, FFmpeg will make your life a lot easier and get things done for your much quicker.