ffmpegGUI's native interface lets you choose source and output files, set audio/video codecs and container format, bitrate, framerate, samplerate etc., change video resolution and crop the picture.
You can also make a lossless '1:1 copy' of the audio or video track to quickly transcode to another container format.
ffmpegGUI assembles the resulting ffmpeg commandline, that you can then tweak manually or copy to use in your own scripts if needed. Or you simply click 'Start' to begin the encoding. You can also create encoding jobs to process them all in a batch later.
Currently included container formats/codecs:
* Video containers: avi, mkv, mp4, mpeg-1, ogg, webm
* Audio containers: mp3, oga, wav
* Video codecs: mjpeg, mpeg4, theora, vp8, vp9, wmv1, wmv2
* Audio codecs: aac, ac3, dts, flac, mp3, pcm16, vorbis (only with video codec theora)