# mp4box > MPEG-4 Systems Toolbox: muxe streams into MP4 container. > More information: . - Display information about an existing MP4 file: `mp4box -info {{path/to/file}}` - Add an SRT subtitle file into an MP4 file: `mp4box -add {{input_subs.srt}}:lang=eng -add {{input.mp4}} {{output.mp4}}` - Combine audio from one file and video from another: `mp4box -add {{input1.mp4}}#audio -add {{input2.mp4}}#video {{output.mp4}}`