A DTM file is a Dolphin TAS movie created by Dolphin, an emulator used to play GameCube and Wii games. It contains controller input data used to recreate a gameplay recording. DTM files do not store actual video.

You can create DTM files in Dolphin by selecting Emulation → Start Recording. The DTM file is created to store data such as the game ID, recording start time, controller input data, and other in-game settings. You can use the Dolphin emulator to view the DTM file. You can also use DTM Editor (only for GameCube controller data) to edit the buttons, triggers, D-Pad , and stick positions for each frame.