How can I get a dmg copy of instructional video to open in the original format?

1. You can drag-and-drop the VIDEO_TS parent folder onto the Apple DVD Player app’s Open dialog box, or navigate to it, then select the VIDEO_TS folder to open. That will open it as-if it were a physical DVD-Video disc.
2. You can drag-and-drop the VIDEO_TS folder onto the VLC app icon. That will open it as-if it were a physical DVD-Video disc. It helps when you made VLC an item in the Dock. Menus may be of slightly lesser functionality, as VLC is not an officially licensed DVD video player.
3. You can burn the VIDEO_TS and AUDIO_TS folders onto a DVD-R disc in UDF format, then play it in a DVD player. You may need a third party burning app for that.

1. Mount the DMG: Double-click to open the DMG file.
2. Extract Videos: Drag video files from the DMG to your Mac.
3. Convert Videos:

• QuickTime: Open video > File > Export As.
• HandBrake: Open video > Choose settings > Start.
• VLC: File > Convert/Stream > Add video > Choose format > Save.

This will convert your video files to the desired format.

[Edited by Moderator]

In a video-DVD the actual movie is in VTS_01_1.VOB etc files. The .dmg image should contain them.

https://en.wikipedia.org/wiki/DVD-Video

Try to mount the .dmg and play the movie with DVD Player.app. You should find it via Spotlight or at

/Applications/Utilities/DVD Player.app

or:

/System/Library/CoreServices/DVD Player.app