MkvDefaultTrackChanger - Fast Mkv Default Audio and Subtitle Track Changer

[johnnyquid]

MkvDefaultTrackChanger can change the default audio and subtitle tracks of a MKV file without remuxing. This makes MkvDefaultTrackChanger very fast. The default track changes can be done via the program GUI or command line.

The original author was MikeMoolenaarand. Some enhancements were done by IDisposable. This version adds command line usage.

I've asked for the program to be added to VideoHelp's software section. It may be awhile until is accepted (if it is). In the meantime, you can see details at
https://github.com/Ranft65/MkvDefaultTrackChanger/tree/feat/add-flags-and-command-line

I have found test cases where using this program more than once on a file can cause it to become unreadable. It appears that the file corruption only occurs only when there are forced tracks and the files are operated on more than once. As of 5/30/2026, this issue exists in all versions of this program (original and modified) except for versions 1.4 and above released by Ranft65. I have filled an issue for the affected versions.

Version 1.5.0: Fixes potential file corruption issue.
Version 1.5.1: Adds drag and drop for file selection.