IINA Version

1.4.0-beta1 build 152

Release Channel

Beta

macOS Version

15.5

Steps to Reproduce

• Add the following lines to input.conf:

MBTN_BACK add speed 0.5
MBTN_FORWARD add speed -0.5

• Open a video in IINA
• Test the corresponding mouse buttons (back and forward).

Expected Behavior

The MBTN_BACK and MBTN_FORWARD buttons should be correctly recognized and trigger the assigned actions.

Actual Behavior

The MBTN_BACK and MBTN_FORWARD keys are recognized and function correctly in mpv.net on Windows, but they are not recognized in IINA.
https://mpv.io/manual/master/#mouse-control
https://mpv.io/manual/stable/#options-input-keylist

Crash Report or Process Sample

No response

Logs

No response

Sample Files

No response

How often can you reproduce the issue

everytime

Required Actions

• I tried my best to search from the existing issues (including closed issues) and didn't find duplicated issues.

Optional Actions

• I tested with the Nightly build and confirmed the issue is not fixed.
• I tested with the latest version of mpv and confirmed mpv doesn't have this issue.