Aegisub vs OpenSpeaks Subtitler

Aegisub is a free, open-source tool for creating and modifying subtitles on Linux, macOS, and Windows. Its audio interface includes waveform and spectrum views for timing subtitles, while video mode previews edits as they are made. Visual controls on the video frame let users position, rotate, scale, and clip subtitles. Aegisub imports and exports several subtitle formats, including MPEG-4 Timed Text and MicroDVD, and it supports subtitle translation. Editing aids include a translation assistant, spell checking, a thesaurus, syntax highlighting, and macros. The Automation module runs Lua scripts for macros and export filters. Multi-level undo and redo, autosaving, backups, and emergency recovery saving are included. Direct saving to SRT is blocked when override tags would lose information, though the Export dialog can export to SRT. Aegisub does not create DVD subtitles directly; its FAQ describes using an external program to convert SSA to VOBSubs. The optional update checker sends anonymous operating-environment details, including an IP address, and can be left disabled. Version 3.5.0 is listed for download.

OpenSpeaks Subtitler has no write-up on Specifiction yet; its figures are above.