T4a is a focused follow-up to T4. It is mostly bug-fixes and a batch of new audio and Dolby Vision tuning, on top of everything T4 already shipped. If you are coming from T3b or earlier, read the T4 notes first — this release builds straight on them.
The headline changes:
- A whole new set of audio controls: AC3/EAC3 dynamic range compression, DTS/DTS-HD/DTS:X dialnorm defeat, a finer centre-channel boost, LFE downmix up to 300%, and LAV Full is now the default passthrough sync mode.
- Fixed decoded AC3/EAC3 jumping louder after a seek and staying that way (the decoder's range compression was switched off on the first seek).
- A new toggle (on by default) that gives audio the same DDR-bus priority as video, closing a rare split-second HDMI dropout under heavy 4K/Dolby Vision decode.
- Several playback glitches gone: the post-seek picture freeze, the pause/resume video wedge, and the green flash at the start of p