Audio track "Auto-passthrough" and order-of-operations

[GREENBUTTON]

I have MKVs ripped from BDs -- I want to preserve their multiple multi-channel audio tracks. how?

I'm trying to encode a whole bunch of MKVs … they have varying multi-channel audio tracks inside (some have AC-3, some have DTS, etc.) I did a pass using the preset "Super HQ 1080p30 Surround" -- but then noticed that many of the resulting files ONLY had a stereo AAC track, and the multi-track audio tracks weren't present.

I looked at the preset, and it uses:
<1st source track> codec <aac> mixdown <dolby prologic II> <-- this produces the stereo AAC. Check.
<1st source track> <AC-3 passthrough> <-- here's the issue. If the source has AC-3.. it works! If not.. you get nothing.

I wanted to try to create a new preset that would "do this automatically"... but I'm unclear how the setting "Auto passthrough" works. If I put in one of these, will it pick ONLY THE FIRST multi-track audio track? Then I'll get a random collection... AND … I know that True HD won't passthrough if my resulting file isn't an MKV … so if I'm rendering an m4v will it just skip this?

My question: is there a way to get it to *predictably* pass through ALL the non-True-HD multi-channel tracks without me manually tweaking each file as I load up the queue?

Thanks!


HandBrake version (e.g., 1.0.7)
Windows 10 Spring Creators Update Insider build

[BradleyS]

If I recall correctly, the behavior of AC3 pass through differed on Windows for the 1.0.0 release series. Please try the nightly build.

[FrontierDK]

I use the latest nightly build, and "auto-pass-through" usually does the trick when finding a Dolby TrueHD blu-ray...(If I select it manually, Handbrake skips the encode entirely).