Why does BD-RB re-encode the AC3 core?

[buffyangel108]

I love BD Rebuilder and have been using it for quite some time. I just have one question on BD-RB's handling of Dolby TrueHD audio tracks (I've searched the forum and guides but as yet to no avail.)

If I have a TrueHD track, I understand BD-RB will first extract the core/embedded 640kbps ac3 track, then encode it to... a 640kbps ac3 track. If not to save space, could I please ask why this re-encode step is necessary? Forgive me if I'm asking a dumb question; I admit to knowing very little about audio processing!

I also understand that I can disable the re-encode step in the BD-RB options, but I'm curious as to what benefit it brings?

Many thanks and keep up the great work!

[jdobbs]

Hmm... good question. I need to go back and look at the code. It seems silly to reencode from 640Kbs AC3 to 640Kbs AC3 if that's what is happening. It seems there was a reason for why I was doing it the way I am -- but it escapes me now.

[setarip_old]

@jdobbs

Hi!It seems silly to reencode from 640Kbs AC3 to 640Kbs AC3 if that's what is happening. It seems there was a reason for why I was doing it the way I am -- but it escapes me now. I believe it has to do with reducing the audiostream to 16bit...