Woodstock wrote: ↑Tue May 26, 2020 2:17 am
Audio is, as you have seen, its own can of worms. I generally do a passthrough of AC3 and a conversion to AAC (in that order) for the audio track on a DVD. It gets far more complicated when Bluray enters the equation, but I still use AC3 and AAC as the first tracks for player compatibility. I think I mentioned I gave up on rules-based selections...
I tried to render the first epsiode from M.A.S.H:
$ ls title_t00.mkv Woodstock.m4v MASH_YR1_D1_t00_VF22.m4v MASH_YR1_D1_t00_F22.m4v
-rwxrwx---+ 1 tja None 936149381 May 24 01:05 title_t00.mkv*
-rwxrwxr-x+ 1 tja None 441351270 Jun 6 15:00 Woodstock.m4v*
-rwxrwxr-x+ 1 tja None 380447566 Jun 6 15:23 MASH_YR1_D1_t00_VF22.m4v*
-rwxrwxr-x+ 1 tja None 410712755 Jun 6 15:35 MASH_YR1_D1_t00_F22.m4v*
As you can see, the original MKV file is about 936 MB, your command resulted in 441 MB and my tried with Very Fast and Fast, also at quality 22 were 380 and 410 MB ...
But this is only about 50% of the original PAL DVD version.
To be honest, i thought that the resulting files would be smaller.
And this is already the worst acceptable quality.