There isn't really any lossless mode like that in Audials (doesn't have x264 codec option btw).
This is really annoying. DMM/r18.com has HD versions of releases that are otherwise only out on DVD/DVD quality elsewhere. I cannot find any way to play the DRM files in linux without doing something stupid like running a windows virtual machine, which is completely ridiculous.
I did try drmdbg/fairuse4wm etc in an XP virtual machine, but had no luck. It looks like the WMV files request a newer version of the protection to play, and it can't (as far as I know) be cracked with the known released versions of those apps.
I guess you could use a hardware capture card and play the video on one machine, then record it on another PC with a capture card, I figure that would work losslessly without any frame drop, but at this stage it's far too much effort. I doubt I'll bother buying from DMM/r18.com anymore, rather I'll just put up with DVD releases, unless I can figure something out.
I'll try capturing just a normal DVD res movie with Audials and see if it's any different.
When I get a chance I'll share my capture. I'm sure some would consider it fine, it's not like crazy amounts of dropped frames, but it seems like maybe 2 a minute or so. I personally do notice it as the motion does not seem as it should be.