|TL;DR version: What tools to use to reliably convert DVD video without audio getting out of sync? No need to rip; all files are already on disk.
The full version:
Years (decades?) ago most standalone DVD players were rather finicky about what they could play back, and most would only work with "proper" DVDs with the traditional AUDIO_TS / VIDEO_TS folder structure containing .VOB files.
Because of this, I've had a tendency to burn everything to DVD in that format, so I'd stand the best chance of being able to play them back on regular players. As such, by now I have a pretty big pile of DVDs with "regular DVD format" content.
As some might remember, a few weeks ago I mentioned I made the decision to stop burning everything to DVD and just store everything on hard drives, as mass storage disks are now cheaper than blank DVDs. I've started copying those DVDs back to hard drives and have been making steady progress.
Here's the thing: As video can now be streamed from my computer to a TV or projector, I'm no longer as concerned about "maintaining compatibility with the lowest-common denominator", so to speak. A plain standard 4.35GB DVD using standard 720x480 VOB/MPG can be converted to a single < 1GB AVI/MP4/MKV file, with multiple audio tracks, with no appreciable loss in audio or video quality. Obviously, if I can store all of those videos in a quarter of the space, I won't mind the time it'll take to perform the one-time conversion.
Now...the whole reason I bring this up...I've had less than stellar results with what's out there to perform said conversion. My primary concern is that I've seen plenty of perfectly fine DVDs with the video now getting out of sync with the audio once converted, say, to MKV. To make matters worse, if I hit Play and go to random spots, the problem doesn't manifest itself - generally it's only when I play something from the start and just let it run that it'll start slowly drifting out of sync over time. Obviously I'm not going to sit back and watch everything just to verify whether something was converted correctly or not.
So who here has done such conversions and can swear by this-or-that particular product? I won't name what I've tried so far (to protect the innocent and avoid introducing my own bias in the discussion), but suffice it to say that I did try a few different apps, all with somewhat inconsistent results.
I really only have 2 criteria...just one if it really comes down to it:
a) Being absolutely confident it won't introduce synchronization issues. If it can't satisfy this criteria, it's a non-starter
b) Nice to have: If multiple audio tracks are available (for example, 5.1 vs stereo), assume I want both to be included in the final file
The ability to do batch processing would be a great bonus...for example, the ideal application would be pointed to a folder that contains subfolders A, B and C, each containing its own respective AUDIO_TS and VIDEO_TS subfolders, and then spit out A.mp4, B.mp4 and C.mp4 (or .MKV or whatever) without much further input from myself. Come to think of it, even if it doesn't have that ability, if it can alternatively be invoked from the command prompt, I should be able to write a script to automate that myself.
But again, these are nice-to-haves - I'd rather do the conversion one folder at a time and be confident I have no audio/video drift, than any other convenience feature.