What these apps do is [hopefully] handle the DRM on a retail video DVD, then re-encode the audio & video, optionally re-sizing the video frame at the same time. They're based on ffmpeg, which includes the x264 encoder, so they're good for AVC/H.264 or H.265 encoded video, e.g. for a tablet or cell or media player box.
I like WonderFox software because it has little impact on Windows [files are stored in the program's folder & (My) Documents with no registry dependencies]. AFAIK they've never turned off their giveaways [e.g. WinX]. Otherwise their conversion software uses ffmpeg as the real engine, & QT code libraries for re-sizing & such, just like most every converter out of China. They all tend to have bugs sometimes in one version or another, and they tend to use older versions of ffmpeg, & they're usually easier to use than software that allows you greater control over the encoder & re-sizing settings or methods. OTOH we're talking DVDs here -- not HD -- so it's really [IMHO Highly] questionable how much encoder quality related settings & better re-sizing matters. Put another way, if you can't see a difference it might as well not exist.
Xvid output is available [sometimes *called* DivX, though little comparison with current DivX], but don't know why anyone would use it... it's not loss-less enough for editing, & not efficient enough as a final format. Mpg2 is also available, but ffmpeg's mpg2 is far from the best. AAC audio is OK, though like the use of the x264 encoder, you can do better taking more time & trouble processing it with less convenient software & methods. And depending on your intended player, you may be better off keeping the original AC3, though that can involve replacing the audio track in the video file you got out of the converter -- it's very doable.
If you want to process one or more the files on a DVD manually, one handy tool is PgcDemux, which will give you the .m2v video file, AC3 audio, .sup files for the subtitles, & a Celltimes.txt file with the chapter times. There are also tools to copy the audio & video from a set of .VOB files to a single mpg2 file, or you can use DVD Shrink to copy the DVD's files, with a single .VOB file rather than the usual 4 or so [the .VOB files are broken up so they're less than 2 GB each for compatibility].
At least one of the comments on the download page reflected some confusion over frame sizes & aspect ratios. DVDs were intended to be watched on regular TVs with picture tubes, so old rules & standards apply. NTSC in the US is 720 x 480 while PAL is 720 x 576, both using non-square pixels -- simplified that means that if you open video files in those sizes in a regular player on your PC/laptop they're aspect ratio will be distorted, so you have to use a player that understands that to see them properly, e.g. PowerDVD. Widescreen DVD video is anamorphic, meaning the video's the same frame size but the player stretches the video further -- again you need software that understands that.
Now I'm going to make things more complicated... several video formats associated with PCs & such can also use non-square pixels &/or be anamorphic, & if you use either [non-square pixels &/or anamorphic], as above the player needs to be able to understand that. Why bother with such things? It can let you create smaller files. Unfortunately software isn't always crystal clear about whether they're including 1 or both features in some of their output files, nor can you always just turn that sort of thing off. You have to test & use your eyes -- here's a pretty simple way to do it...
Open & play the original DVD in DVD player software -- I use PowerDVD but any real DVD player should handle it. Then take a screen shot, using either the player's built in feature or a separate app. Open that in an image editor, & you've got your display size right there. Want to change frame sizes -- change the image size in your editing software, *maintaining aspect ratio*, & you'll see near instantly what the height should be for any width, & vice versa. And you can easily save the re-sized picture for later reference -- compare that to a test file you re-encoded in the player [&/or on the device] you plan to use to watch the video. If it doesn't match change the settings or software you used to re-encode the video, &/or change the player [when possible].
**IF** you want to do a bit better conversion... The NTSC DVD video fps is 29.976 -- the fps of film is 24. It's pretty complicated to create new frames -- when they put a film on DVD they insert flags in the video file(s) telling the player which frames to repeat instead. If you convert or re-encode that video you can either include all 29.976 frames per second, or you can ignore [remove] those flags & just use the original 24. The only thing that's effected is the size of the video file -- it takes more room to store 29.976 frames than it does to store 24. So if you want to keep your re-encoded file at 1 GB for example, you can use less video compression because you're storing fewer frames, which gives your video higher quality.
Some software will remove pulldown automatically, some won't, sometimes you can set it on/off, sometimes it's referred to as IVC [Inverse Telecine]. MediaInfo is a handy app that integrates with Windows Explorer -- right click the file, select MediaInfo, & you see just what you've got, before &/or afterwards.
The audio end of things is more complicated. Originally movies are designed for theaters, & that means theater sound systems. Usually there's not a big difference between that original version & the mix that's stuck on a DVD or Blu-Ray video disc. DVD & Blu-Ray players [soft & hardware] know this, & generally adjust the mix accordingly. The complication comes when you use software to convert the audio track(s) -- software like today's GOTD uses generalized rules to balance out the tracks, set the volume levels, & in effect add a bit of dynamic compression.
You can do better, but it's more work, more learning, requires more specialized software, & since AC3 is already a lossy format, you'll always lose some quality from any conversion. Practically speaking, you may [or may not] find it works best using the original AC3 -- it depends on your personal standards when it comes to audio, how you play the video, or more precisely the audio decoder & processing, the quality of the hardware you're using to listen to the audio, & whether you have &/or want to spend any added time it takes.
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If you want to know more on any part of this ask...