Or you can grab PCI video card with native MPEG2 decoder. BTW your video card has MPEG1 acceleration.

Virtual wrote on 2021-07-19, 18:20:

My current setup: OS: Windows 98 SE Lite Sleek CPU: Pentium MMX 200MHz Memory: 64MB of RAM Sound Card: SB0100 S3 GPU: S3 Trio […]
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My current setup:
OS: Windows 98 SE Lite Sleek
CPU: Pentium MMX 200MHz
Memory: 64MB of RAM
Sound Card: SB0100 S3
GPU: S3 Trio 64V2/DX 2MB

Oy, that's a weak system. For pure software-decoding, I mean. 😉
For 90s gaming, that's a fine system, though. No offense.

Without any kind of assistance,
even Pentium III would struggle playing back a DVD all on its own.

The setup above is fine for 90s gaming, seriously, but even for MPEG-1 playback,
it's just a bit beyond the requirements.

Anyway, maybe an additional DVD decoder card for PCI bus will do. 😀
They were sold at the turn of the century/millennium.
Creative made one, too, I believe.

Alternatively, try PowerDVD XP or PowerDVD 6.
These were the versions I had best experience with (bot do run on 98SE/XP).
They also support CPU instructions (SIMDs) and acceleration provided through DXVA.

Other versions like PowerDVD v3 or v5 may also work, but I rarely used them.

PowerDVD v7 was a rewrite (?) and became comparatively bloated.
Only thing good it had was its ability to support both HD-DVD/Bluray at one point (there was a short-lived special edition of v7).
WinDVD never worked for me, sadly, even though I gave it many chances.

Edit: Sorry for being so harsh.
I hope this is more helpful:
You can use VLC player 3 to convert to multiple formats.
It will also allow for changing resolutions and applying filters.
Another easy to use program is "Avidemux".
I use v2.7 on a modern PC. It can be used as a tiny video editor, too. 🙂👍

Your system should be able to handle low res (400x300 ish) MPEG1 video software decoding, depending on the bitrate

Virtual wrote on 2021-07-19, 18:20:

My goal is to convert DVD files to a file format, downgrading its quality (but keeping the maximum quality possible), making it […]
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My goal is to convert DVD files to a file format, downgrading its quality (but keeping the maximum quality possible), making it playable on my system.
For this I need to know what program should I use, and what resolution/encoding settings/file format (compatible with subtitles), that would be the best for this task.
I would also like to convert .mp4, .mkv, etc., so I need advice on any software/settings for these as well.
This is off-topic, but I would like to hear about any recommendations regarding retro software to convert these video files for dial-up web use (really low quality encoded, also short clips).

I don't know the answers to your other questions like with subtitles, but the two earliest video codecs for PCs were Cinepak and Indeo. This is what the videos on the Windows 95 CD were encoded with, for example.
As for a container format--I'm not sure. There's .avi obviously, but QuickTime 2.x if anything was more common back then. Also, RealVideo.

Another early codec was MPEG-1. I'm not sure why the proprietary codecs mentioned earlier seemed like they were more popular. Perhaps someone will have some insight.

QuickTime 3 used a heavier codec, Sorenson, that might actually be an ideal match for your system.

Should also mention cutting back your frame rate. Video for Windows came with an example video still remember saying it operated at "15 frames per second, half the rate of television."

And as mentioned, cut the resolution back drastically, maybe even to 320x240.

keenmaster486 wrote on 2021-07-19, 19:08:

Your system should be able to handle low res (400x300 ish) MPEG1 video software decoding, depending on the bitrate

Yes, I think the same. There's a Win95 version of Xing MPEG Player that supports MMX, I think.
Saw an article of it years ago in a PC magazine.
Unfortunately, I have little experience with it, because I sticked to the Windows 3.x version.
In the 90s, Win 3.1 was more the platform I had a soft spot for. 😄
Especially when it comes to early multimedie.
QuickTime, Video for Windows, Real-Player, Autodesk Animation Player..

Edit:

jakethompson1 wrote on 2021-07-19, 19:13:

Should also mention cutting back your frame rate. Video for Windows came with an example video still remember saying it operated at "15 frames per second, half the rate of television."

And as mentioned, cut the resolution back drastically, maybe even to 320x240.

MS Video 1 maybe ? I think many early shareware CDs had AVIs that used that.
Resolution was 160x120, maybe?
MS Video 1 aside, there also was RLE in Video for Windows 1.0, I guess.

Edit: There also was that Ultimotion codec from OS/2.
A Windows version of the codec exists.

Sample video : https://m.youtube.com/watch?v=H3BYvPDdRcQ

Search for umspec.zip and um4win.zip for more information. There also were a few sample videos, but i forgot where they are. 😅

Re: Early Video Codec Comparison with Samples

For my Pentium MMX 233 machine, I encode videos usually as Cinepak AVIs at either 512x384 or 640x480 (if it's widescreen content, then I render with the same width but lower height) and a framerate like 24 or 30fps with FFmpeg or a video editor like Sony Vegas. FFmpeg gives better quality for me, but the encoding time is much slower. The audio is encoded as PCM with varying sample rates, bit depth (8/16), etc. depending on the content. The videos play perfectly and look quite good, but you'll need a larger and fast enough hard drive to handle it. I also play them with Windows Media Player 6.4 since that supports hardware video scaling/decoding.

Thank you all for your insights.

Jo22, I've already tried PowerDVD and it runs too slow. I'm going to take a look at the Xing MPEG Player you mentioned.
I guide myself through a Pokemon music video that came with an audio CD I kept from back in the day which is 320x240 and encoded with Cinepak Video (cvid).

I'll even upload it here for you guys to check it out. The CD comes with quicktime version 3, just like jakethompson1 mentioned would be appropriate for the MMX.

Here's a link for the Pokemon music video (34.4mb):
https://www.dropbox.com/s/rbt04thqjf535vv/pokemon.mov?dl=0

Ok, so I tried Avidemux and inserted a DVD and selected one of it's .vob files and it crashed. I guess I need another program to convert the DVD first... any good open source suggestions?

Thank you thepirategamerboy12 for you input, I'll definitely take a look at FFmpeg and try the resolutions you mentioned.

Edit:
From what I understand, I need to make at least 2 "convertions" to get the DVD movie working on the retro pc:
1st- Use some software to convert the .vob files into a single good quality encoded .mkv for instance;
2nd-Use FFmpeg to encode this .mkv file into a cinepak video file of 640x480 for instance?
Edit2:
I'm going to try MKVToolNix to merge .vobs into a single .mkv file.

P200 MMX will be perfectly suitable for playing a majority of 650MB DivX videos from the era. Some of them were even playing fine on non-MMX P100.
Just don't play it on windows

if you had firewire and a dvd drive connected through that it would reduce cpu utilization. Since integrated IDE will use more cpu than a Firewire controller will.