I think there are other video players for Windows 98 that have built-in support for MP4, without needing to install any additional codecs. I don't remember what they're called, but they're easy to find.

VLC is a great video player, older models had support for Win98...

T-Squared wrote on 2020-05-06, 03:44:

In Windows 98SE, I was previously able to view MP4 files on Windows Media Player 9 (AND Windows Media Player Classic!) with the K-Lite Codec Pack, but now WMP doesn't seem to understand or recognize the MP4 codec, even though it's been installed!

It does play the audio track just fine, though.

MP4 is not a codec, but a container format, as it plays the audio the program is opening the file just fine... what is the actual video codec used?

imi wrote on 2020-05-06, 16:20:

T-Squared wrote on 2020-05-06, 03:44:

In Windows 98SE, I was previously able to view MP4 files on Windows Media Player 9 (AND Windows Media Player Classic!) with the K-Lite Codec Pack, but now WMP doesn't seem to understand or recognize the MP4 codec, even though it's been installed!

It does play the audio track just fine, though.

MP4 is not a codec, but a container format, as it plays the audio the program is opening the file just fine... what is the actual video codec used?

And more: Even if the video codec is MPEG4 aka h.264 - which profile is being used? It might very well be that your old player only supports the base profile, and you are trying to play a higher profile stream with it.

VLC tells me that the video codec is "AVC1", while the audio codec is "MPGA" (WMP said it was MP2/MPEG-Layer II).

Windows Media Player Classic from the K-Lite Codec Pack says it's H.264.

What's confusing me is that I swear I was able to get these MP4 codecs running before, without trouble. I've read these codecs are only for Windows 2000 and XP, but again, somehow it worked on my system.(I was able to watch a stereoscopic 3D video from Youtube, that I re-composed and converted into line-sequential format, then rendered in Photoshop CS4...)

Does it matter which video card one uses in their system?

I seemed to have more luck getting it working with an ATI Rage Pro Chip (in the from of the All-in-Wonder, which seems to use DirectX more tightly) than the one I currently use (An ExpertColor S3 Virge, which was made before Direct X became popular).

you could try this:
MP4 Can Be Played on Windows 95/98/ME!

Maybe it is the video card. Right now I'm using a 2MB s3 Virge video card, but TCPMP says that the buffer size is too small, and it still won't render the video to the screen.

Maybe the largest that MP4 can handle is 4MB of memory?

I think we can finally put this question to rest.

It DOES depend on one of the following, although I can't pinpoint it:
*The video card and/or drivers
*The memory buffer size
*System Acceleration

I tested it on my nVidia geForce 5500, and I get the same error I normally did with the Virge, but somehow, it played normally. (But only on one screen, which isn't a problem.)

T-Squared wrote on 2020-05-13, 21:32:

I think we can finally put this question to rest. […]
Show full quote

I think we can finally put this question to rest.

It DOES depend on one of the following, although I can't pinpoint it:
*The video card and/or drivers
*The memory buffer size
*System Acceleration

I tested it on my nVidia geForce 5500, and I get the same error I normally did with the Virge, but somehow, it played normally. (But only on one screen, which isn't a problem.)

Sounds like it's related to the resolution of the file/maximum size of the YUV overlay that the card supports.

jmarsh wrote on 2020-05-14, 03:03:

Sounds like it's related to the resolution of the file/maximum size of the YUV overlay that the card supports.

You mean the resolution/YUV Overlay size that the Virge supports.

It played AVI files just fine, though.

I wonder if MPEG2 decoding is close enough to MPEG4...

(The VIRGE only has MPEG1)