What's the application? "DOjS framework" doesn't come up with any results. Is this for some sort of modern computers but running DOS, or are we talking 486 CPUs? What target CPU, RAM, and video card specs are you looking at?

What file format(s) specifically? Or just any? Are you playing everyone's videos [a utility], or just your own that you have control over?

I'm not aware of any Allegro 4 era video codec. Those were fairly rare before Windows. And you're not going to get, say, a 486 to decode HVEC. In fact, full speed videos were very rare in the DOS era. Mostly due to needing a CD to fit them. And they were heavily compressed, low bit depth, and interlaced. [ala Crusader No Remorse and C&C]. You didn't get remotely good video till approximately Starcraft with Windows 95. Some(?) CD drives had built-in MPEG decoders in hardware, and MMX for Pentium was specifically added because nobody could reliably do quality video in that era without them.

There's likely some pre-existing DOS compatible video codec source codes out there that could be ported to dump into an ALLEGRO_BITMAP structure, and then drawn so you can use a user interface and Allegro. Those would likely have far far more support/effort/bug-fixes put into them anything internal to Allegro 4.

[edit] Heck, google searches for "DOS video player" come up with almost nothing. The most popular result, Mpxplay can play the audio inside a video file, but not the video. Heck, I remember a 486DX4-100 could BARELY play an MP3, and that's if you set the audio quality to quarter at like 11 KHz!

Any video codecs that run are going to need to be integer based, as floats on pre-Pentium 1 CPUs were horrifically slow, and even then, they still had to come up with MMX to improve video playback after the Pentium 1.

I wonder what other games had DOS FMV videos. There were plenty of "CD FMV" games though. I wonder what codecs they used. Smacker seems like a Windows 95+ mode. Also note that pretty much ZERO FMV games ran with video at fullscreen resolution, or, had any game logic/content running during playback. The entire CPU was dedicated to surviving the one thing it was doing: rendering video.

1995 Warcraft 2 used smacker (supposedly), man it's pretty ugly, compressed, and low frame rate but it was beautiful for the era!

I remember MANY games had an option of half-resolution video too for slower CPUs.

Looks like Wing Commander III in December 1994 might have been one of the earliest.

Ooh baby look at that high compression banding! (And that might be the RE-RELEASE with higher res videos.)

The resolution was a whopping 320x165 at 15 FPS!

Triva: Why 320x165? Now 165 seems odd at first. It's not 200 (320x200 VGA), nor 240 (320x240 ModeX). It's not one half of 200 or 240 (for interlacing). It's 165, because it's letterboxed! [black bars above and below for fake 16:9 format]

APEG is an old lib by Kitty Cat that might play videos if you can find a mirror.

https://www.allegro.cc/forums/thread/580847

https://pmwiki.xaver.me/drdoswiki/index.php?n=Main.Video

https://www.codebus.net/d-5hDN.html

Once again, it depends on the application. Is this a serious work? Made for utilities and many formats? Maybe look into porting a much newer, supported work. If you just want "whatever is easiest" find an Allegro addon like this and hope it works