You cannot use DX or SDL in DOS. You could just write to video ram directly in DOS. Don't need a library.

Thanks for your answer, could you please provide me any guide or code example?

Well, if you are writing a game, do you have some way to drawing to the screen? You can use what you got going already, but I don't know what that is.

On a vga card, the beginning address for the screen is a0000h. Now how to go about setting values in there about that depends on the mode you are using and what format you get the pixels out of ffmpeg.

There are various guides out there. A famous one is Michael Abrash's book:
https://www.jagregory.com/abrash-black-book/#part-ii

It might be easier to use an API already written, but most people writing games did it like how Michael did it by accessing the card directly.

I am using Allegro lib to draw objects to the screen, so I don't access low-level area at the moment.
But thanks though, I will check your line carefully

Noice. DOS community needs a good video player. We only have one "commercial" thing that's outdated, and a Linux port of some kind that is super not user friendly. 😁

There is a good DOS viewer/player called Quickview Pro, I guess. It supports alsmost everything. But not open source, unfortunately. So not very useful info for OP.

Bondi wrote on 2021-10-20, 09:33:

There is a good DOS viewer/player called Quickview Pro, I guess. It supports alsmost everything. But not open source, unfortunately. So not very useful info for OP.

That's why I need to develop my own video player.
There are also Mplayer, but its dos port isn't compiled, and entire source code is so huge to parse and reuse 🙁

could you use the allegro flic player stuff? https://www.allegro.cc/manual/4/api/flic-routines/

llm wrote on 2021-10-20, 12:59:

could you use the allegro flic player stuff? https://www.allegro.cc/manual/4/api/flic-routines/

FLI/FLC format is super old.
The video file format is mp4 and its duration is over 3 minutes, it sizes around 20 MB, resolution is 640x480.
When it is converted to FLC format, its size becomes over 2 GB! How can I use it?

The way I read it, llm wanted to imply that you could perhaps reuse the Allegro part of that player in combination with decoders from FFMPEG.
You would have to dive a little bit into Allegro's source code, though.

have you looked into the code for '8088 Domination' for video playing. 😁

I think that if you ask mplayer authors you may get a better answer as to what DJGPP version is supported. Perhaps some additional libraries are missing or some small tweaks are needed. Maybe you're the first one trying to compile it for DOS for many years.

Mplayer has no official support in upstream, it was ported to DOS by a quick and dirty way. Of course, it still can be compiled after some patching.
FFmpeg is a bit different story, at least configure & make should pass out of the box. But if someone wants to do a normal, non-crippled build with external libraries and assembly enabled, you'll have to fix your toolchain first.