King_Corduroy wrote:

Hey Emosun, interesting work! I eagerly await the results of this as I'd love to be able to play full length movies on my humble Packard corner PC. 😁

Oh btw what are you using to encode the videos? I'm a total noob to all this so I hope when you're done you release a tutorial! 🤣

Im using the multimedia m415 so it should translate well on the corner pc. I did watch an hour long lets play on it and it worked well!

For encoding im using premiere on mpeg and mov but for these other formats ill have to find an older solution.

Nice! You don't mean the ATX one do you? Or did you mod that one yet. 🤣

Nope the m415 is lpx. Its using the 233 mmx so if your corner has the same it should work. I also have one of the regular 166 machines from billy so I can see what those can max out at aswell

Ah my Corner has a 200MMX in it at the moment. What's the resolution settings and stuff you use? If I tried to render a video in Kdenlive what do you think I would have to set it up as to get it to spit out something useable?

King_Corduroy wrote:

Ah my Corner has a 200MMX in it at the moment. What's the resolution settings and stuff you use? If I tried to render a video in Kdenlive what do you think I would have to set it up as to get it to spit out something useable?

i'll make a video about it when i get back home on the 17th i'm not near the computer atm.

Cool beans! Looking forward to it. 😁

I've switched to using a k6-2 450 which seems to handle the higher bitrates better in video over the pentium 1 but I'll still experiment with other pentium 1's to see what they can all do.

Smackpy and SMK format were popular in late 486 and early Pentium times. Many DOS games used SMK for fulscreen videos. My 486 with slow Trident 9440 card played Witchhaven movies without problems.

I just gave the motion pixels player a try.

The issue is it can only play older avi format files which seem to work fine however the files sizes end up being very large. the player also doesn't scale the video to the size of the screen when viewing fullscreen videos.

it might have done better if it played it's native file type along with gpu support , however theres no way to format videos in it's native file type and also no way to get the player linked to the voodoo2

I just finished working on video formats for the 486 and thought I'd return to this thread and post my results

I was able to get solid playback on my 486 dx-40 8mb ram and no mpeg accelerator card. The videos are formatted as cinepak .mov files at 2000kbps at 320x240 using windows media player.

They look surprisingly good for a 40mhz cpu , Anime videos at their native 12.5 fps animation speed look especially good thanks to lower frame rates which results in higher picture quality. The only main issue right now is the cpu isn't quite powerful enough to play both video AND audio at those bitrates. I have to lower the bitrate to 1000kbps if I want it to play audio with the video too.

emosun wrote:

The only main issue right now is the cpu isn't quite powerful enough to play both video AND audio at those bitrates. I have to lower the bitrate to 1000kbps if I want it to play audio with the video too.

This could also have to do with the HDD controller used.
Early controllers on the original PCs and XTs made use of the DMA controller. This allowed them to perform disk transfers in the background. With ATBUS/IDE, things moved to polling loops on the CPU, so you no longer had background transfers.
Fancy controllers that implement their own DMA do exist, but mainly for SCSI or high-end caching IDE controllers perhaps.
Using such a controller may make audio/video playback a lot more efficient.

Here's an example of my original IBM PC/XT 5160 with its stock Seagate HDD and MFM controller streaming audio from the HDD over the PC speaker:
https://youtu.be/387mfVRLGBQ
You'll find that newer PCs with IDE controllers actually have more trouble doing this, because the HDD transfers will block the timer interrupt that outputs the samples to the PC speaker.

Floppies also support DMA. Here's a music player for Tandy/PCjr audio that uses a similar trick, running floppy transfers in the background:
https://youtu.be/ARE6Bzs7Aj4
(Sadly the floppy doesn't quite keep up at all times).

Well I'm not too worried about the drives speed at all as it's more of a cpu speed problem.

The audio for the video doesn't take up nearly as much space as the video itself. Trading video quality for audio playback always results in smaller files overall. the machine has no issues playing 100mb video files with no audio but will struggle with a 60mb video files that are the same length with audio.

The data is moving out of the ssd just fine it's now just a limit of how much the cpu can do. The pentium also has this issue too when working with high bitrate video and can't handle playing audio at the same time as high bitrate video.

The only difference is with the pentium I can monitor the cpu usage to confirm it's the cpu at fault , with the 486 it's of course not fast enough to display it's own cpu usage while playing video but it's very clear thats whats happening.

I think it's a good example of multitasking which the 486 isn't very good at unless the tasks are very light. It can play a terrible quality video with audio just fine , but not good quality video with audio.

emosun wrote:

Well I'm not too worried about the drives speed at all as it's more of a cpu speed problem.

I'm not sure if you understand what DMA is then.
The thing is that without DMA, the CPU has to poll the controller for every single byte it receives. While the CPU is doing that, it cannot do anything else.
With a DMA controller, the CPU only has to start the transfer on the controller. The controller uses DMA to copy the data to memory in the background, and signals the CPU when it is done. In the meantime the CPU can do other stuff. That is why you can play a sample on the PC speaker *and* load new sample data on my IBM 5160.

emosun wrote:

I think it's a good example of multitasking which the 486 isn't very good at unless the tasks are very light. It can play a terrible quality video with audio just fine , but not good quality video with audio.

Again, the rest of the hardware is also important for multitasking. If you see how well an Amiga can multitask with just a 7 MHz 68000 CPU... it's because all other chips can work with DMA alongside the CPU.
PCs have a very poor and inefficient design. The DMA controller on a PC is very weak anyway, and it only got worse when they stopped using DMA at all, and moved to CPU polling.
If your hardware can do things in the background, you get more mileage out of your CPU. A DMA-capable HDD controller could help, just as a video card with acceleration features.

One example I can think about is my Pentium 133. Originally I had an S3 Trio64 card, which allowed me to play VideoCD in 640x480 in 16-bit colour. I couldn't do higher resolutions though, because the CPU had to scale the video up, and this took too much bandwidth.
When I upgraded the Trio64 to a Matrox Mystique, I got hardware-accelerated scaling, so it now played in 1024x768 just as well as in 640x480 before. The scaling was basically 'free' on the CPU now.

Likewise, if you could use a better HDD controller, which saves you some CPU cycles, these cycles could be applied where it matters: the actual decoding of video and audio.

what you're describing makes me think it's not a question of raw cpu power; 1. video is harder to handle than audio 2. you just admitted yourself that throwing a 50% wider data stream at hardware works well (which might also mean its not a pure dma missing problem);

OK , I get what you're saying about dma.

I feel like I already said this but..... I have the ability to create and format any type of video at any bitrate and resolution and codec I want. I find the fastest most stable format the machine can handle , then proceed to ramp up the bitrate and resolution until the cpu cannot keep up any longer.

As far as this machine is concerned , it's maximum is 320x240 cinepak mov at 2000kbps 12.5 fps for animation. Or the same at 1000kbps at 24fps. Thats about it. It isn't going to get better. I'd be surprised if this machine could do better with no hardware changes.

Scali wrote:

A DMA-capable HDD controller could help, just as a video card with acceleration feature

Seems we agree , without changing or adding hardware the machine is maxed. and honestly , i like my method more. Means most 486 machines could playback these files without the need for better gpu's or drive controllers. I find it to be more impressive what this machine can do as is then if I just bought a bunch of hardware to offload everything. might as well just play the videos on a vcr sitting next to the machine.

you did not mention the audio format...? can it be throown at your hardware right after demuxing?
edit: and is the player capable of doing so?
edit2: found it - you're on adpcm? this might be the reaon - have you tried something else? where is this sound going from the player? is there some filtering done by the driver maybe?

emosun wrote:

Seems we agree , without changing or adding hardware the machine is maxed.

Yes, but earlier you said the '486' is maxed. Which I don't necessarily agree on.
As in, the CPU may be bottlenecked by some hardware, which it wouldn't in a different PC.
So it depends on what you're aiming for... a 'safe' format that most 486es would be able to play, or do you want to see how far a 486 could be taken best-case in video playback? If you fine-tune both the software and the hardware, you can do some pretty impressive things.

emosun wrote:

Means most 486 machines could playback these files without the need for better gpu's or drive controllers.

That is always the problem with this sort of thing: what do you take as your lowest common denominator?
Yes, if it works on your 486, then at least all 486es that are faster would be able to play it. But what about 486 machines that are slower?
That's always been the problem with PCs. There's so much hardware out there that it's impossible to test every configuration out there.

mrau wrote:

you did not mention the audio format...? can it be throown at your hardware right after demuxing?
edit: and is the player capable of doing so?

the audio format is IMA 4:1

if possible i would try to change this one - if i understand this well the decompression might be a heavy burden.

i remember playing a simpsons ep i find online on my nanas pentium 1 with 64mb ram it was a divx3 avi 320x240 190kbps audio mp3 48kbps it would lag in windows media player but when i changed some of the audio setting it would run fine even in full screen