hpr-knowledge-base/hpr_transcripts/hpr2997.txt

Episode: 2997
Title: HPR2997: World of Commodore 2019 Episode 7: Video Playback with 1541 Ultimate
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr2997/hpr2997.mp3
Transcribed: 2025-10-24 14:37:57

---

This is Hacker Public Radio Episode 2997 for Tuesday 28 January 2020.
Today's show is entitled World of Commodore 2019 Episode 7, video playback with 1541 Ultimate
and is part of the series, Hobby Electronics. It is hosted by Paul Quirk
and is about 19 minutes long
and carries a clean flag. The summer is. In this seventh episode,
Greg returns to tell us how he got full video playback on a Commodore 64.
This episode of HPR is brought to you by An Honesthost.com
Get 15% discount on all shared hosting with the offer code HPR15
that's HPR15
Better web hosting that's Honest and Fair at An Honesthost.com
Hello, good listeners of Hacker Public Radio.
Paul here with my seventh installment of my World of Commodore mini series.
I hope the new year has been good to you so far and I really hope you're enjoying this series.
If you are, then please stop by my personal, non-commercial blog at pquirk.com and leave me a note.
While you're there, you can see pictures I took of this presentation as well as some of the others from this series.
In this episode, Greg returns with a second presentation where he explains
how he got full screen video with audio to play on a Commodore 64,
which is a pretty impressive feat considering the limitations of this computer from 38 years ago.
I credit the open nature of the Commodore 64, which allowed it to surpass many of its contemporaries back in the day.
It really was a great machine for hackers both then and today.
Unlike the previous six episodes, I had to edit out the demonstration portions of this podcast
as Greg made use of commercial videos he had converted.
While this video itself is pretty grainy, the audio streams through crystal clear
and may present a copyright problem for hacker public radio, so I felt it best just to leave that part out.
It is possible that the Toronto Pet Users Group YouTube channel may decide to leave this part in,
but as of the date of this podcast, they have not yet uploaded anything to their channel from World of Commodore 2019.
Of course, your best bet is to just attend the World of Commodore yourself to enjoy the whole experience
if it returns for the year 2020.
But if you're really interested in hearing the portion that's been edited out for HPR,
send me an email and I'll see what I can do.
And so, with no further ado, I present to you video playback with 1541 Ultimate.
So, my second talk is video playback with the 1541 Ultimate 2.
Okay, so ever since I was a kid, I have wanted to have motion video on my Commodore 64.
The first video that I ever saw was on a 46, running Windows 3.1,
and it was this 3-second clip that was like the size of a poster stamp with no audio,
and it was actually a clip of the Enterprise from Next Generation jumping to warp.
I was amazed.
But I wanted it on my Commodore 64.
So, 64 graphics modes.
The C64 has two native bitmap graphic modes.
It's got high-res multi-color.
So, in these modes, bitmap data and color data are stored in different parts of the memory.
So, for either mode, a full-screen bitmap is 8,000 bytes, so just under 8K.
If you're in high-res mode, you have 1,000 bytes of color data.
And if you're in multi-color, it needs 2001 bytes of color.
And the one byte, by the way, is the background color for the whole screen.
So, that would mean that the smallest native frame size, if you put it in high-res mode,
and you said, well, let's just make it black and white and maybe divor it in order to get some tones.
You could just make the color data static, and you'd end up with only bitmap data.
So, the minimum frame size is around 8K.
So, several challenges.
Memory size.
C64 only has 64K RAM.
So, if we divide how many frames can we fit, it's a maximum of 8 frames.
But, of course, in practice, you need your code, you need IO space, so it's like 6 frames.
Very much video.
Okay, so what approach is, well, you know, we could stream the frames from disk.
We just stream into memory, and, well, the second problem is, discload speed.
I mean, the IEC bus, even with jiffy-doss, according to the jiffy-doss manual,
it's only 6K per second.
So, you know, do some division.
It's less than 1 frame per second.
Still don't have any audio.
And also, the harder you try and read the faster you try and read data from the bus,
it just completely taps the CPU.
Okay, so what about compression, right?
That's the obvious move, which is compressed the frames.
And the problem with compression is that decompression requires the CPU,
and that takes time away from load speed.
So, you know, if you did some really clever work, you know, well, maybe you could get two frames per second.
But, you're not going to get many frames per second.
So, you know, video just needs more memory, and it needs more CPU horsepower.
So, you know, sad face, you know, is my C64?
Is it hopeless to get a video on my C64 support?
Super CPU.
Creative micro designs released the Super CPU in the mid to late 1990s.
It's an accelerator with 20 megahertz, and it has a 16-bit mode, and it has up to 16 megs of ground.
You know, it's like, okay, now we're talking, right?
This is the thing.
Okay, so, I demoed a video player for the Wings operating system in Chicago on Commodore Expo in the early 2000s.
So, Wings was a Unix-like multitasking OS, which was written for the Super CPU.
It was written by Joel's McGinnis from Australia.
And it had the beginnings of a high-res GUI, and it also came with a JPEG renderer
that would convert JPEGs to four-color, dithered, high-res images.
And I started thinking, wow, you know, if I could export JPEG frames,
I could write tools to convert JPEG frames into pre-converted frames of a video on the C64.
You know, then I could pack them together with a raw PCM audio and only crap.
You know, that might actually work.
And it did work.
And it was very impressive.
But, you know, full-motion video with synchronized digital audio.
So, let me tell you how I created those videos for Wings.
I used QuickTime on a Mac and exported a set of frames as JPEGs.
So, let's say it's 1,000 frames.
And as JPEGs, there may be, you know, 2K each.
So, then, yeah, that's, you know, 2MX of data, right?
But in those days, it was actually kind of a pain to transfer data from a Mac to a C64.
And so, believe it or not, the most convenient way was to zip them up and transfer them over a modem to an ID64.
Now, I don't know if you remember what a 56K modem was like, but this is not a fast process.
This is also not a fast process.
Then, I had to unzip the multi-megabyte file on a Commodore 64.
Then, I had to decode and convert 1,000 or more JPEGs on a C64.
This took hours to finish, even at 20 MHz.
So, I'll file a video with Maxo at around 15 megabytes,
because the operating system needed about a meg.
And you'd get about two minutes of playback.
But it worked.
Okay, so playing back.
So, how was a Wings video playback?
I'm saying all this for context, okay?
So, you needed to, I would load from an ID64,
which is probably still to date the fastest native mass storage device on the 64.
Loaded in a super-round.
That took over a minute.
Once that was done, you had two areas of memory.
You had an area for audio, and you had an area of unpacked video frames.
So, audio playback.
The audio playback was done with a device called the Digimax,
which is a little plugs into the user port.
It's an 8-bit stereo DAC.
It was made by a friend, Vanessa Dandenberg.
And it's still actually commercially available.
A couple of lots of go from Sherwer Plus.
Okay, so there's something about the way that the brain works,
that if video stutters a little bit,
it's actually not really not annoying.
But if audio stutters, it's very annoying.
Now, I think this is actually for some sort of evolutionary reason.
Every time you blink, your vision gets disrupted.
Every time you look around it,
it's kind of used to your visuals getting disrupted,
but there's kind of a continuity to audio that we're used to.
So, for that reason, the progress of the audio drove the video frames.
So, wings was multi-threaded.
So, basically, I had one thread that was just dedicated to copying audio data consistently.
And then, ahead of time, it would calculate,
well, how many bytes of audio are there going to be per frame?
And after that many bytes of audio,
it would send a message to the other thread to tell it to push another frame.
So then, the other thread would copy the frame into a wings GUI view buffer.
And the OS would composite the buffers together onto the screen.
The SuperCPU was so fast that it could play three videos simultaneously
in overlapping windows.
It's very cool.
Okay, but the sad reality, right?
Sad reality.
So, the first problem is, of course, creating these videos is very hard work.
Like, I only made maybe four or five samples,
and I only know one other guy who climbed the mountain
and made a wings video.
It was like a clip of himself at some Euro double party drink in a beer.
Okay, the second problem.
SuperCPU is no longer available.
But not only that, many C64 die hearts kind of rejected the SuperCPU.
It's like, well, okay, you did it with the SuperCPU,
but it's not really a C64.
So, more problems.
You needed a lot of hardware.
You needed SuperCPU for playback,
but you also needed SuperRAM to be the memory storage.
And these are actually separate products.
You can want EVA.
You can spend a huge amount of money to get a SuperCPU,
a rare SuperCPU, and it might not even have SuperRAM.
And so, the SuperRAM is actually a separate product that was sold.
You needed the Digimax for half-decent audio,
and you needed an IDE 64 for reasonable load times.
Even with the IDE 64, though,
load time is almost as long as playback time.
So, the sad reality is,
very few people will ever see the Wings videos playing
on their very own C64.
Ah, no SuperCPU.
So, that means we're back to square one, right?
We've got, you know, we have all of our memory limitations, et cetera.
But there's a new piece of hardware in town.
Now, there's a 1541 Ultimate 2,
and I should say that whatever the 1541 Ultimate 2 can do,
can also be done with the Ultimate 64.
So, what is the 1541 Ultimate 2?
If you don't know, I wrote an epic review
of all sorts of stuff that it can do,
and you can find that on c64wise.com if you're interested.
But in a nutshell,
it is kind of a fat cartridge that plugs into the user port.
It is configurable as a standard RAU,
and it's configurable up to 16 megs of memory.
Let's see where this is going.
It also has access to USB-based storage devices.
Plus, it has something very interesting,
called the ultimate audio module.
A festival is commercially available today.
So, you know, when I show stuff like this,
it's encouragement for people.
The first thing I could do,
if I went up 1541 Ultimate 2.
So, once again,
when I got my 1541 Ultimate 2,
and I started reading about all the stuff I could do,
of course, I thought,
I can do a lot of video on my 64 game.
But this time,
the tools available on a Mac or PC are much better.
So, creating an ultimate video.
Here's what you do.
Create an ultimate video.
You find a video on YouTube that is under two minutes and 30 seconds.
Okay, we still do have some memory limitations.
My personal preference is Mootrellers,
because they're kind of punchy and they're like a little story.
You copy the URL of the video,
and you paste it into a PHP script.
At least this is what I do to make these videos.
And it's done.
The video is a video file,
totally transcoded and ready for the C64,
is ready and less than five minutes.
So, how does it do that?
Script uses several tools.
It uses YouTube DL to download the file from YouTube to a local file.
It uses FFNPIG to extract the audio to Rop ECM.
It uses FFNPIG again to extract a series of PNG images.
Frame rate is configurable from 6, 8, 10, 12, 15,
or 20 frames per second.
I usually use 10 frames.
If you want to get a little longer playback,
you can lower the frame rate.
And if the video itself is just shorter,
like it's only one minute clip,
you can raise the frame rate to get smoother playback.
Formatting options are dithered high-res black and white,
which I kind of had a demo of this running last year.
And now there's also dithered multi-color,
thanks to the C64 graphics library by Passe Albert O'Halla.
I think his name is Framist.
So, the result of the video file is,
it's similar in format to the wings movie file format.
It's basically packed, pre-converted frames
with a Rop ECM audio segment and a header.
And it's ready to transfer to your 64.
So, old drawbacks overcome.
You can create a video now in minutes, not hours.
And you can transfer them to your C64 in seconds,
because you just take the USB key out,
stick it in the side of the 54-tonult,
plus 64, right?
You don't have to transfer it over 56-tonult.
Okay, this is big.
You can load the video into the RAU in under five seconds.
Now, how's that possible?
So, the SuperCPU is an accelerator,
but it's not a storage device,
so you have to have your storage device,
and then you need a C64 program to read the data
off the storage device, read it through the CPU,
and put it into SuperRAM.
But the 1541 ultimate is a storage device,
and it's an ultimate audio module,
and it's an RAU, and it's all rolled into one device.
So, you can use the C64 to send a message to the 1541
and tell it, take this file,
and load it into the RAU.
And it will load it into the RAU in the back end very quickly.
Digital audio.
So, let's talk digital audio for just a moment.
Pushing digital audio on a stock C64
is actually very CPU-intensive.
So, let's say that the quality of audio
is something reasonably low,
like 11 kill hertz, 8 bit auto.
That's 11,025 bytes per second.
So, now let's say it takes maybe an average
of, say, 18 cycles per sample.
That's 18 times 11,025 samples per second.
That's darn near 200,000 cycles per second.
But on a one-megahertz machine,
that's like 20 percent of the CPU
just to push raw audio data out the Digimax on user board.
You can imagine that if you were to increase that sample rate
to, say, 22 kill hertz, 8 bit stereo,
all of a sudden it would take 80 percent of the CPU
just to push the audio.
Okay, the ultimate audio module.
The ultimate audio module is something you can enable
on the 1541, and it activates a small range of IO addresses.
And what it does is it plays audio samples
directly out of the RAU memory.
So, it has audio hardware with audio jack
and it just plays the samples out of the RAU.
So, the C64 specifies to it sample rate
and the bit rate and how many channels of audio there are
and where the sample starts and how fast to play it,
and what more even so on, and it plays it.
And while it's playing it,
it uses 0 percent of the C64 CPU.
So, in a nutshell, here's how the video player works.
The C64 commands, the ultimate dust,
load a file into the RAU, and it does that.
The C64 commands, the ultimate audio module,
to start playing the audio.
Then the Victus Rastriar Q is used for the simple counter
to divide the frame rate of the 64 down to the frame rate of the video.
And every time that a frame needs to be updated,
the C64 commands the RAU to copy the next frame's data
into main memory for the Victor render.
And then go.
You've got a full motion within the limit of the frame rate
that I specified, with synchronized digital audio on your C64.
So, we've got all these six minutes or so for a demo.
So, let's do that.
I hope you enjoyed Greg's second presentation.
It really goes to show that, all these years later,
there are still new things to do with a Commodore 64.
Well, that's it for presentations of World of Commodore,
and there is only one episode left.
That being the vote of thanks, as the members of T-Pug talk
about this being their 40th anniversary,
and also give out cake, which I cut.
If you enjoy my podcast and would like to hear more from me,
send me an email, or leave me a message at my personal blog.
You can also get in touch with me in the Fediverse at
paulatcloud.peakwork.com.
Until next time, drive safe and make sure to have fun.
You've been listening to Hecopublic Radio at HecopublicRadio.org.
We are a community podcast network that releases shows every weekday
Monday through Friday.
Today's show, like all our shows,
was contributed by an HBR listener like yourself.
If you ever thought of recording a podcast,
then click on our contributing to find out how easy it really is.
Hecopublic Radio was founded by the digital dog pound
and the Infonomicon Computer Club,
and is part of the binary revolution at binrev.com.
If you have comments on today's show,
please email the host directly,
leave a comment on the website,
or record a follow-up episode yourself.
Unless otherwise status,
today's show is released under creative comments,
attribution, share a life, 3.0 license.