R43 video demo

All aspects of programming on the Commander X16.
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Ed Minchau
Posts: 508
Joined: Sat Jul 11, 2020 3:30 pm

R43 video demo

Post by Ed Minchau »

This video is at 10 frames per second, 160 by 40 pixels. VSCALE of $20 and HSCALE of $13 stretches this image to an aspect ratio of about 2.35 to 1, the widescreen aspect ratio. The audio is 16 bit mono at 12970 Hz, so the PCM audio rate is $22. The audio and video data are interleaved in the BENH.DAT file; 1/10th of a second (2594 bytes) of audio followed by one video frame (6400 bytes), over and over. The AFLOW interrupt triggers the pushing of 2594 bytes of audio from VRAM to the PCM audio data line, followed by the next audio sample load to VRAM, then the next frame of video, and then the switch from the old frame to the new frame (just by changing the layer 0 tilemap location). There is a single palette for the whole video, which was created for the Wolfenstein 3D artwork for another project, and which I'm starting to think of as a "magic palette".
BENH.zip
(14.19 MiB) Downloaded 448 times
just LOAD"BENHUR.PRG",8 and RUN

Try It Now!
hmm. for some reason the Try It Now link isn't working. Did any of you who downloaded get this to work?
Last edited by Ed Minchau on Tue Jul 18, 2023 3:58 pm, edited 1 time in total.
badmai
Posts: 43
Joined: Tue May 16, 2023 2:32 am

Re: R43 video demo

Post by badmai »

Very cool, worked for me. (not the try it now)

I've been working on video playback too, still trying to find to bandwidth limits...so mine is not as good, only 80 x 60 15fps
to stay on topic, I did a Ben Hur clip :)

my converter shows this:
Video Size: 11467200
Total Frames: 2389
Bytes per Frame: 4800
Audio Size: 1946870
Bytes per Frame: 814
Attachments
ben.zip
(4.86 MiB) Downloaded 343 times
kelli217
Posts: 541
Joined: Sun Jul 05, 2020 11:27 pm

Re: R43 video demo

Post by kelli217 »

It's pretty good. Seems to not always quite be fast enough at loading the data? Occasional corrupted frames and accompanying static noises. Example image attached.
BenHur-corruptedframe.png
BenHur-corruptedframe.png (16.68 KiB) Viewed 5815 times
Ed Minchau
Posts: 508
Joined: Sat Jul 11, 2020 3:30 pm

Re: R43 video demo

Post by Ed Minchau »

Yeah, this is pretty much running the X16 at maximum, so if you've got any other programs open the emulator might not keep up. I noticed the same thing when opening Opera while the video clip was running. Or, I might be pushing just a little too much data through the pipe and could need to reduce the vertical resolution a bit. I'm interested to hear from people who have the actual machine if it works for them.
Ed Minchau
Posts: 508
Joined: Sat Jul 11, 2020 3:30 pm

Re: R43 video demo

Post by Ed Minchau »

badmai wrote: Tue Jul 18, 2023 3:26 pm Very cool, worked for me. (not the try it now)

I've been working on video playback too, still trying to find to bandwidth limits...so mine is not as good, only 80 x 60 15fps
to stay on topic, I did a Ben Hur clip :)

my converter shows this:
Video Size: 11467200
Total Frames: 2389
Bytes per Frame: 4800
Audio Size: 1946870
Bytes per Frame: 814
That worked pretty well, but remember to use all capital letters in your filenames. Also, you don't need all 60 rows; it looks like about 13 rows at the top and bottom are black, so you could keep it that way and only have about 34 rows of data, reducing the number of bytes per frame to around 2720. That could get you 20 or maybe even 30 frames per second.
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ahenry3068
Posts: 1194
Joined: Tue Apr 04, 2023 9:57 pm

Re: R43 video demo

Post by ahenry3068 »

I have a challenge for you. (Though it could run afoul of Copyright Law)....

Do this same project for "THRILLER"
Ed Minchau
Posts: 508
Joined: Sat Jul 11, 2020 3:30 pm

Re: R43 video demo

Post by Ed Minchau »

All of these run afoul of copyright law. If I post the results to YouTube it gets flagged, probably because of the audio. I really only do these video demos to explore the limits of VERA.

I'm thinking that there's a way to get better results, or at least a higher frame rate, by using the double PETSCII technique, perhaps with a custom character set.
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ahenry3068
Posts: 1194
Joined: Tue Apr 04, 2023 9:57 pm

Re: R43 video demo

Post by ahenry3068 »

Im in research Mode

The reserch is to just show FLI
s
On x16
kelli217
Posts: 541
Joined: Sun Jul 05, 2020 11:27 pm

Re: R43 video demo

Post by kelli217 »

Ed Minchau wrote: Wed Jul 26, 2023 10:29 pm All of these run afoul of copyright law. If I post the results to YouTube it gets flagged, probably because of the audio. I really only do these video demos to explore the limits of VERA.

I'm thinking that there's a way to get better results, or at least a higher frame rate, by using the double PETSCII technique, perhaps with a custom character set.
That would be great if you can get it to work.
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