4 ms·

The author gives some technical information in this Reddit thread: https://www.reddit.com/r/apple2/comments/mbrh2f/playing_video_on_an_apple_e/ https://www.redd

The author gives some technical information in this Reddit thread: https://www.reddit.com/r/apple2/comments/mbrh2f/playing_video_on_an_apple_e/ https://www.reddit.com/r/apple2/comments/mbrh2f/playing_vide...

ddingus 6y ago
He's running code out of the region of memory that the CF card dumps the data from the disc to! Basically it's an entire 90 kilobyte program that draws the animation! Edit: 90 Megabyte! Something like this could have been possible back in the day, given a DMA capable i/o transfer device. LDA #PIXELS STA #SCREEN . . .
- apricot 6y ago
  The transcoder that he wrote to convert the source video to a 90 MB 6502 program that draws the animation is pretty nifty too: there's no time to update the whole screen between frames, so he diffs them and updates as many pixels as he can, starting with the ones that are most noticeable according to a perceptual distance metric. Details in this talk from two years ago: https://www.youtube.com/watch?v=wM3deQAgMpE https://www.youtube.com/watch?v=wM3deQAgMpE
  - ddingus 6y ago
    Thanks for linking his other talk. The result is pretty great. I will enjoy the details.
- rangibaby 6y ago
  It’s interesting to me that someone smart enough could have thought of this in 1981, but considered it impossible because 90MB was an absurdly large amount of data
  - ddingus 6y ago
    And from what source material?
    - Tabular-Iceberg 6y ago
      Film and video certainly did exist in the 1980s.
      - danparsonson 6y ago
        But could anybody digitise it?
        ddingus 6y ago
        This! Mechner pioneered doing that from VHS when doing his game Prince of Persia. Something like Bad Apple would be a heavy lift.
        retrac 6y ago
        There are experiments with full motion digital video dating back to the 1970s. While computers certainly weren't fast enough to stream video data to or from memory (and you'd fill a supercomputer's entire RAM with 2 seconds of uncompressed video), video could be DAC'd in real time while streaming off digital tape, and vice versa. And such tape data could be read in, processed and written out by a computer (slowly...) Still, while technically possible to do this sort of video compression in 1981, it would have involved extremely specialized hardware to scan the film in the first place, and a good amount of compute time on a real big machine like the Cray-1 to do the compression. (And Rick Astley wasn't a star yet, so what would have been the point?) Fun fact though: just two years later, Cyndi Lauper's iconic music video was edited in digital form, including the insertion of computer-processed video effects: https://youtu.be/PIb6AZdTr-A?t=90 https://youtu.be/PIb6AZdTr-A?t=90 While such things as picture-in-picture are so common today we don't even notice it unless pointed out, that was mind-blowing at the time. But it took hardware worth a million dollars due to the megabytes of RAM required to fit the 10 second clips they worked with.
  - ehaliewicz2 6y ago
    Compiling bitmap sprites into code like this was pretty common actually.
JKCalhoun 6y ago
Would there have been a 95MB disk drive available for the AppleII in those days? (And at what cost?) Amazing though.
- tambourine_man 6y ago
  It was about a megabyte per cassette tape, depending on the encoding, right (counting both sides)? Doable, with lots of tape swapping, I guess :) Though probably a shorter version would be nicer [edit] Forget that, from the Reddit link: “We end up reading data at about 533KB/sec, and are I/O bound.”
  - apricot 6y ago
    A custom-made cassette reading peripheral card in every slot, and eight cassette players running in parallel at high speed?
    - tambourine_man 6y ago
      I like how you think :)
    - ddingus 6y ago
      Lol, this should be done. Dealing with sync issues would be top of the list. Maybe stagger them, so they can be stopped every so often. Reach key data, kill motor, wait, start motor? Or maybe just toggle the motor line quick? Just enough to slow it a little! All kinds of insanity possible. Stereo tapes could possibly deliver 2400 baud x 2. Eight 4,800 baud tapes * 2 minutes 'ish I am coming up with 0.5 to 1MB range numbers :( But I really like this craziness!
- setpatchaddress 6y ago
  Not a chance, no. Here's something from 1985: https://www.atarimagazines.com/creative/v11n8/36_The_Sider_10Mb_of_mass_s.php https://www.atarimagazines.com/creative/v11n8/36_The_Sider_1... > Five years ago I drooled over the new 5Mb Winchester hard disk drives being introduced to the Apple II market. Although I knew how useful a hard disk could be, I also knew that I would never be able to justify the purchase of a $3000 mass storage device for a $2000 computer. I also knew that I would never be able to fill 5Mb of disk space. > How times have changed. Today, a full fledged Apple IIc or IIe costs a little over $1000. And a 10Mb hard disk drive costs only $695. That's right. First Class Peripherals offers the Sider, a hard disk drive with 10Mb partitionable among four operating systems for $695.

ddingus 6y ago

He's running code out of the region of memory that the CF card dumps the data from the disc to! Basically it's an entire 90 kilobyte program that draws the animation! Edit: 90 Megabyte! Something like this could have been possible back in the day, given a DMA capable i/o transfer device. LDA #PIXELS STA #SCREEN . . .

apricot 6y ago
The transcoder that he wrote to convert the source video to a 90 MB 6502 program that draws the animation is pretty nifty too: there's no time to update the whole screen between frames, so he diffs them and updates as many pixels as he can, starting with the ones that are most noticeable according to a perceptual distance metric. Details in this talk from two years ago: https://www.youtube.com/watch?v=wM3deQAgMpE https://www.youtube.com/watch?v=wM3deQAgMpE
- ddingus 6y ago
  Thanks for linking his other talk. The result is pretty great. I will enjoy the details.
rangibaby 6y ago
It’s interesting to me that someone smart enough could have thought of this in 1981, but considered it impossible because 90MB was an absurdly large amount of data
- ddingus 6y ago
  And from what source material?
  - Tabular-Iceberg 6y ago
    Film and video certainly did exist in the 1980s.
    - danparsonson 6y ago
      But could anybody digitise it?
      - ddingus 6y ago
        This! Mechner pioneered doing that from VHS when doing his game Prince of Persia. Something like Bad Apple would be a heavy lift.
      - retrac 6y ago
        There are experiments with full motion digital video dating back to the 1970s. While computers certainly weren't fast enough to stream video data to or from memory (and you'd fill a supercomputer's entire RAM with 2 seconds of uncompressed video), video could be DAC'd in real time while streaming off digital tape, and vice versa. And such tape data could be read in, processed and written out by a computer (slowly...) Still, while technically possible to do this sort of video compression in 1981, it would have involved extremely specialized hardware to scan the film in the first place, and a good amount of compute time on a real big machine like the Cray-1 to do the compression. (And Rick Astley wasn't a star yet, so what would have been the point?) Fun fact though: just two years later, Cyndi Lauper's iconic music video was edited in digital form, including the insertion of computer-processed video effects: https://youtu.be/PIb6AZdTr-A?t=90 https://youtu.be/PIb6AZdTr-A?t=90 While such things as picture-in-picture are so common today we don't even notice it unless pointed out, that was mind-blowing at the time. But it took hardware worth a million dollars due to the megabytes of RAM required to fit the 10 second clips they worked with.
- ehaliewicz2 6y ago
  Compiling bitmap sprites into code like this was pretty common actually.

JKCalhoun 6y ago

Would there have been a 95MB disk drive available for the AppleII in those days? (And at what cost?) Amazing though.

tambourine_man 6y ago
It was about a megabyte per cassette tape, depending on the encoding, right (counting both sides)? Doable, with lots of tape swapping, I guess :) Though probably a shorter version would be nicer [edit] Forget that, from the Reddit link: “We end up reading data at about 533KB/sec, and are I/O bound.”
- apricot 6y ago
  A custom-made cassette reading peripheral card in every slot, and eight cassette players running in parallel at high speed?
  - tambourine_man 6y ago
    I like how you think :)
  - ddingus 6y ago
    Lol, this should be done. Dealing with sync issues would be top of the list. Maybe stagger them, so they can be stopped every so often. Reach key data, kill motor, wait, start motor? Or maybe just toggle the motor line quick? Just enough to slow it a little! All kinds of insanity possible. Stereo tapes could possibly deliver 2400 baud x 2. Eight 4,800 baud tapes * 2 minutes 'ish I am coming up with 0.5 to 1MB range numbers :( But I really like this craziness!
setpatchaddress 6y ago
Not a chance, no. Here's something from 1985: https://www.atarimagazines.com/creative/v11n8/36_The_Sider_10Mb_of_mass_s.php https://www.atarimagazines.com/creative/v11n8/36_The_Sider_1... > Five years ago I drooled over the new 5Mb Winchester hard disk drives being introduced to the Apple II market. Although I knew how useful a hard disk could be, I also knew that I would never be able to justify the purchase of a $3000 mass storage device for a $2000 computer. I also knew that I would never be able to fill 5Mb of disk space. > How times have changed. Today, a full fledged Apple IIc or IIe costs a little over $1000. And a 10Mb hard disk drive costs only $695. That's right. First Class Peripherals offers the Sider, a hard disk drive with 10Mb partitionable among four operating systems for $695.