Video on Spectrum

> DM>> And one more thing. I had one wild idea here, but I still didn’t dare to share it with the wider world. What if you convert frames from some movie
> DM>> (at 15 FPS - you can already watch), record a sound track on
> DM>> cassette, synchronize, and bam - it’s no longer Spectrum, but video. Fortunately
> DM>> there are films up to...., and the ability to shoot in any resolution. True
> DM>> there will be disks....
>
> IG> Or do it like in Powerup. Well, it looks quite cool. And the music plays.
> IG> I wonder how many of these 'videos' will fit on a floppy disk?
>
>If you connect a CD or a screw, then .... Well, you can do it on a bunch of floppy disks (this depends on
>opportunities and desires :). By the way, how many terribly packed pictures will fit on a disk (there is no need to output music), in 16x14 spaces, with the same attributes? (Well, to be able to show at least 15 frames per second, taking into account reading from the disk - or is this completely unrealistic?).
>
> IG> Like a short cartoon. ;)
>
>It's like packing...
>
> IG> By the way, the issue of video discs was raised here a long time ago. Slava
> IG> Mednonogov already once painted a b/w (pixel-by-pixel) video image.
> IG> It seems like the reasoning ended with what the theory givesopportunity
> IG> to do (not a full screen, IMHO) but no one needs it - there is too much work
> IG>.
>
>If people need it (at least 50-100 people), and there is a person ready to write a
>converter and viewer (on the Spectrum) - then I can take on this noble
>mission ;) Fortunately, there is an opportunity. And if things go well, then we can
>put everything on the assembly line: for example, “fifth element 2” (or something else
>comes out), and we’ll immediately speck it.
>
>P.S. In general, if anyone is interested in this topic, do not hesitate to write;)
>With respect, GodFather.
Turn on the CD-drive first! and then fantasize.
The z80 won’t be able to handle 7MHz without a video camera for nothing!
The Sprinter is another matter, but IMHO it won’t be able to handle it either. In addition, the DVD format
old cddrives will not be able to read, and the new ones will cost about another
one Sprinter.
If I’m wrong, let everyone correct me together! ;)

Sincerely, Andrey Savichev/CGS

AS> Turn on the CD-drive first! and then fantasize.

And this is no longer our business!) (By the way, 74 minutes of full-screen
video, unpacked, of course, will fit on a CD. And if you also record sound...)

AS> It won’t handle 7MHz z80 without a video camera for nothing!

This is how to do it. Here the person was considered. The main problem is disk
space. Therefore, in order to fit at least 2 minutes onto a disk, you need a resolution of 8x8 acquaintances, 10 frames per second. It will look worse than we would like - but better than it seems :) Well, the second way is video support. You need to
connect a CD, a sound card, your memory to it....

AS> The Sprinter is another matter, but IMHO it can’t handle it either.

They also thought.... Even without sound, maaaaaaaaaaaaaaaaaaaaaaaaaaaaaally - 15 fps for 32 colors :(

AS> Sincerely, Andrey Savichev/CGS

Sincerely, GodFather.

At 21MHz it’s definitely not possible.

AS> Besides, old cddrives won’t be able to read the DVD format, and new ones will
AS> cost about one more Sprinter.

About 5 more Sprinters.

AS> If I’m wrong, let everyone correct me together! ;)

Yeah.
But the MPEG-2 hardware decoder costs like a sprinter. And the harness for it is still
half a sprinter. But you can do it to watch TV.

With respect, Tim. [Team Aries - Rulez Forever]

DM> This is how to do it. Here the person was considered. The main problem is
DM> disk space. Therefore, in order to fit at least 2 minutes on disk,
DM> you need to make the resolution 8x8 familiar, 10 frames per second. It will look worse
DM> than we would like, but better than it seems :) Well, the second
DM> way is video support. You need to connect a CD, a sound
DM> card, your memory to it....

That is, build another computer (much more powerful than the Spectrum, by the way).

AS> And where ^^^^^^^^^^^^^^^^^^^ this is output on the Spectrum?

Connecting SB :) works via DMA.

AS> Regular mono on beeper 12 kHz 8 bits (PWM) (upper band 4-6 kHz,
AS> 45 moron, approximately dynamic range - in general voices You can hear it, but
AS> high music music is not always there, especially with 2-3 re-recordings)

How can I say... watched "The Wall" on a video disc?

AS> 12 kByte/sec. Total 324 kbytes/sec, 640,000/324 = 1975 sec or 32 minutes
AS> of unpacked 2-bit “gray” video. Regarding unpacking without a resistor:
AS> on the reverse stroke of the scanning beam (2x4ms + 20ms skip frame = 28ms) it is necessary
AS> to unpack a 6kbyte archive - this is about 4.56 µs per archive element. You
AS> yourself understand that for the z80 7MHz this is even if it works

It won’t work.

AS> - then with great difficulty (i.e. you can’t use then intensive
AS> compression, but limit yourself to low compression and easily decoded).

Plus you also need to load this video into memory and output it.

AS> As for the sound, then of course you can create a buffer and
AS> decompress even on the z80, after all, the digital stream over the audio
AS> channel is 12 times!

But the audio (and video) is packaged very badly.

AS> less intense. Although, if you manage to pack it, then a regular CD-ROM
AS> will fit 50-60 minutes of 2 bit"gray" video, and you won't be able to sit still with this quality of image and sound ;)

Well, I don't know... except maybe "for fun". There is no point in doing this seriously.

AS> kbytes/sec
TY>
TY> Still a lot. As far as I know, none of Spec's
TY> carriers will give such
TY> speed. Plus a lack of buffer memory (at least
TY> mega two).
Screw. According to the ATM-a scheme, direct reading from the propeller on a non-turbocharged machine gives a cruising transfer with a propeller buffer of the order of 400-600Kb/sec. Taking into account the time for positioning/searching a sector, it is possible
reading at a speed of 250-350Kb/sec.

DD> 400-600Kb/sec. Taking into account the time for positioning/searching for a sector,
DD> it is possible to read at a speed of 250-350Kb/sec.

the positioning time will be almost unnoticeable.

Good Luck...

... It works! Now, if only I could remember what I did...