22050hertz - a c64 dtv tech demo

one of my early tests on exploiting the dtv hardware.
no borders, samples and sprite oscilloscope fx.

Category:

Film & Animation

Tags:

• c64
• dtv
• demoscene
• tech
• demo

[Atad64]

What is the name of this song? Did You used DTV`s burst mode to achieve that sample rate?

[trsi64]

@Atad64

the song is called "wizzy noise - overvoltage soundtrack edition"

[Atad64]

@trsi64 Looks like something between DPCM and ADPCM complexity. You might consider also 8:2 ADPCM - faster then 8:4, but quality nowhere near 8bit wave.

[trsi64]

@Atad64

i think it would work. check the pastie in my other comment.

[Atad64]

@trsi64 Would be nice.

The ADPCM scheme is "a little" too much for 64, but DPCM timing restrictions can be meet.

[trsi64]

@Atad64

i think you can decode the url by yourself :)

hxxp:// pastie .org/ 1436989

[trsi64]

@Atad64

in this demo it is pre-processed while loading.

but it works in realtime aswell. too bad i cant add an url here. want to show you the very simple decoder sourcecode.

[Atad64]

@trsi64 Nice work. Does it run real time or pre-processing in here? I almost didn't noticed the quality loss. What's the name of this soundtrack?

I'm using for my purposes the ADPCM 8:4 or 12:4 (but not in this REU player) .

[trsi64]

@Atad64

i used 8:4 bit fibonacci compression like used on amiga 8svx samples.

[Atad64]

@trsi64 Your 22KHz on DTV looks for me like 600KB of data. Used some compression scheme to achieve You goal? Yes, i'm aware, that on DTV You have a burst mode and simple 8bit sample playback capabilities ;-) On 64 this sample rate and quality was tough to hit.

I know Your plugin's for MMC64/MMC Replay.

[trsi64]

@Atad64

regarding the reu player... for me it was important that the wave data fits on 2 disksides. i could have filled the whole 2mb of the dtv ram and them back at 96khz.

some years ago i coded a wav plugin for the mmc64. plays at 22khz 8bit or 44khz 4bit.