KSS player with per-channel spectrum analyser online

Expert (113)

22-11-2016, 22:11

I've been creating a new site using the new version of libkss which has the option to generate per channel audio information, so one could use the fast fourier transformation (build into the webaudio API) to generate a per channel spectrum analyser from the audio. The site is far from perfect but I wanted to show it to you, since the spectrum analyser looks pretty cool imho.

The link: msxmusic.eu.pn

By sd_snatcher

Prophet (3675)

22-11-2016, 22:54

Very interesting, indeed! I was expecting the SCC scopes to be more emphasized on the high frequency range. Or are the higher frequencies on the left?

BTW, I also love the openMSX scc_viewer, as it clearly shows the waveforms for each channel and how they change dynamically in some more advanced effects.

By niek

Expert (113)

23-11-2016, 00:15

It's whats the Javascript analyser node is providing, it's supposed to be the frequency-domain data, however I can't seem to find an explanation what that actually means.... still learning.

I'm not entirely happy myself with the current look, I want to see some difference between changing tones, maybe not the whole frequency-domain data but just one small bar on a line depending on the frequency so to speak. So left is low frequency, right is high.

Very nice, the scc_viewer, didn't know that, the waveform thing is nice. I guess this data could be extracted from libkss as well, maybe when I have the time/energy.

By NYYRIKKI

Enlighted (6092)

23-11-2016, 01:04

niek wrote:

The link: msxmusic.eu.pn

Hmm... It seems my computer can't open this link...

niek wrote:

it's supposed to be the frequency-domain data, however I can't seem to find an explanation what that actually means...

That practically means "Equalizer view". From technical point of view you may want to Google for "Fast Fourier transform" or "Discrete Hartley Transform"

By NYYRIKKI

Enlighted (6092)

23-11-2016, 01:25

mmm... It seems I skipped the very first sentence of this forum post... sorry about that.

By meits

Scribe (6571)

23-11-2016, 01:58

It made my firefox crash after a while... Now that was odd

By niek

Expert (113)

23-11-2016, 07:07

Quote:

That practically means "Equalizer view". From technical point of view you may want to Google for "Fast Fourier transform" or "Discrete Hartley Transform"

I've been reading about it, but the answer to the question why the values on the left are always the highest I haven't been able to answer despite all the information. You know this?

Quote:

It made my firefox crash after a while

Hmmm... good to know... maybe I forgot to release some stuff when starting the next kss.

By NYYRIKKI

Enlighted (6092)

23-11-2016, 09:57

niek wrote:

I've been reading about it, but the answer to the question why the values on the left are always the highest I haven't been able to answer despite all the information. You know this?

I could imagine that this problem originates from the problem that frequencies are divided to linear domains while frequencies it self work in logarithmic scale (When Hz rate doubles, you go one octave up) See if there is routine that sums the domains together.

By Metalion

Paragon (1628)

23-11-2016, 19:21

Well, all I've got is the old-school scroller ... Nothing else.

By niek

Expert (113)

23-11-2016, 20:11

Should work now, a fix to avoid stuttering at the start of the song messed things up....

By niek

Expert (113)

30-01-2017, 00:10

- Fixed memory issue
- Increased Spectrum Analyser resolution
- Added experimental note recogniser