Stereo Tool

I can now confirm that there's something wrong with ALL sampling rates. Upto 48 kHz the output is perfect, but contains some slightly too loud spikes. Above 48 kHz the output contains clicks that are not present at lower frequencies.

Edit: 1. Upto 48 kHz, there was an issue with the detection of spikes, not with actual spikes Fixed now.

I think all started when you fix winamp mpx out.

The 'red bar' problem (upto 48 kHz) started when I made some changes to reduce the latency. It's fixed now.
The 'clicks' issue (above 48 kHz) is also present in version 6.00, and probably all older versions as well! Somehow I never detected it (neither did anyone else, apparently). I'm fixing it now, it's not that difficult (although completely removing it seems impossible). --> Fixed (nearly completely gone)

Crashes should be fixed as well.

Something is COMPLETELY wrong with Hard Limit if Quality is lowered at lower latencies... --> Fixed, hope it has no bad effects.

I fixed some issues but actually almost nothing really got solved...

BETA601-014:
- Improved 'red bar' issue at sample rates upto 48 kHz: I fixed some of it, but it still occurs -> and now I see overshoots in the output signal as well (not much, below 0.2%, but I don't understand where it comes from and it must be fixed).
- Improved 'clicking' at higher sample rates. This one is really fixed; audio is expected to sound better (cleaner).
- Crashes when switching between latencies are gone.

I have added a new issue to the todo list: "Attempt to set GAUSS back to 0". This is a value that I'm using to improve Loudness for certain tracks, BUT it causes high frequency artifacts. So I need to figure out where those artifacts are coming from and then try to fix them in another way. This only affects latency 512.

Winamp DSP plugin: http://www.stereotool.com/download/dsp_ ... 01-014.exe
Stand alone version: http://www.stereotool.com/download/ster ... 01-014.exe
VST version: http://www.stereotool.com/download/vst_ ... 01-014.dll
VST version (No SSE2): http://www.stereotool.com/download/vst_ ... 01-014.dll
Command line version: http://www.stereotool.com/download/ster ... 01-014.exe
Linux command line version: http://www.stereotool.com/download/ster ... ETA601-014 [not available]
Linux GUI version: http://www.stereotool.com/download/ster ... ETA601-014 [not available]


What remains for 6.01:
- Multiband: Adjust band 3 (and others?) 'soft limit' behavior at very low latencies. Maybe: Also check clipping (also for band 3, might be re-enabled!). 1 hour
- Multiband: Adjust extreme EQ settings before processing to avoid issues caused by steepness. 1 hour
- Multiband: Add 'Enable' button for steepness. 1 hour
- Performance: Multiband steepness: Moving UP can be done inside current loop, no separate loop needed. Maybe down too. Currently Multiband is FAR more expensive than before. - DONE, solved in a different way. 1 day
- Performance: Multiband: Remove sqrt(sqrt(cos())), pow(x, .75) etc. - too expensive, replace by lookup table. 2 hours
- Reduce downsampling frequency because currently very high frequencies (21-22 kHz @ 176.4 kHz input sampling rate) in the input can cause spikes even if Hard Limit is used. 1 hour
- And I need to check how much the performance is impacted by the latency improvements, in the case where no upsampling and downsampling is needed. This seems to be impacted way more than I expected (could also be Multiband steepness). ???
- MAYBE: Make Steepness smarter. That would much better preserve the audio, especially at very low latencies! How: Instead of setting all the levels at AT MOST the level of neighboring bands + a bit, combine adjacent bands, determine total output level, and then fix it such that this combined output level is approached more. (So one very low, one very high --> one a bit less low, one a bit less high instead of both low).
- Fix NOISE GATE behavior in VST plugin
- Fix 'red output bar' issue. DONE 1 day?
- Attempt to set GAUSS back to 0 - gives MUCH better processing of most filters (no high frequency noise). BUT: Loudness effect in Bjork - It's Oh So Quiet - can that be resolved in another way? 1 day?
- Fix Highpass filter for higher input frequencies.

Questions:
* Multiband: Question: Is Steepness behavior ok?
* Loudness: QUESTION: The changed Punch behavior, is that good or bad?

Check:
Check difference in behavior between 44.1 and 48 kHz input for multiband! This could potentially result in really big differences.

I still Use Beta 08... this last beta 13 has less Bass and Kick at all latencies..

_________________
Sexy Girls in your city

Loudness is causing a lot of CPU usage, jumps from 8% to 16%.
For some reason this is causing audio problems for me, stuttering when my CPU is above 75% cause of other apps.

Bass and lows are louder on my end but I'm losing a some very high freqs (19Khz+).

_________________
<-- I like this guy!

Is this different than in other versions? Nothing has changed in Loudness since version 6.00...

I'll measure the bass and highs level soon.

6.00 and before I used to get 10% cpu usage max.
Does increasing the loudness increase the CPU usage?
I'm wondering if its the just loudness that increases CPU usage or the amount of loudness.

_________________
<-- I like this guy!

Last time I checked, the latest BETA CPU load was about 4% higher than that of version 6.00 with everything enabled.

Loudness level has no (or very little) impact on CPU load. It's either on or off.


EDIT: Just did a new measurement with the latest version, and the difference is now 12%.

But it doesn't seem to have anything to do with latency (without Latency the difference gets bigger, 16%, which makes sense as I'm doing less, so whatever is causing the rise in CPU load is relatively doing more).

The odd thing is that I thought I had fixed most of the issues that caused the CPU load to get bigger.


Edit #2: It's not Loudness, it's Multiband. Without Multiband the difference is about 3-4%, with Multiband it's 12%. Must be caused by Steepness. I'll have to find a smarter way to handle it.

With multiband (and everything else I have enabled) CPU @ 12-17% without multiband CPU @ 8-9%.
Without multiband & loudness CPU @ 3-6%

_________________
<-- I like this guy!