Stereo Tool

This is *VERY* interesting. If I disable the AGC and only use Natural Dynamics and Multiband, there's no big difference in output level if I turn Natural Dynamics on or off. So... This REALLY means that I need to use the unprocessed audio as AGC input.

Will create a new version ASAP.


Edit: Not that soon though... This is a bit tricky: Currently I'm performing Natural Dynamics directly at the input signal (after declipping and noise gate). The AGC is done AFTER Stereo Boost (which makes sense: If Stereo Boost makes the audio louder, you want the AGC to lower it more).

So now I have 3 choices:
1. Ignore Stereo Boost for the AGC. Not a good idea.
2. Perform Stereo Boost (and AZIMUTH, ...) on both the original and the Natural Dynamics signal. Big CPU load impact.
3. Perform Natural Dynamics on the audio after Stereo Boost. I'm not sure what that will do - actually it might even be better...

I'll go for option 3 for now.

"up push strength near minimum reduction" in AGC is not included for 3rd AGC band (?)

Will you add the sliders to stand alone again in next beta?

BETA050:
- Natural Dynamics can now be placed before or after AGC

From the previous beta (still valid):
The CPU load is also pretty high because I'm calculating 32 different tilt levels to find the best match (so automatic tilt detection works, but it needs serious optimization).

New slider: "Declipping margin" - if you set this to 75%, everything above 75% of the maximum level is considered to be potentially clipped.

Changed slider: "Never consider samples to be clipped if they are lower than:" - rule out soft sounds, whatever they look like, they are not clipped.


Winamp DSP plugin: http://www.stereotool.com/download/dsp_ ... 20-050.exe
Stand alone version: http://www.stereotool.com/download/ster ... 20-050.exe
VST version: http://www.stereotool.com/download/vst_ ... 20-050.dll
VST version (No SSE2): http://www.stereotool.com/download/vst_ ... 20-050.dll
Command line version: http://www.stereotool.com/download/ster ... 20-050.exe
Linux command line version: http://www.stereotool.com/download/ster ... ETA620-050 NOT AVAILABLE
Linux GUI version: http://www.stereotool.com/download/ster ... ETA620-050 NOT AVAILABLE

TODO:
- Fix loading changed multiband frequencies
- Add buffer and filter for SCA output (SCA1 ok, SCA2 ok)
- Finish AGC improvement - make mono value configurable (replace checkbox by slider) 1 hour --> NO, not needed - anything else needed? -> NO
- Fix Punch
- Check what to do with new filters (such as bass AGC) - keep them, remove them, change them? --> KEEP
- Save new BASS_AGC setting in VST mode
- Loudness: Annoying cracking sound in bass. Slightly present in 5.00, worse in 6.00, maybe even worse in 6.10. Only when bass is too loud. Much worse than in Final Limiter (at same input level!) - so this clearly indicates a bug. Most likely cause: The filter that was added to remove bass artifacts....... - No, it's the louder bass. But it can be fixed by changing some settings. Default settings updated, and behavior for 'not Very strict' improved. Also Deep bass boost and Very deep bass protection are enabled for latency 512 now.
- Fix crash at program close
- Fix VST plugin version (does not run)
- Dynamically drop 'Allow louder highs, even if it causes vibrations' to 0 when bass filter suspects noticeable voice vibrations. 1-2 hours
- Reduce Loudness CPU load days?
- Check and remove static variables
- Finish new de-essing filter (check what to do with the settings, remove at least some!) 1 day
- Convert Multiband input to MONO, then use arrays [2][4096] --> should give speedup. - FAILED
- RDS issue reported here: viewtopic.php?f=15&t=3703&p=11524#p11524
- Always oversample clipping (configurable)
- Natural Dynamics: Fix or remove transient boost
- Natural Dynamics: Smooth out different bands more to reduce low-bitrate-MP3-like sounds.
- Natural Dynamics: Add expected + strength slider per band
- Declipping filter: Change detection at lower input levels.
- Finish declipping filter (clipping level detection + level reduction in dB). 1. Figure out why removal of unwanted frequencies causes flat lines at high quality setting with small overlap. This causes distortion, with this fixed repairs are MUCH better. 2. Implement MP3 correction, automatically scale down when this deteriorates the sound.
- Update presets? (BASS_AGC etc.) 1 day
- Finish blind interface
- Add AGC start level
- "Test Right Channel" in "FM Transmitter Calibration" does not work since v6.10 (standalone) (bojcha)
- Channels L/R swap in stand alone version when changing filtering/quality (?) (eldoradofm)
- Move pre-emphasis to end of processing 1 day
- Change version number 1 hour
- Release 1 hour
- Add lowpass filter for stereo signal (will cause a lot of extra latency!) - it might be possible to avoid this latency using a Hilbert transform
- Add smarter clipping detection. Maybe something much simpler suffices: Current clipping detection with threshold + flat line detection

I count 9 bands in dynamics filter why not the 10 like in multiband?

How are the Natural Dynamics connected when i select After AGC ?
Because i don't hear more boost when the AGC is going up when i lower the sound.
Or are the dynamics added after the AGC and then always using the sound from before the AGC? Then it's better to change name in Add dynamics after AGC.

There doesn't seem to be a need for 10 bands - the lowest few can be combined without quality issues. At least that's my impression...


Edit: I just compared the sound processing freakday mix with and without Natural Dynamics (settings: Max input level 100 000; Effect multiplier: 2.00 x), with Bojcha's B_Town11_FM4 preset, AGC Target output level lowered to 20.00.

Every track comes out either (nearly) unchanged or better. So this is really helping, also with processing enabled! (although the effect without any processing is MUCH bigger)

I found yet another feature that I can use to determine whether clipping occurs or not. It seems to detect about 99% of real clipping (so some softer clipping won't be restored anymore), but if no clipping is present it indicates less than 50%. So I'll add an option to disable clipping when this filter says that no clipping is present.

(I can hear a slight deterioration in the 'extreme_clipped' sample, however in real world input where a lot of samples are incorrectly considered to be clipped I expect an improvement from this filter).

Note: This filter won't help in case of (volume) compressed audio - so modern tracks like Jack Is Back don't improve at all. However if you're playing 60's, 70's or 80's tracks (not recently remastered ones...) I expect this filter to work very well.

And this is much better for Natural Dynamic filter. Checking ..

Ok.. test ONE:

I've uploaded MPX track where first 01:26 is with Natural Booster OFF and second same 01:26 with Natural.Booster ON. Not default settings at all! -- Damn, sun is up.

http://www66.zippyshare.com/v/65454933/file.html
Any difference?