Stereo Tool

Windows stand alone: http://www.stereotool.com/download/ster ... 41-023.exe
Winamp DSP: http://www.stereotool.com/download/dsp_ ... 41-023.exe
VST32: http://www.stereotool.com/download/vst_ ... 41-023.dll

I'm seeing a rather large CPU load difference when using the composite LIMITER (not clipper!) which I didn't expect and don't understand. So I'm curious what others are seeing.

Changes:
- Hard Limit for composite clipper caused very soft clicks every block!!! Also in older versions...
- Composite Limiter was running in a separate thread, and taking 2 ms extra latency. The new version does not do that anymore, and returns a cleaner spectrum, but it requires a bit more horse power from the PC because it doesn't run on a separate CPU anymore.

Older changes:
- Added HQ mode Not available, for testing only
- Improve Multiband3 and Singleband2 limiting and (to a lesser extent) compression for low latency settings. LQ output should sound similar to normal output! Fixing this will also improve audio at lower latency settings. Compressor is probably more or less ok, limiter is pretty horrible, also at lower latencies!
- Fixed Phase Rotation frequency effects at low latencies (need to compensate for loss at certain freqs in low latency modes)
- Fixed AZIMUTH behavior at lower latencies
- AGC behaves slightly differently for lower latencies - Kinda OK. With shorter block size the drop for short spikes is bigger, which leads to a slightly lower overall output level. But I cannot easily fix that. Other differences are fixed now.
- Clipper (probably only ABDP) does not work well for latency 128. Yup -> if I lower the top bass freq from 400 to 200 Hz it's MUCH better. Fixed.
- Something removes low bass in low latency modes. -> EQ and other things. -> Improved. Difference is still large though.
Rewrote LQ Low Latency monitoring to use the normal processing code. Works reasonable, sound resembles that of the normal latency EXCEPT for the bass limiters and to a lesser extent the compressors in the multiband section. Memory usage for plugin version is reduced by more than 20 MB. Stand alone version might use slightly more than before.
- Fixed FOX TV Carbon Coder R128 normalization issue Waiting for feedback.
- Moved a lot of threads into a single thread. Might improve hiccups that some people have reported.
- Added Power Highs (it's in the same window as Power Bass).
- Moved Power Bass and Power Highs to before the wideband AGC to improve volume level consistency.
- Sudden fast rise of bass or highs is limited, new slider 'Release boost' added. I'm not really sure yet if this is ok; if there's a loud high or low sound it can push the band down a lot, and it comes down slower than before. If needed I can add something to allow it to come back faster after a short spike. Waiting for feedback first though.
- Sidechain checkbox removed (without that doesn't exist anymore).
Attempt #2: Redesigned Simple Clipper. Reduced CPU load.
- Reduced the memory usage
- Fixed most of the Stereo Image artifacts!!! "Deprecated" is removed from the sliders that were marked with it. See (*) for a cool new possibility!
- Removed some more unnecessary steps (AZIMUTH 2x, Stereo Boost 2x). 10 remaining.
Fixed 'Post filter for DC offset' problem.
52. Check CPU load. Start with checking if there's anything left that uses the 'unnecessary steps'. Sevdah Web preset: Data still gets converted 58 times... I think I need to do this one first, it should have some effect on the CPU load. 28 removed - next convert the 2 IIR filters so they can be optimized and the merge/split around it can be removed. I'm not measuring any effect from this though (but it makes the code simpler which is also good)
53. Noise Gate/Stereo Boost: Pre-calculate 1-cos() and sqrt() values.
55. Check MemoryPool behavior for cache improvements -> No effect measured, and might make behavior less constant.
56. Check if we can go in opposite direction for each next step to improve cache.
57. Check if lazy reverse FFT is an option. -> No, difficult and gain does not even seem to be measurable.
58. Created a separate class that performs the processing chain. Currently the same code is repeated twice (once for normal processing, once for low latency processing) - which means that a lot of code is duplicated and it's difficult to add extra chains. Most, not all, of that code is now moved elsewhere.

TO BE DONE:
- Spread over cores is not constant, which causes differences in performance. I *think* it might be the chain2() code that causes this. Actually it might be a good idea to get rid of that completely...
- Get rid of chain2() thread. This should also allow reducing the ASIO latency by 1 step (usually 1.5 ms). Hm.... Or not? I'm confused
- Composite Limiter effect no longer visible in GUI. (Is that bad?)
- New ASIO behavior: Push samples, read them back directly from buffer, skip whole Chain2 stuff. For HQ mode, add redundancy protection.
- Reduce stand alone version memory usage (unused low latency thread items can be removed.)
- Old Hard Limit for composite limiting was slightly tighter input level was very high. And had no overshoots; the new one does.

so far i did nt see any CPU load....
i see only Memory load and i think it changes the output levels.. pls confirm anyone.

_________________
Sexy Girls in your city

what do you mean by memory load changes level ?
Give us some explanation like : when or what happen , what you do , how you do it.

Audio output should be nearly the same; a bit lower for higg fm overdrive levels values. Memory should be marginally lower.

on my system I measured a cpu usage reduction of 9 % that I cannot explain.

CPU load reduction - let`s say yes , a bit.
For memory load - yes reduction is presented too, may be about 10 MB lower.
On audio behavour i cannot see any difference.

Same as Doggy... Memory load was my wrong.

_________________
Sexy Girls in your city

I measured it again tonight using a slightly different method, but I'm seeing the exact same thing. If I use the composite clipper, there's very little difference between this version and version 7.40. When using the composite limiter, there's a reduction of 9%.

Following up on my stuttering issue multiple page ago: it (StationPlaylist) is doing it even with Stereo Tool disabled, although it does it less... so something is eating up my CPU cycles and / or memory that wasn't before, and I no longer believe it is Stereo Tool.

FWIW, "System Properties" tells me I am running Windows XP Pro Service Pack 3 on an Intel 2140 @ 1.60 GHz (1.59 GHz) w/ 1.99 GB of RAM.

I'm doing some basic system maintenance now to try to help the issue (including disabling system updates and forcing Windows to stop telling me I don't have a firewall on), and would you believe what seems to have helped most was a good, old-fashioned defrag? I figured since this computer just sits there and runs that wouldn't have any impact, but I guess over the years a little change here and a little change there can add up.

I still love Power Bass, but I'm not as crazy about Power Highs... it seemed to bring out some distortion in some of my files, but others may have better luck with it.

Keep doing what you're doing, Hans... you are making so many of us sound better and better!

_________________
Gene Savage
BlackLight Radio
https://BlackLightRadio.com
Tulsa, Oklahoma USA

Your CPU is just slow.

Still busy cleaning up code... The next version runs slightly more efficiently on my pc, uses one thread less and uses less memory. If I take a few more steps I think I can lower the ASIO latency by 1 step (usually 1.5 ms). Building...