Re: [LAU] [ANN] meters.lv2 v0.5.1

From: Robin Gareus <robin@email-addr-hidden>
Date: Mon Oct 07 2013 - 21:34:11 EEST

On 10/07/2013 11:59 AM, Jörn Nettingsmeier wrote:
> On 10/05/2013 06:56 PM, Robin Gareus wrote:
>
>> Additionally it includes a Stereo Phase Correlation Meter (needle
>> Display), an EBU-R128 Meter (also based on Fons' implementation) with
>> Histogram and History display, a Digital True-Peak Meter (4x
>> Oversampling, using zita-resampler), a Stereo Phase Scope (Goniometer)
>> and a 31 Band Spectrum-Analyzer.
>
> (insert usual friendly ridicule of animated VU meters here)

lol. yeah, VU meters just exist to look nice :)
Even most of the hardware ones are utterly useless (see "[LAD] vu-meter
DSP" this July). At least this one does conform to spec. Thanks Fons.

> but hey, it does look nice! i've always had this fondness for jellyfish
> meters.

The goniometer(TM) aka Stereo Phase Scope is not a jellyfish display. JF
would be a surround 5.1 variation.

I was actually positively surprised how much information is displayed by
a goniometer. It takes a while to learn to read it, but it's amazing.

We (Chris, Axel and I) went through various stages including
video-taping the LV2 plugin display in order to improve readability and
usefulness. The default preset is very close to that of a DK-Tech MSD600

> and the radar-style r128 meter is a very welcome addition to the
> toolbox, having this history information at a glance is very helpful
> indeed. thanks for sharing this!
>
> built without problems and seems to run very smoothly.

great. thanks for the feedback.

> i believe radar meters have a bright future in different applications.
> for instance, to provide limiter history. fons' zita-dpl1 has short-term
> history already, which is extremely helpful. but to imagine something
> that listens to transport information and provides history of a whole
> song, plus "locate to peaks" from the history so that i can manually
> tame parts where the limiter cut in too sharply, that would be awesome.

'locate to peaks' is a very nice idea. However I'm not aware of any
plugin standard that allows to control the host's transport. A LV2
extension could do that, though. zita-dlp1 could do this via jack-transport.

> i'm currently trying to make sense of the libcairo version number in
> opensuse tumbleweed, but i guess our lady of the segmentation fault will
> let me know if there is a problem...

Depends. Thread-safety and concurrency issues may rather produce strange
effects than segfault right away. It's mainly the EBUR128 meter (rapid
font rendering), Try adding two or more instances of the openGL variant.

It also depends on your graphics card. The plugins render directly to
graphic card memory. It works fine here with an old intel-945 and some
nvidia cards that I have tested: zero CPU. But Axel has various problems
with his Radeon on debian/stable. Also x11/xcb can make a huge
performance difference. -- Anyway, the concurrency issues
cairo/pixman/pango + x11/opengl have been fixed upstream and will soon
find their way int various distros if they have not yet done so.

Cheers!
robin
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Received on Tue Oct 8 08:15:01 2013

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