On Mon, Dec 05, 2011 at 01:12:45AM +0100, Julien Claassen wrote: Every form of peak limiting produces distortion (almost by definition), the question is if it remains acceptable or not. You are right that DPL1 won't produce the amounts of distortion that you would have with e.g. a scaling limiter - it really tries to remain linear in the short term, and gain changes are always smooth even if they can be quite fast. The way it is intended to be used (at least on a mix) is to limit occasional short peaks (which can be done without too much impact on the sound) so as to allow a higher average level. If you drive it so the limiting is active all the time (which can be done with DPL1), little more is gained in terms of loudness, and whatever remains as dynamics is then controlled by peak sample levels which in almost all cases produces something horrible. So you need to monitor what it is doing, and that's one reason why DPL1 has the type of display it has, and why it is not a Ladspa plugin. A second one is that I wrote this to have a limiter that can be used on multichannel (mainly AMB here) mixes. Since Ladspa has no 'create-time' parameters, this would require a different plugin for each channel count. I could make mono and stereo Ladspa versions, but then they would either require some way to monitor the gain reduction (which can't be reduced to some slow-changing number easily), or you'd need careful control of the input level. So that leads to my question: how do you monitor levels ? Ciao, -- FA Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl.

On Mon, 5 Dec 2011 09:40:15 +0000, Fons Adriaensen <fons(a)linuxaudio.org> wrote: Hey Fons, thanks for the limiter! The LV2 plugin spec permits custom GUIs, and the dynparam extension allows the number of parameters to vary (I'm not sure if there's a built-in way to do this). By the way, I may be misreading, but wouldn't the license in dplimit1.cc prohibit others from making plugin ports and from including this in GPL software? Cheers, Caleb

On Thu, Dec 8, 2011 at 6:21 AM, Fons Adriaensen <fons(a)linuxaudio.org> wrote: this isn't really correct. the SUIL library allows cross-embedding (Gtk, Qt, Xlib, ?) GUIs in hosts that use (Gtk, Qt, Xlib, ?). the use of SUIL is not required by the specification, so in theory the host might implement support for the plugin GUI in some other way, but all existing hosts that support custom GUIs are using SUIL at this point. --p (who hopes he got this right.)

On Mon, Dec 05, 2011 at 12:20:24PM +0100, Jörn Nettingsmeier wrote: Applied, thanks. Yes. Actually that is not true - sources would move. Imagine a simple WXY system. You have a source at 45 degrees and one at 90. The one at 90 (say some percussion) makes Y go into limiting. This means the one at 45 will move forward. So any gain change would have to affect equally at least all components of the same degree. And even that can only be done for a short time, as modifying the gain of one degree makes a complete mess of the decoding - rE will drop sharply and rV can take on any value, even go 'negative'. After at most a few tens of milliseconds the other components would have to follow. So that would require separating transient gain changes from longer ones. This would be possible in e.g. a compressor, but for a peak limiter (which has to ensure that no samples are over 0dB whatever happens, and operates in feed-forward mode) it can become quite difficult. I tried something similar: to make transient gain changes affect only the mid and high frequency part of the signal, but I had to abandon that idea (at least for now) - it really gets very hairy. Assuming it could be done, the limiter would have to know which channels belong to the same degree. No problem if you only have complete sets, but I want to support horizontal only and mixed order sets as well. The plugin system in AmbMixer can handle this. Others could mayby do it with a few more extensions, but those would always imply explicit AMB support by the host. Ciao, -- FA Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl.