Andrea A <Andrea69x@xxxxxxxxxx>: > > I'm writing a new equalizer module for PA, > https://github.com/andrea993/audioeqpro/blob/master/pulsemodule/module-eqpro-sink.c > I've almost done but I need some information from developer about how to proceed. Thanks for attempting a contribution. I have attempted to answer your questions regarding the integration, please read below. However, see the end of this email for the biggest reason why I am against accepting this module or any future form of it (but my "no" holds very little weight, so feel free to ignore it). However, in order for the module to be accepted (barring the big objection at the bottom of this email), we need to review the DSP part, and not just the integration part. It would help if you provide, in the form of comments in the source code, some references where the math comes from. And use more descriptive variable names, such as K -> extra_gain. Also, I think it would make sense to use a struct of 10 well-named floats instead of eqp->c. > First of all, I see that current equalizer module manages "autoloaded" have I to manage it? What it does exactly? Old equalizer check "autoloaded" state in a callback "may_move_to", what is it? Have I to implement this callback and manage "autoloaded" like the current equalizer module? It is set by module_filter_apply. The intended effect is to prevent moving the output of the equalizer to a different sink - i.e. if it was autoloaded for "Built-in Audio Analog Stereo" then you cannot move it to "HDMI Digital Stereo" using pavucontrol. See module-virtual-surround-sink.c for known-good usage. Although, I don't know any user of module_filter_apply. Regarding the may_move_to callback, it is called when a user tries to move the equalizer output to a different sink. Please at least prevent creating a loop, i.e. moving the output to the equalizer itself. > After the "autoloaded" management I can send the equalizer as a patch, however I've some questions about how to add my equalizer GUI to the PA branch. Should the GUI remains an external program or the GUI will be inserted to the mainline sources? In the second scenario how the GUI should be inserted? Which is the correct directory in the sources tree and what about the GUI makefile and the GUI installation directory? PulseAudio currently does not depend on any GUI toolkit (well, except the old equalizer GUI). Personally, I am fine with this GUI (or maybe two GUIs - one for GNOME and MATE and XFCE, one for KDE) being in external repositories. > The equalizer needs the messages patches from George Chini > https://patchwork.freedesktop.org/series/41390/ > Have I to write this information as a patch comment or other? Patch comment. > I would like to add some configuration files to my module, for example to load and store equalizer preset, is there a PA specific file format (and directory to store file) to do this? There are database files in ~/.config/pulse. There are multiple backends supported, see the --with-database=... configure argument. The abstraction layer is in src/pulsecore/database.h. Not sure if this is suitable for your needs. > Execuse me for the wall of questions and thanks in advance. You are welcome. Anyway, just a small nitpick: the rewind callback is implemented incorrectly. The real problem is - nobody implements it correctly, especially because the comment in the template module-virtual-sink.c suggest doing such a stupid thing as resetting the filter. And, at least for the case of a resampler, users other than me do notice the imperfection, see https://bugs.freedesktop.org/show_bug.cgi?id=50113 . There are two solutions that I would accept as "proper". 1 - store the history of your input and/or state, restore it when asked to rewind. 2 - do not pretend to support rewinds (but in this case, please limit the latency to something like 20-30 ms, so hat PulseAudio reacts quickly to the new streams). In the name of simplicity, and because the power-saving argument behind the original rewind operation does not hold if there is non-trivial processing, I would prefer option 2. Big warning: I have not tested the module. And here at the bottom of the email, let me explain why I think keeping this module outside of PulseAudio, in a different form, may be a better idea. The reason is that, by accepting this module, we are implicitly taking the responsibility to support it inside the tree. And, you are the best person to support it. So there is an additional (avoidable!) latency between the time when you develop improvements and the time when users see them: namely, the time for someone else to understand and review your code, for PulseAudio team to make a release, and for distributions to package it. A better alternative, in my opinion, would be to create a LADSPA plugin instead. PulseAudio already has module-lasdpa-sink since ages (even with D-Bus interface to change parameters at runtime), so your filter will be available also to all users of old PulseAudio versions. It will be also available to users of pure ALSA-based setup, if they still exist. You can publish improvements any time you want, without needing any potentially slow review from PulseAudio maintainers (but feel free to contact me privately if you do need a review), and your module will be quick to compile, because it is separated from the rest of PulseAudio. You can then publish a GUI application that loads the module into PulseAudio and then controls its filter via D-Bus. And you don't need to care about rewinds and may_move_to and all other pulseaudio-specific boilerplate. Sounds like a win-win situation. Could you please investigate this approach? Thanks again for attempting to replace the current equalizer with something better. -- Alexander E. Patrakov _______________________________________________ pulseaudio-discuss mailing list pulseaudio-discuss@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
