Hey Brian, Sorry about the lack of response on this. Just saw this now, and I'm glad you got things running.
On Sun, 1 Sep 2019, at 5:18 AM, Brian Bulkowski wrote: > Here's what I learned: > > 1. PulseAudio paired with a Rapsberry Pi is an almost unbeatable choice > for art installations. The ability to attach many speakers over USB > audio, the fact that there are no fans whatsoever, the fact that is can > run any manner of high level software to control sound, that you can add > flash drives which are as large as you like, the fact that you can > determine which USB port is which, the fact that you can easily add > buttons and interaction ( since it's a PI ), the ability to control > volume at any level ( speaker, sound, etc ), the easy code to use any > manner of sound file.... it's great. > > 2. The async interface is not well covered in many guides. The examples > are misleading. As an experienced programmer with 30+ years of async c, > I got caught by this, because the examples worked ( but don't if you > start and stop a lot ). I will be posting my project and showing how to > really play sounds and start and stop them. I usually point folks to the sync-playback.c test that we have a starting point, but this is certainly less than ideal. > 3. If you are going to run an unattended service, you need to set > pulseaudio to be a systemd service, and you need to set up your > application as a systemd service. > > In order to do this, you would typically use the 'cookie' file, which is > a binary file of undocumented type ( possibly just the contents of the > file ) which more than one process need access to. My attempts to get > this working with PulseAudio 12.0 failed, with environment variables > ignored, a service auto-creating a file with privs hard to read, but it > turns out there's a simple workaround. The documentation unhelpfully > says "maybe this is a good idea for something like an unattended > headless application but you're probably not running one of those". The documentation is catered to users across the spectrum of use-cases and expertise, but I'm happy to incorporate suggestions for better phrasing for this. > The way out, when you get desperate of using cookie files ( and do try > them first ), is to modify the /etc/pulse/system.pa and find the > load-module line for module-native-protool-unix . Add the > auth-anonymous=1 as below > > load-module module-native-protocol-unix auth-anonymous=1 > > This disables checks, and means that anyone who has access to the > raspberry pi can take over the audio, even if they have a non-pulse or > non-audio user. An installation like this should be air-gapped anyway. > > 4. I can't say "thanks for the excellent community" as I spent lots of > hours on this project, but the underlying code has been sound, so thanks > for writing and contributing it. > > 5. When the code is fixed, I'll post a link for others to use. Thanks for your patience and for writing down your findings for others. Regards, Arun _______________________________________________ pulseaudio-discuss mailing list pulseaudio-discuss@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
