Hello guys,
I wanted to share with other Linux and/or Ubuntu users some technical questions and issues. My config: Pd-extended latest, Ubuntu 11.04

1. Is it common that PD prevents any other non-jack audio applications? E.g. if PD is active all audio activity is stopped on the browser or the media players. This happens even if PD is not connected to jack nor to alsa nor oss. What happens is that the media player, e.g. rythmbox does not read the stream/file (the playback cursor stays still).

2. It sometimes happens that after opening/closing several patches and playing around, PD disappears after a patch is closed.

3. The CPU load is very high (as shown by the load meter applet in the Linux tray) but the load meter shows quite a low value. I have the impression most of the load is due to the control stuff (especially GUI objects) rather than the DSP stuff.

4. Comments with line breaks are put in a single row after opening a previously saved patch.

Hhm, I think that's all, just wanted to check whether it's me or not.

Cheers
Leo

Hello Leopard86:
I am a Debian Squeeze and Ubuntu Karmic Koala user, and I have to sadly admit right away as true three of your four questions:

2: Sometimes the GUI goes unstable and pd suddenly falls upon closing a patch. It happens mostly when you draw elements in negative positions of the canvas or when you make sudden movements of a lot of selected elements. You can check for this instability sometimes copying an object or writing into a comment or box: pd pastes two or three objects or types in two or three characters for each ctrl-v or ctrl-d or keystroke.

3: If your patch has a lot of gui elements, you are in deep manure (to be polite) with refresh. When you come back to the desktop that shows pd gui the tcl/tk motor (which runs in serial, not in parallel) takes as much as two tenths of a second (100ms!) to refresh the window, cutting the audio stream. This is a huge sad bottleneck. I'm currently working in a workaround for this (as many of us are, or course).

4: Yes, comments are "lined" upon reopening, but that doesn't bother me particularly.

Regarding sound card capture by pd, maybe. I had problems with iceweasel/firefox and audio because I don't have any plugin for that program and it's not in my list of priorities to be watching youtube while patching in pd.
I hope this helps you. Best regards.

Sumidero

Thanks sumidero,
useful information.
Regarding the youtube thing... It bothers me because it often happens that I'm looking for Pd patches on the web and I want to see how it sounds or watch a demo on youtube...
Anyway it also happens that I'd like to listen to music while patching or I want to jam with Pd over a recording of mine... This is very annoying. I can't understand if it is related to the integration between jack and alsa or not...

1: This is the hole issue of sound servers in linux. Here (kubuntu 10.10), if I launch pd via the application panel, it cuts the sound of any other application. If I use Alt-F2 pdextended, it doesn't, but pd has no sound.

Applications can share the soundcard only via sound servers. I guess you have pulseaudio, and pd doesn't offer to use this sound server which is not suited for realtime audio. Jack is, and if you have it working, any jack-compatible audio applications can run together. But firefox is not one of them, neither is rhythmbox.

If you managed to have firefox working with jack (I heard it was possible to redirect pulseaudio applications to jack), then you could launch pd via 'pdextended -rt -jack -R "samplerate" ' in launcher/Alt-F2/command line. I didn't try this because I don't need it, but you might find you way with some research.

4: end your comment lines by ;
and they won't reopen lined.

(my 2 cents)

You can work around The limitations of non-JACK applications (like the browser, etc) by telling pulseaudio or alsa to redirect all it's sound into JACK. I've used these methods before in order to sample sounds from Soundcloud or Youtube.

Routing PulseAudio to JACK

Routing Alsa sound into Jack

Or you can use 2 soundcards! One sound card for Alsa/Pulseaudio and one for JACK apps. Physically patch the output of the Alsa on to the inputs of the JACK one. It's a hardware solution, and won't introduce more latency than the software solutions.