Hello there! I've noticed a peculiar symptom using Pulseaudio (0.9.13) on Fedora 10. Particularly this is related to per-application volume. In a nutshell: 1. The "system sounds" entry in pavucontrol pays no attention to what volume level you set for it: on my system, it consistently resets itself to 50%, and at random, jumps up to 100%. This causes some system event sounds to be too quiet while others are obnoxiously loud. 2. System sounds themselves seem to disregard this and play at different volumes anyway. For example, the "dialog-cancel" sound, when a dialog box is closed or cancelled, is a giant "thump!" several times louder than the default close-window sound. (I recall reading somewhere that a "libcanberra" is responsible for system-event-sounds, so perhaps the error lies there). The login sound varies on its own from obscenely loud to randomly soft. 3. Applications tend to forget their per-audio settings (this may be related to an earlier post I read on the December 2008 posts, where streams that change between mono and stereo may possible reset their volume levels, and another one from June 2007, where some crazy X session voodoo may prevent Pulseaudio from remembering per-app settings. But I had hoped this was fixed.). As a suggestion, it would be useful if Pavucontrol had a "Previous Applications" tab which displayed the levels of previously encountered streams/programs, and let you change the volume there. (Pulseaudio seems to notice a program ONLY when it plays a sound, and in the case of Pidgin for example, many sounds are too short to reach Pavucontrol in time to change settings. Compare Windows Vista, where a program's sound settings are persistently shown in Volume Control, even when the program is silent.) Also, in regards to #3 (the mono/stereo thing), the post that I found on the mailing lists earlier mentions that PulseAudio will have an intelligent algorithm to adjust the volume when a stream switches from Mono to Stereo. This seems a little counterintuitive, as it always means there will be some information loss when going from Mono to Stereo. You'll notice that Windows Vista doesn't suffer from this problem, since it doesn't expose different channels at all: each source has only one master volume control for that whole source, ignoring per-channel volume. I think this is a smart thing: should it be PulseAudio's job to figure out the channel arrangements of every app? But if it should, then how about the following idea: what if Pulseaudio exposed two things. 1) A master volume control for each source, similar to Vista, that is channel-agnostic 2) A separate set of channel values, which are relative scalar to each other. So a user can set a balance between the different channels (say, 25% left, 100% right), and still control the overall volume using a single slider; this allows him to set a balance for the channels using the full slider range that is independent of the actual intensity of sound coming from the channel. So instead of setting 10% left, 20% right, he can set 20% overall, 100% right, and 50% left. Pulseaudio would use the overall volume, and the channel-specific volumes, to mix that source. This would allow you to simplify the interface of Pavucontrol as well: instead of each source exposing "Mono/Stereo" information and sliders for each channel, merely expose the Overall volume level. The individual channel balances could be accessible via a popup window, removing a lot of clutter from the interface but still allowing a startling degree of power. At the moment, PulseAudio is very interesting, but the random volume vagaries often serve to drive me batty; nothing seems to properly remember what volume it should be. But it will be quite a marvel when it finishes maturing.
