Every time I go to a web site that has a video to play, pulseaudio racks up 20% of cpu even if I do not play the video. Playing the video, I get plugin-container racks up 24.0% of cpu, and pulseaudio racks up another 15.5% of cpu.
I kill the tab of the web page, and pulseaudio cpu load goes way down, and plugin-container remains at a fixed 5.6% to 6.3% of cpu.
Is this normal for a unicore athlon64 3200+ laptop?
I'd say Flash doesn't have a great reputation (I assume plugin-container is running Flash here) and that's one the reasons why. I also have a constant load even when the video is paused, in the order of 0.7-1.3%.
About PulseAudio though.. it's definitely not normal (at least I don't see that). I've never really debugged PA so I wouldn't know which tools to use to get more visibility, but I'm sure they have some information in their documentation.
It probably won't take you very far, but you could also try PowerTOP, they have some tunables that might influence PA's CPU usage.