Tweaks for skips/dropouts on lower-spec hardware?
Hi, all, first-time poster here.
I'm running Lubuntu 14.04.2 i386 desktop on a Pentium 4 @ 3.0 GHz (with hyperthreading) and 2 GB. (Actually some Dell's and IBM's, all with similar specs.) I'm using the audio chips integrated on the motherboards. I believe it's an Intel chip on the Dell, at any rate.
With Audacious at default settings (including PulseAudio output and 500ms buffering), CD's (and to some extent MP3's) play with some skips/dropouts, especially during the first 30 seconds, but continuing at some rate after that.
Pardon the comparison, but VLC does not have this problem, and I think that it likewise is using PulseAudio on ALSA, so I am hoping it's a settings issue, since I would much rather use Audacious for this purpose.
I tried, by the way, setting output directly to ALSA. This seems to solve the skips/dropouts, but Audacious volume control falls apart. It goes from too soft to too loud at a single step near the bottom of the slider.
Can I edit Audacious and/or PulseAudio settings to fix or minimize this?
The first thing to try is increasing the buffer size (for example, to 2 or 3 seconds). Also disable any visualizations (including the built-in one: View -> Show Info Bar Visualization).
If that doesn't work, you can try bypassing PulseAudio completely. Doing so takes more than setting the output plugin to ALSA, since PulseAudio takes over ALSA when it is running. Go into the ALSA settings in Audacious and set the PCM device to "hw:0,0" and the mixer device to "hw:0". Then kill the PulseAudio server. If the volume control is still too sensitive with pure ALSA, it's likely that some slider besides "Master" is turned up too high. Often there is a "PCM" slider and sometimes separate ones for speakers and headphones as well. The old alsamixer program will show you all of them (and can therefore be a bit overwhelming)--many GUI mixers secretly hide some of the less-common sliders.
Back in the day, I used to use Audacious (I think it was version 1.2) on a Pentium II @ 300 MHz and never had trouble with dropouts. So with the right settings, you should have no trouble running it on a Pentium 4.
Thanks for the ideas.
I should have noted that I did try increasing the buffer size to 3 seconds, which seemed to help just a little.
John Lindgren wrote:
Then kill the PulseAudio server.
Returning to work on this today and having a closer look at this piece of your course of action: If I kill the PA server permanently so that Audacious always works, it seems that I'm likely to foul up browser audio and anything else that normally relies on it. And even if they generally fall back to ALSA, I'm imagining unexpected results.
In short, this seems less like cosmetic surgery and more like organ removal.
Am I over-reacting?
I don't think John Lindgren was suggesting that you run like that permanently, but just for troubleshooting purposes (to see if it's a problem with pulseaudio or with your hardware/driver). Note that you may need to add your user to the 'audio' group in /etc/group. You'll also need to disable pulseaudio from auto-respawning itself when you kill it:
echo autospawn = no >> ~/.config/pulse/client.conf