> > Just run htop while an alsa-process needs high cpu load. Copy the > line which shows that from (h)top to this bug report. Or just file a > screenshot to a puplic server somewhere. >
Alright: VLC playing a FLAC file on the default device: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 26183 andoru 20 0 1191000 66424 46296 S 13.6 0.8 0:09.43 vlc ___________________________________________________________________________________________________ VLC playing the same file with "Analog Front Speakers" subdevice selected under Audio -> Audio Device: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 26183 andoru 20 0 1195412 69176 48644 S 1.3 0.9 0:11.35 vlc ___________________________________________________________________________________________________ As you can see, the CPU decreased from 13.6% to 1.3% when switching the device. ___________________________________________________________________________________________________ To confirm that this is not an issue with the decoder in VLC here's VLC playing an OGG Vorbis file on the default device: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 26183 andoru 20 0 1263372 76228 48368 S 18.3 1.0 0:15.95 vlc ___________________________________________________________________________________________________ Same test as above, this time with an MP3 file: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 26183 andoru 20 0 1416816 91532 60188 S 17.0 1.2 0:19.64 vlc ___________________________________________________________________________________________________ And foobar2000 playing FLAC OGG and MP3 files, respectively: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2375 andoru 20 0 1153140 62276 13140 S 21.3 0.8 29:36.91 foobar2000+ > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2375 andoru 20 0 1153140 62032 13140 S 24.6 0.8 29:16.33 foobar2000+ > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2375 andoru 20 0 1153140 72756 11808 S 22.6 0.9 29:03.99 foobar2000+ Let me know if you need any additional info. Also, in the initial report, I forgot to mention that when I select "Analog Front Speakers" subdevice in VLC, with some decoders (particularly APE) and when the sample rate is below 44100Hz, I can hear some distortion (crackling on high pitched sounds), so I'm guessing the high CPU usage is maybe due to an inefficient resampler?