At Sat, 16 Jun 2007 16:56:53 +0300, Vasilis Manwlopoulos wrote:
Hi,
Sorry for bothering the list again, but I have major problems with the surround 5.1 sound. I have manually compiled/installed th latest alsa-1.0.14 drivers but nothing improved. I am using Ubuntu 7.04 and my soundcard is the Hercules Fortissimo III. This is, as far as I know by reading on Internet, supported by the module snd-cs46xx in ALSA. I have enabled the surround sound by creating the following .asoundrc file.
pcm.!default { type plug slave.pcm "surround51" slave.channels 6 route_policy duplicate }
The problem is that sound pauses whenever I try to do something "heavy" such as opening a new firefox window or generally another app. Also, there are delays and echo between the front and the rear speakers from time to time. I think that the problem is that, this alsa setup(meaning surround5.1 and the specific soundcard) places a heavy load on the cpu. There are 99% cpu usage times when the only thing active is a player playing a "normal bitrate" mp3. When I delete the .asoundrc file and I switch to default stereo sound using only the 2 front speakers the problems disappear.
Can anyone suggest anything about this?
First, try to investigate whether it's a problem of surround51 implementation or rather the "default" definition above. For example, prepare a 6-channel WAV file, and play directly with surround51 PCM.
But, from the symptom, I'm afraid it's rather a hardware problem. The cs46xx uses three stereo streams for 5.1 output, and they are not strictly synchronized. And, debugging cs46xx driver is really a nightmare...
Takashi