virtualbox.org

Hi All,

I'm trying to use a mic to dictate text (using Dragon Naturally Speaking) to an XP guest. I get no audio on the guest. I have tried ALSA, OSS, you name it but either I get silence or I get very weird results (using windows sound recorder) whereby it either fails to even begin recording or it records about a 1/4 second every 5 seconds. I.e. after 10s of recording I may have a blank file that is only 1 second long. Very odd. But either way, I can't get it to work. I am using ICH AC97 as the emulated h/w.

I see a lot of posts from ppl having problems recording audio, it seems it is not tested well by Oracle as it is considered "rare" usage (http://www.virtualbox.org/ticket/215). I guess it is rarer than audio output, which works fine for me no matter what settings I use BTW.

Thanks folks,

Paul

Host OS: 64 bit Open SUSE 11.1, 2.6.27.54 kernel, AMD 955 4 core CPU, 8GB RAM, VIA VT1708S Audio chipset
Guest OS: 32-bit XP, SP3, 650MB RAM (there are no other apps on there at the moment, just plain Windows).
VB PUEL, 3.2.10.r66523, latest guest additions installed in XP, just upgraded from 3.2.8 to see if it was fixed as it didn't work on .8 either but no luck.

In my experience, a Windows XP guest on a multi-core system uses very high CPU even when the guest is idle. And when there's a lot of disk activity (which would be expected when recording audio) the whole OS bogs down and slows to a crawl, even on a fast computer. When recording audio, this is the last thing you'd want to happen. I would imagine that this is what's causing your audio recording problems. What I would do is first update the HAL in the XP guest, and then move the XP VDI to an SATA controller. I wrote guides on my blog on exactly how to do this. I hope they help you. Good luck.

Updating the HAL
http://winipulator.blogspot.com/2010/11 ... e-for.html
How to enable the SATA controller
http://winipulator.blogspot.com/2010/11 ... r-for.html

thanks a lot for the reply. Even though it doesn't directly address my issue it is still very good information to have. I had no idea that the virtual IDE controller was a CPU hog. Do you happen to know if this is also true for Linux guests? I am presuming not..

From my experience, Ubuntu as a guest is installed with the SATA controller enabled. I suppose VirtualBox does this automatically, because Ubuntu has built-in drivers for SATA. As for HAL issues with Ubuntu, I don't know of any. The only CPU change I do with Ubuntu guests is that I only assign one core (CPU) of my dual-core hardware to the VM. (I do the same with XP.) From what I've read in the forums, VB doesn't seem to utilize multi-cores assigned to a guest very well. From my own experience, I've noticed that VMs seem to run smoother with only one CPU assigned. Maybe the upcoming release of VB may address some of these issues.

I hope I may have been able to help resolve some of your audio recording issues. Good luck.

EDIT: Another thing I thought of, try using a fixed-size disk instead of dynamically-resizing. Because with a dynamic size disk, VB will have the added overhead of having to allocate more space during the recording process. In addition, the resizing will likely add to external fragmentation of the VDI file, which will slow down things even more. After you create a fixed-size disk, turn off VB and do a defrag of the drive that stores the VDI file. Then, start your XP guest and do an internal defrag of the drive from inside. Then you should be good to go. Good luck.

i am a newbie.

pls advise how to setup to record audio. I would like to use rdesktop to connect to virtualbox guest but rdesktop (rdp) does not support audio input as i know.

i was having the same problem with capturing audio in the guest OS (Windows7 and ubuntu - i am using cam studio for video capturing in windows). My host is Windows 2008. I finally managed to capture audio and video using seamless mode. Obviously there is a problem in virtualbox in case of audio input. So what i did was to switch to seamless mode.The source video was running in the guest OS and the capturing software was running in the host OS. Everything worked perfect. Saved the captured file to the sharing folder and then back again to guest os to go on with more editing. Hope this is helpful.