README file for Winnov Videum Linux Audio Driver 1999 September 21 This file describes how to install the audio driver for the Winnov Videum cards. The driver depends on the video capture drivers, so get the video capture drivers and read wnvreadme.txt if you haven't already. 1. About the Driver The audio driver supports all the audio features of the Videum card, including recording, playing, and all volume control and mixer functions. It follows the OSS sound API. It implements "/dev/dsp" and "/dev/mixer" device types. For more information about OSS and the device types see http://www.opensound.com/pguide/intro.html The driver can record or play audio at 8kHz, 11.025kHz, 12kHz, 16kHz, 22.05kHz, 24kHz, 32kHz, 44.1kHz, and 48kHz. It always uses 16-bit samples. It can use mono or stereo formats. The Videum hardware can support full duplex (simultaneously recording and playing) with some limitations, but the driver was not designed or tested for full duplex. Of course, you can use the audio features of the card simultaneously with video capture, including audio recording or playback. The mixer device supports the following channels: Channel Volume Control Record source? ------- -------------- -------------- Vol Speaker output volume Pcm Digital audio play volume CD CD play volume yes Mix Record source monitor volume Rec Record input gain control Line -none- (LINE input mini-jack) yes Mic -none- (MIC input mini-jack) yes Video -none- (MXC camera microphone) yes All channels are stereo except the camera mic. The record gain control and speaker volume have independent left and right controls, others have a single control that sets both left and right channels the same. 2. Compiling the Driver The driver source file is wnvaud.c. Put this file in the sound driver directory. Typical commands would be: # cd /usr/src/linux/drivers/sound # tar zxvf wnvaud19990827.tgz Edit the Makefile in linux/drivers/sound and find the "obj-m :=" line. Add wnvaud.o to that line like this: obj-m := wnvaud.o Now build modules. # cd /usr/src/linux # make dep # make modules; make modules_install # depmod -a 3. Loading the Driver To load the driver do: # modprobe wnvaud You will have to do that each time after you boot up before you can use the Videum audio. You might want to put that command in your /etc/rc.d/rc.local file. 4. Compatibility The driver does not work with all Videums. It requires the WAVI-97 and CS4218 chips for recording and playback. Therefore it will only work with PCI AV, PnP ISA AV and maybe some legacy ISA cards. For other AV cards, you will have the mixer functions, but you will not be able to record audio or play audio files (for example mp3 or wav files). You will be able to play CDs and hear audio from an input jack. On some older ISA cards, you might not even have the mixer, or it might not work right. It is not tested. Obviously it won't work with VO (video only) cards. If you have a problem check your /var/log/messages file or /proc/kmsg file for error messages. 5. Other Issues I have only tested it on a PCI AV card. I don't really know how well it works on ISA cards. The driver makes a noticable pop sound through the speakers when loading. I don't know what causes that. Maybe one of these days I'll track it down.... You might hear some slight popping or crackling sounds when playing audio while simultaneously capturing video at high rates. This is a minor hardware bug. Thankfully, it only affects playing, not recording. RealProducer does not work properly with Videum when encoding audio below 8kbps. Always encode audio at 8kbps or more. Bill.