[LAU] USB device gives wrong data?

Hi group,

   I think I have found a problem with the USB sound driver? It appears
that the current drive returns a x'81' for silence but it should be a
x'7f'.

   When I use my laptop's sound device and record without a mic, I get
a file full of x'7f's. If I do the same with my cheap-o USB device
I get a file full of x'81's. The sound quality from the laptop is
unacceptable, so that is way I want to use the USB device.

   I have written a recording program that I have a 'silence' filter
that filters out segments of dead air. It works with the laptop's
sound device but not the USB device. The filter works by remove
x'7f's after allowing a selectable amount. I get the results using
arecord which does not have the filtering.

   The USB device is a C -Media Electronics, Inc. I am running FC6.

> [root@email-addr-hidden ~]# lsmod |grep snd
> snd_usb_audio 81985 0
> snd_usb_lib 21057 1 snd_usb_audio
> snd_rawmidi 28481 1 snd_usb_lib
> snd_hwdep 13637 1 snd_usb_audio
> snd_ali5451 27853 1
> snd_ac97_codec 99813 1 snd_ali5451
> snd_ac97_bus 6593 1 snd_ac97_codec
> snd_seq_dummy 8133 0
> snd_seq_oss 37057 0
> snd_seq_midi_event 11841 1 snd_seq_oss
> snd_seq 57009 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi_event
> snd_seq_device 12365 4 snd_rawmidi,snd_seq_dummy,snd_seq_oss,snd_seq
> snd_pcm_oss 46433 0
> snd_mixer_oss 20545 1 snd_pcm_oss
> snd_pcm 80965 4 snd_usb_audio,snd_ali5451,snd_ac97_codec,snd_pcm_oss
> snd_timer 26693 2 snd_seq,snd_pcm
> snd 58181 140 snd_usb_audio,snd_rawmidi,snd_hwdep,snd_ali5451,snd_ac97_codec,snd_seq_oss,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer
> soundcore 12193 1 snd
> snd_page_alloc 14281 1 snd_pcm

   Where do I report this 'bug' or how do I fix it?

   Thanks for your time. Sorry for the multiple posting, not sure where is
should have gone.

-- 
William Estrada
MrUmunhum@email-addr-hidden
Mt-Umunhum-Wireless.net ( http://Mt-Umunhum-Wireless.net )
Ymessenger: MrUmunhum
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@email-addr-hidden
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user