[mythtv-users] Using btaudio

clloyd at lloyd.dyndns.org clloyd at lloyd.dyndns.org
Fri Feb 28 19:36:52 UTC 2003


I should have seen the stereo in the description, sorry.

Your analog experience still sounds similar to mine.
Did you try a sampling rate of 448000 (Don't forget 
the extra 0) and then let sox linear interpolate?


Quoting David Tarkowski <david.tarkowski at verizon.net>:

> * Chuck Lloyd (clloyd at lloyd.dyndns.org) [030227 21:51]:
> > I've had a similar experience with my WinTV GO. My guess
> > is that if the card doesn't advertise that it supports
> > stereo, then the digital stereo input doesn't work.
> 
> The card that I am using is the AverTV Stereo, so it should support the
> digital interface.  The documentation for btaudio says that the rate
> parameter to the module might help, but I've tried all of the logical rates
> that I could think of without success.
> 
> > I had similar experience with the crappy analog audio.
> > I think it is a mismatch in the sampling rates. I found
> > that the sound was good if I oversampled with sox.
> > 
> > 	http://lloyd.dyndns.org/index.php?Btaudio%20installation
> > 
> > I was working on a code fix to do a simple linear resample.
> > I haven't decided whether to put it in the AudioReader thread
> > or just outside. 
> 
> According to the btaudio doc, the driver supports downsampling to many
> standard rates.  I get the same quality no matter what sampling rate I use.
> The two main problems are pops and a high frequency hiss.  I've figured out
> that the pops were just clipping (I don't understand why there was
> clipping,
> but I can work around it).  
> 
> I was playing around last night and was doing some signal analysis of the
> signal that I get from the btaudio and I discovered that the frequency
> distribtion has two peaks around 15 kHz and 21 kHz IIRC.  The peaks are
> actually present in the line in signal, but they are many dB smaller.  I'm
> going to play around with some digital filtering this weekend if I get a
> chance and how much of a difference that makes.
> 
> -Dave
> 
> 
> > 
> > Chuck
> > 
> > -----Original Message-----
> > From: mythtv-users-bounces at snowman.net
> > [mailto:mythtv-users-bounces at snowman.net]On Behalf Of David Tarkowski
> > Sent: Thursday, February 27, 2003 8:29 PM
> > To: mythtv-users at snowman.net
> > Subject: [mythtv-users] Using btaudio
> > 
> > 
> > Hi,
> > 
> > I noticed in the hardware database that a lot of people are using AverTv
> > cards.  I'm using the AverTV stereo card, and was wondering if anybody
> has
> > made it work with the btaudio driver.  I can get sound from the analog
> > device, but the digital device doesn't give me anything.  The analog
> sound
> > sounds awful.  Has anybody had more success than me?
> > 
> > If not, is there a list of hardware anywhere that works well with the
> > btaudio driver?  I would really like to do the pausing live TV thing.
> > 
> > Thanks,
> > Dave
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users at snowman.net
> > http://www.snowman.net/mailman/listinfo/mythtv-users
> > 
> 
> -- 
> "Do not taunt Happy Fun Ball"  -SNL
> 





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