Re: NVrec patch to improve working with btaudio sound

["Brian J. Murrell" <v4l@xxxxxxxxxxxxxxx>]

On Sun, Dec 30, 2001 at 01:26:28AM +0000, Stephen Davies wrote:
> 
> Hi,

Hi Stephen,

> But there is a unpleasant interaction between that code and the btaudio
> drivers' fixed 8k fragment size.

Indeed.

> The big fragments mean a lot of jitter
> in the sampled number of bytes written.  Resulting in NVrec making rather
> large adjustments to the resampling.

Uh-huh!

> The result is 4 or 5% "wow" added to
> the audio. (remember old tape recorders with a flat pinch wheel?)

Good example of what it actually sounds like.

> This patch changes NVrec to change the resampling rate much more
> slowly - so the jitter is proportionatly smaller.  This eliminates the
> wow.

It sure does!  Works slicker than snot on a door-knob!

Now I can stop fussing around with v4l2 volume controls, mixer
settings and all the like and just record with the btaudio device.
Yay!!

> I'd appreciate confirmation from any brave person who'll give this a try -
> I believe Justin's away till the 20th.

Works great on my v4l2/bttv2 0.7.x.

Thanx!

b.

-- 
Brian J. Murrell