uaudio - distorted output

[Alexander Leidinger]

Quoting Hans Petter Selasky <hps at selasky.org> (from Mon, 9 Oct 2017  
22:38:32 +0200):

> On 10/09/17 21:47, Alexander Leidinger wrote:
>>> If you are using multi channel audio equipment with 24-bits, try  
>>> to avoid FULL-speed ones!

I have now tried every single USB connector, external and internal.  
None of them attaches to the EHCI bus. :( The only connector which I  
was not able to test is labeled "USB SSD" and has a smaller pin-grid  
than those other internal usb-PIN-connectors with cables to the front  
of the case.

I think I will now buy a PCIe USB3.0 card. Anything I should avoid?  
Anything you recommend? I found this:
     
www.amazon.de/CSL-Express-Controller-SATA-Stromanschluss-Schnittstellenkarte/dp/B00OBACW0G
which seems to have some VLI chip on it. I haven't found anything  
usable in terms of vendor/product ID or such.
4 ports may be enough, for an external USB backup HD, the soundcard,  
and a video device, but for ~10 EUR difference...

>> Well... first I want to get the 2 channel 16bit case working...  
>> then I will have a look at extending this to 5.1 (most probably  
>> 16bit, that's enough to watch action movies).
>
> Hi,
>
> Some more ideas:
>
> 2 channel 16 bit will only work if you turn off bitperfect. The

I activated bitperfect as a test because I got the distortion and was  
hoping to either gain some lower-latency or at least get rid of some  
layers of code to rule out issues there.

> lowest number of channels the device exports is 4 for playback. That  
> means the kernel will re-format 2 channels to 4 channels always and  
> that is done by the PCM feeder. You'll need to check that there is a  
> filter which handle that.
>
> You might want to install virtual_oss from ports to handle this  
> device properly.

In the end I want 5.1 output, so if the bus speed doesn't give me  
this: no need to waste our time with the slow ports.

Bye,
Alexander.

-- 
http://www.Leidinger.net Alexander at Leidinger.net: PGP 0x8F31830F9F2772BF
http://www.FreeBSD.org    netchild at FreeBSD.org  : PGP 0x8F31830F9F2772BF
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