David Ward wrote:
On 06/08/2009 10:17 AM, Devin Heitmueller wrote:
On Mon, Jun 8, 2009 at 10:14 AM, Steven Toth<stoth@xxxxxxxxxxxxxx>
wrote:
Please let me know how I should proceed in solving this. I would be
happy
to provide samples of captured video, results from new tests, etc.
When you tune using azap, and you can see UNC and BER values, what is
the
SNR value and does it move over the course of 30 seconds?
--
Steven Toth - Kernel Labs
http://www.kernellabs.com
Also, I believe UNC and BER display garbage when signal lock is lost,
so do you see the "status" field change when the BER/UNC fields show
data?
Devin
Steven, Devin,
Thanks for your replies. The signal and SNR are usually in the range
0x0128 - 0x0140. They may increment or decrement on a per-second basis
but otherwise remain steady. The status field does not change most of
the time when bit errors occur, but it does lose the lock from time to
time for a second. Here is a representative sample:
david@delldimension:~$ azap -r RTN
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 555000000 Hz
video pid 0x0051, audio pid 0x0052
status 00 | signal 0000 | snr 0000 | ber 00000000 | unc 00000000 |
status 00 | signal 0000 | snr 0000 | ber 00000000 | unc 00000000 |
status 1f | signal 012e | snr 012e | ber 00001b04 | unc 00001b04 |
FE_HAS_LOCK
status 1f | signal 012c | snr 012e | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
Your SNR is very low, 0x12c is 30db. I assume you're using digital cable this is
borderline.
I like my cable system at home to be atleast 32db (0x140) bare minimum, it's
typically 0x160 (36db) for comfort.
It's possible that the tuner and 1409 driver are a little more optimized under
windows.
How much attenuation can you add under windows with signal loss? It's probably
reasonably close to the edge also.
--
Steven Toth - Kernel Labs
http://www.kernellabs.com
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