[linux-dvb] Re: Newstruct and DVB-C with QAM_256

[bruce@staff.cs.usyd.edu.au (Bruce Janson)]

    ...
    Date: Wed, 03 Jul 2002 11:52:03 +0200
    From: Holger Waechtler <holger@convergence.de>
    ...
    To: Martin Neuditschko <yosuke.tomoe@gmx.net>
    CC: DVB-ML <linux-dvb@linuxtv.org>
    ...
    
    Martin Neuditschko wrote:
    ...
    > If I do "./czap RTL2", I get following output:
    > status 00 | signal 9696 | snr d6d6 | ber 000fffff | unc 0000007f |
    > status 00 | signal 8080 | snr d8d8 | ber 000fffff | unc 0000007f |
    > status 00 | signal 7c7c | snr d7d7 | ber 000fffff | unc 0000007f |
    > status 1f | signal ffff | snr eded | ber 000fffff | unc 0000007f | FE_HAS_LOCK
    > status 1f | signal ffff | snr eeee | ber 0001f3df | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eeee | ber 0001f3df | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009efb | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009dea | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr ecec | ber 00009dea | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009d9c | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009d9c | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr ebeb | ber 00009d0b | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009d0b | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009c1d | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009e96 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009e96 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009f49 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eaea | ber 00009f49 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009ed4 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009f2a | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eeee | ber 00009f2a | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr ecec | ber 00009d50 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009d50 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eded | ber 00009c07 | unc 00000000 | FE_HAS_LOCK
    > status 1f | signal ffff | snr eeee | ber 00009eb3 | unc 00000000 | FE_HAS_LOCK
    ...
    signal: signal strength, usually evaluated by the inverse gain value
             of the AGC circuit. This is a 16bit unsigned integer, 0xffff
             means a saturated AGC circuit, if you run in troubles you might
             want to try to install a signal attentuator between your antenna
             cable and the DVB card
    
    snr:    signal-to-noise ratio, a 16bit unsigned int. 0x0000 means a bad
             signal, 0xffff is too good to be real
    ...

Holger,
    In the above output, both signal and snr are unusual 16-bit
values in that they each appear to have identical most significant
and least significant bytes.  Is this coincidence or are they really
just duplicated 8-bit values?

Cheers,
bruce.




-- 
Info:
To unsubscribe send a mail to listar@linuxtv.org with "unsubscribe linux-dvb" as subject.