[mythtv-users] Best tuner? - now driver question
stephen_agent at jsw.gen.nz
Wed Jan 13 14:59:02 UTC 2021
On Tue, 12 Jan 2021 08:53:16 -0800, you wrote:
>I've been studying the performance of my new Hauppauge Quad vs the
>performance of my Old Dvico Fusion dual.
Bare in mind that the signal strength and s/n ratio values reported by
different cards (even from the same manufacturer) can not be compared,
as they will report different values for the same multiplex. These
values are uncalibrated.
>With a -s command line argument, my app will successively monitor each
>of the channels in the file for 10 seconds and log the results,
>including the card used for tuning. With other command line arguments,
>I can specify which card to use and which .conf file to use. Using cron
>jobs, I've been logging signal strength and SNR statistics hourly for
>each of the cards for about 4 days.
>Info was interesting: some times on some channels the Dvico did better,
>other times/channels the Hauppauge did better. Overall, though, they
>are very similar. One of the parameters logged is how many of the
>samples have a lock. 100% lock for the full monitor time (also
>configurable) indicates a reliable recording. Anything less relates to
>varying degrees of pixelation. My signals are mostly good, but some are
>very weather-dependent. When a low moves through with associated south
>wind, forget KOMO!
>After a couple of days, I stopped checking the data and let it run for a
>week before looking again. Unfortunately, after about 3 days the logged
>card started to always be "unknown". That's the default. When the
>program starts, it checks for adapters by listing /dev/dvb. It then
>finds the chip for each adapter using "dmesg | grep 'DVB: registering
>adapter '" which lets me build a unique name for each card. The problem
>occurred when dmesg got overloaded with messages and the old ones were
>dropped. No more output from the dmesg | grep command.
>Whenever I've used dmesg in the past, it showed history all the way back
>to the boot. I never even realized there was a limit, but now the
>driver for the Hauppauge spams dmesg every time it changes channels with
>"xc5000: Firmware dvb-fe-xc5000-1.6.114.fw loaded and running"
>(ridiculous!). With my app changing channels 12 times every hour (plus
>normal use), it takes about 4 days to fill the dmesg ring buffer. The
>Dvico does a similar output to dmesg, but only once per app invocation.
>Are there any experts on drivers on this list? Is there a way I can
>silence these (somewhat) useless log entries? I started to look into
>changing the source for the driver, but that got overwhelming pretty
>quick. I know, now, that relying on dmesg will always, eventually
>break, but normally I end up rebooting every couple of weeks or so for
>other reasons. I'd like to keep my logging working for more than a few
>days, and I can always just record the card ID with something that runs
>on boot, but it just bothers me that something spams my system logs this
>way. Suggestions appreciated.
What distro are you using? If it is Ubuntu, then you should find all
the dmesg logging also in the /var/log/kern.log.* files. These are
rotated by the system in accordance with the settings in the
/etc/logrotate.d/rsyslog file. If you want to keep more in each
kern.log* file, and keep the older logs uncompressed, then you can
make a different entry there for kern.log with customised settings.
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