On 12-04-24 06:42 PM, Andy Walls wrote:
>
> Signal level varaition coupled with the HVR-1600's, at times, mediocre
> digital tuning side:
Ahh. Pity.
> Run 'femon' on the cx18's dvb frontend when you have a live QAM capture
> ongoing.
OK. Ran it all evening during the evening capture window. Started it
at 20:30, sharp to coincide with the evening's recording from that card
also starting at 20:30 sharp. Here's where it found anomalies:
$ nl /var/tmp/femon.out | grep -v "| ber 00000000 | unc 00000000 |"
So you can see, since femon prints an output line each second, the
number on the left is the seconds since 20:30 and we are looking
for any line showing a ber or unc that is non-zero:
1 FE: Samsung S5H1409 QAM/8VSB Frontend (ATSC)
67 status SCVYL | signal 013a | snr 013a | ber 00000198 | unc 00000198 | FE_HAS_LOCK
313 status SCVYL | signal 013c | snr 013c | ber 0000026b | unc 0000026b | FE_HAS_LOCK
457 status SCVYL | signal 013a | snr 013a | ber 0000026e | unc 0000026e | FE_HAS_LOCK
802 status SCVYL | signal 013c | snr 013c | ber 00000265 | unc 00000265 | FE_HAS_LOCK
1093 status SCVYL | signal 013a | snr 013a | ber 0000014b | unc 0000014b | FE_HAS_LOCK
1184 status SCVYL | signal 013a | snr 013a | ber 000001ca | unc 000001ca | FE_HAS_LOCK
1192 status SCVYL | signal 013a | snr 013a | ber 00000267 | unc 00000267 | FE_HAS_LOCK
1385 status SCVYL | signal 013c | snr 013c | ber 0000025d | unc 0000025d | FE_HAS_LOCK
1435 status SCVYL | signal 013c | snr 013c | ber 00000268 | unc 00000268 | FE_HAS_LOCK
1511 status SCVYL | signal 013c | snr 013c | ber 0000026c | unc 0000026c | FE_HAS_LOCK
1657 status SCVYL | signal 013a | snr 013a | ber 0000026a | unc 0000026a | FE_HAS_LOCK
1693 status SCVYL | signal 013a | snr 013c | ber 0000026f | unc 0000026f | FE_HAS_LOCK
1749 status SCVYL | signal 013c | snr 013c | ber 00000184 | unc 00000184 | FE_HAS_LOCK
1796 status SCVYL | signal 013a | snr 013a | ber 00001a8b | unc 00001a8b | FE_HAS_LOCK
1814 status SCVYL | signal 013c | snr 013c | ber 0000026d | unc 0000026d | FE_HAS_LOCK
2028 status SCVYL | signal 013c | snr 013c | ber 00000275 | unc 00000275 | FE_HAS_LOCK
2081 status SCVYL | signal 013c | snr 013c | ber 0000023a | unc 0000023a | FE_HAS_LOCK
2261 status SCVYL | signal 013c | snr 013c | ber 00000264 | unc 00000264 | FE_HAS_LOCK
2307 status SCVYL | signal 013c | snr 013c | ber 00000279 | unc 00000279 | FE_HAS_LOCK
2318 status SCVYL | signal 013c | snr 013c | ber 0000026b | unc 0000026b | FE_HAS_LOCK
2474 status SCVYL | signal 013a | snr 013a | ber 0000026f | unc 0000026f | FE_HAS_LOCK
2533 status SCVYL | signal 013c | snr 013c | ber 00000098 | unc 00000098 | FE_HAS_LOCK
2612 status SCVYL | signal 013a | snr 013a | ber 0000026a | unc 0000026a | FE_HAS_LOCK
2627 status SCVYL | signal 013c | snr 013c | ber 00000108 | unc 00000108 | FE_HAS_LOCK
2671 status SCVYL | signal 013c | snr 013c | ber 00000196 | unc 00000196 | FE_HAS_LOCK
2870 status SCVYL | signal 013c | snr 013c | ber 00000264 | unc 00000264 | FE_HAS_LOCK
3084 status SCVYL | signal 013c | snr 013c | ber 00000274 | unc 00000274 | FE_HAS_LOCK
3220 status SCVYL | signal 013c | snr 013c | ber 00000275 | unc 00000275 | FE_HAS_LOCK
3323 status SCVYL | signal 013c | snr 013c | ber 0000026b | unc 0000026b | FE_HAS_LOCK
3406 status SCVYL | signal 013c | snr 013c | ber 0000024f | unc 0000024f | FE_HAS_LOCK
3433 status SCVYL | signal 013c | snr 013a | ber 0000022a | unc 0000022a | FE_HAS_LOCK
3946 status SCVYL | signal 013c | snr 013c | ber 00000270 | unc 00000270 | FE_HAS_LOCK
4129 status SCVYL | signal 013c | snr 013c | ber 0000026d | unc 0000026d | FE_HAS_LOCK
4275 status SCVYL | signal 013c | snr 013c | ber 00000273 | unc 00000273 | FE_HAS_LOCK
4284 status SCVYL | signal 013c | snr 013c | ber 00000267 | unc 00000267 | FE_HAS_LOCK
4411 status SCVYL | signal 013c | snr 013c | ber 00000270 | unc 00000270 | FE_HAS_LOCK
4718 status SCVYL | signal 013c | snr 013c | ber 00000204 | unc 00000204 | FE_HAS_LOCK
4779 status SCVYL | signal 013c | snr 013c | ber 00000181 | unc 00000181 | FE_HAS_LOCK
4927 status SCVYL | signal 013c | snr 013c | ber 0000025e | unc 0000025e | FE_HAS_LOCK
4973 status SCVYL | signal 013c | snr 013c | ber 00000157 | unc 00000157 | FE_HAS_LOCK
5024 status SCVYL | signal 013c | snr 013c | ber 0000024c | unc 0000024c | FE_HAS_LOCK
5310 status SCVYL | signal 013c | snr 013c | ber 00000190 | unc 00000190 | FE_HAS_LOCK
5328 status SCVYL | signal 013c | snr 013c | ber 00000277 | unc 00000277 | FE_HAS_LOCK
5439 status SCVYL | signal 013a | snr 013a | ber 0000026a | unc 0000026a | FE_HAS_LOCK
5441 status SCVYL | signal 0138 | snr 0138 | ber 0000024f | unc 0000024f | FE_HAS_LOCK
5447 status SCVYL | signal 0138 | snr 0138 | ber 00000266 | unc 00000266 | FE_HAS_LOCK
5885 status SCVYL | signal 013a | snr 013a | ber 000000b3 | unc 000000b3 | FE_HAS_LOCK
5928 status SCVYL | signal 013a | snr 013a | ber 0000020b | unc 0000020b | FE_HAS_LOCK
5942 status SCVYL | signal 013a | snr 013a | ber 0000026b | unc 0000026b | FE_HAS_LOCK
5966 status SCVYL | signal 013a | snr 013a | ber 000004d4 | unc 000004d4 | FE_HAS_LOCK
6178 status SCVYL | signal 013a | snr 013a | ber 0000026c | unc 0000026c | FE_HAS_LOCK
6657 status SCVYL | signal 0138 | snr 013a | ber 0000026e | unc 0000026e | FE_HAS_LOCK
6761 status SCVYL | signal 013a | snr 013a | ber 00000268 | unc 00000268 | FE_HAS_LOCK
6769 status SCVYL | signal 013a | snr 013a | ber 00000276 | unc 00000276 | FE_HAS_LOCK
6777 status SCVYL | signal 013a | snr 013a | ber 00000277 | unc 00000277 | FE_HAS_LOCK
6814 status SCVYL | signal 013a | snr 013a | ber 00000267 | unc 00000267 | FE_HAS_LOCK
6868 status SCVYL | signal 0138 | snr 0138 | ber 00000171 | unc 00000171 | FE_HAS_LOCK
6881 status SCVYL | signal 0138 | snr 0138 | ber 00000198 | unc 00000198 | FE_HAS_LOCK
6891 status SCVYL | signal 0136 | snr 0138 | ber 00000249 | unc 00000249 | FE_HAS_LOCK
6924 status SCVYL | signal 0138 | snr 0138 | ber 0000026b | unc 0000026b | FE_HAS_LOCK
7116 status SCVYL | signal 0138 | snr 0138 | ber 00000150 | unc 00000150 | FE_HAS_LOCK
7119 status SCVYL | signal 0138 | snr 0138 | ber 00000197 | unc 00000197 | FE_HAS_LOCK
7140 status SCVYL | signal 0138 | snr 0138 | ber 00000270 | unc 00000270 | FE_HAS_LOCK
7602 status SCVYL | signal 0138 | snr 0138 | ber 00000264 | unc 00000264 | FE_HAS_LOCK
7716 status SCVYL | signal 0138 | snr 0138 | ber 00000194 | unc 00000194 | FE_HAS_LOCK
7732 status SCVYL | signal 0138 | snr 0138 | ber 00000272 | unc 00000272 | FE_HAS_LOCK
7751 status SCVYL | signal 013a | snr 0138 | ber 00000181 | unc 00000181 | FE_HAS_LOCK
7770 status SCVYL | signal 013a | snr 013a | ber 00000270 | unc 00000270 | FE_HAS_LOCK
7781 status SCVYL | signal 0138 | snr 0138 | ber 0000026f | unc 0000026f | FE_HAS_LOCK
7796 status SCVYL | signal 0138 | snr 0138 | ber 00000275 | unc 00000275 | FE_HAS_LOCK
7808 status SCVYL | signal 0138 | snr 0138 | ber 0000022f | unc 0000022f | FE_HAS_LOCK
7816 status SCVYL | signal 013a | snr 0138 | ber 0000024e | unc 0000024e | FE_HAS_LOCK
7822 status SCVYL | signal 013a | snr 013a | ber 00000270 | unc 00000270 | FE_HAS_LOCK
7956 status SCVYL | signal 0138 | snr 0138 | ber 00000268 | unc 00000268 | FE_HAS_LOCK
8008 status SCVYL | signal 0138 | snr 0138 | ber 0000026d | unc 0000026d | FE_HAS_LOCK
8011 status SCVYL | signal 0138 | snr 0138 | ber 00000260 | unc 00000260 | FE_HAS_LOCK
8232 status SCVYL | signal 013a | snr 013a | ber 0000024b | unc 0000024b | FE_HAS_LOCK
8235 status SCVYL | signal 013a | snr 013a | ber 00000073 | unc 00000073 | FE_HAS_LOCK
8255 status SCVYL | signal 0138 | snr 0138 | ber 00000254 | unc 00000254 | FE_HAS_LOCK
8274 status SCVYL | signal 0138 | snr 0138 | ber 0000024e | unc 0000024e | FE_HAS_LOCK
8303 status SCVYL | signal 0138 | snr 0138 | ber 0000017f | unc 0000017f | FE_HAS_LOCK
8305 status SCVYL | signal 0138 | snr 0138 | ber 00000184 | unc 00000184 | FE_HAS_LOCK
8354 status SCVYL | signal 013a | snr 0138 | ber 00000270 | unc 00000270 | FE_HAS_LOCK
8442 status SCVYL | signal 0138 | snr 0138 | ber 0000024b | unc 0000024b | FE_HAS_LOCK
8473 status SCVYL | signal 0138 | snr 0138 | ber 0000014b | unc 0000014b | FE_HAS_LOCK
8510 status SCVYL | signal 0138 | snr 0138 | ber 00000253 | unc 00000253 | FE_HAS_LOCK
8557 status SCVYL | signal 013a | snr 013a | ber 00000260 | unc 00000260 | FE_HAS_LOCK
8578 status SCVYL | signal 013a | snr 013a | ber 00000259 | unc 00000259 | FE_HAS_LOCK
8639 status SCVYL | signal 0138 | snr 0138 | ber 00000151 | unc 00000151 | FE_HAS_LOCK
8742 status SCVYL | signal 013a | snr 0138 | ber 0000018c | unc 0000018c | FE_HAS_LOCK
8820 status SCVYL | signal 0138 | snr 0138 | ber 00000265 | unc 00000265 | FE_HAS_LOCK
First recording of the evening shows "glitches" at the following
intervals:
4
130
157
396
742
790
1035
1035
1035
1071
1134
1146
1203
1256
1328
1338
1378
1602
1638
1694
Not sure if that's a close enough correlation or not. Not even sure
what those ber and unc values even mean.
> Watch for the BER or UNCorrectable block count to increase at about the
> same time you view a glitch in the video. If this is the case, there is
> something about the signal the HVR-1600 is having trouble with. (The
> older models don't have the best digital tuner and digital demod
> combination out there.)
So just sucky hardware in general?
> If the signal shown in femon is at a relatively high level most of the
> time, then the cable signal probably has an instantaneous signal that
> sometimes overdrives the frontend. An inline attenuator might make the
> problem go away.
> If the signal is at a low level, it may drop below threshold
> occasionally. An in line amplifier, installed as close to where the
> signal comes into you home as possible, might help.
Not sure if those signal and snr values represent normal, low or high
levels. The values displayed above are fairly representative of the
rest of the samples for the period in terms of signal and snr.
> If it's not signal level related and not DMA related, then it is a
> problem with the cx18 driver feeding things to the DVB core, or a
> problem with the DVB core itself.
I guess I will have to leave that up to the expert(s). :-)
b.
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