On 05/28/2015 01:27 AM, Hurda wrote:
Hello.
I think I came across a bug in either of the drivers si2168 and dvbsky
regarding
blind-scanning DVB-T2-frequencies.
HW: Technotrend CT2-4400v2 (afaik based on or the same as DVBSky T330)
demod: Si2168-B40
tuner: Si2158-A20
OS: Ubuntu 15.04 (kernel 3.19)
In Austria, the DVB-T2-service "SimpliTV" is currently airing up to four
muxes, next to one or two DVB-T-muxes.
In my region, the frequencies are 490MHz, 546MHz, 690MHz, 714MHz for
DVB-T2,
and 498MHz for DVB-T.
These numbers might be of interest when reading the logs.
The peculiar aspect of these T2-muxes is that they're aired on PLP 1
without
there being a PLP 0. I think this is also the root of my problem.
dvbv5-scan is working, but w_scan not?
Could you hack si2168.c file and test?
if (c->delivery_system == SYS_DVBT2) {
/* select PLP */
cmd.args[0] = 0x52;
cmd.args[1] = c->stream_id & 0xff;
// cmd.args[2] = c->stream_id == NO_STREAM_ID_FILTER ? 0 : 1;
cmd.args[2] = 0;
cmd.wlen = 3;
cmd.rlen = 1;
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
}
Antti
When doing a blind-scan using w_scan 20140727 on Ubuntu 15.04 (kernel
3.19),
w_scan does not find any of these four DVB-T2-muxes.
It just finds the DVB-T-mux.
Logs:
media-tree_dmesg_lsusb.txt http://pastebin.com/0ixFPMSA
media-tree_w_scan.txt http://pastebin.com/yyG3jSwj
The found transponder:
initial_v3_media_build_trunk.conf http://pastebin.com/LmFQavpy
initial_v5.conf http://pastebin.com/Jx6kymVt
I also tried a fresh checkout from git.linuxtv.org as of last weekend
and the
most recent w_scan version (20141122).
As you can see, w_scan tries to tune(?) the DVB-T2-frequencies, but
ultimately doesn't find anything on them.
Then I tried the DVBSky-linux-driver[1]
(media_build-bst-20150322.tar.gz)[2]
from their site, which is using a binary called sit2 for this card.
Using this driver, w_scan found all four DVB-T2-muxes and the DVB-T-mux.
Additionally, it found the DVB-T2-muxes during the DVB-T-scan.
Logs:
media_build-bst_dmesg_lsusb.txt http://pastebin.com/vJeDMxtu
media_build-bst_w_scan.txt http://pastebin.com/yhwAYjen
Found transponders:
initial_v3_bst.conf http://pastebin.com/ECKQvRWX
initial_v5_bst.conf http://pastebin.com/CbhY6Hpz
Of course, doing a channel-scan using dvbv5-scan on these transponders
worked
too:
dvbv5_sit2.conf http://pastebin.com/3W52bbhv
dvbv5_sit2.log http://pastebin.com/nc66PTkt
Afterwards, I tried to do a channel-scan with the same initial tuning-file
using the opensource-driver, which also worked:
dvbv5_si2168.conf http://pastebin.com/A6FbqUL1
dvbv5_si2168.log http://pastebin.com/ewyVPJR2
This should verify that tuning PLP 1 without there being PLP 0 is not
the issue.
Additionally, if you compare the two channel-lists, you find interesting
differences:
The scan with si2168 has AUTO for "MODULATION" and "INVERSION" for
DVB-T2-channels, and for "CODE_RATE_LP" and "INVERSION" for DVB-T-channels.
The scan with sit2 has the respective values in the channel-list.
The dvbv5-scan-logs also differ, as using sit2 also displays the signal
quality
during tuning.
I know that there were changes regarding DVB-T2-scanning[3], but as the
blog-
article specifically mentions si2168 and w_scan to be fully dvbv5-compliant
and good for using with DVB-T2, I thought you should know about this
particular problem.
In the attachment I've packed the previously linked logs, for archival
reasons.
Thank you for your attention.
[1] http://www.dvbsky.net/Support_linux.html
[2] http://www.dvbsky.net/download/linux/media_build-bst-150322.tar.gz
[3] http://blog.palosaari.fi/2014/09/linux-dvb-t2-tuning-problems.html
PS: Interesting comments regarding auto-detection for si2168:
http://blog.palosaari.fi/2014/09/linux-dvb-t2-tuning-problems.html?showComment=1427233615765#c8591459871945922951
http://blog.palosaari.fi/2014/09/linux-dvb-t2-tuning-problems.html?showComment=1427234034259#c6500661729983566638
--
http://palosaari.fi/
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