Re: Problems with ngene based DVB cards (Digital Devices Cine S2 Dual DVB-S2 , Mystique SaTiX S2 Dual)

[Marco Lohse <mlohse@motama.com>]

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Marco Lohse wrote:
> Devin Heitmueller wrote:
> [..]
>> Hi Marco,
>>
>> Ok, great.  Like I said, I will see if I can reproduce it here, as
>> that will help narrow down whether it's really an issue with the ngene
>> bridge, or whether it's got something to do with that particular
>> bridge/demod/tuner combination.
>>
> 
> We made some more tests and found some additional issues that we would
> like to report.
> 

Sorry, I forgot the attachment (modified szap-s2)

> Have fun, Marco
> 
> *Problem A revisited * *****************************
> 
> It was suggested that due to a bug the dvr should never be closed (as a
> work-around)
> 
> How does this affect channel tuning times?
> 
> Test (using the latest version of the modified szap-s2)
> 
> 0) su -c "rmmod ngene && modprobe ngene one_adapter=0"
> 
> 1) Run szap-s2 using a channels.conf with "Das Erste" and "ZDF" on
> different transponders
> 
> szap-s2 -S 1 -H -c channels_DVB-S2_transponder_switch.conf -a 0 -n 1 -i
> reading channels from file 'channels_DVB-S2_transponder_switch.conf'
> 
>>>> Das Erste
> zapping to 1 'Das Erste':
> delivery DVB-S2, modulation QPSK
> sat 0, frequency 11836 MHz H, symbolrate 27500000, coderate auto,
> rolloff 0.35
> vpid 0x0065, apid 0x0066, sid 0x0068
> using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
> Opened frontend
> Opened video demux
> Opened audio demux
> status 1f | signal  69% | snr  67% | ber 1 | unc -2 | FE_HAS_LOCK
> Delay zap_to : 0.586872
> 
>>>> ZDF
> zapping to 2 'ZDF':
> delivery DVB-S2, modulation QPSK
> sat 0, frequency 11953 MHz H, symbolrate 27500000, coderate auto,
> rolloff 0.35
> vpid 0x006e, apid 0x0078, sid 0x0082
> status 1f | signal  67% | snr  63% | ber 1 | unc -2 | FE_HAS_LOCK
> Delay zap_to : 0.580473
> 
>>>> Das Erste
> zapping to 1 'Das Erste':
> delivery DVB-S2, modulation QPSK
> sat 0, frequency 11836 MHz H, symbolrate 27500000, coderate auto,
> rolloff 0.35
> vpid 0x0065, apid 0x0066, sid 0x0068
> status 1f | signal  69% | snr  67% | ber 1 | unc -2 | FE_HAS_LOCK
> Delay zap_to : 0.553754
> 
> => Good, you will see low tuning times.
> 
> 2) in parallel to 1) - and without terminating 1) - run a second
> instance of szap-s2 that reads from the device
> 
> szap-s2 -S 1 -H -c channels_DVB-S2_transponder_switch.conf -a 1 -n 1 -r
> reading channels from file 'channels_DVB-S2_transponder_switch.conf'
> zapping to 1 'Das Erste':
> delivery DVB-S2, modulation QPSK
> sat 0, frequency 11836 MHz H, symbolrate 27500000, coderate auto,
> rolloff 0.35
> vpid 0x0065, apid 0x0066, sid 0x0068
> using '/dev/dvb/adapter1/frontend0' and '/dev/dvb/adapter1/demux0'
> Opened frontend
> Opened video demux
> Opened audio demux
> ..
> 
> 3) while 2) is running, go back to 1) and tune to different transponders
> again:
> 
>>>> ZDF
> zapping to 2 'ZDF':
> delivery DVB-S2, modulation QPSK
> sat 0, frequency 11953 MHz H, symbolrate 27500000, coderate auto,
> rolloff 0.35
> vpid 0x006e, apid 0x0078, sid 0x0082
> status 1f | signal  67% | snr  63% | ber 1 | unc -2 | FE_HAS_LOCK
> Delay zap_to : 1.774598
> 
>>>> Das Erste
> zapping to 1 'Das Erste':
> delivery DVB-S2, modulation QPSK
> sat 0, frequency 11836 MHz H, symbolrate 27500000, coderate auto,
> rolloff 0.35
> vpid 0x0065, apid 0x0066, sid 0x0068
> status 1f | signal  69% | snr  67% | ber 1 | unc -2 | FE_HAS_LOCK
> Delay zap_to : 1.772805
> 
> => Not good, whenver you use both tuners you will see tuning times to
> increase from approx. 0.5 secs to 1.7 secs.
> 
> 
> *Problem B revisited * *****************************
> 
> We also found that when reading data from the dvr device immediately
> after tuning was completed (e.g. the lock was successful), then approx.
> once in 50 iterations, we still get "old" data from the device. With
> "old" I mean from the transponder previously tuned to.
> 
> This results, for example, in the wrong "old" PAT received first.
> 
> Work-around: Simple and annoying. Add a sleep(1) before starting to read
> from device.
> 
> *Remark*
> 
> Both problems can _not_ be reproduced with any other board we tested
> (Tevii, KNC, ..)
> 
> 
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