[linux-dvb] linux-dvb Digest, Vol 41, Issue 93

Zenon Mousmoulas zmousm at admin.grnet.gr
Tue Jun 24 13:30:44 CEST 2008


I can't say. I have only tested this with VLC, which seems to report  
errors mostly for the transport stream (libdvbpsi) and not the video  
decoding itself (ffmpeg). However I am not sure about this, I am  
unable to draw clear conclusions from VLC debugging messages.

I have recorded/dumped a few seconds for each of the two services  
(Astra HD Promo, Anixe HD). Playing back the files with VLC does give  
a slightly better result, i.e. I do get to see some frames of the  
video, when I wouldn't be able to see any while streaming. And it  
looks like Anixe HD is slightly better than Astra HD Promo, but that  
just may be a coincidence. However VLC crashes again eventually. Here  
are some of the relevant messages logged (just a sample):

libdvbpsi error (PSI decoder): TS discontinuity (received 1, expected  
0) for PID 0
libdvbpsi error (PSI decoder): TS duplicate (received 12, expected 13)  
for PID 100
No accelerated IMDCT transform found
libdvbpsi error (misc PSI): Bad CRC_32 (0x055e9456) !!!
libdvbpsi error (misc PSI): Bad CRC_32 (0x25f13ddd) !!!
[00000381] ffmpeg decoder error: more than 5 seconds of late video ->  
dropping frame (computer too slow ?)
and then...
24/06/2008 1:39:09 ΜΜ com.apple.launchd[316]  
([0x0-0x1f31f3].org.videolan.vlc[5229]) Exited abnormally: Bus error

I have published these short clips if you want to try them out yourself:
http://www.admin.grnet.gr/pub/zmousm/astrahd.ts
http://www.admin.grnet.gr/pub/zmousm/anixehd.ts

If you could suggest the necessary ffmpeg syntax, I could try it out.

I seem to have trouble with both these services on this transponder,  
while there's at least one other report that Anixe HD is OK. So I'm  
wondering if it could be the case that my LNB/receiver/dish  
positioning combination is simply not good (sensitive?) enough for  
this specific transponder?

Thanks,
Z.

On 23 Ιουν 2008, at 9:58 ΜΜ, linux-dvb-request at linuxtv.org wrote:

> have you the same problem as I described in vdr list ?
> http://linuxtv.org/pipermail/vdr/2008-May/016766.html
>
>
>
>> I have a Hauppauge HVR-4000. My system is running the latest Debian
>> testing kernel (2.6.24-7) plus drivers from  http://linuxtv.org/hg/v4l-dvb/rev/127f67dea087
>>  patched with http://dev.kewl.org/hauppauge/experimental/mfe-s2-7285.diff
>> , as per the wiki notes (mostly): http://www.linuxtv.org/wiki/index.php/Hauppauge_WinTV-HVR-4000#Drivers
>>
>> I have no problem tuning with http://dev.kewl.org/hauppauge/experimental/szap-meow.tgz
>>  to any DVB-S or DVB-S2 QPSK/8PSK transponder I have tried. However
>> there seems to be a problem with the reception of the Astra HD Promo
>> service at 11914500H on Astra1H. I don't know what the problem is
>> exactly, since tuning seems to work:
>>
>> tvbox2:~# szap-meow -r -p -c diseqc2_Astra-19.2E -m 1 -e 9 -o 2 -w 2
>> ASTRAHDPROMO
>> reading channels from file 'diseqc2_Astra-19.2E'
>> zapping to 1 'ASTRAHDPROMO':
>> sat 1, frequency = 11914 MHz H, symbolrate 27500000, vpid = 0x04ff,
>> apid = 0x0503 sid = 0x0083
>> using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
>> status 1f | signal fd40 | snr 6199 | ber 00000000 | unc 00000000 |
>> FE_HAS_LOCK
>> status 1f | signal fe80 | snr 64cd | ber 00000000 | unc 00000000 |
>> FE_HAS_LOCK
>> status 1f | signal fe40 | snr 6333 | ber 00000000 | unc 00000000 |
>> FE_HAS_LOCK
>> status 1f | signal fd80 | snr 6333 | ber 00000000 | unc 00000000 |
>> FE_HAS_LOCK
>> status 1f | signal fe40 | snr 6199 | ber 00000000 | unc 00000000 |
>> FE_HAS_LOCK
>> status 1f | signal fe80 | snr 6000 | ber 00000000 | unc 00000000 |
>> FE_HAS_LOCK
>>
>> There is an occasional ber > 0 and the snr is not exceptional, but
>> there are other services with much worse snr/ber that have no problem
>> whatsoever.
>>
>> I don't have vdr, mythtv etc. applications installed on the system. I
>> test by redirecting the output of vdr0 to a file, to play back the TS
>> later, or by piping to VLC, to stream on the lan. VLC clearly shows
>> there is a problem because there is always a flood of messages from
>> libdvbpsi on stderr like Bad CRC_32, TS discontinuity, invalid
>> section, PSI section too long etc. I'm not that confident about VLC
>> debugging, but I know for sure this doesn't happen when the service
>> works right.
>>
>> I've tried tuning to freq 11915 as well as using different values for
>> roll-off (-o) and pilot (-w). It doesn't make any difference (-w 1
>> doesn't work if I remember right).
>>
>> The same thing happens with the Anixe HD service, also on the same
>> transponder.
>>
>> I have no problem tuning to other transponders on Astra1H that  
>> carry a
>> mix of scrambled+FTA or FTA-only services, like 11875500H or
>> 12051000V, but they are DVB-S. I also have no problem tuning to DVB- 
>> S2
>> transponders on other LNBs (I have a 4x1 diseqc v1.0 switch with this
>> LNB in position AB), but I could not test any other such transponders
>> with QPSK modulation.
>>
>> I'm wondering what could be the cause of this problem:
>>
>> At first I thought the problem could be that the transponder carries
>> scrambled services as well, but that does not seem to be the case.
>> Then I thought the problem could be the H.264 video payload of the
>> video ES of these services, confusing VLC, hence the many error
>> messages, but I've been able to stream/play at least one other
>> "similar" service (Luxe TV) with no particular problems.
>>
>> Finally I reconsidered the "saga" of the HVR-4000 driver, and started
>> thinking that perhaps I should have gone with one of the other
>> implementations in the first place. I had this card setup a few  
>> months
>> ago with 2.6.24 and multiproto, but I had to redo the installation  
>> and
>> this time I wanted to try to stick with the official linuxtv.org  
>> tree.
>> Could this be the reason? If so, however, I suppose tuning wouldn't
>> work at all, right?
>>
>> Am I missing something here? Any ideas/suggestions you may have are
>> more than welcome...
>>
>> Thanks,
>> Z.
>>
>> PS: Somewhat off-topic question, but here goes anyway, since I have
>> not found a definitive answer: Is there any device with DVB-S2 *and*
>> CI and driver support for both? I have noticed that TT-budget S2-3200
>> + CI could possibly be the one, but I believe the CI part still
>> doesn't work.
>>
>




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