Strange Discontinuities

[SirDester]

Hi all,

I posted my problem in General section because it's not strictly connected with DVBViewer or Recording Services (I use both of them).

 

I have a SkyStar USB2 HD CI and I always noticed that recording on some specific Channels (FOX and FOX CRIME) I had a lot of discontinuities errors in the log file resulting from the recording. Analyzing the resultin TS file, it results that all the video and audio PIDs are perfect, while the Teletext PID is full of continuity errors.

 

The transponder is Hotbird13E - 11785H (DVB-S2) 29900 SR, 3/4 FEC.

 

Then I decided to go at a "deeper level", that is not using DVBViewer or Recording Services, but opening the problematic Transponder directly in TransEdit and Analyzing realtime all the traffic on that transponder, to eliminate interaction with the CAM and / or video-audio drivers.

 

That is the result shown in the attachment (and it's only a few minutes of transmission).

 

As you can see, you have only missing packets on the 2 Teletext PIDS regarding the 2 channels above. Leaving it for more time, it will result in an increasing missing packets on them, leaving all the other pids to 0 errors.

 

I also tried some other DVBS-2 transponder, with channels with Teletext PIDs, and the problem does not occurs.

 

The datarate is always something around 64-65Mpbs, both in problematic transponder and in not problematic ones.

The signal is always something arount 98% strength.

 

What I tried so far

- Changing phisical sat cable, connecting the SS2 to another cable coming from the dish -> same result

- Activating or disactivating the "Open Whole Transponder" in DVBViewer or Recording Service configuration -> same result

 

Any advice on where/what I can look to solve this problem ?

 

Thanks in advance to all.

Maurizio.

[hifi25nl]

Do you have also image stuttering? With the same SkyStar USB2 HD CI I have some image stuttering in Sky Italia 29900 bit rate HD channels (more on sports channels), but not in free HD channels on Astra or RAI HD (encryped) on Hotbird.

[Derrick]

The missing packets must be already missing in the transmitted signal. If packets can't be detected correctly at the receiver due to a bad signal, the high rate H.264 streams will be the 1st that will show errors

[SirDester]

@hifi25nl

 

I don't have great shuttering on HD channels, I use mostly recording services rather than live TV with DVBViewer, but using CoreAVC h264 video codec, I don't have great problems.

As you see in the screenshot, VIDEO and AUDIO packets are sent always correctly (except if REAL transmission error happens).

 

@Derrick

 

So, if I understand well, you think it's a source transmission problem ? It can be usefull to test that transponder on another dish and/or with another hardware to confirm this.

Infact it's really strange that only one transponder and 2 PIDs on that transponder are so full of continuity errors.

 

I can also add that, after some other tests, the missing packets arrives at THE SAME TIME on both the problematic PIDs; infact if you leave TS Analyzer opened for a while on that transponder, you'll receive always almost the same missing packets on both PIDs.

 

It's so wierd that the trasmission is bad at the source... but as they happen on the Teletext stream, it can't be noticed so easily... I have to check with original decoder, but it's hard to understand if packets are loss in the subtitle stream using that decoder.

 

If someone has access to Hotbird 13E, can test 10-15 min with TS Analyzer?

 

Thanks for all the time spent.

Maurizio.

[QBox User]

I have looked at 11785H in TransEdit Analyzer. The signal is 74% quality. Over 10+ minutes, there is a normal distribution of missing packets on all PIDs over 150kbps (about 100 on the 10Mbps PID), and 0 or 1 missing packets on lower bit-rate PIDs. There are zero missing packets showing on the two Teletext PIDs.

[SirDester]

Thanks "QBox User" for the test.

 

So my idea was wrong... I really don't understand what can cause this missing packets on the 2 teletext PIDs I'm lost...