ORF 2 Stream Crash on TVH Server

phaze75

Hi there,

For the past few weeks, I’ve been experiencing an issue with the ORF 2 channel stream provided by the Austrian Broadcasting Corporation. This channel is somewhat unique: every day shortly before 19:00, the “national stream” from Vienna switches to one of nine “regional streams” broadcasted by the respective state’s regional station. After about 25 minutes (regional news and weather), the broadcast switches back to the national stream.

These stream switches have always caused brief glitches - sometimes the picture froze but could be fixed by changing channels and returning, other times the stream simply skipped and continued normally.

Recently, however, these glitches seem to cause the ORF 2 stream to crash completely on the TVH server. When that happens, the channel does not recover by itself or by changing channels. All other channels continue to work fine, but ORF 2 remains unavailable until the TVH service is restarted.

I’ve tried enabling debug logs, but unfortunately, there are no error messages at all when the channel crashes. As a result, I now need to restart the TVH service manually almost every day, which is quite inconvenient - especially for my family when I’m not at home.

Could you please advise what I can do to narrow down or diagnose this issue?

Best regards!

DaveH

Here in the UK, BBC output is regularly switched between national and regional broadcasts, particularly for news bulletins, and they don't cause problems. So there may be something in the specifics of how ORF does the broadcasts and switching. Are they satellite or terrestrial for starters? Here we're getting terrestrial broadcasts from the same transmitter, so the switching is done in some location before the transmitter.
It sounds like you're seeing some discontinuity in the signal that's exposing a weakness in TVH's processing. I'd suggest trying to find out exactly what happens when ORF makes the switch (will they tell you?) and that may point to an area in the TVH code that needs examination.

phaze75

DaveH

Are they satellite or terrestrial for starters?

There are terrestrial and satellite broadcasts available. I use the satellite broadcast via Astra 19.2E due to the higher signal bandwith. The signal is scrabled with Irdeto, so I have to use my personal ORF card to descramble the signal.

I'd suggest trying to find out exactly what happens when ORF makes the switch (will they tell you?)

I could try, but I doubt they will tell me - TVH is for sure a non-standard solution for them that is neither tested nor "certified".

DaveH

phaze75 I'd suggest trying to find out exactly what happens when ORF makes the switch (will they tell you?)

I could try, but I doubt they will tell me - TVH is for sure a non-standard solution for them that is neither tested nor "certified".

Your question to them needn't involve TVH at all. You'd be asking about what they do.

You perhaps could also try to see if the terrestrial signal has the same problem.

DeltaMikeCharlie

You could try recording the entire mux as the broadcaster changes the stream. You could then use a DVB analysis tool to see which parameters, if any, change.

phaze75

DeltaMikeCharlie
As TVH crashes I guess I can't record the mux with TVH, can I? This would mean I have to record the mux directly from my minisatip server leaving out TVH entirely, or does the recording need to be descrambled? Which tools would you recommend (preferrably for Win11)?

phaze75

DaveH

Your question to them needn't involve TVH at all. You'd be asking about what they do.

Email's out. Let's see what customer service can do for me. ;-)

You perhaps could also try to see if the terrestrial signal has the same problem.

Unfortunately I don't have the equipment for terrestrial broadcasts.

DeltaMikeCharlie

phaze75 As TVH crashes I guess I can't record the mux with TVH, can I?

You can record the mux without playing or decoding it.

https://docs.tvheadend.org/documentation/creating-a-mux-dump

phaze75

DeltaMikeCharlie

You can record the mux without playing or decoding it.

https://docs.tvheadend.org/documentation/creating-a-mux-dump

Perfect! I will create a dump tonight. Any suggestions on how and what to analyze afterwards?

DeltaMikeCharlie

I have used DVB Inspector,dvbsnoop and tsduck in the past, but only for metadata analysis, not programme streams.

Perhaps even something like FFMPEG may report a change in programme stream parameters during conversion.

You could also play the entire stream using VLC, selecting individual programmes and see if one glitches.

I'm not sure how any of these tools handle encrypted streams. They probably need to be decrypted first. I'm not sure if a TVH mux dump provides a raw encrypted stream or a decrypted one.