Tvheadend

The problem is 100% reproducable. Affected channels are always the same.

have to correct myself. it's not always the same channels. so, sometimes it does not work for some channels. :-(

Some more info: "not working" in this context means: pause/resume works in most cases, but skip forward/back always jumps to behin auf timeshift buffer.

And I now can say for sure that it happens exactly, when I say following log line:

2017-01-07 18:13:50.845 [ ERROR] tsfix: transport stream TELETEXT, DTS discontinuity. DTS = 0, last = 1762995681

For every channel producing a line like this timeshift does not work, for all others it does.

I will attach a log where a was tuned to a channel, paused and resumed, tuned next channel ... There you can see that some of the channels have the line in question, some hane not.

Yeah, if I use a stream filter to remove all teletext streams, timeshifting works.

Kai Sommerfeld wrote:

Some more info: "not working" in this context means: pause/resume works in most cases, but skip forward/back always jumps to behin auf timeshift buffer.

And I now can say for sure that it happens exactly, when I say following log line:

2017-01-07 18:13:50.845 [ ERROR] tsfix: transport stream TELETEXT, DTS discontinuity. DTS = 0, last = 1762995681

For every channel producing a line like this timeshift does not work, for all others it does.

I will attach a log where a was tuned to a channel, paused and resumed, tuned next channel ... There you can see that some of the channels have the line in question, some hane not.

Interesting, I have here two channels where timeshifting is not working, dropped and skipped frames in SPMC, if I indeed disable the teletext streams it is working as expected.
On the channels where timeshifting is not working I get:

tsfix: The timediff for TELETEXT is big (1425438079), using current dts

But on other channels where timeshifting is working I also have a timediff error (for example 1 channel):

tsfix: The timediff for TELETEXT is big (4197519308), using current dts

When I start TVH with trace timeshift I don’t see any error in the TVH log sadly :(

I can confirm this.

tsfix: The timediff for TELETEXT is big (1425438079), using current dts

allone does not cause the timeshift bug. For me, only above log entry in combination with

tsfix: transport stream TELETEXT, DTS discontinuity. DTS = 0, last = 1762995681

causes trouble.

Kai Sommerfeld wrote:

I can confirm this.

tsfix: The timediff for TELETEXT is big (1425438079), using current dts

allone does not cause the timeshift bug. For me, only above log entry in combination with

tsfix: transport stream TELETEXT, DTS discontinuity. DTS = 0, last = 1762995681

causes trouble.

Youre right, on the channels where I also have timeshift problems I see indeed the line

tsfix: transport stream TELETEXT, DTS discontinuity. DTS = 0, last = 1425419359

Fixed in v4.1-2412-g349fa78 - the TELETEXT packets may be processed only for LIVE state. It's configurable (default is ignore TELETEXT when shifted).

Hmm, this fix does not seem to work.

No change at all if a keeo the new setting unchecked - timeshift still not working, no functional change to behavior without the fix. Even woorse, if I check the new setting, channels do no longer tune.

Anything I can do to support finding a working fix?

Kai Sommerfeld wrote:

Hmm, this fix does not seem to work.

No change at all if a keeo the new setting unchecked - timeshift still not working, no functional change to behavior without the fix. Even woorse, if I check the new setting, channels do no longer tune.

Anything I can do to support finding a working fix?

Same here, playing with the new option and when I enable the new setting tvh is crashing (and also the external cwc program) sadly.

Update to current master and rebuild, see https://github.com/tvheadend/tvheadend/commit/489ba951501a569042850d6ea0e573a12ceffda7

Crash/deadlock fixed with latest commit, but fix is not working. Toggling the new setting has no effect. TS not working for the channels with described teletext problems.

Kai Sommerfeld wrote:

Crash/deadlock fixed with latest commit, but fix is not working. Toggling the new setting has no effect. TS not working for the channels with described teletext problems.

The same experience here.

awesome, i've got now stable timeshift! I don't need teletext, so that workaround is fine! Thanks for this!

Please, retest with v4.1-2439-gedc9e6c. The 'Include teletext' field should be off (unchecked).

Did a quick check; seems to work now. Thanks.

OK. Note that the teletext data are sent in the live mode to clients but they are not saved to the timeshift buffer / files.

Kai Sommerfeld wrote:

Did a quick check; seems to work now. Thanks.

I also did a quick test with the channels that had teletext problems,it seems to work now, thanx!