Bug #4166

timeshift not working for some channels

Added by Kai Sommerfeld 9 months ago. Updated 8 months ago.

Status:FixedStart date:2017-01-06
Priority:NormalDue date:
Assignee:Jaroslav Kysela% Done:

100%

Category:Timeshift
Target version:-
Found in version:4.1-2405 Affected Versions:

Description

timeshift not working for some channels. trace log attached.

Tuned two channels, for every channel I

1) started playback
2) paused
3) unpaused
4) stopped playback

first channel works okay, second channel not.

could not find a pattern which kind of channels work and which not. It's not SD vs HD, it's not encrypted vs unecrypted. afaik the problem occurred only with encrypted channels, but not with all of them. strange.

hope, the trace log shown the problem and gives a hint for a solution.

debug.txt Magnifier - timeshift trace log (6.23 MB) Kai Sommerfeld, 2017-01-06 20:09

service.log - [ ERROR] tsfix: transport stream TELETEXT, DTS discontinuity. DTS = 0, last = (17.3 KB) Kai Sommerfeld, 2017-01-07 18:25

filter.png (132 KB) Mark Clarkstone, 2017-01-07 19:59

Associated revisions

Revision 349fa78c
Added by Jaroslav Kysela 9 months ago

timeshift: do not save TELETEXT packets (configurable), fixes #4166

Revision edc9e6cb
Added by Jaroslav Kysela 8 months ago

teletext: avoid to update last_wr_time from TELETEXT packets, fixes #4166

History

#1 Updated by Kai Sommerfeld 9 months ago

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

#2 Updated by Kai Sommerfeld 9 months ago

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

#3 Updated by Kai Sommerfeld 9 months ago

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.

#4 Updated by Kai Sommerfeld 9 months ago

#5 Updated by Mark Clarkstone 9 months ago

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

To confirm, use a stream filter to remove the teletext :).

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.

#6 Updated by Kai Sommerfeld 9 months ago

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

#7 Updated by zapp -it 9 months ago

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 :(

#8 Updated by Kai Sommerfeld 9 months ago

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.

#9 Updated by zapp -it 9 months ago

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

#10 Updated by Jaroslav Kysela 9 months ago

  • Status changed from New to Fixed
  • % Done changed from 0 to 100

#11 Updated by Jaroslav Kysela 9 months ago

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).

#12 Updated by Kai Sommerfeld 9 months ago

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?

#13 Updated by zapp -it 9 months ago

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.

#15 Updated by Kai Sommerfeld 9 months ago

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.

#16 Updated by zapp -it 9 months ago

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.

#17 Updated by Jaroslav Kysela 9 months ago

  • Status changed from Fixed to Accepted
  • Assignee changed from Adam Sutton to Jaroslav Kysela

#18 Updated by Eddsch K 9 months ago

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

#19 Updated by Jaroslav Kysela 8 months ago

  • Status changed from Accepted to Fixed

#20 Updated by Jaroslav Kysela 8 months ago

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

#21 Updated by Kai Sommerfeld 8 months ago

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

#22 Updated by Jaroslav Kysela 8 months ago

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

#23 Updated by zapp -it 8 months ago

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!

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