Channel change on watching live tv starts playing old recording

[mythtv@…]

1. Start watching live tv
2. Let the different programs roll over
3. Try and change channel
4. More often than not, the channel does change on the backend and gets recorded, the frontend however rewinds the stream back to the beginning of that session.

This has been happening on head since around April.

[Kenni Lund [kenni a kelu dot dk]]

Please attach full logs from the backend and the frontend when the issue occurs.

I can confirm from a friend of mine that this bug also affects latest 0.27-fixes and apparently has done it for at least a couple of months. I'll see if I can get him to provide logs from 0.27-fixes.

[mythtv@…]

mythbackend log file

[mythtv@…]

mythfrontend log file

[mythtv@…]

I've uploaded the log files.

Files started from 13:43 when both frontend & backend were restarted.

There was a live program change at 13:45 which I let run for a few seconds.

I then attempted to change channel.

The system then began playing the stream from the beginning off the session, ie 13:43.

When I let it continue, it finished playing the previous media and began playing what it should have from the new channel.

[bib_aab@…]

Is this ever going to get fixed. It's still happening 7 months later and seems to afdfect everyone.

[stuartm]

If it affected everyone it would probably have been fixed already, it doesn't, not even close.

If developers are unable to reproduce the problem it's very difficult to come up with a fix.

[Jonatan Lindblad]

After a few hours of looking at the logs and the code I think it looks like a race between the LIVETV_CHAIN UPDATE event sent from the backend when a recording is finished and the frontend reading directly from the database.

Looking at the frontend log there are two LIVETV_CHAIN UPDATE events received at 13:45:32.402590 and 13:45:32.543229 with 3 and 4 entries in the chain respectively.

Shortly after at 13:45:32.640686 the live TV chain is read from the database where 4 entries are found.

At 13:45:33.962783 the LIVETV_CHAIN UPDATE event with 3 entries is now processed and the fourth entry is removed. In LiveTVChain::ReloadAll?() m_curpos has now been reset to 0, probably because the entry matching m_cur_chanid/m_cur_startts can no longer be found in m_chain.

At 13:45:33.976393 RingBuffer? calls LiveTVChain::SwitchToNext? which switches back to the second entry in the chain, i.e. m_curpos = 1.

[bib_aab@…]

And still not fixed. It is better on fast systems, but if you have a less powerful one, the problem is more than annoying.

[Stuart Auchterlonie]

Closing all old tickets in trac.

If your issue still persists, please open an issue in Github ​https://github.com/MythTV/mythtv/issues

and reference the existing trac ticket.