[mythtv] Call for testing branch devel/ffmpeg-resync (mpegts-harmonize)

[Paul Harrison]

On 25/07/2022 13:37, John Pilkington wrote:

> On 25/07/2022 12:03, Klaas de Waal wrote:
>> FYI, Fedora in itself does not cause the additional boundary checks 
>> on std::array.
>> This happens in the RPMFusion package builds because they define a 
>> special GCC preprocessor symbol -D_GLIBCXX_ASSERTIONS.
>> If you define this symbol in an Ubuntu build then I expect it will do 
>> the boundary checking as well.
>> The backtrace itself does not indicate a boundary check so I think 
>> this is a different problem.
>>
>> Klaas.
>>
>>
>> On Mon, 25 Jul 2022 at 12:39, Paul Harrison <mythtv at mythqml.net 
>> <mailto:mythtv at mythqml.net>> wrote:
>>
>>     On 24/07/2022 18:42, John Pilkington wrote:
>>
>>      > On 24/07/2022 16:57, Paul Harrison wrote:
>>      >>
>>      >> I wonder if this could be related to the other Fedora crash
>>     reported
>>      >> recently in Issue #589. It seems by default there is more bounds
>>      >> checking being done in Fedora which can cause aborts.
>>      >>
>>      >> https://github.com/MythTV/mythtv/issues/589
>>     <https://github.com/MythTV/mythtv/issues/589>
>>      >>
>>      >>
>>      >> If you can get a backtrace it may be possible to track down
>>     where the
>>      >> problem is.
>>      >>
>>      >>
>>      >> Paul H.
>>      >
>>      > It's certainly true that my update from the
>>      > devel/ffmpeg-resync/morelogs branch to yesterday's
>>     devel/ffmpeg-resync
>>      > was accompanied by what appeared to be a big update of F35,
>>     icluding a
>>      > new kernel.
>>      >
>>      > gdb output attached.
>>      >
>>      >
>>
>>     The backtrace appears to show the abort on shutting down the preview
>>     generator which is consistent with the abort on playback end. It 
>> looks
>>     like something has changed that is causing an abort when closing
>>     playback down. The crash is in FFMpeg but it could be something 
>> we are
>>     doing to cause it. Maybe Scott has a better idea what has changed to
>>     cause this. It could also be that the bug was already there in 
>> previous
>>     versions and the extra bounds checking in Fedora is highlighting the
>>     problem.
>>
>>
>>     Can you reproduce this if you revert back to plain master without 
>> the
>>     ffmpeg-resync changes?
>>
>>
>>     Try to keep your testing as simple as possible. If you have to use
>>     external scripts then that is not really helpful. We need to be 
>> able to
>>     reproduce the problem in stock MythTV if possible.
>>
>>
>>     Paul H.
>>
>
> The last builds I have of master before resync are  32Pre509 from 3 
> July.  There was no hint of this then, or with resyncs before the 
> batch on 23 July.  I don't expect difficulty in building current 
> master for F35, but I haven't done it yet.
>
> Attached is gdb output for mythcommflag --rebuild on a BBC ONE DVB-T 
> raw fragment.
>
> John P
>

That looks like same as the other abort in malloc_consolidate() you 
reported so it's consistent at least :) Any chance you can run it under 
valgrind?


Paul H.