[mythtv-users] mac build

James Linder jam at tigger.ws
Fri Feb 5 08:53:28 UTC 2021



> On 3 Feb 2021, at 6:43 am, James Linder <jam at tigger.ws> wrote:
> 
> 
> 
>> On 2 Feb 2021, at 10:57 pm, John Pilkington <johnpilk222 at gmail.com> wrote:
>> 
>> On 02/02/2021 13:52, Mark Kendall wrote:
>>> On Tue, 2 Feb 2021 at 00:08, James Linder <jam at tigger.ws> wrote:
>>>> 
>>>> Looks like a good start point, say if you want more:
>>>> 
>>>> * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x16c13e008)
>>>>  * frame #0: 0x00000001044689a8 myth`AudioOutputGraph::GetImage(long long) const + 2008
>>>> myth`AudioOutputGraph::GetImage:
>>>> ->  0x1044689a8 <+2008>: movswl (%rax), %ecx
>>>>    0x1044689ab <+2011>: movl   %ecx, -0x168(%rbp)
>>>>    0x1044689b1 <+2017>: cmpl   $0x1, -0x154(%rbp)
>>>>    0x1044689b8 <+2024>: jle    0x1044689d4               ; <+2052>
>>>> 
>>> If I were a betting man, I'd guess that:-
>>> https://github.com/MythTV/mythtv/blob/fixes/31/mythtv/libs/libmyth/audio/audiooutputgraph.cpp#L287
> 
> Actually that makes sense
> 
> if *most* timestamps are valid and you choose those by chance then all is well
> but if you skip to a bad one then tilt.I never get a crash on E or <space> only on skip
> Also editing good streams (either fixed or good luck recording) then no problems
> 
>>> is the problem. e.g. the timestamps are bogus (due to the problematic
>>> stream) and the error is not picked up and/or checked, we then convert
>>> that timestamp to an offset into a buffer - and don't bounds check the
>>> offset in:-
>>> https://github.com/MythTV/mythtv/blob/fixes/31/mythtv/libs/libmyth/audio/audiooutputgraph.cpp#L123
>>> However - I would expect the issue to be 100% repeatable if that were
>>> the case...
> 
> As I said if you choose the same point then it is repeatable (no doubt) but for testing Johns builg I marked and cut at random :-)
> 
>>> James - when it doesn't crash - do you sometimes see garbage in the
>>> audio graph or does it look 'normal'?
> 
> I'll pay attention and report back
> 
> Thanks Mark, just one niggling point why the mac frontend but never my linux front ends. For past ages I have done my HD cutlist on linux and have never had a crash (SuSE and ubuntu, only built from source) crash.
> On my laptop (mac) I run an ubuntu VM just for editing! (ansible just works on ubuntu, but needs handholding on SuSE)
> 
> (A comment: To some extent I find ubuntu leading the charge in "You WILL do what WE think is best" eg mythtv user for mythtv, sillypasswords not mythtv for sql, you want gsudo? forget it! It's a bad idea and you dont need it.
> at least SuSE have xdg_menu_su)

John is the git repo clean for all your fiddling (presumably debug, not release hence the debug version)

v31-016630a35c

Is mostly working for me, I’d like to build it for High Sierra. Are the fixes John P suggested comitted?
Does your build-script address the python packages oops?

Thanks
James




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