[FFmpeg-user] Zeranoe Windows builds spiking CPU to 100% randomly

[Roger Pack]

> I finally got the hang to appear and that was after completely updating the
> toolchain+x264+ffmpeg to the latest. This is in fact a issue with the latest
> of everything.
>
> I bet the MinGW-w64 guys would know more about this issue. If someone could
> send over the information to their mailing list that would really help. I
> will if no one else can, but it might take a while.

Ok I believe I was able to capture some stack traces during the hang
(thanks to Andy Sheen's build):

https://gist.github.com/3125847

I presume it was built using this script to get the cross compiler:
http://ffmpeg.zeranoe.com/blog/?p=96

I guess I should just forward on all this information to mingw-w64 then?

Also am I correct in presuming that there are basically 2 "mingw"
pthreads libraries out there--this:
https://mingw-w64.svn.sourceforge.net/svnroot/mingw-w64/experimental/winpthreads
and also this:
http://sourceware.org/pthreads-win32/index.html (which is apparently
compatible with 64-bit builds
http://en.wikipedia.org/wiki/POSIX_Threads#POSIX_Threads_for_Windows)

If so then maybe using one instead of the other would work-around the
problem? (it wouldn't fix the bug, of course, but just wondering).

Also this note from the "very sleepy" author:

> Looking at the ffmpeg stuff, my guess would be it's sitting in some kind of spinlock maybe? i.e. every time Sleepy samples the callstack, it causes Windows to schedule a different thread, breaking the spinlock.

Cheers!
-roger-