[Bug lto/85132] ffmpeg runtime segfault with lto

[manuel.lauss at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85132

--- Comment #4 from Manuel Lauss <manuel.lauss at googlemail dot com> ---
(In reply to Martin Liška from comment #3)
> (In reply to Manuel Lauss from comment #2)
> > This is the most minimal ffmpeg config that can trigger the segfault. The
> > interesting switch is "--enabled-hardcoded-tables".  I use the "mpv" Player
> > with a standard mp4 video file to trigger it
> > (https://github.com/mpv-player/mpv/archive/v0.27.2.zip)
> 
> Good. so we have minimal set of options for ffmpeg. Now please explain me
> how to build the MPV tool? Is it really needed? Can't one trigger that
> directly with ffmepg? Please upload somewhere the mp4 file so that I can
> reproduce it.

The segfault happens during initialization of ffmpeg when mpv player starts.  I
can also trigger it with firefox on e.g. youtube: it crashes the tab.


ad mpv: unpack, configure with the following line (you need python3):
CCFLAGS="-O3 -march=znver1 -mtune=znver1 -flto=16 -fno-fat-lto-objects -pipe"
LINKFLAGS="-O3 -march=znver1 -mtune=znver1 -flto=16 -fno-fat-lto-objects -pipe
-Wl,--no-as-needed" ./waf --prefix=/usr --libdir=/usr/lib64 --confdir=/etc/mpv
--docdir=/usr/share/doc/mpv-0.27.2 --htmldir=/usr/share/doc/mpv-0.27.2/html
--enable-libmpv-shared --disable-libmpv-static --disable-static-build
--disable-optimize --disable-debug-build --enable-html-build
--disable-pdf-build --enable-cplugins --disable-zsh-comp --disable-test
--disable-android --enable-iconv --disable-libsmbclient --enable-lua
--lua=luajit --disable-javascript --enable-x11  --disable-build-date configure

./waf build