On Mon, 28 Jul 2025 at 02:04, Daniel Bermond <danielberm...@gmail.com> wrote: > > When FFmpeg is compiled with support for both avisynth and libvmaf, > a segmentation fault occurs when using avisynth (.avs) input. > > This happens because both avisynthplus and vmaf have the exactly > same C++ symbol 'Cache::~Cache()'[1][2], which is a C++ destructor. > When using avisynth input, this destructor is also called in the > vmaf side, although no vmaf object was created, thus causing a > segmentation fault. > > Without changing this conflicting symbol in avisynthplus and/or > vmaf upstream code, a solution is to switch the 'RTLD_LOCAL'[3]
I'm not opposed to a workaround to the issues as an interim solution, but has this issue been reported to upstream? Classes with such generic names should be put in a namespace in the respective projects. Additionally it would be good for those projects to be built with -fvisibility=hidden to reduce the amount of exposed symbols and only expose API entry points. - Kacper > flag for 'RTLD_DEEPBIND'[4] when calling 'dlopen()' on the > avisynthplus library. This will make the avisynthplus symbols > loaded by 'dlopen()' to be ahead of the symbols loaded in the > global scope, and consequently avoid the segmentation fault by > preventing the conflicting vmaf C++ destructor to be called. > > More details can be seen in the discussion of the Arch Linux bug > report[5] about this issue. > > [1] > https://github.com/AviSynth/AviSynthPlus/blob/v3.7.5/avs_core/core/cache.h#L62 > [2] https://github.com/Netflix/vmaf/blob/v3.0.0/libvmaf/src/svm.cpp#L75 > [3] https://man.archlinux.org/man/dlopen.3#RTLD_LOCAL > [4] https://man.archlinux.org/man/dlopen.3#RTLD_DEEPBIND > [5] > https://gitlab.archlinux.org/archlinux/packaging/packages/ffmpeg/-/issues/19 > > Signed-off-by: Daniel Bermond <danielberm...@gmail.com> > --- > libavformat/avisynth.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/libavformat/avisynth.c b/libavformat/avisynth.c > index cb2be10925..bef61b4a60 100644 > --- a/libavformat/avisynth.c > +++ b/libavformat/avisynth.c > @@ -120,7 +120,7 @@ typedef struct AviSynthContext { > > static av_cold int avisynth_load_library(AviSynthContext *avs) > { > - avs->avs_library.library = dlopen(AVISYNTH_LIB, RTLD_NOW | RTLD_LOCAL); > + avs->avs_library.library = dlopen(AVISYNTH_LIB, RTLD_NOW | > RTLD_DEEPBIND); > if (!avs->avs_library.library) > return AVERROR_UNKNOWN; > > -- > 2.50.1 > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
