zren / bomi Goto Github PK

• Support Ubuntu 16.04 LTS

Otherwise I won't be able to build on KDE Neon. Either I find a way to build ffmpeg and statically link it to mpv/bomi, or I continue development in a rolling distro (possibly in a VM), or docker.

• mpv v0.24.0 doesn't recognize --enable-libswresample --disable-libavresample

libswresample checks are hardcoded so the flag is no longer needed.
Note that while this fixes compiling a build, there is currently a runtime segfault when loading a video.

Caused by: mpv-player/mpv@cfda696

• Segfault at runtime when loading a video.

Edit: This is probably because I haven't been properly building libmpv since v0.23.0.

There isn't a segfault if you load bomi without a video, but it will segfault when you open one after.

gdb build/bomi then type run [Enter] told me that the error was in VideoProcessor::open

I added #include "misc/log.hpp" and DECLARE_LOG_CONTEXT(VideoProcessor) to the top of videoprocessor.cpp, then littered the function with _Info("VideoProcessor::open");

The offending line is p->vp->d->vf = vf; which means p->vp is probably foobarred. There's some magical casting going on for p->vp.

auto VideoProcessor::open(vf_instance *vf) -> int
{
    _Info("VideoProcessor::open");
    auto p = reinterpret_cast<bomi_vf_priv*>(vf->priv);
    _Info("reinterpret_cast");
    p->vp = address_cast<VideoProcessor*>(p->address);
    _Info("address_cast");
    p->vp->d->vf = vf; // <= Segfault
    _Info("p->vp->d->vf");
    auto d = p->vp->d;
    _Info("p->vp->d");
    if (p->swdec_deint)
        d->deint_swdec = DeintOption::fromString(_L(p->swdec_deint));
    if (p->hwdec_deint)
        d->deint_hwdec = DeintOption::fromString(_L(p->hwdec_deint));
    _Info("hwdec_deint");

I had no idea what commit broke it. Normally I have a keyword to go on, but the history of vf.c and vf.h didn't reveal anything obvious. So I had to test every single commit between mpv 23 and 24.

I wrote a script ./test to run:

./checkoutmpv $1
./configure --prefix=/usr \
    && make -Winvalid-pch
testVideo="/home/chris/Videos/testvid.mp4"
build/bomi "$testVideo"

Then I ran cd src/mpv && git log --oneline > testall

I trimmed the testall file to only list the commits between 23 and 24. Then I reverse all lines (so it's chronological). I then converted each line into:

# ./test "bbdecb7" "hwdec: add a AVBufferRef(AVHWDeviceContext) field"
# ./test "6b00663" "vo_opengl: hwdec_cuda: export AVHWDeviceContext"
# ./test "3a85976" "cuda: fix AVHWFramesContext initialization"
# ./test "8a23892" "vo_opengl: hwdec_cuda: add yuv420p support"

# ./test "91fb707" "vf_lavfi: switch to AVBufferSrcParameters"

./test "1b1771f" "video: support filtering hardware frames via libavfilter"

./test "083e470" "manpage: add comment about --alpha being broken on X11/EGL/Mesa"
./test "fb6481e" "stream_bluray: use proper 0-based idx"
./test "64041f9" "cuda: fix 10 bit decoding"

Using binary search, I eventually found the offending commit that broke things.

Caused by: mpv-player/mpv@1b1771f

video: support filtering hardware frames via libavfilter
Requires a bunch of hacks:

^--- Yay...

After reading the commit, I realized I probably should have started testing with the 2 or 3 commits (and the commit that preceded them) that touched vf.c and vf.h. Oh well.

I'm not quite sure what to do here...