FFmpeg random SIGSEGV calling av_dump_format on wrapper

[zt64]

Hi I'm having a very strange issue. I'm using the bytedeco ffmpeg preset and I made a class that wraps the native classes from bytedeco. It's very simple: class AVFormatContextWrapper(internal val native: org.bytedeco.ffmpeg.avformat.AVFormatContext)

override fun dumpFormat(
    index: Int,
    url: String,
    isOutput: Boolean
) {
    av_dump_format(native, index, url, if (isOutput) 1 else 0)
}

And an instance is created like this:

val formatContext = avformat_alloc_context()

avformat_open_input(
    formatContext,
    url,
    null,
    null
).checkError()

return AVFormatContextWrapper(formatContext)

The issue is sometimes when calling certain methods on this wrapper class it will lead to a SIGSEGV, but sometimes it runs fine. All the methods do is pass the native field to the methods. Now if I call the methods directly without the wrapper class, I haven't been able to produce a SIGSEGV, but it's far less convenient and defeats the purpose of my project. I think I've narrowed it down to it being a result of some optimization but I don't know how to verify that and fix it.

hs_err_pid119018.log

I've also seen a few times it produced SIGSEGV when closing using this function

fun close() {
    avformat_close_input(native)
}

It happens much less than av_dump_format. In my entire test I remux a video and its only those two methods that have caused a crash

[saudet]

Please try to set the "org.bytedeco.javacpp.nopointergc" system property to "true".

[zt64]

Thank you for the quick response. I think that did make the crashes stop. Either that or it's very very rare and it just hasn't happened again. I'm gonna keep developing/testing and see what happens

[saudet]

That probably means you're allocating some struct in Java, but not keeping any Java references anywhere, so it gets garbage collected