[popcornmix]

That issue was fixed in #0530 and reappeared in #0709. 

If it is that issue, then it's the detection of inline asm. Prior to #709 we had a fix for the issue in the patches, but from #709 the fix should be upstream in ffmpeg code.

@Milhouse can you confirm this line is present in the ffmpeg source tree of your build?
https://github.com/xbmc/FFmpeg/blob/4.0....gure#L1039

It should look like

Code:

"\"$2\""

rather than

Code:

"$2"

Edit: Milhouse have you bumped to ffmpeg 4.0.2 like kodi has?