Created attachment 206446 [details] patch Clang needs a fix from https://ffmpeg.org/pipermail/ffmpeg-devel/2019-August/247682.html to compile ffmpeg with Altivec. Since VSX is supported only in little-endian variant, we only need a patch for libswscale/ppc/swscale_altivec.c.
The 2019Q3 branch contains ffmpeg-4.1, the patch does not apply there.
A commit references this bug: Author: riggs Date: Fri Aug 23 13:26:29 UTC 2019 New revision: 509646 URL: https://svnweb.freebsd.org/changeset/ports/509646 Log: Fix build on ppc64 / clang. Details: - Import build fix from upstream, see: https://ffmpeg.org/pipermail/ffmpeg-devel/2019-August/247682.html https://trac.ffmpeg.org/ticket/7861 PR: 239782 Submitted by: pkubaj Changes: head/multimedia/ffmpeg/files/patch-libswscale_ppc_swscale__altivec.c