This little patch makes it build though:
--- a/operations/external/ff-load.c	2018-12-18 09:22:34.467409854 +0100
+++ b/operations/external/ff-load.c	2018-12-18 09:22:50.921379092 +0100
@@ -309,8 +309,8 @@
           g_warning ("codec not found");
         }
 
-      if (p->codec->capabilities & CODEC_CAP_TRUNCATED)
-        p->enc->flags |= CODEC_FLAG_TRUNCATED;
+      if (p->codec->capabilities & AV_CODEC_CAP_TRUNCATED)
+        p->enc->flags |= AV_CODEC_FLAG_TRUNCATED;
 
       if (avcodec_open2 (p->enc, p->codec, NULL) < 0)
         {