libav: link with libavcodec

diff --git a/configure b/configure
index d8cb018980fff170c1d421bd1497d27d01eadd31..870f2a4ad66cee5dc60c4305153ccc89f2c1aaed 100755 (executable)
--- a/configure
+++ b/configure
@@ -108,6 +108,14 @@ fi
 if enabled_or_auto libav; then
   has_libav=true
 
+  if $has_libav && ! check_pkg libavcodec "<=55.0.0"; then
+    has_libav=false
+  fi
+
+  if $has_libav && ! check_pkg libavcodec ">=52.96.0"; then
+    has_libav=false
+  fi
+
   if $has_libav && ! check_pkg libavutil ">=50.43.0"; then
     has_libav=false
   fi