ffmpeg_4: Enable support for AV1 decoding via dav1d by default

This is e.g. required for mpv (depends on ffmpeg_4) to play AV1 videos.
Fixes #54990.

But since dav1d is only a AV1 decoder this doesn't support AV1 encoding
as well (that would require an additional dependency on libaom).
The dependency on dav1d can be disabled by overriding it to null.

1 files changed, 4 insertions, 2 deletions

diff --git a/pkgs/development/libraries/ffmpeg/generic.nix b/pkgs/development/libraries/ffmpeg/generic.nix
index 84260f3f57c..cf2dc56b90a 100644
--- a/pkgs/development/libraries/ffmpeg/generic.nix
+++ b/pkgs/development/libraries/ffmpeg/generic.nix
@@ -1,7 +1,7 @@
 { stdenv, fetchurl, pkgconfig, perl, texinfo, yasm
 , alsaLib, bzip2, fontconfig, freetype, gnutls, libiconv, lame, libass, libogg
 , libssh, libtheora, libva, libdrm, libvorbis, libvpx, lzma, libpulseaudio, soxr
-, x264, x265, xvidcore, zlib, libopus, speex, nv-codec-headers
+, x264, x265, xvidcore, zlib, libopus, speex, nv-codec-headers, dav1d
 , openglSupport ? false, libGLU_combined ? null
 # Build options
 , runtimeCpuDetectBuild ? true # Detect CPU capabilities at runtime
@@ -145,6 +145,7 @@ stdenv.mkDerivation rec {
       (ifMinVer "2.8" "--enable-libopus")
       "--enable-libspeex"
       (ifMinVer "2.8" "--enable-libx265")
+      (ifMinVer "4.2" (enableFeature (dav1d != null) "libdav1d"))
     # Developer flags
       (enableFeature debugDeveloper "debug")
       (enableFeature optimizationsDeveloper "optimizations")
@@ -170,7 +171,8 @@ stdenv.mkDerivation rec {
     ++ optional isLinux alsaLib
     ++ optionals isDarwin darwinFrameworks
     ++ optional vdpauSupport libvdpau
-    ++ optional sdlSupport (if reqMin "3.2" then SDL2 else SDL);
+    ++ optional sdlSupport (if reqMin "3.2" then SDL2 else SDL)
+    ++ optional (reqMin "4.2") dav1d;
 
   enableParallelBuilding = true;