firefox: upstream moved to ffmpeg from gstreamer

Sadly, they don't support using system library yet (or I was unattentive).

pkgs/applications/networking/browsers/firefox/default.nix

@@ -3,7 +3,7 @@
 , freetype, fontconfig, file, alsaLib, nspr, nss, libnotify
 , yasm, mesa, sqlite, unzip, makeWrapper, pysqlite
 , hunspell, libevent, libstartup_notification, libvpx
-, cairo, gstreamer, gst_plugins_base, icu, libpng, jemalloc, libpulseaudio
+, cairo, icu, libpng, jemalloc, libpulseaudio
 , enableGTK3 ? false
 , debugBuild ? false
 , # If you want the resulting program to call itself "Firefox" instead
@@ -36,7 +36,7 @@ common = { pname, version, sha512 }: stdenv.mkDerivation rec {
       xorg.libXScrnSaver xorg.scrnsaverproto pysqlite
       xorg.libXext xorg.xextproto sqlite unzip makeWrapper
       hunspell libevent libstartup_notification /* libvpx */ /* cairo */
-      gstreamer gst_plugins_base icu libpng jemalloc
+      icu libpng jemalloc
       libpulseaudio # only headers are needed
     ]
     ++ lib.optional enableGTK3 gtk3;
@@ -58,7 +58,6 @@ common = { pname, version, sha512 }: stdenv.mkDerivation rec {
       "--enable-system-pixman"
       "--enable-system-sqlite"
       #"--enable-system-cairo"
-      "--enable-gstreamer"
       "--enable-startup-notification"
       "--enable-content-sandbox"            # available since 26.0, but not much info available
       "--disable-content-sandbox-reporter"  # keeping disabled for now

pkgs/applications/networking/browsers/firefox/wrapper.nix

@@ -2,7 +2,7 @@
 
 ## various stuff that can be plugged in
 , gnash, flashplayer, hal-flash
-, MPlayerPlugin, gecko_mediaplayer, gst_all, xorg, libpulseaudio, libcanberra
+, MPlayerPlugin, gecko_mediaplayer, ffmpeg, xorg, libpulseaudio, libcanberra
 , supportsJDK, jrePlugin, icedtea_web
 , trezor-bridge, bluejeans, djview4, adobe-reader
 , google_talk_plugin, fribid, gnome3/*.gnome_shell*/
@@ -45,12 +45,11 @@ let
       ++ lib.optional (cfg.enableAdobeReader or false) adobe-reader
       ++ lib.optional (cfg.enableEsteid or false) esteidfirefoxplugin
      );
-  libs = [ gst_all.gstreamer gst_all.gst-plugins-base ]
+  libs = [ ffmpeg ]
          ++ lib.optionals (cfg.enableQuakeLive or false)
          (with xorg; [ stdenv.cc libX11 libXxf86dga libXxf86vm libXext libXt alsaLib zlib ])
          ++ lib.optional (enableAdobeFlash && (cfg.enableAdobeFlashDRM or false)) hal-flash
          ++ lib.optional (config.pulseaudio or false) libpulseaudio;
-  gst-plugins = with gst_all; [ gst-plugins-base gst-plugins-good gst-plugins-bad gst-plugins-ugly gst-ffmpeg ];
   gtk_modules = [ libcanberra ];
 
 in
@@ -76,7 +75,7 @@ stdenv.mkDerivation {
     ];
   };
 
-  buildInputs = [makeWrapper] ++ gst-plugins;
+  buildInputs = [makeWrapper];
 
   buildCommand = ''
     if [ ! -x "${browser}/bin/${browserName}" ]
@@ -91,7 +90,6 @@ stdenv.mkDerivation {
         --suffix LD_LIBRARY_PATH ':' "$libs" \
         --suffix-each GTK_PATH ':' "$gtk_modules" \
         --suffix-each LD_PRELOAD ':' "$(cat $(filterExisting $(addSuffix /extra-ld-preload $plugins)))" \
-        --prefix GST_PLUGIN_SYSTEM_PATH : "$GST_PLUGIN_SYSTEM_PATH" \
         --prefix-contents PATH ':' "$(filterExisting $(addSuffix /extra-bin-path $plugins))" \
         --set MOZ_OBJDIR "$(ls -d "${browser}/lib/${browserName}"*)"