--- a/mozilla-libavcodec58_91.patch	Sat Mar 27 21:45:50 2021 +0100
+++ b/mozilla-libavcodec58_91.patch	Sat May 29 22:52:13 2021 +0200
@@ -1,20 +1,34 @@
-Index: firefox-78.0.2/dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp
-===================================================================
---- firefox-78.0.2.orig/dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp
-+++ firefox-78.0.2/dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp
-@@ -30,6 +30,7 @@ static FFmpegLibWrapper sLibAV;
+# HG changeset patch
+# Parent  e4abeadbbb7a0c63c17177f1d14ea04c77c6128e
+
+diff --git a/dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp b/dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp
+--- a/dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp
++++ b/dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp
+@@ -22,23 +22,27 @@ class FFmpegDecoderModule {
+   static already_AddRefed<PlatformDecoderModule> Create(FFmpegLibWrapper*);
+ };
+ 
+ static FFmpegLibWrapper sLibAV;
+ 
  static const char* sLibs[] = {
  // clang-format off
  #if defined(XP_DARWIN)
++  "libavcodec.58.134.dylib",
 +  "libavcodec.58.91.dylib",
    "libavcodec.58.dylib",
    "libavcodec.57.dylib",
    "libavcodec.56.dylib",
-@@ -37,6 +38,7 @@ static const char* sLibs[] = {
+   "libavcodec.55.dylib",
    "libavcodec.54.dylib",
    "libavcodec.53.dylib",
  #else
++  "libavcodec.so.58.134",
 +  "libavcodec.so.58.91",
    "libavcodec.so.58",
    "libavcodec-ffmpeg.so.58",
    "libavcodec-ffmpeg.so.57",
+   "libavcodec-ffmpeg.so.56",
+   "libavcodec.so.57",
+   "libavcodec.so.56",
+   "libavcodec.so.55",
+   "libavcodec.so.54",