opencv: support building with ffmpeg 8 (#456828)

pkgs/by-name/ml/mlt/package.nix

@@ -6,7 +6,7 @@
   cmake,
   pkg-config,
   which,
-  ffmpeg_7,
+  ffmpeg,
   fftw,
   frei0r,
   libdv,
@@ -71,8 +71,8 @@ stdenv.mkDerivation rec {
   ];
 
   buildInputs = [
-    (opencv4.override { inherit ffmpeg_7; })
-    ffmpeg_7
+    (opencv4.override { inherit ffmpeg; })
+    ffmpeg
     fftw
     frei0r
     libdv
@@ -137,7 +137,7 @@ stdenv.mkDerivation rec {
   '';
 
   passthru = {
-    ffmpeg = ffmpeg_7;
+    inherit ffmpeg;
   };
 
   passthru.updateScript = gitUpdater {

pkgs/development/libraries/opencv/4.x.nix

@@ -3,6 +3,7 @@
   stdenv,
   fetchurl,
   fetchFromGitHub,
+  fetchpatch,
   cmake,
   pkg-config,
   unzip,
@@ -58,7 +59,7 @@
   enableVtk ? false,
   vtk,
   enableFfmpeg ? true,
-  ffmpeg_7,
+  ffmpeg,
   enableGStreamer ? true,
   elfutils,
   gst_all_1,
@@ -299,6 +300,16 @@ effectiveStdenv.mkDerivation {
   patches = [
     ./cmake-don-t-use-OpenCVFindOpenEXR.patch
     ./0001-cmake-OpenCVUtils.cmake-invalidate-Nix-store-paths-b.patch
+    (fetchpatch {
+      name = "ffmpeg-8-support.patch";
+      url = "https://github.com/opencv/opencv/commit/90c444abd387ffa70b2e72a34922903a2f0f4f5a.patch";
+      hash = "sha256-iRRparDJoNhrvELH6cAagWcVzpiE2lfivHVxvZyi3ik=";
+    })
+    (fetchpatch {
+      name = "fix-ffmpeg-8-support.patch";
+      url = "https://github.com/opencv/opencv/commit/dbb622b7f59c3f0e5bd3487252ef37cf72dcdcdb.patch";
+      hash = "sha256-MS9WizZQu0Gxw/daDDFmETxcDJYRTyhSq/xK0X5lAZM=";
+    })
   ]
   ++ optionals enableCuda [
     ./cuda_opt_flow.patch
@@ -365,7 +376,7 @@ effectiveStdenv.mkDerivation {
     openjpeg
   ]
   ++ optionals enableFfmpeg [
-    ffmpeg_7
+    ffmpeg
   ]
   ++ optionals (enableGStreamer && effectiveStdenv.hostPlatform.isLinux) [
     elfutils