qtscrcpy: switch to latest ffmpeg

[Aleksanaa]

Per the request of #340257 (comment). Tested and seems nothing broken.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 25.05 Release Notes (or backporting 24.11 and 25.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[emilazy]

Thanks. I take it FFmpeg 7 fails? Do you have the error message?

[Aleksanaa]

Thanks. I take it FFmpeg 7 fails? Do you have the error message?

No but the higher the upgrade, the more breaking changes there should be.

[emilazy]

We are trying to move away from these old FFmpeg versions entirely. Arch, for instance, ships FFmpeg 4 for compatibility with a few (mostly binary) packages, and FFmpeg 7, but no FFmpeg 6. Old versions should only be pinned where there is a compatibility issue and it is not possible to get a patch from upstream or another distro; please see the advice in pkgs/development/libraries/ffmpeg/default.nix. If it builds with just unversioned ffmpeg, that’s what it should use.

See also the prior work:

• ffmpeg_5: drop #326618
• ffmpeg_4: almost drop #336401

[emilazy]

This builds:

diff --git a/pkgs/by-name/qt/qtscrcpy/package.nix b/pkgs/by-name/qt/qtscrcpy/package.nix
index 88f13a04d0..88b6f36132 100644
--- a/pkgs/by-name/qt/qtscrcpy/package.nix
+++ b/pkgs/by-name/qt/qtscrcpy/package.nix
@@ -7,7 +7,7 @@
   libsForQt5,
   scrcpy,
   android-tools,
-  ffmpeg_4,
+  ffmpeg,
   makeDesktopItem,
   copyDesktopItems,
 }:
@@ -49,6 +49,8 @@
     substituteInPlace QtScrcpy/sndcpy/sndcpy.sh \
       --replace-fail 'ADB=./adb' "ADB=${lib.getExe' android-tools "adb"}" \
       --replace-fail 'SNDCPY_APK=sndcpy.apk' "SNDCPY_APK=$out/share/qtscrcpy/sndcpy.apk"
+    substituteInPlace QtScrcpy/QtScrcpyCore/src/device/decoder/decoder.cpp \
+      --replace-fail 'avcodec_close(m_codecCtx);' ""
   '';
 
   nativeBuildInputs = [
@@ -61,7 +63,7 @@
   buildInputs =
     [
       scrcpy
-      ffmpeg_4
+      ffmpeg
     ]
     ++ (with libsForQt5; [
       qtbase

The deprecated avcodec_close is unnecessary given the immediately following avcodec_free_context call. Since we’re already patching this a bunch it seems fine to me and better than pinning FFmpeg 6. Of course an actual .patch file would be better but that’s probably true of some of the existing postPatch already.