diff --git a/pkgs/by-name/gp/gpac/package.nix b/pkgs/by-name/gp/gpac/package.nix
index ea9f1df7280d..5603ae754edf 100644
--- a/pkgs/by-name/gp/gpac/package.nix
+++ b/pkgs/by-name/gp/gpac/package.nix
@@ -2,12 +2,14 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  gitUpdater,
+  unstableGitUpdater,
   cctools,
   pkg-config,
   zlib,
-  ffmpeg,
+  ffmpeg-headless,
   freetype,
-  libjpeg,
+  libjpeg_turbo,
   libpng,
   libmad,
   faad2,
@@ -18,7 +20,6 @@
   nghttp2,
   openjpeg,
   libcaca,
-  libXv,
   mesa,
   mesa_glu,
   xvidcore,
@@ -28,42 +29,67 @@
   pulseaudio,
   SDL2,
   curl,
+  xorg,
 
   withFullDeps ? false,
   withFfmpeg ? withFullDeps,
   releaseChannel ? "stable",
 }:
 
-stdenv.mkDerivation rec {
+let
+  stable = rec {
+    version = "2.4.0"; # See below TODO.
+    src = fetchFromGitHub {
+      owner = "gpac";
+      repo = "gpac";
+      rev = "v${version}";
+      hash = "sha256-RADDqc5RxNV2EfRTzJP/yz66p0riyn81zvwU3r9xncM=";
+    };
+    updateScript = gitUpdater {
+      odd-unstable = true;
+      rev-prefix = "v";
+      ignoredVersions = "^(abi|test)";
+    };
+  }
+  // {
+    # ffmpeg 7.0.2 works, but 7.1.1 (which is packaged in nixpkgs) doesn't
+    # because v2.4.0 of this package relies on internal private ffmpeg fields.
+    # TODO: remove this, and switch to simply using ffmpeg-headless,
+    #       when updating stable to 2.6
+    ffmpeg-headless = ffmpeg-headless.override {
+      version = "7.0.2";
+      hash = "sha256-6bcTxMt0rH/Nso3X7zhrFNkkmWYtxsbUqVQKh25R1Fs=";
+    };
+  };
+  unstable = {
+    version = "2.4-unstable-2025-10-26";
+    src = fetchFromGitHub {
+      owner = "gpac";
+      repo = "gpac";
+      rev = "e1a54e81b3befba2b0bffd1d4c1cf50da516c5f3";
+      hash = "sha256-jSMBPuWPmTDCebImdmAcCZl0hEQpJK4QMNGcEXgs3A4=";
+    };
+    updateScript = unstableGitUpdater {
+      tagFormat = "v*";
+      tagPrefix = "v";
+    };
+    inherit ffmpeg-headless;
+  };
+  channelToUse = if releaseChannel == "unstable" then unstable else stable;
+in
+stdenv.mkDerivation (finalAttrs: {
   pname = "gpac";
-  version = if releaseChannel == "nightly" then "2.4-unstable-2025-10-26" else "2.4.0";
+  inherit (channelToUse) version src;
 
-  src =
-    if releaseChannel == "nightly" then
-      fetchFromGitHub {
-        owner = "gpac";
-        repo = "gpac";
-        rev = "e1a54e81b3befba2b0bffd1d4c1cf50da516c5f3";
-        hash = "sha256-jSMBPuWPmTDCebImdmAcCZl0hEQpJK4QMNGcEXgs3A4=";
-      }
-    else
-      fetchFromGitHub {
-        owner = "gpac";
-        repo = "gpac";
-        rev = "v${version}";
-        hash = "sha256-RADDqc5RxNV2EfRTzJP/yz66p0riyn81zvwU3r9xncM=";
-      };
-
-  nativeBuildInputs =
-    [
-      pkg-config
-    ]
-    ++ lib.optionals stdenv.hostPlatform.isDarwin [
-      cctools
-    ]
-    ++ lib.optionals withFfmpeg [
-      ffmpeg
-    ];
+  nativeBuildInputs = [
+    pkg-config
+  ]
+  ++ lib.optionals stdenv.hostPlatform.isDarwin [
+    cctools
+  ]
+  ++ lib.optionals withFfmpeg [
+    channelToUse.ffmpeg-headless
+  ];
 
   # ref: https://wiki.gpac.io/Build/build/GPAC-Build-Guide-for-Linux/#gpac-easy-build-recommended-for-most-users
   buildInputs = [
@@ -71,7 +97,7 @@ stdenv.mkDerivation rec {
   ]
   ++ lib.optionals withFullDeps [
     freetype
-    libjpeg
+    libjpeg_turbo
     libpng
     libmad
     faad2
@@ -82,7 +108,9 @@ stdenv.mkDerivation rec {
     nghttp2
     openjpeg
     libcaca
-    libXv
+    xorg.libX11
+    xorg.libXv
+    xorg.xorgproto
     mesa
     mesa_glu
     xvidcore
@@ -96,6 +124,8 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
+  passthru.updateScript = channelToUse.updateScript;
+
   meta = {
     description = "Open Source multimedia framework for research and academic purposes";
     longDescription = ''
@@ -118,4 +148,4 @@ stdenv.mkDerivation rec {
     ];
     platforms = lib.platforms.unix;
   };
-}
+})
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index aaa4994a3284..1f983ac7f56a 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -14540,16 +14540,7 @@ with pkgs;
     php = php83; # https://github.com/tchapi/davis/issues/195
   };
 
-  gpac = callPackage ../by-name/gp/gpac/package.nix {
-    ffmpeg = ffmpeg.override {
-      version = "7.0.2";
-      hash = "sha256-6bcTxMt0rH/Nso3X7zhrFNkkmWYtxsbUqVQKh25R1Fs=";
-      ffmpegVariant = "headless";
-    };
-  };
-
-  gpac_nightly = callPackage ../by-name/gp/gpac/package.nix {
-    ffmpeg = ffmpeg-headless;
-    releaseChannel = "nightly";
+  gpac-unstable = callPackage ../by-name/gp/gpac/package.nix {
+    releaseChannel = "unstable";
   };
 }