Move definition of LINUX var

Author: NicolasHug

CMakeLists.txt

@@ -1,6 +1,13 @@
 cmake_minimum_required(VERSION 3.18)
 project(TorchCodec)
 
+# Define LINUX platform variable globally
+if (UNIX AND NOT APPLE)
+    set(LINUX TRUE)
+else()
+    set(LINUX FALSE)
+endif()
+
 add_subdirectory(src/torchcodec/_core)
 
 

src/torchcodec/_core/fetch_and_expose_non_gpl_ffmpeg_libs.cmake

@@ -9,12 +9,6 @@ endif()
 
 include(FetchContent)
 
-if (UNIX AND NOT APPLE)
-    set(LINUX TRUE)
-else()
-    set(LINUX FALSE)
-endif()
-
 set(
     base_url
     https://pytorch.s3.amazonaws.com/torchcodec/ffmpeg/2025-03-14
@@ -136,6 +130,7 @@ FetchContent_Declare(
 
 FetchContent_MakeAvailable(f4 f5 f6 f7 f8)
 
+# makes add_ffmpeg_target available
 include("${CMAKE_CURRENT_SOURCE_DIR}/../share/cmake/TorchCodec/ffmpeg_versions.cmake")
 
 # Note: the f?_SOURCE_DIR variables were set by FetchContent_MakeAvailable

src/torchcodec/share/cmake/TorchCodec/ffmpeg_versions.cmake

@@ -39,7 +39,7 @@ set(TORCHCODEC_SUPPORTED_FFMPEG_VERSIONS "4;5;6;7;8")
 
 # Below we define FFmpeg library names we expect to have for each FFmpeg
 # major version on each platform we support.
-if (UNIX AND NOT APPLE)
+if (LINUX)
     set(
        f4_library_file_names
        libavutil.so.56
@@ -212,7 +212,7 @@ function(add_ffmpeg_target ffmpeg_major_version prefix)
 
     set(target "torchcodec::ffmpeg${ffmpeg_major_version}")
     set(incdir "${prefix}/include")
-    if (UNIX OR APPLE)
+    if (LINUX OR APPLE)
         set(libdir "${prefix}/lib")
     elseif (WIN32)
         set(libdir "${prefix}/bin")