feat(build): add avcpp deps

nix/0001-fix-build-use-absolute-install-directories.patch

@@ -0,0 +1,62 @@
+From ee5bad7f97fd1cdbc97bf46d2dd17cd8974b6922 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Jonas=20R=C3=B6ger?= <jonas.roeger@tu-dortmund.de>
+Date: Sun, 23 Nov 2025 19:11:49 +0100
+Subject: [PATCH] fix(build): use absolute install directories
+
+---
+ src/CMakeLists.txt | 18 +++++++++---------
+ 1 file changed, 9 insertions(+), 9 deletions(-)
+
+diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
+index b4b53ca..c08d9bb 100644
+--- a/src/CMakeLists.txt
++++ b/src/CMakeLists.txt
+@@ -33,7 +33,7 @@ foreach(TARGET ${AV_TARGETS})
+     target_include_directories(${TARGET}
+         PUBLIC
+           $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+-          $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/avcpp>
++          $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+         PRIVATE
+           ${CMAKE_CURRENT_SOURCE_DIR})
+     set_target_properties(${TARGET} PROPERTIES PUBLIC_HEADER "${AV_HEADERS}")
+@@ -77,12 +77,12 @@ if (AVCPP_NOT_SUBPROJECT)
+ 
+     install(TARGETS ${AV_TARGETS} FFmpeg
+         EXPORT avcpp-targets
+-        LIBRARY DESTINATION        ${CMAKE_INSTALL_LIBDIR}
+-        ARCHIVE DESTINATION        ${CMAKE_INSTALL_LIBDIR}
+-        RUNTIME DESTINATION        ${CMAKE_INSTALL_BINDIR}
+-        INCLUDES DESTINATION       ${CMAKE_INSTALL_INCLUDEDIR}/avcpp
+-        PRIVATE_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/avcpp
+-        PUBLIC_HEADER DESTINATION  ${CMAKE_INSTALL_INCLUDEDIR}/avcpp)
++        LIBRARY DESTINATION        ${CMAKE_INSTALL_FULL_LIBDIR}
++        ARCHIVE DESTINATION        ${CMAKE_INSTALL_FULL_LIBDIR}
++        RUNTIME DESTINATION        ${CMAKE_INSTALL_FULL_BINDIR}
++        INCLUDES DESTINATION       ${CMAKE_INSTALL_FULL_INCLUDEDIR}/avcpp
++        PRIVATE_HEADER DESTINATION ${CMAKE_INSTALL_FULL_INCLUDEDIR}/avcpp
++        PUBLIC_HEADER DESTINATION  ${CMAKE_INSTALL_FULL_INCLUDEDIR}/avcpp)
+ 
+     #cmake_policy(SET CMP0022 OLD)
+     install(EXPORT avcpp-targets
+@@ -94,7 +94,7 @@ if (AVCPP_NOT_SUBPROJECT)
+     configure_package_config_file(
+       "Config.cmake.in"
+       "avcpp-config.cmake"
+-      INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/avcpp
++      INSTALL_DESTINATION ${CMAKE_INSTALL_FULL_LIBDIR}/cmake/avcpp
+ #      PATH_VARS
+ #        CMAKE_INSTALL_LIBDIR
+       )
+@@ -106,7 +106,7 @@ if (AVCPP_NOT_SUBPROJECT)
+           "${CMAKE_CURRENT_BINARY_DIR}/avcpp-config.cmake"
+           "${CMAKE_CURRENT_BINARY_DIR}/avcpp-config-version.cmake"
+         DESTINATION
+-          "${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/cmake/avcpp"
++          "${CMAKE_INSTALL_FULL_LIBDIR}/cmake/avcpp"
+       )
+ 
+     if (PKG_CONFIG_FOUND)
+-- 
+2.50.1
+