[ffmpeg] no longer hardcode version strings in FindFFMPEG script

ports/ffmpeg/CONTROL

@@ -1,6 +1,6 @@
 Source: ffmpeg
 Version: 4.3.2
-Port-Version: 2
+Port-Version: 3
 Homepage: https://ffmpeg.org
 Description: a library to decode, encode, transcode, mux, demux, stream, filter and play pretty much anything that humans and machines have created.
   FFmpeg is the leading multimedia framework, able to decode, encode, transcode, mux, demux, stream, filter and play pretty much anything that humans and machines have created. It supports the most obscure ancient formats up to the cutting edge. No matter if they were designed by some standards committee, the community or a corporation. It is also highly portable: FFmpeg compiles, runs, and passes our testing infrastructure FATE across Linux, Mac OS X, Microsoft Windows, the BSDs, Solaris, etc. under a wide variety of build environments, machine architectures, and configurations.

ports/ffmpeg/FindFFMPEG.cmake.in

@@ -105,7 +105,7 @@ function(find_platform_dependent_optional_libraries)
   set(FFMPEG_PLATFORM_DEPENDENT_LIBS ${FFMPEG_PLATFORM_DEPENDENT_LIBS} PARENT_SCOPE)
 endfunction()
 
-set(FFMPEG_VERSION "4.3.2")
+set(FFMPEG_VERSION "@FFMPEG_VERSION@")
 
 find_dependency(Threads)
 if(UNIX)
@@ -409,28 +409,28 @@ FFMPEG_FIND(libavutil       avutil     avutil.h)
 if (FFMPEG_libavutil_FOUND)
   list(REMOVE_DUPLICATES FFMPEG_INCLUDE_DIRS)
   list(REMOVE_DUPLICATES FFMPEG_LIBRARY_DIRS)
-  set(FFMPEG_libavutil_VERSION "56.51.100" CACHE STRING "")
+  set(FFMPEG_libavutil_VERSION "@LIBAVUTIL_VERSION@" CACHE STRING "")
 
   if(FFMPEG_libavcodec_FOUND)
-    set(FFMPEG_libavcodec_VERSION "58.91.100" CACHE STRING "")
+    set(FFMPEG_libavcodec_VERSION "@LIBAVCODEC_VERSION@" CACHE STRING "")
   endif()
   if(FFMPEG_libavdevice_FOUND)
-    set(FFMPEG_libavdevice_VERSION "58.10.100" CACHE STRING "")
+    set(FFMPEG_libavdevice_VERSION "@LIBAVDEVICE_VERSION@" CACHE STRING "")
   endif()
   if(FFMPEG_libavfilter_FOUND)
-    set(FFMPEG_libavfilter_VERSION "7.85.100" CACHE STRING "")
+    set(FFMPEG_libavfilter_VERSION "@LIBAVFILTER_VERSION@" CACHE STRING "")
   endif()
   if(FFMPEG_libavformat_FOUND)
-    set(FFMPEG_libavformat_VERSION "58.45.100" CACHE STRING "")
+    set(FFMPEG_libavformat_VERSION "@LIBAVFORMAT_VERSION@" CACHE STRING "")
   endif()
   if(FFMPEG_libavresample_FOUND)
-    set(FFMPEG_libavresample_VERSION "4.0.0" CACHE STRING "")
+    set(FFMPEG_libavresample_VERSION "@LIBAVRESAMPLE_VERSION@" CACHE STRING "")
   endif()
   if(FFMPEG_libswresample_FOUND)
-    set(FFMPEG_libswresample_VERSION "3.7.100" CACHE STRING "")
+    set(FFMPEG_libswresample_VERSION "@LIBSWRESAMPLE_VERSION@" CACHE STRING "")
   endif()
   if(FFMPEG_libswscale_FOUND)
-    set(FFMPEG_libswscale_VERSION "5.7.100" CACHE STRING "")
+    set(FFMPEG_libswscale_VERSION "@LIBSWSCALE_VERSION@" CACHE STRING "")
   endif()
 
   list(APPEND FFMPEG_LIBRARIES

ports/ffmpeg/portfile.cmake

@@ -675,6 +675,62 @@ endif()
 
 vcpkg_fixup_pkgconfig()
 
+# Handle version strings
+
+function(extract_regex_from_file out)
+    cmake_parse_arguments(PARSE_ARGV 1 "arg" "" "FILE;REGEX" "")
+    file(READ "${arg_FILE}" contents)
+    if (contents MATCHES "${arg_REGEX}")
+        if(NOT CMAKE_MATCH_COUNT EQUAL 1)
+            message(FATAL_ERROR "Could not identify match group in regular expression \"${arg_REGEX}\"")
+        endif()
+    else()
+        message(FATAL_ERROR "Could not find line matching \"${arg_REGEX}\" in file \"${arg_FILE}\"")
+    endif()
+    set("${out}" "${CMAKE_MATCH_1}" PARENT_SCOPE)
+endfunction()
+
+function(extract_version_from_component out)
+    cmake_parse_arguments(PARSE_ARGV 1 "arg" "" "COMPONENT" "")
+    string(TOLOWER "${arg_COMPONENT}" component_lower)
+    string(TOUPPER "${arg_COMPONENT}" component_upper)
+    extract_regex_from_file(major_version
+        FILE "${SOURCE_PATH}/${component_lower}/version.h"
+        REGEX "#define ${component_upper}_VERSION_MAJOR[ ]+([0-9]+)"
+    )
+    extract_regex_from_file(minor_version
+        FILE "${SOURCE_PATH}/${component_lower}/version.h"
+        REGEX "#define ${component_upper}_VERSION_MINOR[ ]+([0-9]+)"
+    )
+    extract_regex_from_file(micro_version
+        FILE "${SOURCE_PATH}/${component_lower}/version.h"
+        REGEX "#define ${component_upper}_VERSION_MICRO[ ]+([0-9]+)"
+    )
+    set("${out}" "${major_version}.${minor_version}.${micro_version}" PARENT_SCOPE)
+endfunction()
+
+extract_regex_from_file(FFMPEG_VERSION
+    FILE "${CURRENT_BUILDTREES_DIR}/${TARGET_TRIPLET}-rel/libavutil/ffversion.h"
+    REGEX "#define FFMPEG_VERSION[ ]+\"(.+)\""
+)
+
+extract_version_from_component(LIBAVUTIL_VERSION
+    COMPONENT libavutil)
+extract_version_from_component(LIBAVCODEC_VERSION
+    COMPONENT libavcodec)
+extract_version_from_component(LIBAVDEVICE_VERSION
+    COMPONENT libavdevice)
+extract_version_from_component(LIBAVFILTER_VERSION
+    COMPONENT libavfilter)
+extract_version_from_component( LIBAVFORMAT_VERSION
+    COMPONENT libavformat)
+extract_version_from_component(LIBAVRESAMPLE_VERSION
+    COMPONENT libavresample)
+extract_version_from_component(LIBSWRESAMPLE_VERSION
+    COMPONENT libswresample)
+extract_version_from_component(LIBSWSCALE_VERSION
+    COMPONENT libswscale)
+
 # Handle copyright
 file(STRINGS ${CURRENT_BUILDTREES_DIR}/build-${TARGET_TRIPLET}-rel-out.log LICENSE_STRING REGEX "License: .*" LIMIT_COUNT 1)
 if(LICENSE_STRING STREQUAL "License: LGPL version 2.1 or later")

versions/baseline.json

@@ -1942,7 +1942,7 @@
     },
     "ffmpeg": {
       "baseline": "4.3.2",
-      "port-version": 2
+      "port-version": 3
     },
     "ffnvcodec": {
       "baseline": "10.0.26.0",
@@ -6613,4 +6613,4 @@
       "port-version": 1
     }
   }
-}
+}

versions/f-/ffmpeg.json

@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "d70a90e893854dbcb0efbe740f286baf47adafef",
+      "version-string": "4.3.2",
+      "port-version": 3
+    },
     {
       "git-tree": "95a584d785f17bb9158d505bedfda26aa1c52db1",
       "version-string": "4.3.2",