[DO-971] ffmpeg recipe with requirements (!9)

Co-authored-by: aleksandr.vodyanov <aleksandr.vodyanov@avroid.tech>
Reviewed-on: https://git.avroid.tech/Conan/conan_build/pulls/9

recipes/opus/all/patches/1.3.1-add-opus_buildtype-cmake.patch

@@ -0,0 +1,30 @@
+# They forgot to package that file into the tarball for 1.3.1
+# See https://github.com/xiph/opus/issues/129
+
+new file mode 100755
+--- /dev/null
++++ opus_buildtype.cmake
+@@ -0,0 +1,23 @@
++# Set a default build type if none was specified
++
++if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
++  if(CMAKE_C_FLAGS)
++    message(STATUS "CMAKE_C_FLAGS: " ${CMAKE_C_FLAGS})
++  else()
++    set(default_build_type "Release")
++    message(
++      STATUS
++        "Setting build type to '${default_build_type}' as none was specified and no CFLAGS was exported."
++      )
++    set(CMAKE_BUILD_TYPE "${default_build_type}"
++        CACHE STRING "Choose the type of build."
++        FORCE)
++    # Set the possible values of build type for cmake-gui
++    set_property(CACHE CMAKE_BUILD_TYPE
++                 PROPERTY STRINGS
++                          "Debug"
++                          "Release"
++                          "MinSizeRel"
++                          "RelWithDebInfo")
++  endif()
++endif()