msdk: allow user build this plugin against MFX version 2.2+ (oneVPL)

Intel oneVPL SDK (oneVPL) is a successor to Intel Media SDK (MSDK)[1].
User may use -Dmfx_api=MSDK or -Dmfx_api=oneVPL to specify the required
SDK when building this plugin. If the SDK is not specified, meson will
try MSDK firstly, then oneVPL if MSDK is not available

Version 2.2+ is required in this patch because pkg-config file was not
provided officially before version 2.2

[1]https://spec.oneapi.com/versions/latest/elements/oneVPL/source/appendix/VPL_intel_media_sdk.html

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1503>

meson_options.txt

@@ -186,6 +186,10 @@ option('hls-crypto', type : 'combo', value : 'auto', choices : ['auto', 'nettle'
 option('sctp-internal-usrsctp', type: 'feature', value : 'enabled',
        description: 'Whether to use the bundled usrsctp library or the system one')
 
+# MSDK plugin options
+option('mfx_api', type : 'combo', choices : ['MSDK', 'oneVPL', 'auto'], value : 'auto',
+       description : 'Select MFX API to build against')
+
 # Common feature options
 option('examples', type : 'feature', value : 'auto', yield : true)
 option('tests', type : 'feature', value : 'auto', yield : true)

sys/msdk/meson.build

@@ -32,17 +32,24 @@ endif
 
 have_msdk = false
 msdk_dep = []
+use_msdk = false
+use_onevpl = false
 
 msdk_option = get_option('msdk')
 if msdk_option.disabled()
   subdir_done()
 endif
 
-mfx_dep = dependency('libmfx', required: false)
+mfx_api = get_option('mfx_api')
-if mfx_dep.found()
+
+if mfx_api != 'oneVPL'
+  mfx_dep = dependency('libmfx', version: ['>= 1.0', '<= 1.99'], required: false)
+
+  if mfx_dep.found()
     mfx_incdir = mfx_dep.get_pkgconfig_variable('includedir')
     mfx_inc = []
-else
+    use_msdk = true
+  else
     # Old versions of MediaSDK don't provide a pkg-config file
     mfx_root = run_command(python3, '-c', 'import os; print(os.environ.get("INTELMEDIASDKROOT", os.environ.get("MFX_HOME", "")))').stdout().strip()
 
@@ -59,20 +66,39 @@ else
       mfx_lib = cxx.find_library('mfx', dirs: mfx_libdir, required: msdk_option)
       mfx_inc = include_directories(mfx_incdir)
       mfx_dep = declare_dependency(include_directories: mfx_inc, dependencies: mfx_lib)
-  elif msdk_option.enabled()
+      use_msdk = true
-    error('msdk plugin enabled but Intel Media SDK not found: consider setting PKG_CONFIG_PATH, INTELMEDIASDKROOT or MFX_HOME')
+    endif
+  endif
+endif
+
+if not use_msdk and mfx_api != 'MSDK'
+  mfx_dep = dependency('vpl', version: '>= 2.2', required: false)
+
+  if mfx_dep.found()
+    mfx_incdir = mfx_dep.get_pkgconfig_variable('includedir')
+    mfx_inc = []
+    use_onevpl = true
+  endif
+endif
+
+if not use_msdk and not use_onevpl
+  if msdk_option.enabled()
+    error('msdk plugin enabled but the Intel Media SDK or the oneVPL SDK not found: consider setting PKG_CONFIG_PATH, INTELMEDIASDKROOT or MFX_HOME')
   else
     subdir_done()
   endif
 endif
 
-# Old versions of MediaSDK don't have the 'mfx' directory prefix
+# Check oneVPL firstly
-if cxx.has_header('mfx/mfxdefs.h', args: '-I' + mfx_incdir)
+if use_onevpl
+  mfx_incdir = join_paths([mfx_incdir, 'vpl'])
+  mfx_inc = include_directories(mfx_incdir)
+elif cxx.has_header('mfx/mfxdefs.h', args: '-I' + mfx_incdir)
   mfx_incdir = join_paths([mfx_incdir, 'mfx'])
   mfx_inc = include_directories(mfx_incdir)
 endif
 
-if cxx.has_header('mfxvp9.h', args: '-I' + mfx_incdir)
+if use_onevpl or cxx.has_header('mfxvp9.h', args: '-I' + mfx_incdir)
   msdk_sources += [ 'gstmsdkvp9dec.c' ]
   cdata.set10('USE_MSDK_VP9_DEC', 1)
 endif