VapourSynth: add lsmas.Version for better version transparency

Signed-off-by: akarin <i@akarin.info>

VapourSynth/README

@@ -170,3 +170,11 @@
                     Same as 'ff_loglevel' of LibavSMASHSource().
                 + cachedir (default : DEFAULT_CACHEDIR)
                     Create *.lwi file under this directory with names encoding the full path to avoid collisions. Set to "" to restore the previous behavior (storing *.lwi along side the source video file).
+
+        [Version]
+            Version()
+                * This function returns a dict containing the following keys:
+                    + version: lsmas version
+                    + config: extra configuration options used during meson build.
+                    + ffmpeg_version: the ffmpeg version used.
+

VapourSynth/lsmashsource.c

@@ -29,6 +29,13 @@
 
 #include "lsmashsource.h"
 
+#include "libavutil/ffversion.h"
+#include "libavcodec/version.h"
+#include "libavformat/version.h"
+#include "libavutil/version.h"
+#include "libswscale/version.h"
+#include "version.h"
+
 void set_error
 (
     lw_log_handler_t *lhp,
@@ -64,6 +71,17 @@ void set_error_on_init
 extern void VS_CC vs_libavsmashsource_create( const VSMap *in, VSMap *out, void *user_data, VSCore *core, const VSAPI *vsapi );
 extern void VS_CC vs_lwlibavsource_create( const VSMap *in, VSMap *out, void *user_data, VSCore *core, const VSAPI *vsapi );
 
+void VS_CC vs_version_create( const VSMap *in, VSMap *out, void *user_data, VSCore *core, const VSAPI *vsapi )
+{
+    vsapi->propSetData(out, "version", VERSION, -1, paAppend);
+    vsapi->propSetData(out, "config", config_opts, -1, paAppend);
+    vsapi->propSetData(out, "ffmpeg_version", FFMPEG_VERSION, -1, paAppend);
+    vsapi->propSetData(out, "ffmpeg_version", LIBAVCODEC_IDENT, -1, paAppend);
+    vsapi->propSetData(out, "ffmpeg_version", LIBAVFORMAT_IDENT, -1, paAppend);
+    vsapi->propSetData(out, "ffmpeg_version", LIBAVUTIL_IDENT, -1, paAppend);
+    vsapi->propSetData(out, "ffmpeg_version", LIBSWSCALE_IDENT, -1, paAppend);
+}
+
 VS_EXTERNAL_API(void) VapourSynthPluginInit( VSConfigPlugin config_func, VSRegisterFunction register_func, VSPlugin *plugin )
 {
     config_func
@@ -92,5 +110,13 @@ VS_EXTERNAL_API(void) VapourSynthPluginInit( VSConfigPlugin config_func, VSRegis
         NULL,
         plugin
     );
+    register_func
+    (
+        "Version",
+        "",
+        vs_version_create,
+        NULL,
+        plugin
+    );
 #undef COMMON_OPTS
 }

VapourSynth/meson.build

@@ -3,6 +3,14 @@ project('L-SMASH-Works', 'c',
   meson_version: '>=0.48.0'
 )
 
+version_h = declare_dependency(
+    sources: vcs_tag(
+        command: ['git', 'describe', '--tags', '--long'],
+        input: 'version.h.in',
+        output: 'version.h'
+    )
+)
+
 add_project_arguments('-DXXH_INLINE_ALL', '-D_FILE_OFFSET_BITS=64', '-DDEFAULT_CACHEDIR=' + get_option('cachedir'), language: 'c')
 
 sources = [
@@ -44,7 +52,8 @@ deps = [
   dependency('libavcodec', version: '>=58.91.0'),
   dependency('libavformat', version: '>=58.45.0'),
   dependency('libavutil', version: '>=56.51.0'),
-  dependency('libswscale', version: '>=5.7.0')
+  dependency('libswscale', version: '>=5.7.0'),
+  version_h
 ]
 
 if host_machine.cpu_family().startswith('x86')

VapourSynth/version.h.in

@@ -0,0 +1,5 @@
+#define VERSION "@VCS_TAG@"
+
+#define STRINGIFY_(x) #x
+#define STRINGIFY(x) STRINGIFY_(x)
+static const char *config_opts = "-Dcachedir=\"" STRINGIFY(DEFAULT_CACHEDIR) "\"";