decoder/gme: require GME 0.6 or later

This allows dropping a few compile-time version checks and we can use
pkg-config to detect the library.

NEWS

@@ -16,6 +16,7 @@ ver 0.24 (not yet released)
   - curl: fix busy loop after connection failed
 * decoder
   - ffmpeg: require FFmpeg 4.0 or later
+  - gme: require GME 0.6 or later
   - hybrid_dsd: remove
   - opus: implement bitrate calculation
   - wavpack: require libwavpack version 5

src/decoder/plugins/GmeDecoderPlugin.cxx

@@ -41,20 +41,17 @@ struct GmeContainerPath {
 	unsigned track;
 };
 
-#if GME_VERSION >= 0x000600
 static int gme_accuracy;
-#endif
 static unsigned gme_default_fade;
 
 static bool
 gme_plugin_init([[maybe_unused]] const ConfigBlock &block)
 {
-#if GME_VERSION >= 0x000600
 	auto accuracy = block.GetBlockParam("accuracy");
 	gme_accuracy = accuracy != nullptr
 		? (int)accuracy->GetBoolValue()
 		: -1;
-#endif
+
 	auto fade = block.GetBlockParam("default_fade");
 	gme_default_fade = fade != nullptr
 		? fade->GetUnsignedValue() * 1000
@@ -148,10 +145,8 @@ gme_file_decode(DecoderClient &client, Path path_fs)
 	FmtDebug(gme_domain, "emulator type '{}'",
 		 gme_type_system(gme_type(emu)));
 
-#if GME_VERSION >= 0x000600
 	if (gme_accuracy >= 0)
 		gme_enable_accuracy(emu, gme_accuracy);
-#endif
 
 	gme_info_t *ti;
 	const char *gme_err = gme_track_info(emu, &ti, container.track);

src/decoder/plugins/meson.build

@@ -80,7 +80,7 @@ if libfaad_dep.found()
   decoder_plugins_sources += 'FaadDecoderPlugin.cxx'
 endif
 
-libgme_dep = c_compiler.find_library('gme', required: get_option('gme'))
+libgme_dep = dependency('libgme', version: '>= 0.6', required: get_option('gme'))
 decoder_features.set('ENABLE_GME', libgme_dep.found())
 if libgme_dep.found()
   decoder_plugins_sources += 'GmeDecoderPlugin.cxx'