SoundFont 2: skip "marker" presets that reference no samples

documentation/CHANGELOG.md

@@ -35,6 +35,8 @@
 * Omnisphere
   * Fixed: Reading an Omnisphere preset with multiple sample voice elements did only return the samples of the last voice.
   * Fixed: Save formatting of ampersand character when writing.
+* SoundFont 2 (thanks to Douglas Carmichael)
+  * Fixed: "Marker" presets that reference no samples (commercial SoundFonts often include one or two named after the vendor or copyright, e.g. "E-mu Systems 2007") were converted into empty instruments. Presets without any samples are now skipped.
 * TX16W
   * Fixed: First check if the referenced absolute sample file path exists before searching all local folders.
 * Waldorf Quantum/Iridium (thanks to Douglas Carmichael)

src/main/java/de/mossgrabers/convertwithmoss/format/sf2/Sf2Detector.java

@@ -140,6 +140,17 @@ private List<IMultisampleSource> parseSF2File (final File sourceFile, final Sf2F
             if (this.settingsConfiguration.addFileName () || this.settingsConfiguration.addProgramNumber ())
                 presetName = this.addPrefixes (presetName, preset.getProgramNumber (), FileUtils.getNameWithoutType (sourceFile));
             final IMultisampleSource multisampleSource = this.createMultisampleSource (sourceFile, parts, presetName, this.combineToStereo (groups));
+
+            // Skip "empty" presets which reference no samples. Commercial SoundFonts often carry
+            // marker presets named after the vendor or the copyright (e.g. "E-mu Systems 2007")
+            // whose instrument has no zones; without this guard they would be written as empty
+            // instruments.
+            if (multisampleSource.getNonEmptyGroups (false).isEmpty ())
+            {
+                this.notifier.log ("IDS_NOTIFY_SF2_SKIP_EMPTY_PRESET", presetName);
+                continue;
+            }
+
             this.fillMetadata (sf2File, parts, multisampleSource.getMetadata ());
             multisamples.add (multisampleSource);
         }

src/main/resources/Strings.properties

@@ -57,6 +57,7 @@ IDS_NOTIFY_SFZ_PARTIALLY_UNSUPPORTED_TRIGGER=Partially unsupported trigger value
 IDS_NOTIFY_SFZ_UNSUPPORTED_TRIGGER=Unsupported trigger value: %1\n
 IDS_NOTIFY_UNSUPPORTED_OPCODES=Unused SFZ opcodes: %1\n
 IDS_NOTIFY_UNSUPPORTED_GENERATORS=Unused SF2 generators: %1\n
+IDS_NOTIFY_SF2_SKIP_EMPTY_PRESET=Skipping SoundFont preset '%1' because it contains no samples.\n
 IDS_NOTIFY_UNSUPPORTED_ATTRIBUTES=Unused <%1> attributes: %2\n
 IDS_NOTIFY_UNSUPPORTED_ELEMENTS=Unused <%1> child elements: %2\n
 IDS_NOTIFY_ERR_NO_SAMPLE_LENGTH=Could not retrieve length of sample.\n