fix: missing guard for NO_XIPH_LIBS in mixer_output and in some tests

CHANGELOG.md

@@ -1,6 +1,6 @@
-
 ##### 4.1.5 (XX Xxx 2026)
 - fix web: crash with `--optimization-level=0` due to HEAPU8.buffer declared as JSArrayBuffer #526
+- fix: missing guard for NO_XIPH_LIBS that prevents building when using it #528
 
 ##### 4.1.4 (31 Jul 2026)
 - fix: the voice-ended callback is no longer invoked while SoLoud's audio mutex is held. The symptom was a wedged engine: handles and sources still looked valid, no audio was produced, and `deinit()` never completed. Ended voices are now queued and dispatched once the mutex is released. Thanks to @Colton127 #518

example/tests/tests/async_multi_load.dart

@@ -10,7 +10,7 @@ Future<OutputBuffer> testAsyncMultiLoad() async {
     SoLoud.instance.loadAsset('assets/audio/8_bit_mentality.mp3'),
     SoLoud.instance.loadAsset('assets/audio/explosion.mp3'),
     SoLoud.instance.loadAsset('assets/audio/IveSeenThings.mp3'),
-    SoLoud.instance.loadAsset('assets/audio/sample-vorbis.ogg'),
+    SoLoud.instance.loadAsset('assets/audio/sample-MP3.mp3'),
     SoLoud.instance.loadAsset('assets/audio/tic-1.wav'),
     SoLoud.instance.loadAsset('assets/audio/tic-2.wav'),
   ];

example/tests/tests/mixer_output_capture.dart

@@ -2,6 +2,8 @@ import 'dart:async';
 import 'dart:typed_data';
 
 import 'package:flutter_soloud/flutter_soloud.dart';
+import 'package:flutter_soloud/src/bindings/soloud_controller_ffi.dart'
+    if (dart.library.js_interop) 'package:flutter_soloud/src/bindings/soloud_controller_web.dart';
 
 import 'common.dart';
 
@@ -11,6 +13,15 @@ import 'common.dart';
 Future<OutputBuffer> testMixerOutputCapture() async {
   final output = OutputBuffer();
 
+  final isXiphAvailable = SoLoudController().soLoudFFI.areXiphLibsAvailable();
+
+  if (!isXiphAvailable) {
+    output.writeln(
+      'Skipping mixer output capture test: Xiph libraries not available',
+    );
+    return output;
+  }
+
   await initialize();
 
   final sound = await SoLoud.instance.loadWaveform(

example/tests/tests/mixing_bus.dart

@@ -14,8 +14,7 @@ Future<OutputBuffer> testMixingBus() async {
       await SoLoud.instance.loadAsset('assets/audio/8_bit_mentality.mp3');
   final iveSeenThings =
       await SoLoud.instance.loadAsset('assets/audio/IveSeenThings.mp3');
-  final sample =
-      await SoLoud.instance.loadAsset('assets/audio/sample-vorbis.ogg');
+  final sample = await SoLoud.instance.loadAsset('assets/audio/sample-MP3.mp3');
 
   // Get initial bus count
   final initialBusCount = Buses().buses.length;

example/tests/tests/pull_buffer_test.dart

@@ -19,7 +19,7 @@ Future<OutputBuffer> testPullBuffer() async {
   final strBuf = OutputBuffer();
   await initialize();
 
-  final bytes = (await rootBundle.load('assets/audio/sample-OPUS.opus'))
+  final bytes = (await rootBundle.load('assets/audio/sample-MP3.mp3'))
       .buffer
       .asUint8List();
 

lib/src/exceptions/exceptions_from_cpp.dart

@@ -34,8 +34,8 @@ class SoLoudFileLoadFailedException extends SoLoudCppException {
   @override
   String get description =>
       'File found, but could not be loaded! '
-      'Could be a permission error or the file is corrupted. '
-      '(on the C++ side).';
+      'Could be a permission error, or the file is corrupted, '
+      'or the format is not supported. (on the C++ side).';
 }
 
 // Note: PlayerErrors.fileAlreadyLoaded is not thrown as an exception.

src/mixeroutput/mixer_output.cpp

@@ -39,6 +39,15 @@ PlayerErrors MixerOutput::start(MixerOutputFormat format, int sampleRate,
     return invalidParameter;
   }
 
+#if defined(NO_XIPH_LIBS)
+  // Without the Xiph libraries only the PCM formats (and the WAV encoder,
+  // which does not depend on them) are supported.
+  if (format == MIXER_OUTPUT_OPUS || format == MIXER_OUTPUT_VORBIS ||
+      format == MIXER_OUTPUT_FLAC) {
+    return xiphLibsNotFound;
+  }
+#endif
+
   const bool isCompressed = format == MIXER_OUTPUT_OPUS ||
                             format == MIXER_OUTPUT_VORBIS ||
                             format == MIXER_OUTPUT_FLAC ||

src/soloud/src/audiosource/wav/soloud_wavstream.cpp

@@ -182,12 +182,14 @@ namespace SoLoud
 	{
 		switch (mParent->mFiletype)
 		{
+#if !defined(NO_XIPH_LIBS)
 		case WAVSTREAM_OGG:
 			if (mCodec.mOgg)
 			{
 				delete mCodec.mOgg;
 			}
 			break;
+#endif
 		case WAVSTREAM_FLAC:
 			if (mCodec.mFlac)
 			{
@@ -267,6 +269,7 @@ namespace SoLoud
 				return offset;
 			}
 		break;
+#if !defined(NO_XIPH_LIBS)
 		case WAVSTREAM_OGG:
 			{
 				unsigned int i;
@@ -285,6 +288,7 @@ namespace SoLoud
 				return offset;
 			}
 			break;
+#endif
 		case WAVSTREAM_WAV:
 			{
 				unsigned int i, j, k;
@@ -319,13 +323,15 @@ namespace SoLoud
 
 			switch (mParent->mFiletype)
 			{
+#if !defined(NO_XIPH_LIBS)
 			case WAVSTREAM_OGG:
 				mCodec.mOgg->seek(pos);
 				mOffset = pos;
 				newPosition = float(pos / mBaseSamplerate);
 				mStreamPosition = newPosition;
 				mStreamEnded = false;
 				return 0;
+#endif
 			case WAVSTREAM_FLAC:
 				drflac_seek_to_pcm_frame(mCodec.mFlac, pos);
 				mOffset = pos;
@@ -364,12 +370,14 @@ namespace SoLoud
 	{
 		switch (mParent->mFiletype)
 		{
+#if !defined(NO_XIPH_LIBS)
 		case WAVSTREAM_OGG:
 			if (mCodec.mOgg)
 			{
 				mCodec.mOgg->rewind();
 			}
 			break;
+#endif
 		case WAVSTREAM_FLAC:
 			if (mCodec.mFlac)
 			{