Vocabulary Log Probabilities API

flutter/sherpa_onnx/lib/src/offline_recognizer.dart

@@ -736,6 +736,7 @@ class OfflineRecognizerResult {
   OfflineRecognizerResult({
     required this.text,
     required this.tokens,
+    required this.tokenLogProbs,
     required this.timestamps,
     required this.lang,
     required this.emotion,
@@ -746,6 +747,10 @@ class OfflineRecognizerResult {
     return OfflineRecognizerResult(
       text: json['text'] as String? ?? '',
       tokens: (json['tokens'] as List?)?.map((e) => e as String).toList() ?? [],
+      tokenLogProbs: (json['token_log_probs'] as List?)
+              ?.map((e) => (e as num).toDouble())
+              .toList() ??
+          [],
       timestamps:
           (json['timestamps'] as List?)
               ?.map((e) => (e as num).toDouble())
@@ -759,12 +764,13 @@ class OfflineRecognizerResult {
 
   @override
   String toString() {
-    return 'OfflineRecognizerResult(text: $text, tokens: $tokens, timestamps: $timestamps, lang: $lang, emotion: $emotion, event: $event)';
+    return 'OfflineRecognizerResult(text: $text, tokens: $tokens, tokenLogProbs: $tokenLogProbs, timestamps: $timestamps, lang: $lang, emotion: $emotion, event: $event)';
   }
 
   Map<String, dynamic> toJson() => {
     'text': text,
     'tokens': tokens,
+    'token_log_probs': tokenLogProbs,
     'timestamps': timestamps,
     'lang': lang,
     'emotion': emotion,
@@ -773,6 +779,7 @@ class OfflineRecognizerResult {
 
   final String text;
   final List<String> tokens;
+  final List<double> tokenLogProbs;
   final List<double> timestamps;
   final String lang;
   final String emotion;
@@ -793,31 +800,32 @@ class OfflineRecognizer {
   /// method of the returned instance to avoid memory leak.
 
   factory OfflineRecognizer(OfflineRecognizerConfig config) {
-    final c = convertConfig(config);
-
     if (SherpaOnnxBindings.createOfflineRecognizer == null) {
       throw Exception("Please initialize sherpa-onnx first");
     }
 
-    final ptr = SherpaOnnxBindings.createOfflineRecognizer?.call(c) ?? nullptr;
+    final c = convertConfig(config);
 
-    if (ptr == nullptr) {
-      throw Exception(
-        "Failed to create offline recognizer. Please check your config",
-      );
+    try {
+      final ptr = SherpaOnnxBindings.createOfflineRecognizer!.call(c);
+      if (ptr == nullptr) {
+        throw Exception(
+          "Failed to create offline recognizer. Please check your config",
+        );
+      }
+      return OfflineRecognizer._(ptr: ptr, config: config);
+    } finally {
+      freeConfig(c);
     }
-
-    freeConfig(c);
-
-    return OfflineRecognizer._(ptr: ptr, config: config);
   }
 
   void setConfig(OfflineRecognizerConfig config) {
     final c = convertConfig(config);
-
-    SherpaOnnxBindings.offlineRecognizerSetConfig?.call(ptr, c);
-
-    freeConfig(c);
+    try {
+      SherpaOnnxBindings.offlineRecognizerSetConfig?.call(ptr, c);
+    } finally {
+      freeConfig(c);
+    }
     // we don't update this.config
   }
 
@@ -1033,6 +1041,7 @@ class OfflineRecognizer {
       return OfflineRecognizerResult(
         text: '',
         tokens: [],
+        tokenLogProbs: [],
         timestamps: [],
         lang: '',
         emotion: '',
@@ -1044,13 +1053,8 @@ class OfflineRecognizer {
 
     SherpaOnnxBindings.destroyOfflineStreamResultJson?.call(json);
 
-    return OfflineRecognizerResult(
-      text: parsedJson['text'],
-      tokens: List<String>.from(parsedJson['tokens']),
-      timestamps: List<double>.from(parsedJson['timestamps']),
-      lang: parsedJson['lang'],
-      emotion: parsedJson['emotion'],
-      event: parsedJson['event'],
+    return OfflineRecognizerResult.fromJson(
+      parsedJson as Map<String, dynamic>,
     );
   }
 

flutter/sherpa_onnx/lib/src/offline_stream.dart

@@ -33,5 +33,49 @@ class OfflineStream {
     calloc.free(p);
   }
 
+  Map<String, List<double>>? getVocabLogProbs() {
+    final getFunc = SherpaOnnxBindings.getOfflineStreamVocabLogProbs;
+    final destroyFunc = SherpaOnnxBindings.destroyVocabLogProbs;
+
+    if (getFunc == null || destroyFunc == null) {
+      return null;
+    }
+
+    final vocabPtr = getFunc(ptr);
+    if (vocabPtr == nullptr) {
+      return null;
+    }
+
+    final vocabLogProbs = vocabPtr.ref;
+    final numTokens = vocabLogProbs.numTokens;
+    final vocabSize = vocabLogProbs.vocabSize;
+
+    // Defensive validation for native values
+    if (numTokens < 0 ||
+        vocabSize < 0 ||
+        numTokens > 10000 ||
+        vocabSize > 100000) {
+      destroyFunc(vocabPtr);
+      return null;
+    }
+
+    final Map<String, List<double>> result = {};
+
+    for (int tokenIdx = 0; tokenIdx < numTokens; tokenIdx++) {
+      final List<double> tokenProbs = [];
+
+      for (int vocabIdx = 0; vocabIdx < vocabSize; vocabIdx++) {
+        final index = tokenIdx * vocabSize + vocabIdx;
+        final logProb = vocabLogProbs.logProbs[index];
+        tokenProbs.add(logProb);
+      }
+
+      result['token_$tokenIdx'] = tokenProbs;
+    }
+
+    destroyFunc(vocabPtr);
+    return result;
+  }
+
   Pointer<SherpaOnnxOfflineStream> ptr;
 }

flutter/sherpa_onnx/lib/src/online_recognizer.dart

@@ -327,32 +327,37 @@ class OnlineRecognizerConfig {
 
 class OnlineRecognizerResult {
   OnlineRecognizerResult(
-      {required this.text, required this.tokens, required this.timestamps});
+      {required this.text, required this.tokens, required this.timestamps, this.ysProbs = const <double>[]});
 
   factory OnlineRecognizerResult.fromJson(Map<String, dynamic> json) {
     return OnlineRecognizerResult(
-      text: json['text'] as String,
-      tokens: List<String>.from(json['tokens'] as List),
-      timestamps: (json['timestamps'] as List)
-          .map<double>((e) => (e as num).toDouble())
-          .toList(),
+      text: json['text'] as String? ?? '',
+      tokens: (json['tokens'] as List?)?.cast<String>().toList() ?? const <String>[],
+      timestamps: (json['timestamps'] as List?)
+          ?.map<double>((e) => (e as num).toDouble())
+          .toList() ?? const <double>[],
+      ysProbs: (json['ys_probs'] as List?)
+          ?.map<double>((e) => (e as num).toDouble())
+          .toList() ?? const <double>[],
     );
   }
 
   @override
   String toString() {
-    return 'OnlineRecognizerResult(text: $text, tokens: $tokens, timestamps: $timestamps)';
+    return 'OnlineRecognizerResult(text: $text, tokens: $tokens, timestamps: $timestamps, ysProbs: $ysProbs)';
   }
 
   Map<String, dynamic> toJson() => {
         'text': text,
         'tokens': tokens,
         'timestamps': timestamps,
+        'ys_probs': ysProbs,
       };
 
   final String text;
   final List<String> tokens;
   final List<double> timestamps;
+  final List<double> ysProbs;
 }
 
 class OnlineRecognizer {
@@ -496,10 +501,9 @@ class OnlineRecognizer {
 
     SherpaOnnxBindings.destroyOnlineStreamResultJson?.call(json);
 
-    return OnlineRecognizerResult(
-        text: parsedJson['text'],
-        tokens: List<String>.from(parsedJson['tokens']),
-        timestamps: List<double>.from(parsedJson['timestamps']));
+    return OnlineRecognizerResult.fromJson(
+      parsedJson as Map<String, dynamic>,
+    );
   }
 
   void reset(OnlineStream stream) {

flutter/sherpa_onnx/lib/src/online_stream.dart

@@ -37,5 +37,49 @@ class OnlineStream {
     SherpaOnnxBindings.onlineStreamInputFinished?.call(ptr);
   }
 
+  Map<String, List<double>>? getVocabLogProbs() {
+    final getFunc = SherpaOnnxBindings.getOnlineStreamVocabLogProbs;
+    final destroyFunc = SherpaOnnxBindings.destroyVocabLogProbs;
+
+    if (getFunc == null || destroyFunc == null) {
+      return null;
+    }
+
+    final vocabPtr = getFunc(this.ptr);
+    if (vocabPtr == nullptr) {
+      return null;
+    }
+
+    final vocabLogProbs = vocabPtr.ref;
+    final numTokens = vocabLogProbs.numTokens;
+    final vocabSize = vocabLogProbs.vocabSize;
+
+    // Defensive validation for native values
+    if (numTokens < 0 ||
+        vocabSize < 0 ||
+        numTokens > 10000 ||
+        vocabSize > 100000) {
+      destroyFunc(vocabPtr);
+      return null;
+    }
+
+    final Map<String, List<double>> result = {};
+
+    for (int tokenIdx = 0; tokenIdx < numTokens; tokenIdx++) {
+      final List<double> tokenProbs = [];
+
+      for (int vocabIdx = 0; vocabIdx < vocabSize; vocabIdx++) {
+        final index = tokenIdx * vocabSize + vocabIdx;
+        final logProb = vocabLogProbs.logProbs[index];
+        tokenProbs.add(logProb);
+      }
+
+      result['token_$tokenIdx'] = tokenProbs;
+    }
+
+    destroyFunc(vocabPtr);
+    return result;
+  }
+
   Pointer<SherpaOnnxOnlineStream> ptr;
 }

flutter/sherpa_onnx/lib/src/sherpa_onnx_bindings.dart

@@ -776,6 +776,17 @@ final class SherpaOnnxSpokenLanguageIdentificationResult extends Struct {
 
 final class SherpaOnnxSpokenLanguageIdentification extends Opaque {}
 
+final class SherpaOnnxVocabLogProbs extends Struct {
+  // Flattened 2D array
+  external Pointer<Float> logProbs;
+
+  @Int32()
+  external int numTokens;
+
+  @Int32()
+  external int vocabSize;
+}
+
 final class SherpaOnnxOfflineSpeechDenoiser extends Opaque {}
 
 typedef SherpaOnnxCreateOfflineSpeechDenoiserNative =
@@ -1724,6 +1735,20 @@ typedef SherpaOnnxGetGitSha1 = SherpaOnnxGetGitSha1Native;
 typedef SherpaOnnxGetGitDateNative = Pointer<Utf8> Function();
 typedef SherpaOnnxGetGitDate = SherpaOnnxGetGitDateNative;
 
+typedef SherpaOnnxOnlineStreamGetVocabLogProbsNative
+    = Pointer<SherpaOnnxVocabLogProbs> Function(
+        Pointer<SherpaOnnxOnlineStream> stream);
+
+typedef SherpaOnnxOfflineStreamGetVocabLogProbsNative
+    = Pointer<SherpaOnnxVocabLogProbs> Function(
+        Pointer<SherpaOnnxOfflineStream> stream);
+
+typedef SherpaOnnxDestroyVocabLogProbsNative = Void Function(
+    Pointer<SherpaOnnxVocabLogProbs> logProbs);
+
+typedef SherpaOnnxDestroyVocabLogProbsDart = void Function(
+    Pointer<SherpaOnnxVocabLogProbs>);
+
 class SherpaOnnxBindings {
   static SherpaOnnxCreateOfflineSpeechDenoiser?
   sherpaOnnxCreateOfflineSpeechDenoiser;
@@ -1951,6 +1976,12 @@ class SherpaOnnxBindings {
   static SherpaOnnxGetGitSha1? getGitSha1;
   static SherpaOnnxGetGitDate? getGitDate;
 
+  static SherpaOnnxOnlineStreamGetVocabLogProbsNative?
+      getOnlineStreamVocabLogProbs;
+  static SherpaOnnxOfflineStreamGetVocabLogProbsNative?
+      getOfflineStreamVocabLogProbs;
+  static SherpaOnnxDestroyVocabLogProbsDart? destroyVocabLogProbs;
+
   static void init(DynamicLibrary dynamicLibrary) {
     sherpaOnnxCreateOfflineSpeechDenoiser ??= dynamicLibrary
         .lookup<NativeFunction<SherpaOnnxCreateOfflineSpeechDenoiserNative>>(
@@ -2674,5 +2705,23 @@ class SherpaOnnxBindings {
           'SherpaOnnxGetGitDate',
         )
         .asFunction();
+
+    getOnlineStreamVocabLogProbs ??= dynamicLibrary
+        .lookup<NativeFunction<SherpaOnnxOnlineStreamGetVocabLogProbsNative>>(
+          'SherpaOnnxOnlineStreamGetVocabLogProbs',
+        )
+        .asFunction();
+
+    getOfflineStreamVocabLogProbs ??= dynamicLibrary
+        .lookup<NativeFunction<SherpaOnnxOfflineStreamGetVocabLogProbsNative>>(
+          'SherpaOnnxOfflineStreamGetVocabLogProbs',
+        )
+        .asFunction();
+
+    destroyVocabLogProbs ??= dynamicLibrary
+        .lookup<NativeFunction<SherpaOnnxDestroyVocabLogProbsNative>>(
+          'SherpaOnnxDestroyVocabLogProbs',
+        )
+        .asFunction();
   }
 }