From ba4cb6169f29efa24c7eef7c3c17897c393c67b3 Mon Sep 17 00:00:00 2001
From: Parth Khiera <83587266+parth-khiera@users.noreply.github.com>
Date: Thu, 8 Aug 2024 06:40:17 +0530
Subject: [PATCH] feat: addition of blank_penalty config in online_recognizer
 (#1232)

---
 scripts/go/sherpa_onnx.go  | 5 +++++
 sherpa-onnx/c-api/c-api.cc | 2 ++
 sherpa-onnx/c-api/c-api.h  | 1 +
 3 files changed, 8 insertions(+)

diff --git a/scripts/go/sherpa_onnx.go b/scripts/go/sherpa_onnx.go
index 0422b3bad..d7d794341 100644
--- a/scripts/go/sherpa_onnx.go
+++ b/scripts/go/sherpa_onnx.go
@@ -129,6 +129,7 @@ type OnlineRecognizerConfig struct {
 	Rule3MinUtteranceLength float32
 	HotwordsFile            string
 	HotwordsScore           float32
+	BlankPenalty            float32
 	CtcFstDecoderConfig     OnlineCtcFstDecoderConfig
 	RuleFsts                string
 	RuleFars                string
@@ -212,6 +213,7 @@ func NewOnlineRecognizer(config *OnlineRecognizerConfig) *OnlineRecognizer {
 	defer C.free(unsafe.Pointer(c.hotwords_file))
 
 	c.hotwords_score = C.float(config.HotwordsScore)
+	c.blank_penalty = C.float(config.BlankPenalty)
 
 	c.rule_fsts = C.CString(config.RuleFsts)
 	defer C.free(unsafe.Pointer(c.rule_fsts))
@@ -421,6 +423,7 @@ type OfflineRecognizerConfig struct {
 	MaxActivePaths int
 	HotwordsFile   string
 	HotwordsScore  float32
+	BlankPenalty   float32
 	RuleFsts       string
 	RuleFars       string
 }
@@ -530,6 +533,8 @@ func NewOfflineRecognizer(config *OfflineRecognizerConfig) *OfflineRecognizer {
 
 	c.hotwords_score = C.float(config.HotwordsScore)
 
+	c.blank_penalty = C.float(config.BlankPenalty)
+
 	c.rule_fsts = C.CString(config.RuleFsts)
 	defer C.free(unsafe.Pointer(c.rule_fsts))
 
diff --git a/sherpa-onnx/c-api/c-api.cc b/sherpa-onnx/c-api/c-api.cc
index f6b253065..75885af00 100644
--- a/sherpa-onnx/c-api/c-api.cc
+++ b/sherpa-onnx/c-api/c-api.cc
@@ -105,6 +105,8 @@ SherpaOnnxOnlineRecognizer *SherpaOnnxCreateOnlineRecognizer(
   recognizer_config.hotwords_score =
       SHERPA_ONNX_OR(config->hotwords_score, 1.5);
 
+  recognizer_config.blank_penalty = SHERPA_ONNX_OR(config->blank_penalty, 0.0);
+
   recognizer_config.ctc_fst_decoder_config.graph =
       SHERPA_ONNX_OR(config->ctc_fst_decoder_config.graph, "");
   recognizer_config.ctc_fst_decoder_config.max_active =
diff --git a/sherpa-onnx/c-api/c-api.h b/sherpa-onnx/c-api/c-api.h
index dd86eee1f..17f3d6efe 100644
--- a/sherpa-onnx/c-api/c-api.h
+++ b/sherpa-onnx/c-api/c-api.h
@@ -142,6 +142,7 @@ SHERPA_ONNX_API typedef struct SherpaOnnxOnlineRecognizerConfig {
 
   /// Bonus score for each token in hotwords.
   float hotwords_score;
+  float blank_penalty;
 
   SherpaOnnxOnlineCtcFstDecoderConfig ctc_fst_decoder_config;
   const char *rule_fsts;