Add C API for streaming HLG decoding (#734)

scripts/go/_internal/streaming-hlg-decoding/.gitignore

@@ -0,0 +1 @@
+streaming-hlg-decoding

scripts/go/_internal/streaming-hlg-decoding/go.mod

@@ -0,0 +1,5 @@
+module streaming-hlg-decoding
+
+go 1.12
+
+replace github.com/k2-fsa/sherpa-onnx-go/sherpa_onnx => ../

scripts/go/_internal/streaming-hlg-decoding/main.go

@@ -0,0 +1 @@
+../../../../go-api-examples/streaming-hlg-decoding/main.go

scripts/go/_internal/streaming-hlg-decoding/run.sh

@@ -0,0 +1 @@
+../../../../go-api-examples/streaming-hlg-decoding/run.sh

scripts/go/sherpa_onnx.go

@@ -99,6 +99,11 @@ type FeatureConfig struct {
 	FeatureDim int
 }
 
+type OnlineCtcFstDecoderConfig struct {
+	Graph     string
+	MaxActive int
+}
+
 // Configuration for the online/streaming recognizer.
 type OnlineRecognizerConfig struct {
 	FeatConfig  FeatureConfig
@@ -120,6 +125,7 @@ type OnlineRecognizerConfig struct {
 	Rule1MinTrailingSilence float32
 	Rule2MinTrailingSilence float32
 	Rule3MinUtteranceLength float32
+	CtcFstDecoderConfig     OnlineCtcFstDecoderConfig
 }
 
 // It contains the recognition result for a online stream.
@@ -190,6 +196,10 @@ func NewOnlineRecognizer(config *OnlineRecognizerConfig) *OnlineRecognizer {
 	c.rule2_min_trailing_silence = C.float(config.Rule2MinTrailingSilence)
 	c.rule3_min_utterance_length = C.float(config.Rule3MinUtteranceLength)
 
+	c.ctc_fst_decoder_config.graph = C.CString(config.CtcFstDecoderConfig.Graph)
+	defer C.free(unsafe.Pointer(c.ctc_fst_decoder_config.graph))
+	c.ctc_fst_decoder_config.max_active = C.int(config.CtcFstDecoderConfig.MaxActive)
+
 	recognizer := &OnlineRecognizer{}
 	recognizer.impl = C.CreateOnlineRecognizer(&c)