Add a C# api for offline-recognizer of sherpa-onnx (#129)

sherpa-onnx/csharp-api/offline-api.cpp

@@ -0,0 +1,136 @@
+// sherpa-onnx/sharp-api/offline-api.cpp
+//
+// Copyright (c)  2023  Manyeyes Corporation
+
+#include "offline-api.h"
+
+#include "sherpa-onnx/csrc/display.h"
+#include "sherpa-onnx/csrc/offline-recognizer.h"
+
+namespace sherpa_onnx
+{
+	struct SherpaOnnxOfflineRecognizer {
+		sherpa_onnx::OfflineRecognizer* impl;
+	};
+
+	struct SherpaOnnxOfflineStream {
+		std::unique_ptr<sherpa_onnx::OfflineStream> impl;
+		explicit SherpaOnnxOfflineStream(std::unique_ptr<sherpa_onnx::OfflineStream> p)
+			: impl(std::move(p)) {}
+	};
+
+	struct SherpaOnnxDisplay {
+		std::unique_ptr<sherpa_onnx::Display> impl;
+	};
+
+	SherpaOnnxOfflineRecognizer* __stdcall CreateOfflineRecognizer(
+	    const SherpaOnnxOfflineRecognizerConfig* config) {
+		sherpa_onnx::OfflineRecognizerConfig recognizer_config;
+
+		recognizer_config.feat_config.sampling_rate = config->feat_config.sample_rate;
+		recognizer_config.feat_config.feature_dim = config->feat_config.feature_dim;
+
+		if (strlen(config->model_config.transducer.encoder_filename) > 0) {
+			recognizer_config.model_config.transducer.encoder_filename =
+				config->model_config.transducer.encoder_filename;
+			recognizer_config.model_config.transducer.decoder_filename =
+				config->model_config.transducer.decoder_filename;
+			recognizer_config.model_config.transducer.joiner_filename =
+				config->model_config.transducer.joiner_filename;
+		}
+		else if (strlen(config->model_config.paraformer.model) > 0) {
+			recognizer_config.model_config.paraformer.model =
+				config->model_config.paraformer.model;
+		}
+		else if (strlen(config->model_config.nemo_ctc.model) > 0) {
+			recognizer_config.model_config.nemo_ctc.model =
+				config->model_config.nemo_ctc.model;
+		}
+
+		recognizer_config.model_config.tokens =
+		    config->model_config.tokens;
+		recognizer_config.model_config.num_threads =
+		    config->model_config.num_threads;
+		recognizer_config.model_config.debug =
+		    config->model_config.debug;
+
+		recognizer_config.decoding_method = config->decoding_method;
+
+		SherpaOnnxOfflineRecognizer* recognizer =
+		    new SherpaOnnxOfflineRecognizer;
+		recognizer->impl =
+		    new sherpa_onnx::OfflineRecognizer(recognizer_config);
+
+		return recognizer;
+	}
+
+	SherpaOnnxOfflineStream* __stdcall CreateOfflineStream(
+	    SherpaOnnxOfflineRecognizer* recognizer) {
+		SherpaOnnxOfflineStream* stream =
+		    new SherpaOnnxOfflineStream(recognizer->impl->CreateStream());
+		return stream;
+	}
+
+	void __stdcall AcceptWaveform(
+	    SherpaOnnxOfflineStream* stream,
+	    int32_t sample_rate,
+		const float* samples, int32_t samples_size) {
+		std::vector<float> waveform{ samples, samples + samples_size };
+		stream->impl->AcceptWaveform(sample_rate, waveform.data(), waveform.size());
+	}
+
+	void __stdcall DecodeOfflineStream(
+	    SherpaOnnxOfflineRecognizer* recognizer,
+		SherpaOnnxOfflineStream* stream) {
+		recognizer->impl->DecodeStream(stream->impl.get());
+	}
+
+	void __stdcall DecodeMultipleOfflineStreams(
+	    SherpaOnnxOfflineRecognizer* recognizer,
+		SherpaOnnxOfflineStream** streams, int32_t n) {
+		std::vector<sherpa_onnx::OfflineStream*> ss(n);
+		for (int32_t i = 0; i != n; ++i) {
+			ss[i] = streams[i]->impl.get();
+		}
+		recognizer->impl->DecodeStreams(ss.data(), n);
+	}
+
+	SherpaOnnxOfflineRecognizerResult* __stdcall GetOfflineStreamResult(
+	    SherpaOnnxOfflineStream* stream) {
+		sherpa_onnx::OfflineRecognitionResult result =
+		    stream->impl->GetResult();
+		const auto& text = result.text;
+		auto r = new SherpaOnnxOfflineRecognizerResult;
+		r->text = new char[text.size() + 1];
+		std::copy(text.begin(), text.end(), const_cast<char*>(r->text));
+		const_cast<char*>(r->text)[text.size()] = 0;
+		r->text_len = text.size();
+		return r;
+	}
+
+
+	/// Free a pointer returned by CreateOfflineRecognizer()
+	///
+	/// @param p A pointer returned by CreateOfflineRecognizer()
+	void __stdcall DestroyOfflineRecognizer(
+	    SherpaOnnxOfflineRecognizer* recognizer) {
+		delete recognizer->impl;
+		delete recognizer;
+	}
+
+	/// Destory an offline stream.
+	///
+	/// @param stream A pointer returned by CreateOfflineStream()
+	void __stdcall DestroyOfflineStream(SherpaOnnxOfflineStream* stream) {
+		delete stream;
+	}
+
+	/// Destroy the pointer returned by GetOfflineStreamResult().
+	///
+	/// @param r A pointer returned by GetOfflineStreamResult()
+	void __stdcall DestroyOfflineRecognizerResult(
+	    SherpaOnnxOfflineRecognizerResult* r) {
+		delete r->text;
+		delete r;
+	}
+}// namespace sherpa_onnx