Add C API for speech enhancement GTCRN models (#1984)

.github/workflows/c-api.yaml

@@ -79,6 +79,40 @@ jobs:
             otool -L ./install/lib/libsherpa-onnx-c-api.dylib
           fi
 
+      - name: Test speech enhancement (GTCRN)
+        shell: bash
+        run: |
+          name=speech-enhancement-gtcrn-c-api
+          gcc -o $name ./c-api-examples/$name.c \
+            -I ./build/install/include \
+            -L ./build/install/lib/ \
+            -l sherpa-onnx-c-api \
+            -l onnxruntime
+
+          ls -lh $name
+
+          if [[ ${{ matrix.os }} == ubuntu-latest || ${{ matrix.os }} == ubuntu-22.04-arm ]]; then
+            ldd ./$name
+            echo "----"
+            readelf -d ./$name
+          fi
+          curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/speech-enhancement-models/gtcrn_simple.onnx
+          curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/speech-enhancement-models/inp_16k.wav
+
+          export LD_LIBRARY_PATH=$PWD/build/install/lib:$LD_LIBRARY_PATH
+          export DYLD_LIBRARY_PATH=$PWD/build/install/lib:$DYLD_LIBRARY_PATH
+
+          ./$name
+          rm -fv *.onnx
+          mkdir denoised-wavs
+          cp -v inp_16k.wav denoised-wavs
+          cp -v enhanced_16k.wav denoised-wavs
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: denoised-wavs-${{ matrix.os }}
+          path: ./denoised-wavs/*.wav
+
       - name: Test FireRedAsr
         shell: bash
         run: |

c-api-examples/CMakeLists.txt

@@ -7,6 +7,9 @@ target_link_libraries(decode-file-c-api sherpa-onnx-c-api cargs)
 add_executable(kws-c-api kws-c-api.c)
 target_link_libraries(kws-c-api sherpa-onnx-c-api)
 
+add_executable(speech-enhancement-gtcrn-c-api speech-enhancement-gtcrn-c-api.c)
+target_link_libraries(speech-enhancement-gtcrn-c-api sherpa-onnx-c-api)
+
 if(SHERPA_ONNX_ENABLE_TTS)
   add_executable(offline-tts-c-api offline-tts-c-api.c)
   target_link_libraries(offline-tts-c-api sherpa-onnx-c-api cargs)

c-api-examples/speech-enhancement-gtcrn-c-api.c

@@ -0,0 +1,55 @@
+// c-api-examples/speech-enhancement-gtcrn-c-api.c
+//
+// Copyright (c)  2025  Xiaomi Corporation
+//
+// We assume you have pre-downloaded model
+// from
+// https://github.com/k2-fsa/sherpa-onnx/releases/tag/speech-enhancement-models
+//
+//
+// An example command to download
+// clang-format off
+/*
+wget https://github.com/k2-fsa/sherpa-onnx/releases/download/speech-enhancement-models/gtcrn_simple.onnx
+wget https://github.com/k2-fsa/sherpa-onnx/releases/download/speech-enhancement-models/inp_16k.wav
+*/
+// clang-format on
+#include <stdio.h>
+#include <string.h>
+
+#include "sherpa-onnx/c-api/c-api.h"
+
+int32_t main() {
+  SherpaOnnxOfflineSpeechDenoiserConfig config;
+  const char *wav_filename = "./inp_16k.wav";
+  const char *out_wave_filename = "./enhanced_16k.wav";
+
+  memset(&config, 0, sizeof(config));
+  config.model.gtcrn.model = "./gtcrn_simple.onnx";
+
+  const SherpaOnnxOfflineSpeechDenoiser *sd =
+      SherpaOnnxCreateOfflineSpeechDenoiser(&config);
+  if (!sd) {
+    fprintf(stderr, "Please check your config");
+    return -1;
+  }
+
+  const SherpaOnnxWave *wave = SherpaOnnxReadWave(wav_filename);
+  if (wave == NULL) {
+    SherpaOnnxDestroyOfflineSpeechDenoiser(sd);
+    fprintf(stderr, "Failed to read %s\n", wav_filename);
+    return -1;
+  }
+
+  const SherpaOnnxDenoisedAudio *denoised = SherpaOnnxOfflineSpeechDenoiserRun(
+      sd, wave->samples, wave->num_samples, wave->sample_rate);
+
+  SherpaOnnxWriteWave(denoised->samples, denoised->n, denoised->sample_rate,
+                      out_wave_filename);
+
+  SherpaOnnxDestroyDenoisedAudio(denoised);
+  SherpaOnnxFreeWave(wave);
+  SherpaOnnxDestroyOfflineSpeechDenoiser(sd);
+
+  fprintf(stdout, "Saved to %s\n", out_wave_filename);
+}

sherpa-onnx/c-api/c-api.cc

@@ -24,6 +24,7 @@
 #include "sherpa-onnx/csrc/macros.h"
 #include "sherpa-onnx/csrc/offline-punctuation.h"
 #include "sherpa-onnx/csrc/offline-recognizer.h"
+#include "sherpa-onnx/csrc/offline-speech-denoiser.h"
 #include "sherpa-onnx/csrc/online-punctuation.h"
 #include "sherpa-onnx/csrc/online-recognizer.h"
 #include "sherpa-onnx/csrc/resample.h"
@@ -1967,6 +1968,77 @@ int32_t SherpaOnnxFileExists(const char *filename) {
   return sherpa_onnx::FileExists(filename);
 }
 
+struct SherpaOnnxOfflineSpeechDenoiser {
+  std::unique_ptr<sherpa_onnx::OfflineSpeechDenoiser> impl;
+};
+
+static sherpa_onnx::OfflineSpeechDenoiserConfig GetOfflineSpeechDenoiserConfig(
+    const SherpaOnnxOfflineSpeechDenoiserConfig *config) {
+  sherpa_onnx::OfflineSpeechDenoiserConfig c;
+  c.model.gtcrn.model = SHERPA_ONNX_OR(config->model.gtcrn.model, "");
+  c.model.num_threads = SHERPA_ONNX_OR(config->model.num_threads, 1);
+  c.model.debug = config->model.debug;
+  c.model.provider = SHERPA_ONNX_OR(config->model.provider, "cpu");
+
+  if (c.model.debug) {
+#if __OHOS__
+    SHERPA_ONNX_LOGE("%{public}s\n", c.ToString().c_str());
+#else
+    SHERPA_ONNX_LOGE("%s\n", c.ToString().c_str());
+#endif
+  }
+
+  return c;
+}
+
+const SherpaOnnxOfflineSpeechDenoiser *SherpaOnnxCreateOfflineSpeechDenoiser(
+    const SherpaOnnxOfflineSpeechDenoiserConfig *config) {
+  auto sd_config = GetOfflineSpeechDenoiserConfig(config);
+
+  if (!sd_config.Validate()) {
+    SHERPA_ONNX_LOGE("Errors in config");
+    return nullptr;
+  }
+
+  SherpaOnnxOfflineSpeechDenoiser *sd = new SherpaOnnxOfflineSpeechDenoiser;
+
+  sd->impl = std::make_unique<sherpa_onnx::OfflineSpeechDenoiser>(sd_config);
+
+  return sd;
+}
+
+void SherpaOnnxDestroyOfflineSpeechDenoiser(
+    const SherpaOnnxOfflineSpeechDenoiser *sd) {
+  delete sd;
+}
+
+int32_t SherpaOnnxOfflineSpeechDenoiserGetSampleRate(
+    const SherpaOnnxOfflineSpeechDenoiser *sd) {
+  return sd->impl->GetSampleRate();
+}
+
+const SherpaOnnxDenoisedAudio *SherpaOnnxOfflineSpeechDenoiserRun(
+    const SherpaOnnxOfflineSpeechDenoiser *sd, const float *samples, int32_t n,
+    int32_t sample_rate) {
+  auto audio = sd->impl->Run(samples, n, sample_rate);
+
+  auto ans = new SherpaOnnxDenoisedAudio;
+
+  float *denoised_samples = new float[audio.samples.size()];
+  std::copy(audio.samples.begin(), audio.samples.end(), denoised_samples);
+
+  ans->samples = denoised_samples;
+  ans->n = audio.samples.size();
+  ans->sample_rate = audio.sample_rate;
+
+  return ans;
+}
+
+void SherpaOnnxDestroyDenoisedAudio(const SherpaOnnxDenoisedAudio *p) {
+  delete[] p->samples;
+  delete p;
+}
+
 #if SHERPA_ONNX_ENABLE_SPEAKER_DIARIZATION == 1
 
 struct SherpaOnnxOfflineSpeakerDiarization {
@@ -2244,6 +2316,19 @@ void SherpaOnnxOfflineSpeakerDiarizationDestroyResult(
 
 #ifdef __OHOS__
 
+const SherpaOnnxOfflineSpeechDenoiser *
+SherpaOnnxCreateOfflineSpeechDenoiserOHOS(
+    const SherpaOnnxOfflineSpeechDenoiserConfig *config,
+    NativeResourceManager *mgr) {
+  auto sd_config = GetOfflineSpeechDenoiserConfia(config);
+
+  SherpaOnnxOfflineSpeechDenoiser *sd = new SherpaOnnxOfflineSpeechDenoiser;
+
+  sd->impl = std::make_unique<sherpa_onnx::OfflineSpeechDenoiser>(sd_config);
+
+  return sd;
+}
+
 const SherpaOnnxOnlineRecognizer *SherpaOnnxCreateOnlineRecognizerOHOS(
     const SherpaOnnxOnlineRecognizerConfig *config,
     NativeResourceManager *mgr) {

sherpa-onnx/c-api/c-api.h

@@ -1639,11 +1639,72 @@ SherpaOnnxOfflineSpeakerDiarizationProcessWithCallbackNoArg(
 SHERPA_ONNX_API void SherpaOnnxOfflineSpeakerDiarizationDestroyResult(
     const SherpaOnnxOfflineSpeakerDiarizationResult *r);
 
+// =========================================================================
+// For offline speech enhancement
+// =========================================================================
+SHERPA_ONNX_API typedef struct SherpaOnnxOfflineSpeechDenoiserGtcrnModelConfig {
+  const char *model;
+} SherpaOnnxOfflineSpeechDenoiserGtcrnModelConfig;
+
+SHERPA_ONNX_API typedef struct SherpaOnnxOfflineSpeechDenoiserModelConfig {
+  SherpaOnnxOfflineSpeechDenoiserGtcrnModelConfig gtcrn;
+  int32_t num_threads;
+  int32_t debug;  // true to print debug information of the model
+  const char *provider;
+} SherpaOnnxOfflineSpeechDenoiserModelConfig;
+
+SHERPA_ONNX_API typedef struct SherpaOnnxOfflineSpeechDenoiserConfig {
+  SherpaOnnxOfflineSpeechDenoiserModelConfig model;
+} SherpaOnnxOfflineSpeechDenoiserConfig;
+
+SHERPA_ONNX_API typedef struct SherpaOnnxOfflineSpeechDenoiser
+    SherpaOnnxOfflineSpeechDenoiser;
+
+// The users has to invoke SherpaOnnxDestroyOfflineSpeechDenoiser()
+// to free the returned pointer to avoid memory leak
+SHERPA_ONNX_API const SherpaOnnxOfflineSpeechDenoiser *
+SherpaOnnxCreateOfflineSpeechDenoiser(
+    const SherpaOnnxOfflineSpeechDenoiserConfig *config);
+
+// Free the pointer returned by SherpaOnnxCreateOfflineSpeechDenoiser()
+SHERPA_ONNX_API void SherpaOnnxDestroyOfflineSpeechDenoiser(
+    const SherpaOnnxOfflineSpeechDenoiser *sd);
+
+SHERPA_ONNX_API int32_t SherpaOnnxOfflineSpeechDenoiserGetSampleRate(
+    const SherpaOnnxOfflineSpeechDenoiser *sd);
+
+SHERPA_ONNX_API typedef struct SherpaOnnxDenoisedAudio {
+  const float *samples;  // in the range [-1, 1]
+  int32_t n;             // number of samples
+  int32_t sample_rate;
+} SherpaOnnxDenoisedAudio;
+
+// Run speech denosing on input samples
+// @param samples  A 1-D array containing the input audio samples. Each sample
+//           should be in the range [-1, 1].
+// @param n  Number of samples
+// @param sample_rate Sample rate of the input samples
+//
+// The user MUST use SherpaOnnxDestroyDenoisedAudio() to free the returned
+// pointer to avoid memory leak.
+SHERPA_ONNX_API const SherpaOnnxDenoisedAudio *
+SherpaOnnxOfflineSpeechDenoiserRun(const SherpaOnnxOfflineSpeechDenoiser *sd,
+                                   const float *samples, int32_t n,
+                                   int32_t sample_rate);
+
+SHERPA_ONNX_API void SherpaOnnxDestroyDenoisedAudio(
+    const SherpaOnnxDenoisedAudio *p);
+
 #ifdef __OHOS__
 
 // It is for HarmonyOS
 typedef struct NativeResourceManager NativeResourceManager;
 
+SHERPA_ONNX_API const SherpaOnnxOfflineSpeechDenoiser *
+SherpaOnnxCreateOfflineSpeechDenoiserOHOS(
+    const SherpaOnnxOfflineSpeechDenoiserConfig *config,
+    NativeResourceManager *mgr);
+
 /// @param config  Config for the recognizer.
 /// @return Return a pointer to the recognizer. The user has to invoke
 //          SherpaOnnxDestroyOnlineRecognizer() to free it to avoid memory leak.

sherpa-onnx/csrc/offline-speech-denoiser-gtcrn-impl.h

@@ -33,7 +33,6 @@ class OfflineSpeechDenoiserGtcrnImpl : public OfflineSpeechDenoiserImpl {
 
   DenoisedAudio Run(const float *samples, int32_t n,
                     int32_t sample_rate) const override {
-    SHERPA_ONNX_LOGE("n: %d, sample_rate: %d", n, sample_rate);
     const auto &meta = model_.GetMetaData();
 
     std::vector<float> tmp;