C api (#60)

c-api-examples/decode-file-c-api.c

@@ -0,0 +1,113 @@
+// c-api-examples/decode-file-c-api.cc
+//
+// Copyright (c)  2023  Xiaomi Corporation
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sherpa-onnx/c-api/c-api.h"
+
+const char *kUsage =
+    "\n"
+    "Usage:\n "
+    "  ./bin/decode-file-c-api \\\n"
+    "    /path/to/tokens.txt \\\n"
+    "    /path/to/encoder.onnx \\\n"
+    "    /path/to/decoder.onnx \\\n"
+    "    /path/to/joiner.onnx \\\n"
+    "    /path/to/foo.wav [num_threads]\n"
+    "\n\n"
+    "Please refer to \n"
+    "https://k2-fsa.github.io/sherpa/onnx/pretrained_models/index.html\n"
+    "for a list of pre-trained models to download.\n";
+
+int32_t main(int32_t argc, char *argv[]) {
+  if (argc < 6 || argc > 7) {
+    fprintf(stderr, "%s\n", kUsage);
+    return -1;
+  }
+  SherpaOnnxOnlineRecognizerConfig config;
+  config.model_config.tokens = argv[1];
+  config.model_config.encoder = argv[2];
+  config.model_config.decoder = argv[3];
+  config.model_config.joiner = argv[4];
+
+  int32_t num_threads = 4;
+  if (argc == 7 && atoi(argv[6]) > 0) {
+    num_threads = atoi(argv[6]);
+  }
+  config.model_config.num_threads = num_threads;
+  config.model_config.debug = 0;
+
+  config.feat_config.sample_rate = 16000;
+  config.feat_config.feature_dim = 80;
+
+  config.enable_endpoint = 1;
+  config.rule1_min_trailing_silence = 2.4;
+  config.rule2_min_trailing_silence = 1.2;
+  config.rule3_min_utterance_length = 300;
+
+  SherpaOnnxOnlineRecognizer *recognizer = CreateOnlineRecognizer(&config);
+  SherpaOnnxOnlineStream *stream = CreateOnlineStream(recognizer);
+
+  const char *wav_filename = argv[5];
+  FILE *fp = fopen(wav_filename, "rb");
+  if (!fp) {
+    fprintf(stderr, "Failed to open %s\n", wav_filename);
+    return -1;
+  }
+
+  // Assume the wave header occupies 44 bytes.
+  fseek(fp, 44, SEEK_SET);
+
+  // simulate streaming
+
+#define N 3200  // 0.2 s. Sample rate is fixed to 16 kHz
+
+  int16_t buffer[N];
+  float samples[N];
+
+  while (!feof(fp)) {
+    size_t n = fread((void *)buffer, sizeof(int16_t), N, fp);
+    if (n > 0) {
+      for (size_t i = 0; i != n; ++i) {
+        samples[i] = buffer[i] / 32768.;
+      }
+      AcceptWaveform(stream, 16000, samples, n);
+      while (IsOnlineStreamReady(recognizer, stream)) {
+        DecodeOnlineStream(recognizer, stream);
+      }
+
+      SherpaOnnxOnlineRecognizerResult *r =
+          GetOnlineStreamResult(recognizer, stream);
+      if (strlen(r->text)) {
+        fprintf(stderr, "%s\n", r->text);
+      }
+      DestroyOnlineRecognizerResult(r);
+    }
+  }
+  fclose(fp);
+
+  // add some tail padding
+  float tail_paddings[4800] = {0};  // 0.3 seconds at 16 kHz sample rate
+  AcceptWaveform(stream, 16000, tail_paddings, 4800);
+
+  InputFinished(stream);
+  while (IsOnlineStreamReady(recognizer, stream)) {
+    DecodeOnlineStream(recognizer, stream);
+  }
+
+  SherpaOnnxOnlineRecognizerResult *r =
+      GetOnlineStreamResult(recognizer, stream);
+  if (strlen(r->text)) {
+    fprintf(stderr, "%s\n", r->text);
+  }
+
+  DestroyOnlineRecognizerResult(r);
+
+  DestoryOnlineStream(stream);
+  DestroyOnlineRecognizer(recognizer);
+
+  return 0;
+}