Add more C API examples (#1255)

C API examples for zipformer, paraformer, and TeleSpeech-ASR CTC models.

c-api-examples/streaming-zipformer-c-api.c

@@ -0,0 +1,138 @@
+// c-api-examples/streaming-zipformer-c-api.c
+//
+// Copyright (c)  2024  Xiaomi Corporation
+
+//
+// This file demonstrates how to use streaming Zipformer with sherpa-onnx's C API.
+// clang-format off
+// 
+// wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-en-20M-2023-02-17.tar.bz2
+// tar xvf sherpa-onnx-streaming-zipformer-en-20M-2023-02-17.tar.bz2
+// rm sherpa-onnx-streaming-zipformer-en-20M-2023-02-17.tar.bz2
+//
+// clang-format on
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sherpa-onnx/c-api/c-api.h"
+
+int32_t main() {
+
+  const char *wav_filename = "sherpa-onnx-streaming-zipformer-en-20M-2023-02-17/test_wavs/0.wav";
+  const char *encoder_filename = "sherpa-onnx-streaming-zipformer-en-20M-2023-02-17/encoder-epoch-99-avg-1.onnx";
+  const char *decoder_filename = "sherpa-onnx-streaming-zipformer-en-20M-2023-02-17/decoder-epoch-99-avg-1.onnx";
+  const char *joiner_filename = "sherpa-onnx-streaming-zipformer-en-20M-2023-02-17/joiner-epoch-99-avg-1.onnx";
+  const char *tokens_filename = "sherpa-onnx-streaming-zipformer-en-20M-2023-02-17/tokens.txt";
+  const char *provider = "cpu";
+
+
+  const SherpaOnnxWave *wave = SherpaOnnxReadWave(wav_filename);
+  if (wave == NULL) {
+    fprintf(stderr, "Failed to read %s\n", wav_filename);
+    return -1;
+  }
+  
+  // Zipformer config
+  SherpaOnnxOnlineTransducerModelConfig zipformer_config;
+  memset(&zipformer_config, 0, sizeof(zipformer_config));
+  zipformer_config.encoder = encoder_filename;
+  zipformer_config.decoder = decoder_filename;
+  zipformer_config.joiner = joiner_filename;
+  
+
+  // Online model config
+  SherpaOnnxOnlineModelConfig online_model_config;
+  memset(&online_model_config, 0, sizeof(online_model_config));
+  online_model_config.debug = 1;
+  online_model_config.num_threads = 1;
+  online_model_config.provider = provider;
+  online_model_config.tokens = tokens_filename;
+  online_model_config.transducer = zipformer_config;
+
+  // Recognizer config
+  SherpaOnnxOnlineRecognizerConfig recognizer_config;
+  memset(&recognizer_config, 0, sizeof(recognizer_config));
+  recognizer_config.decoding_method = "greedy_search";
+  recognizer_config.model_config = online_model_config;
+
+  SherpaOnnxOnlineRecognizer *recognizer =
+      SherpaOnnxCreateOnlineRecognizer(&recognizer_config);
+
+  if (recognizer == NULL) {
+    fprintf(stderr, "Please check your config!\n");
+    SherpaOnnxFreeWave(wave);
+    return -1;
+  }
+
+  SherpaOnnxOnlineStream *stream = SherpaOnnxCreateOnlineStream(recognizer);
+
+  const SherpaOnnxDisplay *display = SherpaOnnxCreateDisplay(50);
+  int32_t segment_id = 0;
+
+// simulate streaming. You can choose an arbitrary N
+#define N 3200
+
+  fprintf(stderr, "sample rate: %d, num samples: %d, duration: %.2f s\n",
+          wave->sample_rate, wave->num_samples,
+          (float)wave->num_samples / wave->sample_rate);
+
+  int32_t k = 0;
+  while (k < wave->num_samples) {
+    int32_t start = k;
+    int32_t end =
+        (start + N > wave->num_samples) ? wave->num_samples : (start + N);
+    k += N;
+
+    SherpaOnnxOnlineStreamAcceptWaveform(stream, wave->sample_rate,
+                                         wave->samples + start, end - start);
+    while (SherpaOnnxIsOnlineStreamReady(recognizer, stream)) {
+      SherpaOnnxDecodeOnlineStream(recognizer, stream);
+    }
+
+    const SherpaOnnxOnlineRecognizerResult *r =
+        SherpaOnnxGetOnlineStreamResult(recognizer, stream);
+
+    if (strlen(r->text)) {
+      SherpaOnnxPrint(display, segment_id, r->text);
+    }
+
+    if (SherpaOnnxOnlineStreamIsEndpoint(recognizer, stream)) {
+      if (strlen(r->text)) {
+        ++segment_id;
+      }
+      SherpaOnnxOnlineStreamReset(recognizer, stream);
+    }
+
+    SherpaOnnxDestroyOnlineRecognizerResult(r);
+  }
+
+  // add some tail padding
+  float tail_paddings[4800] = {0};  // 0.3 seconds at 16 kHz sample rate
+  SherpaOnnxOnlineStreamAcceptWaveform(stream, wave->sample_rate, tail_paddings,
+                                       4800);
+
+  SherpaOnnxFreeWave(wave);
+
+  SherpaOnnxOnlineStreamInputFinished(stream);
+  while (SherpaOnnxIsOnlineStreamReady(recognizer, stream)) {
+    SherpaOnnxDecodeOnlineStream(recognizer, stream);
+  }
+
+  const SherpaOnnxOnlineRecognizerResult *r =
+      SherpaOnnxGetOnlineStreamResult(recognizer, stream);
+
+  if (strlen(r->text)) {
+    SherpaOnnxPrint(display, segment_id, r->text);
+  }
+
+  SherpaOnnxDestroyOnlineRecognizerResult(r);
+
+  SherpaOnnxDestroyDisplay(display);
+  SherpaOnnxDestroyOnlineStream(stream);
+  SherpaOnnxDestroyOnlineRecognizer(recognizer);
+  fprintf(stderr, "\n");
+
+  return 0;
+}