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

/**
 * Copyright (c)  2023  Xiaomi Corporation (authors: Fangjun Kuang)
 *
 * See LICENSE for clarification regarding multiple authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "sherpa-ncnn/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.ncnn.param \\\n"
    "    /path/to/encoder.ncnn.bin \\\n"
    "    /path/to/decoder.ncnn.param \\\n"
    "    /path/to/decoder.ncnn.bin \\\n"
    "    /path/to/joiner.ncnn.param \\\n"
    "    /path/to/joiner.ncnn.bin \\\n"
    "    /path/to/foo.wav [<num_threads> [decode_method, can be "
    "greedy_search/modified_beam_search]]"
    "\n\n"
    "Please refer to \n"
    "https://k2-fsa.github.io/sherpa/ncnn/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 < 9 || argc > 11) {
    fprintf(stderr, "%s\n", kUsage);
    return -1;
  }
  SherpaNcnnModelConfig model_config;
  model_config.tokens = argv[1];
  model_config.encoder_param = argv[2];
  model_config.encoder_bin = argv[3];
  model_config.decoder_param = argv[4];
  model_config.decoder_bin = argv[5];
  model_config.joiner_param = argv[6];
  model_config.joiner_bin = argv[7];

  int32_t num_threads = 4;
  if (argc >= 10 && atoi(argv[9]) > 0) {
    num_threads = atoi(argv[9]);
  }
  model_config.num_threads = num_threads;
  model_config.use_vulkan_compute = 0;

  SherpaNcnnDecoderConfig decoder_config;
  decoder_config.decoding_method = "greedy_search";

  if (argc == 11) {
    decoder_config.decoding_method = argv[10];
  }
  decoder_config.num_active_paths = 4;
  decoder_config.enable_endpoint = 0;
  decoder_config.rule1_min_trailing_silence = 2.4;
  decoder_config.rule2_min_trailing_silence = 1.2;
  decoder_config.rule3_min_utterance_length = 300;

  SherpaNcnnRecognizer *recognizer =
      CreateRecognizer(&model_config, &decoder_config);

  const char *wav_filename = argv[8];
  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(recognizer, 16000, samples, n);
      Decode(recognizer);
      SherpaNcnnResult *r = GetResult(recognizer);
      if (strlen(r->text)) {
        fprintf(stderr, "%s\n", r->text);
      }
      DestroyResult(r);
    }
  }
  fclose(fp);

  // add some tail padding
  float tail_paddings[4800] = {0};  // 0.3 seconds at 16 kHz sample rate
  AcceptWaveform(recognizer, 16000, tail_paddings, 4800);

  InputFinished(recognizer);

  Decode(recognizer);
  SherpaNcnnResult *r = GetResult(recognizer);
  fprintf(stderr, "%s\n", r->text);
  DestroyResult(r);

  DestroyRecognizer(recognizer);

  return 0;
}