1/*
2 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include "webrtc/modules/audio_coding/neteq/tools/audio_loop.h"
12
13#include <assert.h>
14#include <stdio.h>
15#include <string.h>
16
17namespace webrtc {
18namespace test {
19
20bool AudioLoop::Init(const std::string file_name,
21                     size_t max_loop_length_samples,
22                     size_t block_length_samples) {
23  FILE* fp = fopen(file_name.c_str(), "rb");
24  if (!fp) return false;
25
26  audio_array_.reset(new int16_t[max_loop_length_samples +
27                                 block_length_samples]);
28  size_t samples_read = fread(audio_array_.get(), sizeof(int16_t),
29                              max_loop_length_samples, fp);
30  fclose(fp);
31
32  // Block length must be shorter than the loop length.
33  if (block_length_samples > samples_read) return false;
34
35  // Add an extra block length of samples to the end of the array, starting
36  // over again from the beginning of the array. This is done to simplify
37  // the reading process when reading over the end of the loop.
38  memcpy(&audio_array_[samples_read], audio_array_.get(),
39         block_length_samples * sizeof(int16_t));
40
41  loop_length_samples_ = samples_read;
42  block_length_samples_ = block_length_samples;
43  return true;
44}
45
46const int16_t* AudioLoop::GetNextBlock() {
47  // Check that the AudioLoop is initialized.
48  if (block_length_samples_ == 0) return NULL;
49
50  const int16_t* output_ptr = &audio_array_[next_index_];
51  next_index_ = (next_index_ + block_length_samples_) % loop_length_samples_;
52  return output_ptr;
53}
54
55
56}  // namespace test
57}  // namespace webrtc
58