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
17 namespace webrtc {
18 namespace test {
19
Init(const std::string file_name,size_t max_loop_length_samples,size_t block_length_samples)20 bool 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
GetNextBlock()46 rtc::ArrayView<const int16_t> AudioLoop::GetNextBlock() {
47 // Check that the AudioLoop is initialized.
48 if (block_length_samples_ == 0)
49 return rtc::ArrayView<const int16_t>();
50
51 const int16_t* output_ptr = &audio_array_[next_index_];
52 next_index_ = (next_index_ + block_length_samples_) % loop_length_samples_;
53 return rtc::ArrayView<const int16_t>(output_ptr, block_length_samples_);
54 }
55
56
57 } // namespace test
58 } // namespace webrtc
59