1 /*
2 * Copyright (c) 2014 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/common_audio/wav_writer.h"
12
13 #include <algorithm>
14 #include <cstdio>
15 #include <limits>
16
17 #include "webrtc/base/checks.h"
18 #include "webrtc/common_audio/include/audio_util.h"
19 #include "webrtc/common_audio/wav_header.h"
20
21 namespace webrtc {
22
23 // We write 16-bit PCM WAV files.
24 static const WavFormat kWavFormat = kWavFormatPcm;
25 static const int kBytesPerSample = 2;
26
WavFile(const std::string & filename,int sample_rate,int num_channels)27 WavFile::WavFile(const std::string& filename, int sample_rate, int num_channels)
28 : sample_rate_(sample_rate),
29 num_channels_(num_channels),
30 num_samples_(0),
31 file_handle_(fopen(filename.c_str(), "wb")) {
32 CHECK(file_handle_);
33 CHECK(CheckWavParameters(num_channels_,
34 sample_rate_,
35 kWavFormat,
36 kBytesPerSample,
37 num_samples_));
38
39 // Write a blank placeholder header, since we need to know the total number
40 // of samples before we can fill in the real data.
41 static const uint8_t blank_header[kWavHeaderSize] = {0};
42 CHECK_EQ(1u, fwrite(blank_header, kWavHeaderSize, 1, file_handle_));
43 }
44
~WavFile()45 WavFile::~WavFile() {
46 Close();
47 }
48
WriteSamples(const int16_t * samples,size_t num_samples)49 void WavFile::WriteSamples(const int16_t* samples, size_t num_samples) {
50 #ifndef WEBRTC_ARCH_LITTLE_ENDIAN
51 #error "Need to convert samples to little-endian when writing to WAV file"
52 #endif
53 const size_t written =
54 fwrite(samples, sizeof(*samples), num_samples, file_handle_);
55 CHECK_EQ(num_samples, written);
56 num_samples_ += static_cast<uint32_t>(written);
57 CHECK(written <= std::numeric_limits<uint32_t>::max() ||
58 num_samples_ >= written); // detect uint32_t overflow
59 CHECK(CheckWavParameters(num_channels_,
60 sample_rate_,
61 kWavFormat,
62 kBytesPerSample,
63 num_samples_));
64 }
65
WriteSamples(const float * samples,size_t num_samples)66 void WavFile::WriteSamples(const float* samples, size_t num_samples) {
67 static const size_t kChunksize = 4096 / sizeof(uint16_t);
68 for (size_t i = 0; i < num_samples; i += kChunksize) {
69 int16_t isamples[kChunksize];
70 const size_t chunk = std::min(kChunksize, num_samples - i);
71 RoundToInt16(samples + i, chunk, isamples);
72 WriteSamples(isamples, chunk);
73 }
74 }
75
Close()76 void WavFile::Close() {
77 CHECK_EQ(0, fseek(file_handle_, 0, SEEK_SET));
78 uint8_t header[kWavHeaderSize];
79 WriteWavHeader(header, num_channels_, sample_rate_, kWavFormat,
80 kBytesPerSample, num_samples_);
81 CHECK_EQ(1u, fwrite(header, kWavHeaderSize, 1, file_handle_));
82 CHECK_EQ(0, fclose(file_handle_));
83 file_handle_ = NULL;
84 }
85
86 } // namespace webrtc
87
rtc_WavOpen(const char * filename,int sample_rate,int num_channels)88 rtc_WavFile* rtc_WavOpen(const char* filename,
89 int sample_rate,
90 int num_channels) {
91 return reinterpret_cast<rtc_WavFile*>(
92 new webrtc::WavFile(filename, sample_rate, num_channels));
93 }
94
rtc_WavClose(rtc_WavFile * wf)95 void rtc_WavClose(rtc_WavFile* wf) {
96 delete reinterpret_cast<webrtc::WavFile*>(wf);
97 }
98
rtc_WavWriteSamples(rtc_WavFile * wf,const float * samples,size_t num_samples)99 void rtc_WavWriteSamples(rtc_WavFile* wf,
100 const float* samples,
101 size_t num_samples) {
102 reinterpret_cast<webrtc::WavFile*>(wf)->WriteSamples(samples, num_samples);
103 }
104
rtc_WavSampleRate(const rtc_WavFile * wf)105 int rtc_WavSampleRate(const rtc_WavFile* wf) {
106 return reinterpret_cast<const webrtc::WavFile*>(wf)->sample_rate();
107 }
108
rtc_WavNumChannels(const rtc_WavFile * wf)109 int rtc_WavNumChannels(const rtc_WavFile* wf) {
110 return reinterpret_cast<const webrtc::WavFile*>(wf)->num_channels();
111 }
112
rtc_WavNumSamples(const rtc_WavFile * wf)113 uint32_t rtc_WavNumSamples(const rtc_WavFile* wf) {
114 return reinterpret_cast<const webrtc::WavFile*>(wf)->num_samples();
115 }
116