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_file.h"
12
13 #include <algorithm>
14 #include <cstdio>
15 #include <limits>
16
17 #include "webrtc/base/checks.h"
18 #include "webrtc/base/safe_conversions.h"
19 #include "webrtc/common_audio/include/audio_util.h"
20 #include "webrtc/common_audio/wav_header.h"
21
22 namespace webrtc {
23
24 // We write 16-bit PCM WAV files.
25 static const WavFormat kWavFormat = kWavFormatPcm;
26 static const int kBytesPerSample = 2;
27
28 // Doesn't take ownership of the file handle and won't close it.
29 class ReadableWavFile : public ReadableWav {
30 public:
ReadableWavFile(FILE * file)31 explicit ReadableWavFile(FILE* file) : file_(file) {}
Read(void * buf,size_t num_bytes)32 virtual size_t Read(void* buf, size_t num_bytes) {
33 return fread(buf, 1, num_bytes, file_);
34 }
35
36 private:
37 FILE* file_;
38 };
39
WavReader(const std::string & filename)40 WavReader::WavReader(const std::string& filename)
41 : file_handle_(fopen(filename.c_str(), "rb")) {
42 RTC_CHECK(file_handle_ && "Could not open wav file for reading.");
43
44 ReadableWavFile readable(file_handle_);
45 WavFormat format;
46 int bytes_per_sample;
47 RTC_CHECK(ReadWavHeader(&readable, &num_channels_, &sample_rate_, &format,
48 &bytes_per_sample, &num_samples_));
49 num_samples_remaining_ = num_samples_;
50 RTC_CHECK_EQ(kWavFormat, format);
51 RTC_CHECK_EQ(kBytesPerSample, bytes_per_sample);
52 }
53
~WavReader()54 WavReader::~WavReader() {
55 Close();
56 }
57
ReadSamples(size_t num_samples,int16_t * samples)58 size_t WavReader::ReadSamples(size_t num_samples, int16_t* samples) {
59 #ifndef WEBRTC_ARCH_LITTLE_ENDIAN
60 #error "Need to convert samples to big-endian when reading from WAV file"
61 #endif
62 // There could be metadata after the audio; ensure we don't read it.
63 num_samples = std::min(rtc::checked_cast<uint32_t>(num_samples),
64 num_samples_remaining_);
65 const size_t read =
66 fread(samples, sizeof(*samples), num_samples, file_handle_);
67 // If we didn't read what was requested, ensure we've reached the EOF.
68 RTC_CHECK(read == num_samples || feof(file_handle_));
69 RTC_CHECK_LE(read, num_samples_remaining_);
70 num_samples_remaining_ -= rtc::checked_cast<uint32_t>(read);
71 return read;
72 }
73
ReadSamples(size_t num_samples,float * samples)74 size_t WavReader::ReadSamples(size_t num_samples, float* samples) {
75 static const size_t kChunksize = 4096 / sizeof(uint16_t);
76 size_t read = 0;
77 for (size_t i = 0; i < num_samples; i += kChunksize) {
78 int16_t isamples[kChunksize];
79 size_t chunk = std::min(kChunksize, num_samples - i);
80 chunk = ReadSamples(chunk, isamples);
81 for (size_t j = 0; j < chunk; ++j)
82 samples[i + j] = isamples[j];
83 read += chunk;
84 }
85 return read;
86 }
87
Close()88 void WavReader::Close() {
89 RTC_CHECK_EQ(0, fclose(file_handle_));
90 file_handle_ = NULL;
91 }
92
WavWriter(const std::string & filename,int sample_rate,int num_channels)93 WavWriter::WavWriter(const std::string& filename, int sample_rate,
94 int num_channels)
95 : sample_rate_(sample_rate),
96 num_channels_(num_channels),
97 num_samples_(0),
98 file_handle_(fopen(filename.c_str(), "wb")) {
99 RTC_CHECK(file_handle_ && "Could not open wav file for writing.");
100 RTC_CHECK(CheckWavParameters(num_channels_, sample_rate_, kWavFormat,
101 kBytesPerSample, num_samples_));
102
103 // Write a blank placeholder header, since we need to know the total number
104 // of samples before we can fill in the real data.
105 static const uint8_t blank_header[kWavHeaderSize] = {0};
106 RTC_CHECK_EQ(1u, fwrite(blank_header, kWavHeaderSize, 1, file_handle_));
107 }
108
~WavWriter()109 WavWriter::~WavWriter() {
110 Close();
111 }
112
WriteSamples(const int16_t * samples,size_t num_samples)113 void WavWriter::WriteSamples(const int16_t* samples, size_t num_samples) {
114 #ifndef WEBRTC_ARCH_LITTLE_ENDIAN
115 #error "Need to convert samples to little-endian when writing to WAV file"
116 #endif
117 const size_t written =
118 fwrite(samples, sizeof(*samples), num_samples, file_handle_);
119 RTC_CHECK_EQ(num_samples, written);
120 num_samples_ += static_cast<uint32_t>(written);
121 RTC_CHECK(written <= std::numeric_limits<uint32_t>::max() ||
122 num_samples_ >= written); // detect uint32_t overflow
123 }
124
WriteSamples(const float * samples,size_t num_samples)125 void WavWriter::WriteSamples(const float* samples, size_t num_samples) {
126 static const size_t kChunksize = 4096 / sizeof(uint16_t);
127 for (size_t i = 0; i < num_samples; i += kChunksize) {
128 int16_t isamples[kChunksize];
129 const size_t chunk = std::min(kChunksize, num_samples - i);
130 FloatS16ToS16(samples + i, chunk, isamples);
131 WriteSamples(isamples, chunk);
132 }
133 }
134
Close()135 void WavWriter::Close() {
136 RTC_CHECK_EQ(0, fseek(file_handle_, 0, SEEK_SET));
137 uint8_t header[kWavHeaderSize];
138 WriteWavHeader(header, num_channels_, sample_rate_, kWavFormat,
139 kBytesPerSample, num_samples_);
140 RTC_CHECK_EQ(1u, fwrite(header, kWavHeaderSize, 1, file_handle_));
141 RTC_CHECK_EQ(0, fclose(file_handle_));
142 file_handle_ = NULL;
143 }
144
145 } // namespace webrtc
146
rtc_WavOpen(const char * filename,int sample_rate,int num_channels)147 rtc_WavWriter* rtc_WavOpen(const char* filename,
148 int sample_rate,
149 int num_channels) {
150 return reinterpret_cast<rtc_WavWriter*>(
151 new webrtc::WavWriter(filename, sample_rate, num_channels));
152 }
153
rtc_WavClose(rtc_WavWriter * wf)154 void rtc_WavClose(rtc_WavWriter* wf) {
155 delete reinterpret_cast<webrtc::WavWriter*>(wf);
156 }
157
rtc_WavWriteSamples(rtc_WavWriter * wf,const float * samples,size_t num_samples)158 void rtc_WavWriteSamples(rtc_WavWriter* wf,
159 const float* samples,
160 size_t num_samples) {
161 reinterpret_cast<webrtc::WavWriter*>(wf)->WriteSamples(samples, num_samples);
162 }
163
rtc_WavSampleRate(const rtc_WavWriter * wf)164 int rtc_WavSampleRate(const rtc_WavWriter* wf) {
165 return reinterpret_cast<const webrtc::WavWriter*>(wf)->sample_rate();
166 }
167
rtc_WavNumChannels(const rtc_WavWriter * wf)168 int rtc_WavNumChannels(const rtc_WavWriter* wf) {
169 return reinterpret_cast<const webrtc::WavWriter*>(wf)->num_channels();
170 }
171
rtc_WavNumSamples(const rtc_WavWriter * wf)172 uint32_t rtc_WavNumSamples(const rtc_WavWriter* wf) {
173 return reinterpret_cast<const webrtc::WavWriter*>(wf)->num_samples();
174 }
175