[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/common_audio/wav_file.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/common_audio/wav_file.h"
 
 #include <algorithm>
 #include <cstdio>
 #include <limits>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/safe_conversions.h"
 #include "webrtc/common_audio/include/audio_util.h"
 #include "webrtc/common_audio/wav_header.h"
 
 namespace webrtc {
 
 // We write 16-bit PCM WAV files.
 static const WavFormat kWavFormat = kWavFormatPcm;
-static const int kBytesPerSample = 2;
+static const size_t kBytesPerSample = 2;
 
 // Doesn't take ownership of the file handle and won't close it.
 class ReadableWavFile : public ReadableWav {
  public:
   explicit ReadableWavFile(FILE* file) : file_(file) {}
   virtual size_t Read(void* buf, size_t num_bytes) {
     return fread(buf, 1, num_bytes, file_);
   }
 
  private:
   FILE* file_;
 };
 
 WavReader::WavReader(const std::string& filename)
     : file_handle_(fopen(filename.c_str(), "rb")) {
   CHECK(file_handle_ && "Could not open wav file for reading.");
 
   ReadableWavFile readable(file_handle_);
   WavFormat format;
-  int bytes_per_sample;
+  size_t bytes_per_sample;
   CHECK(ReadWavHeader(&readable, &num_channels_, &sample_rate_, &format,
                       &bytes_per_sample, &num_samples_));
   num_samples_remaining_ = num_samples_;
   CHECK_EQ(kWavFormat, format);
   CHECK_EQ(kBytesPerSample, bytes_per_sample);
 }
 
 WavReader::~WavReader() {
   Close();
 }
 
 size_t WavReader::ReadSamples(size_t num_samples, int16_t* samples) {
 #ifndef WEBRTC_ARCH_LITTLE_ENDIAN
 #error "Need to convert samples to big-endian when reading from WAV file"
 #endif
   // There could be metadata after the audio; ensure we don't read it.
-  num_samples = std::min(rtc::checked_cast<uint32_t>(num_samples),
-                         num_samples_remaining_);
+  num_samples = std::min(num_samples, num_samples_remaining_);
   const size_t read =
       fread(samples, sizeof(*samples), num_samples, file_handle_);
   // If we didn't read what was requested, ensure we've reached the EOF.
   CHECK(read == num_samples || feof(file_handle_));
   CHECK_LE(read, num_samples_remaining_);
-  num_samples_remaining_ -= rtc::checked_cast<uint32_t>(read);
+  num_samples_remaining_ -= read;
   return read;
 }
 
 size_t WavReader::ReadSamples(size_t num_samples, float* samples) {
   static const size_t kChunksize = 4096 / sizeof(uint16_t);
   size_t read = 0;
   for (size_t i = 0; i < num_samples; i += kChunksize) {
     int16_t isamples[kChunksize];
     size_t chunk = std::min(kChunksize, num_samples - i);
     chunk = ReadSamples(chunk, isamples);
     for (size_t j = 0; j < chunk; ++j)
       samples[i + j] = isamples[j];
     read += chunk;
   }
   return read;
 }
 
 void WavReader::Close() {
   CHECK_EQ(0, fclose(file_handle_));
   file_handle_ = NULL;
 }
 
 WavWriter::WavWriter(const std::string& filename, int sample_rate,
-                     int num_channels)
+                     size_t num_channels)
     : sample_rate_(sample_rate),
       num_channels_(num_channels),
       num_samples_(0),
       file_handle_(fopen(filename.c_str(), "wb")) {
   CHECK(file_handle_ && "Could not open wav file for writing.");
   CHECK(CheckWavParameters(num_channels_,
                            sample_rate_,
                            kWavFormat,
                            kBytesPerSample,
                            num_samples_));
 
   // Write a blank placeholder header, since we need to know the total number
   // of samples before we can fill in the real data.
   static const uint8_t blank_header[kWavHeaderSize] = {0};
   CHECK_EQ(1u, fwrite(blank_header, kWavHeaderSize, 1, file_handle_));
 }
 
 WavWriter::~WavWriter() {
   Close();
 }
 
 void WavWriter::WriteSamples(const int16_t* samples, size_t num_samples) {
 #ifndef WEBRTC_ARCH_LITTLE_ENDIAN
 #error "Need to convert samples to little-endian when writing to WAV file"
 #endif
   const size_t written =
       fwrite(samples, sizeof(*samples), num_samples, file_handle_);
   CHECK_EQ(num_samples, written);
-  num_samples_ += static_cast<uint32_t>(written);
-  CHECK(written <= std::numeric_limits<uint32_t>::max() ||
-        num_samples_ >= written);  // detect uint32_t overflow
+  num_samples_ += written;
+  CHECK(num_samples_ >= written);  // detect size_t overflow
 }
 
 void WavWriter::WriteSamples(const float* samples, size_t num_samples) {
   static const size_t kChunksize = 4096 / sizeof(uint16_t);
   for (size_t i = 0; i < num_samples; i += kChunksize) {
     int16_t isamples[kChunksize];
     const size_t chunk = std::min(kChunksize, num_samples - i);
     FloatS16ToS16(samples + i, chunk, isamples);
     WriteSamples(isamples, chunk);
   }
 }
 
 void WavWriter::Close() {
   CHECK_EQ(0, fseek(file_handle_, 0, SEEK_SET));
   uint8_t header[kWavHeaderSize];
   WriteWavHeader(header, num_channels_, sample_rate_, kWavFormat,
                  kBytesPerSample, num_samples_);
   CHECK_EQ(1u, fwrite(header, kWavHeaderSize, 1, file_handle_));
   CHECK_EQ(0, fclose(file_handle_));
   file_handle_ = NULL;
 }
 
 }  // namespace webrtc
 
 rtc_WavWriter* rtc_WavOpen(const char* filename,
                            int sample_rate,
-                           int num_channels) {
+                           size_t num_channels) {
   return reinterpret_cast<rtc_WavWriter*>(
       new webrtc::WavWriter(filename, sample_rate, num_channels));
 }
 
 void rtc_WavClose(rtc_WavWriter* wf) {
   delete reinterpret_cast<webrtc::WavWriter*>(wf);
 }
 
 void rtc_WavWriteSamples(rtc_WavWriter* wf,
                          const float* samples,
                          size_t num_samples) {
   reinterpret_cast<webrtc::WavWriter*>(wf)->WriteSamples(samples, num_samples);
 }
 
 int rtc_WavSampleRate(const rtc_WavWriter* wf) {
   return reinterpret_cast<const webrtc::WavWriter*>(wf)->sample_rate();
 }
 
-int rtc_WavNumChannels(const rtc_WavWriter* wf) {
+size_t rtc_WavNumChannels(const rtc_WavWriter* wf) {
   return reinterpret_cast<const webrtc::WavWriter*>(wf)->num_channels();
 }
 
 uint32_t rtc_WavNumSamples(const rtc_WavWriter* wf) {
   return reinterpret_cast<const webrtc::WavWriter*>(wf)->num_samples();
 }