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input_audio_file.cc (3377B)


      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 "modules/audio_coding/neteq/tools/input_audio_file.h"
     12 
     13 #include <cstddef>
     14 #include <cstdint>
     15 #include <cstdio>
     16 #include <string>
     17 
     18 #include "absl/strings/string_view.h"
     19 #include "rtc_base/checks.h"
     20 
     21 namespace webrtc {
     22 namespace test {
     23 
     24 InputAudioFile::InputAudioFile(absl::string_view file_name, bool loop_at_end)
     25    : loop_at_end_(loop_at_end) {
     26  fp_ = fopen(std::string(file_name).c_str(), "rb");
     27  RTC_DCHECK(fp_) << file_name << " could not be opened.";
     28 }
     29 
     30 InputAudioFile::~InputAudioFile() {
     31  RTC_DCHECK(fp_);
     32  fclose(fp_);
     33 }
     34 
     35 bool InputAudioFile::Read(size_t samples, int16_t* destination) {
     36  if (!fp_) {
     37    return false;
     38  }
     39  size_t samples_read = fread(destination, sizeof(int16_t), samples, fp_);
     40  if (samples_read < samples) {
     41    if (!loop_at_end_) {
     42      return false;
     43    }
     44    // Rewind and read the missing samples.
     45    rewind(fp_);
     46    size_t missing_samples = samples - samples_read;
     47    if (fread(destination + samples_read, sizeof(int16_t), missing_samples,
     48              fp_) < missing_samples) {
     49      // Could not read enough even after rewinding the file.
     50      return false;
     51    }
     52  }
     53  return true;
     54 }
     55 
     56 bool InputAudioFile::Seek(int samples) {
     57  if (!fp_) {
     58    return false;
     59  }
     60  // Find file boundaries.
     61  const long current_pos = ftell(fp_);
     62  RTC_CHECK_NE(EOF, current_pos)
     63      << "Error returned when getting file position.";
     64  RTC_CHECK_EQ(0, fseek(fp_, 0, SEEK_END));  // Move to end of file.
     65  const long file_size = ftell(fp_);
     66  RTC_CHECK_NE(EOF, file_size) << "Error returned when getting file position.";
     67  // Find new position.
     68  long new_pos = current_pos + sizeof(int16_t) * samples;  // Samples to bytes.
     69  if (loop_at_end_) {
     70    new_pos = new_pos % file_size;  // Wrap around the end of the file.
     71    if (new_pos < 0) {
     72      // For negative values of new_pos, newpos % file_size will also be
     73      // negative. To get the correct result it's needed to add file_size.
     74      new_pos += file_size;
     75    }
     76  } else {
     77    new_pos = new_pos > file_size ? file_size : new_pos;  // Don't loop.
     78  }
     79  RTC_CHECK_GE(new_pos, 0)
     80      << "Trying to move to before the beginning of the file";
     81  // Move to new position relative to the beginning of the file.
     82  RTC_CHECK_EQ(0, fseek(fp_, new_pos, SEEK_SET));
     83  return true;
     84 }
     85 
     86 void InputAudioFile::DuplicateInterleaved(const int16_t* source,
     87                                          size_t samples,
     88                                          size_t channels,
     89                                          int16_t* destination) {
     90  // Start from the end of `source` and `destination`, and work towards the
     91  // beginning. This is to allow in-place interleaving of the same array (i.e.,
     92  // `source` and `destination` are the same array).
     93  for (int i = static_cast<int>(samples - 1); i >= 0; --i) {
     94    for (int j = static_cast<int>(channels - 1); j >= 0; --j) {
     95      destination[i * channels + j] = source[i];
     96    }
     97  }
     98 }
     99 
    100 }  // namespace test
    101 }  // namespace webrtc