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/*
* Copyright (c) 2017 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 "modules/audio_processing/test/conversational_speech/simulator.h"
#include <math.h>
#include <algorithm>
#include <memory>
#include <set>
#include <utility>
#include <vector>
#include "absl/strings/string_view.h"
#include "api/array_view.h"
#include "common_audio/include/audio_util.h"
#include "common_audio/wav_file.h"
#include "modules/audio_processing/test/conversational_speech/wavreader_interface.h"
#include "rtc_base/logging.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "test/testsupport/file_utils.h"
namespace webrtc {
namespace test {
namespace {
using conversational_speech::MultiEndCall;
using conversational_speech::SpeakerOutputFilePaths;
using conversational_speech::WavReaderInterface;
// Combines output path and speaker names to define the output file paths for
// the near-end and far=end audio tracks.
std::unique_ptr<std::map<std::string, SpeakerOutputFilePaths>>
InitSpeakerOutputFilePaths(const std::set<std::string>& speaker_names,
absl::string_view output_path) {
// Create map.
auto speaker_output_file_paths_map =
std::make_unique<std::map<std::string, SpeakerOutputFilePaths>>();
// Add near-end and far-end output paths into the map.
for (const auto& speaker_name : speaker_names) {
const std::string near_end_path =
test::JoinFilename(output_path, "s_" + speaker_name + "-near_end.wav");
RTC_LOG(LS_VERBOSE) << "The near-end audio track will be created in "
<< near_end_path << ".";
const std::string far_end_path =
test::JoinFilename(output_path, "s_" + speaker_name + "-far_end.wav");
RTC_LOG(LS_VERBOSE) << "The far-end audio track will be created in "
<< far_end_path << ".";
// Add to map.
speaker_output_file_paths_map->emplace(
std::piecewise_construct, std::forward_as_tuple(speaker_name),
std::forward_as_tuple(near_end_path, far_end_path));
}
return speaker_output_file_paths_map;
}
// Class that provides one WavWriter for the near-end and one for the far-end
// output track of a speaker.
class SpeakerWavWriters {
public:
SpeakerWavWriters(const SpeakerOutputFilePaths& output_file_paths,
int sample_rate)
: near_end_wav_writer_(output_file_paths.near_end, sample_rate, 1u),
far_end_wav_writer_(output_file_paths.far_end, sample_rate, 1u) {}
WavWriter* near_end_wav_writer() { return &near_end_wav_writer_; }
WavWriter* far_end_wav_writer() { return &far_end_wav_writer_; }
private:
WavWriter near_end_wav_writer_;
WavWriter far_end_wav_writer_;
};
// Initializes one WavWriter instance for each speaker and both the near-end and
// far-end output tracks.
std::unique_ptr<std::map<std::string, SpeakerWavWriters>>
InitSpeakersWavWriters(const std::map<std::string, SpeakerOutputFilePaths>&
speaker_output_file_paths,
int sample_rate) {
// Create map.
auto speaker_wav_writers_map =
std::make_unique<std::map<std::string, SpeakerWavWriters>>();
// Add SpeakerWavWriters instance into the map.
for (auto it = speaker_output_file_paths.begin();
it != speaker_output_file_paths.end(); ++it) {
speaker_wav_writers_map->emplace(
std::piecewise_construct, std::forward_as_tuple(it->first),
std::forward_as_tuple(it->second, sample_rate));
}
return speaker_wav_writers_map;
}
// Reads all the samples for each audio track.
std::unique_ptr<std::map<std::string, std::vector<int16_t>>> PreloadAudioTracks(
const std::map<std::string, std::unique_ptr<WavReaderInterface>>&
audiotrack_readers) {
// Create map.
auto audiotracks_map =
std::make_unique<std::map<std::string, std::vector<int16_t>>>();
// Add audio track vectors.
for (auto it = audiotrack_readers.begin(); it != audiotrack_readers.end();
++it) {
// Add map entry.
audiotracks_map->emplace(std::piecewise_construct,
std::forward_as_tuple(it->first),
std::forward_as_tuple(it->second->NumSamples()));
// Read samples.
it->second->ReadInt16Samples(audiotracks_map->at(it->first));
}
return audiotracks_map;
}
// Writes all the values in `source_samples` via `wav_writer`. If the number of
// previously written samples in `wav_writer` is less than `interval_begin`, it
// adds zeros as left padding. The padding corresponds to intervals during which
// a speaker is not active.
void PadLeftWriteChunk(rtc::ArrayView<const int16_t> source_samples,
size_t interval_begin,
WavWriter* wav_writer) {
// Add left padding.
RTC_CHECK(wav_writer);
RTC_CHECK_GE(interval_begin, wav_writer->num_samples());
size_t padding_size = interval_begin - wav_writer->num_samples();
if (padding_size != 0) {
const std::vector<int16_t> padding(padding_size, 0);
wav_writer->WriteSamples(padding.data(), padding_size);
}
// Write source samples.
wav_writer->WriteSamples(source_samples.data(), source_samples.size());
}
// Appends zeros via `wav_writer`. The number of zeros is always non-negative
// and equal to the difference between the previously written samples and
// `pad_samples`.
void PadRightWrite(WavWriter* wav_writer, size_t pad_samples) {
RTC_CHECK(wav_writer);
RTC_CHECK_GE(pad_samples, wav_writer->num_samples());
size_t padding_size = pad_samples - wav_writer->num_samples();
if (padding_size != 0) {
const std::vector<int16_t> padding(padding_size, 0);
wav_writer->WriteSamples(padding.data(), padding_size);
}
}
void ScaleSignal(rtc::ArrayView<const int16_t> source_samples,
int gain,
rtc::ArrayView<int16_t> output_samples) {
const float gain_linear = DbToRatio(gain);
RTC_DCHECK_EQ(source_samples.size(), output_samples.size());
std::transform(source_samples.begin(), source_samples.end(),
output_samples.begin(), [gain_linear](int16_t x) -> int16_t {
return rtc::saturated_cast<int16_t>(x * gain_linear);
});
}
} // namespace
namespace conversational_speech {
std::unique_ptr<std::map<std::string, SpeakerOutputFilePaths>> Simulate(
const MultiEndCall& multiend_call,
absl::string_view output_path) {
// Set output file paths and initialize wav writers.
const auto& speaker_names = multiend_call.speaker_names();
auto speaker_output_file_paths =
InitSpeakerOutputFilePaths(speaker_names, output_path);
auto speakers_wav_writers = InitSpeakersWavWriters(
*speaker_output_file_paths, multiend_call.sample_rate());
// Preload all the input audio tracks.
const auto& audiotrack_readers = multiend_call.audiotrack_readers();
auto audiotracks = PreloadAudioTracks(audiotrack_readers);
// TODO(alessiob): When speaker_names.size() == 2, near-end and far-end
// across the 2 speakers are symmetric; hence, the code below could be
// replaced by only creating the near-end or the far-end. However, this would
// require to split the unit tests and document the behavior in README.md.
// In practice, it should not be an issue since the files are not expected to
// be signinificant.
// Write near-end and far-end output tracks.
for (const auto& speaking_turn : multiend_call.speaking_turns()) {
const std::string& active_speaker_name = speaking_turn.speaker_name;
const auto source_audiotrack =
audiotracks->at(speaking_turn.audiotrack_file_name);
std::vector<int16_t> scaled_audiotrack(source_audiotrack.size());
ScaleSignal(source_audiotrack, speaking_turn.gain, scaled_audiotrack);
// Write active speaker's chunk to active speaker's near-end.
PadLeftWriteChunk(
scaled_audiotrack, speaking_turn.begin,
speakers_wav_writers->at(active_speaker_name).near_end_wav_writer());
// Write active speaker's chunk to other participants' far-ends.
for (const std::string& speaker_name : speaker_names) {
if (speaker_name == active_speaker_name)
continue;
PadLeftWriteChunk(
scaled_audiotrack, speaking_turn.begin,
speakers_wav_writers->at(speaker_name).far_end_wav_writer());
}
}
// Finalize all the output tracks with right padding.
// This is required to make all the output tracks duration equal.
size_t duration_samples = multiend_call.total_duration_samples();
for (const std::string& speaker_name : speaker_names) {
PadRightWrite(speakers_wav_writers->at(speaker_name).near_end_wav_writer(),
duration_samples);
PadRightWrite(speakers_wav_writers->at(speaker_name).far_end_wav_writer(),
duration_samples);
}
return speaker_output_file_paths;
}
} // namespace conversational_speech
} // namespace test
} // namespace webrtc