96 lines
3.2 KiB
C++
96 lines
3.2 KiB
C++
#include "voiceActivityDetection.h"
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#include <gsl_util.h>
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#include <webrtc/common_audio/vad/include/webrtc_vad.h>
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#include <webrtc/common_audio/vad/vad_core.h>
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#include <boost/range/adaptor/transformed.hpp>
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#include "DcOffset.h"
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#include "logging/logging.h"
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#include "processing.h"
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#include "SampleRateConverter.h"
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#include "tools/pairs.h"
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#include "tools/parallel.h"
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using boost::adaptors::transformed;
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using fmt::format;
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using std::runtime_error;
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using std::unique_ptr;
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using std::vector;
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JoiningBoundedTimeline<void> detectVoiceActivity(
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const AudioClip& inputAudioClip, ProgressSink& progressSink
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) {
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// Prepare audio for VAD
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constexpr int webRtcSamplingRate = 8000;
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const unique_ptr<AudioClip> audioClip =
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inputAudioClip.clone() | resample(webRtcSamplingRate) | removeDcOffset();
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VadInst* vadHandle = WebRtcVad_Create();
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if (!vadHandle) throw runtime_error("Error creating WebRTC VAD handle.");
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auto freeHandle = gsl::finally([&]() { WebRtcVad_Free(vadHandle); });
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int error = WebRtcVad_Init(vadHandle);
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if (error) throw runtime_error("Error initializing WebRTC VAD.");
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const int aggressiveness = 2; // 0..3. The higher, the more is cut off.
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error = WebRtcVad_set_mode(vadHandle, aggressiveness);
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if (error) throw runtime_error("Error setting WebRTC VAD aggressiveness.");
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// Detect activity
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JoiningBoundedTimeline<void> activity(audioClip->getTruncatedRange());
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centiseconds time = 0_cs;
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const size_t frameSize = webRtcSamplingRate / 100;
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const auto processBuffer = [&](const vector<int16_t>& buffer) {
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// WebRTC is picky regarding buffer size
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if (buffer.size() < frameSize) return;
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const int result =
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WebRtcVad_Process(vadHandle, webRtcSamplingRate, buffer.data(), buffer.size());
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if (result == -1) throw runtime_error("Error processing audio buffer using WebRTC VAD.");
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// Ignore the result of WebRtcVad_Process, instead directly interpret the internal VAD flag.
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// The result of WebRtcVad_Process stays 1 for a number of frames after the last detected
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// activity.
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const bool isActive = reinterpret_cast<VadInstT*>(vadHandle)->vad == 1;
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if (isActive) {
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activity.set(time, time + 1_cs);
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}
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time += 1_cs;
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};
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process16bitAudioClip(*audioClip, processBuffer, frameSize, progressSink);
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// Fill small gaps in activity
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const centiseconds maxGap(10);
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for (const auto& pair : getPairs(activity)) {
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if (pair.second.getStart() - pair.first.getEnd() <= maxGap) {
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activity.set(pair.first.getEnd(), pair.second.getStart());
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}
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}
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// Discard very short segments of activity
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const centiseconds minSegmentLength(5);
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for (const auto& segment : Timeline<void>(activity)) {
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if (segment.getDuration() < minSegmentLength) {
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activity.clear(segment.getTimeRange());
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}
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}
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logging::debugFormat(
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"Found {} sections of voice activity: {}",
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activity.size(),
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join(
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activity | transformed([](const Timed<void>& t) {
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return format("{0}-{1}", t.getStart(), t.getEnd());
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}),
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", "
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)
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);
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return activity;
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}
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