diff options
Diffstat (limited to 'third_party/libwebrtc/modules/audio_coding/neteq/comfort_noise.cc')
-rw-r--r-- | third_party/libwebrtc/modules/audio_coding/neteq/comfort_noise.cc | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/neteq/comfort_noise.cc b/third_party/libwebrtc/modules/audio_coding/neteq/comfort_noise.cc new file mode 100644 index 0000000000..8a906593d7 --- /dev/null +++ b/third_party/libwebrtc/modules/audio_coding/neteq/comfort_noise.cc @@ -0,0 +1,129 @@ +/* + * Copyright (c) 2012 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_coding/neteq/comfort_noise.h" + +#include <cstdint> +#include <memory> + +#include "api/array_view.h" +#include "modules/audio_coding/codecs/cng/webrtc_cng.h" +#include "modules/audio_coding/neteq/audio_multi_vector.h" +#include "modules/audio_coding/neteq/audio_vector.h" +#include "modules/audio_coding/neteq/decoder_database.h" +#include "modules/audio_coding/neteq/dsp_helper.h" +#include "modules/audio_coding/neteq/sync_buffer.h" +#include "rtc_base/buffer.h" +#include "rtc_base/checks.h" +#include "rtc_base/logging.h" + +namespace webrtc { + +void ComfortNoise::Reset() { + first_call_ = true; +} + +int ComfortNoise::UpdateParameters(const Packet& packet) { + // Get comfort noise decoder. + if (decoder_database_->SetActiveCngDecoder(packet.payload_type) != kOK) { + return kUnknownPayloadType; + } + ComfortNoiseDecoder* cng_decoder = decoder_database_->GetActiveCngDecoder(); + RTC_DCHECK(cng_decoder); + cng_decoder->UpdateSid(packet.payload); + return kOK; +} + +int ComfortNoise::Generate(size_t requested_length, AudioMultiVector* output) { + // TODO(hlundin): Change to an enumerator and skip assert. + RTC_DCHECK(fs_hz_ == 8000 || fs_hz_ == 16000 || fs_hz_ == 32000 || + fs_hz_ == 48000); + // Not adapted for multi-channel yet. + if (output->Channels() != 1) { + RTC_LOG(LS_ERROR) << "No multi-channel support"; + return kMultiChannelNotSupported; + } + + size_t number_of_samples = requested_length; + bool new_period = false; + if (first_call_) { + // Generate noise and overlap slightly with old data. + number_of_samples = requested_length + overlap_length_; + new_period = true; + } + output->AssertSize(number_of_samples); + // Get the decoder from the database. + ComfortNoiseDecoder* cng_decoder = decoder_database_->GetActiveCngDecoder(); + if (!cng_decoder) { + RTC_LOG(LS_ERROR) << "Unknwown payload type"; + return kUnknownPayloadType; + } + + std::unique_ptr<int16_t[]> temp(new int16_t[number_of_samples]); + if (!cng_decoder->Generate( + rtc::ArrayView<int16_t>(temp.get(), number_of_samples), new_period)) { + // Error returned. + output->Zeros(requested_length); + RTC_LOG(LS_ERROR) + << "ComfortNoiseDecoder::Genererate failed to generate comfort noise"; + return kInternalError; + } + (*output)[0].OverwriteAt(temp.get(), number_of_samples, 0); + + if (first_call_) { + // Set tapering window parameters. Values are in Q15. + int16_t muting_window; // Mixing factor for overlap data. + int16_t muting_window_increment; // Mixing factor increment (negative). + int16_t unmuting_window; // Mixing factor for comfort noise. + int16_t unmuting_window_increment; // Mixing factor increment. + if (fs_hz_ == 8000) { + muting_window = DspHelper::kMuteFactorStart8kHz; + muting_window_increment = DspHelper::kMuteFactorIncrement8kHz; + unmuting_window = DspHelper::kUnmuteFactorStart8kHz; + unmuting_window_increment = DspHelper::kUnmuteFactorIncrement8kHz; + } else if (fs_hz_ == 16000) { + muting_window = DspHelper::kMuteFactorStart16kHz; + muting_window_increment = DspHelper::kMuteFactorIncrement16kHz; + unmuting_window = DspHelper::kUnmuteFactorStart16kHz; + unmuting_window_increment = DspHelper::kUnmuteFactorIncrement16kHz; + } else if (fs_hz_ == 32000) { + muting_window = DspHelper::kMuteFactorStart32kHz; + muting_window_increment = DspHelper::kMuteFactorIncrement32kHz; + unmuting_window = DspHelper::kUnmuteFactorStart32kHz; + unmuting_window_increment = DspHelper::kUnmuteFactorIncrement32kHz; + } else { // fs_hz_ == 48000 + muting_window = DspHelper::kMuteFactorStart48kHz; + muting_window_increment = DspHelper::kMuteFactorIncrement48kHz; + unmuting_window = DspHelper::kUnmuteFactorStart48kHz; + unmuting_window_increment = DspHelper::kUnmuteFactorIncrement48kHz; + } + + // Do overlap-add between new vector and overlap. + size_t start_ix = sync_buffer_->Size() - overlap_length_; + for (size_t i = 0; i < overlap_length_; i++) { + /* overlapVec[i] = WinMute * overlapVec[i] + WinUnMute * outData[i] */ + // The expression (*output)[0][i] is the i-th element in the first + // channel. + (*sync_buffer_)[0][start_ix + i] = + (((*sync_buffer_)[0][start_ix + i] * muting_window) + + ((*output)[0][i] * unmuting_window) + 16384) >> + 15; + muting_window += muting_window_increment; + unmuting_window += unmuting_window_increment; + } + // Remove `overlap_length_` samples from the front of `output` since they + // were mixed into `sync_buffer_` above. + output->PopFront(overlap_length_); + } + first_call_ = false; + return kOK; +} + +} // namespace webrtc |