audio_opus_encoder.cc | Explore in Territory

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "media/audio/audio_opus_encoder.h"

#include <utility>

#include "base/containers/heap_array.h"
#include "base/functional/bind.h"
#include "base/logging.h"
#include "base/memory/raw_ptr.h"
#include "base/numerics/checked_math.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "build/build_config.h"
#include "media/base/audio_encoder.h"
#include "media/base/channel_mixer.h"
#include "media/base/converting_audio_fifo.h"
#include "media/base/encoder_status.h"
#include "media/base/timestamp_constants.h"

namespace media {

namespace {

// Opus preferred sampling rate for encoding. This is also the one WebM likes
// to have: https://wiki.xiph.org/MatroskaOpus.
constexpr int kOpusPreferredSamplingRate = …;

// For Opus, 20ms is the suggested default.
constexpr base::TimeDelta kDefaultOpusBufferDuration = …;

// Deletes the libopus encoder instance pointed to by |encoder_ptr|.
inline void OpusEncoderDeleter(OpusEncoder* encoder_ptr) { … }

base::TimeDelta GetFrameDuration(
    const std::optional<AudioEncoder::OpusOptions> opus_options) { … }

AudioParameters CreateInputParams(const AudioEncoder::Options& options,
                                  base::TimeDelta frame_duration) { … }

// Creates the audio parameters of the converted audio format that Opus prefers,
// which will be used as the input to the libopus encoder.
AudioParameters CreateOpusCompatibleParams(const AudioParameters& params,
                                           base::TimeDelta frame_duration) { … }

}  // namespace


AudioOpusEncoder::AudioOpusEncoder()
    : … { … }

void AudioOpusEncoder::Initialize(const Options& options,
                                  OutputCB output_callback,
                                  EncoderStatusCB done_cb) { … }

AudioOpusEncoder::~AudioOpusEncoder() = default;

AudioOpusEncoder::CodecDescription AudioOpusEncoder::PrepareExtraData() { … }

void AudioOpusEncoder::Encode(std::unique_ptr<AudioBus> audio_bus,
                              base::TimeTicks capture_time,
                              EncoderStatusCB done_cb) { … }

void AudioOpusEncoder::Flush(EncoderStatusCB done_cb) { … }

void AudioOpusEncoder::DrainFifoOutput() { … }

void AudioOpusEncoder::DoEncode(const AudioBus* audio_bus) { … }

// Creates and returns the libopus encoder instance. Returns nullptr if the
// encoder creation fails.
EncoderStatus::Or<OwnedOpusEncoder> AudioOpusEncoder::CreateOpusEncoder(
    const std::optional<AudioEncoder::OpusOptions>& opus_options) { … }

}  // namespace media
chromium/media/audio/audio_opus_encoder.cc
