blob: 46a717379a2c40ccdeba93ddc987ad73ce6f80ee [file] [log] [blame]
// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <cstdint>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "base/containers/flat_map.h"
#include "base/containers/flat_set.h"
#include "base/macros.h"
#include "chromecast/public/media/media_pipeline_backend.h"
#include "chromecast/public/media/redirected_audio_output.h"
#include "chromecast/public/volume_control.h"
namespace media {
class AudioBus;
} // namespace media
namespace chromecast {
namespace media {
class MixerInput;
// Empty interface so we can use a pointer to AudioOutputRedirector as the
// token.
class AudioOutputRedirectorToken {};
// The AudioOutputRedirector class determines which MixerInputs match the config
// conditions, and adds an AudioOutputRedirectorInput to each one.
// When the mixer is writing output, it tells each AudioOutputRedirector to
// create a new buffer (by calling PrepareNextBuffer()). As audio is pulled from
// each MixerInput, the resulting audio is passed through any added
// AudioOutputRedirectorInputs and is mixed into the redirected buffer by the
// AudioOutputRedirector (with appropriate fading to avoid pops/clicks, and
// volume applied if desired). Once all MixerInputs have been processed, the
// mixer will call FinishBuffer() on each AudioOutputRedirector; the
// redirected buffer is then sent to the RedirectedAudioOutput associated
// with each redirector.
class AudioOutputRedirector : public AudioOutputRedirectorToken {
using RenderingDelay = MediaPipelineBackend::AudioDecoder::RenderingDelay;
AudioOutputRedirector(const AudioOutputRedirectionConfig& config,
std::unique_ptr<RedirectedAudioOutput> output);
int order() const { return config_.order; }
int num_output_channels() const { return config_.num_output_channels; }
int64_t extra_delay_microseconds() const {
return config_.extra_delay_microseconds;
// Adds/removes mixer inputs. The mixer adds/removes all mixer inputs from
// the AudioOutputRedirector; this class does the work to determine which
// inputs match the desired conditions.
void AddInput(MixerInput* mixer_input);
void RemoveInput(MixerInput* mixer_input);
// Updates the set of patterns used to determine which inputs should be
// redirected by this AudioOutputRedirector. Any inputs which no longer match
// will stop being redirected.
void UpdatePatterns(
std::vector<std::pair<AudioContentType, std::string>> patterns);
// Indicates that mixer output is starting at the given sample rate of
// |output_samples_per_second|.
void Start(int output_samples_per_second);
// Indicates that mixer output is stopping.
void Stop();
// Called by the mixer when it is preparing to write another buffer of
// |num_frames| frames.
void PrepareNextBuffer(int num_frames);
// Mixes audio into the redirected output bufer. Called by the
// AudioOutputRedirectorInput implementation to mix in audio from each
// matching MixerInput.
void MixInput(MixerInput* mixer_input,
::media::AudioBus* data,
int num_frames,
RenderingDelay rendering_delay);
// Called by the mixer once all MixerInputs have been processed; passes the
// redirected audio buffer to the output plugin.
void FinishBuffer();
class InputImpl;
bool ApplyToInput(MixerInput* mixer_input);
AudioOutputRedirectionConfig config_;
const std::unique_ptr<RedirectedAudioOutput> output_;
int output_samples_per_second_ = 0;
int next_num_frames_ = 0;
int64_t next_output_timestamp_ = INT64_MIN;
int input_count_ = 0;
std::unique_ptr<::media::AudioBus> mixed_;
std::vector<float*> channel_data_;
base::flat_map<MixerInput*, std::unique_ptr<InputImpl>> inputs_;
base::flat_set<MixerInput*> non_redirected_inputs_;
} // namespace media
} // namespace chromecast