ladybird/Userland/Applications/SoundPlayer/PlaybackManager.h
kleines Filmröllchen c748c0726a SoundPlayer: Don't enqueue samples depending on the GUI loop
Previously, SoundPlayer would read and enqueue samples in the GUI loop
(through a Timer). Apart from general problems with doing audio on the
GUI thread, this is particularly bad as the audio would lag or drop out
when the GUI lags (e.g. window resizes and moves, changing the
visualizer). As Piano does, now SoundPlayer enqueues more audio once the
audio server signals that a buffer has finished playing. The GUI-
dependent decoding is still kept as a "backup" and to start the entire
cycle, but it's not solely depended on. A queue of buffer IDs is used to
keep track of playing buffers and how many there are. The buffer
overhead, i.e. how many buffers "too many" currently exist, is currently
set to its absolute minimum of 2.
2022-01-02 22:18:37 +01:00

68 lines
2.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Queue.h>
#include <AK/Vector.h>
#include <LibAudio/Buffer.h>
#include <LibAudio/ClientConnection.h>
#include <LibAudio/Loader.h>
#include <LibCore/Timer.h>
class PlaybackManager final {
public:
PlaybackManager(NonnullRefPtr<Audio::ClientConnection>);
~PlaybackManager();
void play();
void stop();
void pause();
void seek(const int position);
void loop(bool);
bool toggle_pause();
void set_loader(NonnullRefPtr<Audio::Loader>&&);
RefPtr<Audio::Loader> loader() const { return m_loader; }
size_t device_sample_rate() const { return m_device_sample_rate; }
int last_seek() const { return m_last_seek; }
bool is_paused() const { return m_paused; }
float total_length() const { return m_total_length; }
RefPtr<Audio::Buffer> current_buffer() const { return m_current_buffer; }
NonnullRefPtr<Audio::ClientConnection> connection() const { return m_connection; }
Function<void()> on_update;
Function<void(Audio::Buffer&)> on_load_sample_buffer;
Function<void()> on_finished_playing;
private:
// Number of buffers we want to always keep enqueued.
static constexpr size_t always_enqueued_buffer_count = 2;
void next_buffer();
void set_paused(bool);
bool m_paused { true };
bool m_loop = { false };
size_t m_last_seek { 0 };
float m_total_length { 0 };
size_t m_device_sample_rate { 44100 };
size_t m_device_samples_per_buffer { 0 };
size_t m_source_buffer_size_bytes { 0 };
RefPtr<Audio::Loader> m_loader { nullptr };
NonnullRefPtr<Audio::ClientConnection> m_connection;
RefPtr<Audio::Buffer> m_current_buffer;
Queue<i32, always_enqueued_buffer_count + 1> m_enqueued_buffers;
Optional<Audio::ResampleHelper<double>> m_resampler;
RefPtr<Core::Timer> m_timer;
// Controls the GUI update rate. A smaller value makes the visualizations nicer.
static constexpr u32 update_rate_ms = 50;
// Number of milliseconds of audio data contained in each audio buffer
static constexpr u32 buffer_size_ms = 100;
};